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Home My WebLink Aboutagenda.council.worksession.20080630Housing Subcommittee Report to Citizen Budget Task Force on Burlingame and other Affordable Housing Projects BASIC ASSUMPTIONS - Burlingame Ranch is Aspen's unique, high potential Affordable Housing resource - Burlingame has been approved on two occasions by vote of Aspen citizens - City Council is committed'to Burlingame II and III - Funding for Burlingame Phases II and III requires a bond issue or other forms of multi-year financing as the RETT based fund is significantly depleted - Passage of a bond issue requires broad based citizen support - The present confusion as to actual vs. projected costs as presented in the 2005 brochure has weakened public trust BACKGROUND - Given the variances between projections and actual costs for Burlingame I, it is important to correct the inefficiencies in the management systems prior to proceeding with Burlingame Phases II and III - An independent audit, for a full accounting of Burlingame I, has been approved by City Council, as recommended by the Citizen Budget Task Force - A "Construction Experts" Group convened by the City manager has initiated a review of plans for Burlingame Phases II and III - Total subsidies for Burlingame I -III were publicized in the Spring 2005 brochure at $14.7 million but appear now to exceed $85 million - To help streamline and create more efficiencies, anew set of management control systems and performance expectations is needed - Per City Eden report, Burlingame Phase I subsidy totals $30.2 million, which is approximately 60% of the $50.9 million total Phase I cost. The average per unit subsidy was $331,567 or 59% of the $559,184 unit cost. Page 1 of 5 RECOMMENDATIONS Until the actions listed below are adopted the Citizen Budget Task Force believes there is risk that a bond issue vote may fail. Restoring public trust is necessary. Therefore the Citizen Budget Task Force recommends that prior to sending a proposal fora Burlingame phase II bond issue to the voters, the City Council accept and commit to implement the following recommendations. DEVELOPMENT RELATED 1. Study and incorporate Burlingame Development Options by Contractors Group for Phases II-III as well as future Affordable Housing projects A. Construction Methods B. Public private partnership development opportunities to lessen public subsidies C. Density increases 1) Sizing of units 2) Number of units D. More economical finishes 1) Utilizes City's buying power to negotiate better pricing. 2) Develop programs for owner purchased upgrades. (Possible allowance budgets) 2. Preparation of a detailed plan and a iromprehensive budget for Burlingame Phases II-III using recommendations from Contractors Group FINANCIAL AND MANAGEMENT CONTROL SYSTEMS Page 2 of 5 1.Engage the City's independent audit firm to perform a financial and management systems review of the Burlingame Ranch Project. The scope of this work will include validating the dollar amounts included in the City's Burlingame Ranch Project Reconciliation, testing a sample of payments made to the construction contractor, review of the City's internal control systems surrounding multi-year capital projects, and making recommendations for improvement in the processes used to prepare construction budgets and forecasts. 2.Engage an independent consulting firm to perform a performance audit of the processes and procedures used for the City's overall construction management administration. The scope of this work will include interviews with stakeholders, review of project management skills, and review of policies and procedures used for project plan development, procurement, contract development, cost management and risk management. 3. City Council to direct Staff to recommend for immediate implementation of process and control recommendations taking into account the Post Completion Audit of Burlingame Phase I. 4. Review of Burlingame Phase II -III budget by independent industry professional prior to contract execution for value engineering options. 5. City Council to request City Manager to provide a plan and proposed timeline for the implementation of the recommendations here and recommendations resulting from the two audits specified in "Development Related" points 1 and 2 above. City Council to approve a specific plan and City Manager to regularly update the City Council at specified intervals, and City Council to report to community at least quarterly on progress until all recommendations are implemented. 6. Assessment of all future AH project needs, resources, skill sets, to ensure staffing capabilities and experience for necessary oversight of proposed projects. 7. City Council to direct Staff to develop and implement a routine semiannual reporting procedure for informing City Council and the public Page 3 of 5 of progress on large capital projects (multiyear and single year) against the initial budget. Reports to include updates of revenue streams associated with the capital project. 8. Development and implementation of processes to ensure accuracy of voter information and reasonableness of all financial projections issued by the city. 9. Engage independent consultant for risk assessment and systems assessment after implementation of above suggestions and prior to execution of Burlingame Contracts. 10. City Council to analyze the bonding capacity proposals as presented by the Director of Finance regarding: A. The Affordable Housing fund's (including RETT) ability to absorb any proposed subsidy for AH projects B. The capacity of the City to service any related bond financing for Burlingame II-III, BMC West and other proposed AH projects. C. City Council to make final recommendations with full awareness of and publicity to voters of relationship to reasonably anticipated future funding needs and capacity for Burlingame and other affordable housing projects as well as other major capital improvements generally. li. The Citizen Budget Task Force recommends that City Council establish a written policy and guidelines for Affordable Housing subsidies for current and future Affordable Housing projects. Said policy to acknowledge a connection between subsidy levels and financial capacity of a Affordable Housing project and possible overall impact on City of Aspen financial condition. CONCLUSIONS The desire of the Citizen Budget Task Force is to help facilitate a favorable climate so that Burlingame and future Affordable Housing projects can succeed. Page 4 of 5 A complete review of all items in the development plan including business model, density, modular construction, category mix, unit sizing, complexity, etc. is essential to assure that all AH projects deliver the greatest number of quality housing units, at the lowest cost, as quickly as possible. We believe that these recommendations are crucial prior to preparing for a bond issue for future Affordable Housing development proposals- not just Burlingame II & III and should be implemented as soon as possible. The bond proposal is not a "Burlingame Issue", but involves the future of the Affordable Housing program and the best use of the funds available. We encourage the development of a realistic timeline for these fundamental steps as delineated in our recommendations. Thorough study and rigorous execution plans will increase community confidence and support of Burlingame and the Affordable Housing program. After reviewing much data and meeting with City staff, the Housing Subcommittee feels that the establishment of rigorous planning procedures, budgetary controls, proper review and independent project management, will benefit not just Burlingame, but all future AH projects. The implementation of the above recommendations should solidly put the City of Aspen in a position to fund and build Burlingame II and III as well as other future AH projects. Page 5 of 5 MEMORANDUM TO: Mayor and Council FROM : Trish Nelson, P.E., Senior Project Manager THRU: Steve Barwick, City Manager Bentley Henderson, Assistant City Manager Randy Ready, Assistant City Manager Trish Aragon, P.E., City Engineer DATE OF MEMO: June 26, 2008 MEETING DATE: June 30, 2008 Work Session RE: Proposed Changes to Temporary Encroachments. Summary: Staff is proposing a revision to the municipal code related to temporary encroachments. Following the work session, staff will come back to council to update COA Municipal Code Title 21. Background: Last year the code was revised to clarify the types, durations and time frames for Temporary encroachments. The time frame of the temporary encroachments were not consistent with other Department time frames and did not coincide with material availability in the Winter. Additionally the code did not include limitations on the winter season in the Core. Lastly, construction staging was not addressed in the code. Discussion: Staff is proposing the attached changes to the temporary encroachment requirements: TITLE 21 STREETS, SH)EWALICS AND OTHER PUBLIC PLACESr'Z Chapter 21.12 Construction and Excavation Within Public Rightof-Way Sec. 21.12.120 Street closures no[ permitted Sec. 21.12.130 Limitations on use of public streets, alleys and sidewalks Far construction mata-ial Sec. 21.12.120. Street closures not permitted. Street closures are not pemritted. The City Engineer may peanit lane closures. When lane closures aze permitted, the applicant must (a) Verify the closure specified on the permit with the Engineering Department, the School District and the Roaring Fork Transit Authority (RFTA) at least one (I) week in advance. (b) Notify [he Aspen Communication Center at (970)920-5310 one (1) day prior to closure and at the time of re-opening. (c) Set and maintain, at the applicant's expense, necessary barricades, flashers, construction signs and flaggers; and take all necessary precautions in accordance with the Manual on Uniform Traffic Control Devices (MUTCD). (d) Hours of work will be in compliance with Title 18 anrVor Title 8 Utility work must be_- completed between 7:00 a.m. and~00 p_m., Monda throw Saturda , unless a roved otherwise b Y €~ _ Y PP -- Y _~ the City CouncilY~' -__ _. r v t t_n s __ o __ t a ve- _ _- (Ord. No. 15, 2007, §2) Sec. 21.12.130. Limitations on use of public streets, alleys and sidewalks for construction materials. (a) Purpose. It shall be the purpose of this Section to regulate the use of public streets, alleys and sidewalks for construction material_stomge and placement of pedestrian barricades. This regulation is intended to ensure adequate snow removal in City streets, alleys and sidewalks, allow for safe flow of pedestrian and vehicular traffic and maintain the image of the City as a resort community, while also accommodating construction activity. (b) Definitions. Construction material storage means parking of construction trailers or construction equipment, storage of construction materials for any purpose other than unloading or placement of any structure which is typically accessory [o construction activity. Pedestrian barricades means any structure authorized by the City Engineer to permit [he safe passage of pedestrians past construction sites. Paved street means that portion of [he right-of--way between curbs of drainage swales. Deleted: Complete the Deleted: 7 Formatted: Not Strikethrough Formatted: Not Strikethrough Deleted: Sidewalk means that portion of the right-of--way between a curb or drainage Swale and a property line. .- Formatted: Font NO[ItaGC Staoinr means anv construction related activity that lasts less than one workino day.__ ___ _ , .~' (c) Limitations. (1) The following limitations shall be enacted on the use of the public right-of--way during the celeted: Is period of November 1 to azch 31st: Deleted: April l a S[omge of construction materials shall be prohibited in al] paved streets, alleys and sidewalks in the City. b. Placement of pedestrian barricades shall be prohibited in all paved streets and alleys in the City. c. Placement of pedestrian barricades shall pot be permitted~n sidewalks_in the City Core by _,_.-~ Detetea: be pe.mined obtaining a permit from the City Engineer. -~ cet~; o (2) The following limitations shall be enacted on the use of the public right-of--way during the .. Deleted: is period of April 1 to June 1 and Labor Day to November,) st; .-~'" a. Storage of construction materials in all paved streets, sidewalks and alleys in the City. b. Placement of pedestrian barricades shall be permitted in paved streets, alleys and sidewalks in the City by obtaining a permit from the City Engineer. (3) The following limitations shall be enacted on the use of the public right-of--way during the period of June 1 through Labor Day: a. Storage of construction materials shall be prohibited in all paved streets, sidewalks and alleys in the City. b. Placement of pedestrian barricades shall be permitted in paved sheets, alleys and sidewalks in the City, except within the Commercial Core and Main Street Corridor, by obtaining a permit from the City Engineer. (4) Exceptions. a. The City Engineer or Citv Council may make exceptions to [his Section when special circumstances aze present where strict compliance of these regulations would jeopazdize the public safety or the expeditious continuation of the project and granting the exception is in the public interest. ,~ Deleted: [reserved.] b. Construction staff ma _ oy ccur with limited activities and limited work hours. : '" (d) Permits. (1) The City Engineer shall have the sole responsibility for issuance of permits pursuant to [his Section. Reserved constmction parking permits shall corooly with Section 24.16.240. (2) In determining whether to issue a permit, the City Engineer shall consider the following: a. For the placement of pedestrian barricades in the public right-of--way, the applicant shall demonstrate that the baricade: cannot be functionally located on private property; provides for safe passage of pedestrians according to International Building Code Chanter 33 and Citv Engineer; will be maintained in a usable, safe and attractive manner; and is located so as to minimize the loss of public pazking spaces to the extent practicable. b.~or the_storage of construction materials in City rights-of--way, the applicant shall: ....-- Formatted: Font: toot Bold demonstrate that the materials cannot be functionally located on private property; provide a pedestrian walkway [o replace the sidewalk when it is blocked by construction materials; and ensure that the period of storage is the minimum necessary to accomplish necessary construction activities. (Code 1971, §I9-57; Ord. No. 12-1988, §l; Ord No. 20.1990, §1; Ord. No. 15, 2007, §2) MEMORANDUM TO: Mayor and Council FROM : Trish Aragon, P.E., City Engineer THRU: Steve Barwick, City Manager Bentley Henderson, Assistant City Manager Randy Ready, Assistant City Manager DATE OF MEMO: June 26, 2008 MEETING DATE: June 30, 2008 Work Session RE: Earth Retention Systems and Proposed Changes to Permanent Encroachments. Summary: Staff is proposing a revision to the municipal code related to earth retention systems in the Right of Way (ROW) (ie permanent encroachments). Following the work session, staff will come back to council to update COA Municipal Code Title 21. Background: Earth retention systems are used to stabilize the excavation of a building. Most systems used in the city become non essential after the building's foundation is installed. Typical systems used in the City include micro piles, soldier beam caissons, internally braced system and soil nails. As you know the ROW is for public use, and below the ground surface the ROW is used by utility companies to provide their services to citizens. It is the City's responsibility to protect the ROW for current and any future uses. By allowing earth retention systems in the ROW these systems have the potential to impact current and future uses in the ROW. As a result, the City's current code does not allow the use of ROW for earth retention systems. As a general policy, it is not the City's interest to grant encroachments (such as earth retention systems), thereby providing public property for private use. New structures should be able to accomplish their various needs within the confines of their property boundaries and required setbacks. Mayor and Council June 30, 2008 Work Session Page 2 Discussion: The earth retention systems which do not penetrate the ROW are limited to a maximum depth they can achieve. This depth is 40 feet. For depths greater than 40 feet, the earth retention system requires a horizontal component as a result this component of the earth retention system will most likely penetrate the ROW. Due to this depth limitation, the City may want to consider revising the code to allow encroachments of earth retention systems. The reason is that if a building needs these greater depths it is most likely for the installation of underground parking associated with a large development such as a hotel. The underground pazking has a public benefit therefore the use of ROW for an earth retention system is achieving the goal of utilizing the ROW for public benefit. Before the City allows the use of the ROW for earth retention systems the City needs to ensure that any existing or proposed uses of the ROW are protected. This can be achieved with limitations on the use of earth retention systems in the ROW. These limitations include: o Limiting the location of earth retention systems horizontally and vertically with in the ROW. o Limiting the location of earth retention systems in the proximity of cunent and future utilities. o Providing a mechanism to recover any fixture costs to the City if the earth retention system has to be removed. Recommendation: Staff recommends the following revision to the Municipal Code: Encroachments into the right-of--way associated with earth retention efforts (pilings, soils nails, etc) maybe authorized by the City Engineer under the following conditions: a. The associated structure is commercial or mixed commercial/residential b. The applicant must prove extenuating circumstances preclude using other methods of stabilization that can be contained entirely within project property boundaries. c. The earth retention fixture is sacrificial and can be removed after subsequent structural elements aze completed. d. The soil stabilization structure does not extend past the back of curb of any abutting roadway or into the driving surface of any alley and is installed below any utilities and must be approved by the affected utility company. e. In no circumstance shall any encroaching fixture be within the first 8 feet below grade. f. The applicant shall pay a fee of $250/CY of public rights-of--way encroached upon. This volume will encompass the total horizontal and vertical extent of the appurtenance measured from the property line. Mayor and Council June 30, 2008 Work Session Page 3 Alternatives Instead of revising the code as recommended above, the following alternatives exist: 1. The code could stay the same, it currently allows the City Engineer to allow for variances in the code as related to earth retention systems. However, if the City Engineer allows for a variance it will be more difficult to provide a mechanism to allow the City to recover any future costs to the City if it has to remove the earth retention system. 2. Council could determine on a case by basis whether or not to allow the use of an earth retention system in the ROW. Council may also at that time, impose a fee to recover any future costs to the City. MEMORANDUM TO: City Council; Steve Barwick, City Manager FROM : CJ Oliver, Chazles Bailey THRU: Phil Overeynder Lee Cassin DATE OF MEMO: 4/4/2008 RE~ Fluoride in drinking water SUMMARY: According to new reseazch, the addition of Fluoride to drinking water is not necessary for health benefits and may in fact cause an increase in the risk of bone cancer, bone fractures, and other serious illness. Given that the water sources used for the City of Aspen's drinking water naturally contains some Fluoride, staff recommends the City should discontinue the practice of adding more to our drinking water supply. DISCUSSION: Initial studies showing that the addition of fluoride to drinking water helped to prevent tooth decay were completed in the 1940's. Those studies showed the addition of fluoride helped to harden tooth enamel and prevent tooth decay and cavities. Fluoride indeed does have a beneficial impact on preventing dental cavities but it may have some significant drawbacks as well. Studies indicate that Fluoride's benefits are best realized from a topical application and not from actually ingesting the product. In addition to drinking water, fluoride makes its way into our diet in a number of other ways. Toothpaste, sodas and other beverages, processed food, fresh fruits and vegetables, vitamins and mineral supplements all contribute to the intake of fluoride as well. Because of this it may not be necessary to add more fluoride via the drinking water supply for people to receive the recommended dosage of Fluoride. Here aze a few examples of some common foods and their average Fluoride content in parts per million (ppm): Brewed Black tea 3.73 ppm, Diet Coke 0.6 ppm, Brewed Coffee 0.91 ppm. These levels can be compazed to nation wide average of 0.71 ppm in tap water. Please see page 80 of the attached Scientific American article for fluoride amounts in typical foods. Fluoride is not added to the drinking water for water quality reasons; it is added for its dental health benefits. This is perceived by many as mass medication without consent. If someone wants to add fluoride to their diet they have the ability to do so by the means listed above but if their public water supply comes with a compound added that has been shown to have some risk of serious health effects, the person would have a very difficult time avoiding ingesting fluoride. The compound used to add fluoride to the drinking water is highly toxic and is an occupational hazard to the workers who are exposed to it. In Aspen an average of 3.3 million gallons a day of water is fluoridated to "recommended" levels of 1.1 mg/L. Of that 3.3 million gallons, only 10,000 gallons is actually consumed. In order to do this the city adds 11,000 lbs. of sodium silica fluoride to the water supply every year. Of that 11,000 pounds, 10,956 lbs. or 99.7% of added the Fluoride will never be consumed. This excess Fluoride becomes an environmental pollutant instead of a medical treatment. Because of this, discontinuing the addition of Fluoride to our public water supply will also further our mission of being environmental stewards. Studies done after the widespread use of fluoride in water have raised concerns about health risks of fluoridated water. According to the National Research Council, "Animal studies have suggested the possibility of increased risk of bone cancers in male rats". A study reported in the May 2006 issue of Cancer Causes and Control found that "Among males, exposure to fluoride at or above the target level was associated with an increased risk of developing osteosazcoma. Staff has talked to local dentists as well as the Colorado Deparhnent of Public Health and Environment and both groups are strongly in favor of a Fluoridation program for local water supplies. Both cited the importance of having a Fluoride source for those who could not afford to go to a dentist. The Centers for Disease Control and Prevention says fluoridation is among the top 10 health successes of the last century ENVIRONMENTAL IMPLICATIONS: The environmental implications associated with not using fluoride in drinking water would be reducing the amount found in water effluent being dischazged back into the Roaring Fork River. This is a positive because fluoride is not beneficial to the bugs or fish found in the river. Also the City would be purchasing and using one fewer toxic substance. RECOMMENDATION: Environmental Health and Water Deparhnent Staffs recommend that the City of Aspen Water Department consider no longer adding fluoride to the drinking water supply based on three reasons. 1) Alternatives exist for providing adequate fluoride for dental health. Recent studies indicate that changes in American diets that have increased fluoride intake, making it unnecessary for dental health, 2) Studies have shown that fluoride ingestion may cause or promote certain serious harmful medical conditions, and 3) most fluoride added to the water ends up in the rivers, and its use poses a risk to treatment plant employees. CITY MANAGER COMMENTS: aa~to SCIENTIFIC; , AMEItICA,N F~ i EsfabliRhed 1846 ' EDITOR IN <Xlei. fohn RennM ~: -~ F)IFCYTIVE FOITOR::Matktm DrChWtiN f '. MANAfi1N8 GYITdli" Rukr t.•Rustiog; CXI[P news mrtoq:~Plulip M, Yam 't SENI9a WRItER:'Giry$[iP ~. ~ADMaas: MatkAlpert Stewn Aehley~Pen[B[oWa,_ :GnbAie P. Co111Yii Mork FiMhetei, Steye Minky, ~ ~wRe Mupe[,ChriynN SNe4, ItvrE'iyDng, ' ROgTRIRNTIN6 [OITPRSa W. Way[Gib6s, ' - I'. ~Atatgueeite HOllowry,Mkaslk Pns[, MiehRd Shumer, ' ~., SanhSimpwn - ~i ~ , ~IrplNe IWn OniMkY MApA41N6):DI1 ~ i XEWS EOITOR~ ! nSlgn , I ` ~. NE [1A :d BKllq PSSOCIATfF l ~ fAHU Ciay G[ee+ I SiE<UtPR01[G[B dR ONLINE: i~ ~ ' Chrutophu MlmT ^ F ' -NEWS R[PORFRS, ONLINE ]RMnal,, j. - 'NikhilSwamlNepari `-'A '-CONMYXIlY IOI[OR ONq NI. n•1r1[IRN h01fOn L'OU ART DIREDTOR.Oq^qL RYan Rtid `: ). .rive aqr DlRec[oa: Edward Bdl ali o; 'SENIOR ASSOCIATlAIR DIRE<TOP. Mack Clemens p '- NAB Pf515[AXT gTDIXg<TOR fohnnyfbhnwq 'C b ~ ASSISTANT APT DIAi9TOP. Jen ChtifiianuR e Ci ', PXOTOORPPNT [OITOp: Emily Haiiii6n •. IlOO - - PRODUCTION FOITOR: Richard HUDT; , % ~ '- J e.: ' COPY meEFiOP: vdar4-Ghrininaxelkr stew eorYCN1ET:DaBkIGSehlenoff° ': byt FOPY ANO RESFARCN: MMM1AeI BPtpg6a ~. . John Manon,Aaron Shi[mTk.Ra[kel Dvwkm, tOa Aaron Fagae,Smnhi Alamper.MldjElle Wngh[ ,.~N~d in d mITOnAf ADMlxisifiATDR- Awnellt W Ng 1ENIOR SF<RFTPPY: Maya Harty EPA " r ~ ,'nss'oa.,Tf vunislieR, anoouc[ioN ' '.elfl ' Wilnam Slnsmm . wlnxueA<TYxips uanaseR:genet Cecmak. . $eVi ADVERT({IN,fi PPODUCifON MANROERi GdChembin' -': CO 1 PPlPRE;3 AND OUAIITy MANAGED: SiIRUD<$antii ' - IDODURION M4NAGFR; Cb[q[iN Hipp[li rnf ' - CUSTOM PYBII{XIXI MANAGE(: tGCI Madelyn Kiyia~Mikh LiOI the IS , i, 12i SCIENTIFIC AMERICAN thousands of studies; and the experience of more than 170 million Americans. We wel- come additional peer-reviewed scientific studies that will add ro the body of knowl- edge onthe use of fluoride. Meik Feldman President, American Dental Associadon ^ Cosmic Growth Spurt In "Making Space for Time" (News Scan], Scot[ Dodd explains that cosmic mi- crowave barkgroundradiation shows that allrhme zones and weather conditions, without paying over addit Tonal land. Mathieu Pederspie7 - via a-mail -. Has anyone looked into the effec[s of ,, installing 30,000 squaie mile$ of low-al- bedo surface material? Solar patiel4, by design, have a much Lower albedo than. most Ilatground is the Southwest. How would their greater heat absorptionaffect ' the local environment? s.. Taken Swanson . ~Seatde May 2ooa IeU~LI~ IQIsALTH iVev~ ~~s~arch indicates that a ~a~ity-#ighting treatment c®~id he ~isicy i~ ®~~rused By Dan Fagin ong before the passionate debates over cig- arettes, DDT, asbestos or the ozonehole, most Americans had heard of only one environmental health controversy: fluoridation. Starting in the 1950s, hundreds of communities across the U.S, became embroiled in heated bat- r(es over whether fluorides-ionic compounds containing the element Fluorine-should be added to their water systems. On one side was abroad coalition of scientists from government and industry who argued that adding fluoride to drinking water would protect teeth against decay; on the other side were activists who con- tended that the risks of fluoridation were inad- equately studied and that the practice amount- ed to compulsory medication and thus was a violation of civil liberties. The advocates of fluoride eventually carried [he day, in part by ridiculing opponents such as fhe right-wing John Bitch Society, which called fluoridation a Communist plot to poison Amer- ica. Today almost 60 percent of the-U.S. popu- lation drinks fluoridated water, including resi- dents of 46 of the nation's SOlargest ci[ies. Out- sidetheU.S.,fluoridationhasspread to Canada; the U.K., Aus[ralia, New Zealand and a few other countries. Critics of the practice have gen- erally been dismissed as gadflies or zealocs by mainstream researchers and public health agen- cies in those countries as well as the U,S. (In other nations, however, water fluoridation is rare and con[rover31a1.)The U.S. Centers for Disease Control and Prevention even lists water. fluoridation as one of the 10 greatest health achievements of the 20th century, alongside vaccines and family planning. Now, though, scientific attitudes toward fluo- ridation may be starting to shift in the country. where the practice began. After spending more than two years reviewing and debating htin-. dreds of studies, a committee of the National Research Council (NRC) released a report in q 2006 that gave a tinge of legi[imacy to some. longtime assertions made by antifluorida[ion campaigners. The report concluded that the En- vironmental Protettion Agency's current limit 74 StlENTlfic AMERICAN January 2008 ,~, '~4 p~- ~C,E E ~ 89 w.~ 0 e ..~y .~"~ E~2 i sT ~~ s £ iy v °vi$ a L'O 0~9 e, E~x= ~9 E ~ 6 c =yez~a5~r~o. ~E~s~~9'x';~ e§b~~o` -d=~9 L~ E T 5 n e ~L ~ c° .S ~ ~ ~ o ~ ~ ~ o H ~ E `o z o E o_ °° E m u_ r 8~ C-s L o E 9 n__ ~ s o~= c° m v .E E a j ° ~ E ~ ~ ~ ~.; .E oa Y~{ e m- e c c e p v 4 s` o~ A 'e E ~= ~'d ~~'o 9 E Y o 9 r :.~ 3 e °d s x`39"6~e8=~ z 3 x.a o -. E`o E ~ F Y' v 3 00 a a ~~ ~ N °~ 7 S 01~ w O aA+ •~ X ~ y N ~ .~ ~ ~ V u N Y °G d ~ ,( _. ~ O v ~ 'a a, c ~ t *' ~ ~ d '~" d d Z LL ~gc8d~$,7~~2'2pp a'4 ~~pp Ew E3$4~c Z^~'8'~~ l0 2'99c 'L ~.Y~ ~~ 5 ~S SE='S E6$ @ ^s °°a~ m °$Z°'~ ~-~'~ S~c°3EC ffi9 g°o a~~~g O yx g Ehd 5 ~Oe .n a' o °° ~ nII3~ ~~ E v _ e x~¢~9cap2 CcE `s~eEo'S`~'Se `o q 5 'o ~ ¢ E.S g~~~~z.g5 ~a8<"9 ~':~' EE. p~S ~ ~u.S c..or S ° ° ~_ ~~.°9 = 80~°° q~m.=m o°^ ~QE~ ~~~~S~S ~ ..E g?QHoC°8~ X ~ p fi55 ~-~ ,Y3y c ~ E ~ ~ „ o c 9 $ L3 3 r~ J E~;~~ :ogE~a~ ~Xm 9.: i L L, '' _'.. I;. ~' i for fluoride in drinking water-four milligrams per liter (mg/L)-should be lowered because of health risks to both children and aduhs. In chil- dzen,consistent exposure to fluoride at that lev- el can discolor and disfigure emerging perma- nent teeth-a condition called dental fluorosis. In adults, the same fluoride level appears to in- creasethe risk of bone fracture and, possibly, of moderate skeletal fluorosis, a painful stiffening of the joints. Most fluoridated water conxains much less fluoride than the EPA limit, but the sit- nation is worrisome because there is so much unceztainty over how moth addixional fluoride we ingest #rom food, beverages and dental prod- ucts. Wha[ is more, the NRC panel noted xhat fluoride may also trigger more serious health problems, including bone cancer and damage to the brain and thyroid gland. Although these ef- fects are still unproved, the panel argued chat they deserve further study. The largest long-running investigation of the effec[s of fluoride is the Iowa Fluoride Study, di- h't www.SdAm.coro SCIENi1Flt AMERICAN 7~ uT ~9%ot received fit in 2002 0%-75% ®>75% MT ,o 4 q,: ; `. °~.. 1945: 1965- ` 1985 : - 2002 ~~ ,~ Yeaf 'Dad wrpualic warersysreins norsveilable 6efoie 1964 Dan Fagin is an assotiale profes- sor of journaiismand director of the Science, Health and Environ• mental Reporting Program at New York University. A former environ- mentaland scien<ewriter for Newsday, his articles on cancer epidemiology won the AAAS Science Journalism Award In 2003. Fagin is co-author of Toxic 0ecep- rion (Common Courage Press, 1999) and is working on a book about gene•environment interac- tionsand the childhood cancer cluster in Toms River, N.1. 76 SCIENTIFIC AMERICAN rected by Steven M. Levy of the University of Iowa College of Dentistry. For the past 16 years Levy's research [eam has closely tracked about 700 Iowa children to try to tease out subtle ef- fects of fluoridation that may have been over- looked by previous studies. At the same time, Levy is also leading one of the mos[ extensive efforts ever to measure fluoride concentrations in thousands of products-including foods, drinks and toothpastes-to develop credible es- timates of typical fluoride intake. It is a maddeningly complex area of research because dies, roothbrushing habits and water fluoridation levels vary so much and also be- causegenetic, environmental and even cultural factors appear to leave some people much more susceptible to the effec[s of fluoride-both pos- itiveand negative-than others. Despite all the uncer[ainties, however, Levy and some other fluoride researchers have come around to the view char some children, especially very young ones, are probably getting more fluoride [han they should. Most of those scientists, including Levy, still support water Fluoridation as a proved method of controlling tooth decay, especially in populations where oral hygiene is poor. But the researchers also believe that in communities with good dental care the case for fluoridation oPulation water - is not as strong as it used to be. "Instead of just pushing for more fluoride, we need [o find the right balance," Levy says. The Advent of Fluoride Framed toothpaste advertisements from more than half a century ago hang on the walls of Levy's conference room. One touting Pebeco Toothpaste reads: Do you want your teeth to ache and get ugly?" Another asserts that "Col- gate Chlorophyll Toothpaste Destroys Bad Breath." They axe artifacts of the prefluoride era, when tooth decay-called caries in the par- lance of dentistry-waspervasive and tooth- pastes were marketed with questionable medi- calclaims. The introduction of fluoride changed all that. In 1945 Grand Rapids, Mich., became the first city ro fluoridate its water supply. Ten years lat- er Procter & Gamble introduced Crest, tht firs[ fluoridated toothpaste, which contained stan- nousfluoride (a compound with one atom of tin sad two of fluorine). Colgate-Palmolive fol- lowed in 1967 by modifying its Colgate brand with what has become one of the dominant cav- ity-fighting ingredients in toothpastes: sodium monofluorophosphate. Instead ofsticking with the fluoride salts found in toothpastes and fa- January 2008 1~ S voted by dentists in office treatments, most wa- -°' ter suppliersevenmallyswitchedtothecheaper option of fluoridating with silicofluorides such as hexafluorosilicic acid, a by-product of afez- tilizer manufacturing process in which phos- phate ores are treated with sulfuric acid. By the 1970s and t 980s Amezica was awash in various forms of fluoride, and fluoridation had become the cornerstone of preventative dentis[ty in most English-speaking countries. Exactly why and how much caries incidence de- creased during the same period is a matter of fierce debate, but the consensus among dental researchers is that the decline was steep and that fluoride deserved much of the credit. That was the culture in which Levy got his start in public health dentistry in the mid-1980s. Colgate-Pabnolive funded his early research, which had the effect of encouraging more fluo- ride use in dental offices. But as American den- tists began to see fewer cavities and more fluo- rosis on the teeth of their young patients, Levy started to wonder whether children were get- ting too much of a good thing. "There was a transition in my own thinking from `more fluo- ride indefinitely our goal' [o making sure we un- derstand where the right balance is between caries and fluorosis." Fluoride's role in causing one disease and de- terringanother isrooted inthe fluorine ion's pow- erfulattraction tocalcium-bearing tissues in the body. In fact, more [han 99 percent of ingested fluoride that is not quickly excreted ends up in bones and teeth. Fluoride inhibits cavities through two separate mechanisms. Firs[, fluoride that roaches the enamel-[he hard, white ou[er layer of the teeth-becomes embedded in the ctystal- linestructures of hydroxylapatite, the main min- eralcomponent of teeth and bones. The fluorine ions replace some of the hydroxyl groups in the hydroxylapatitemolecules ofthe enamel, and this substitution makes teeth slightly more resin[ant to the enamel-dissolving acid excreted by bacte- ria inthe mouth as they consume food remnants. Second, the fluoride on the surface of teeth serves as a catalyst that enhances the deposition of cal- ', ciumandphosphate,makingiteasiecforthebody to continuallyrebuildtheenamelcrystalsthatthe bacteria are dissolving. Fluoride has a very different effect, however, when large doses are ingested by young children whose permanent teeth are still developing and have not yet erupted. The key proteins in early tooth formation are called amelogenins, which regulate the formation of hydroxylapatite crys- unnaaldeua ` Bel~lum www.SciAm.com SCIENTIFIC AMERICAN 77 Scientists have focused on fluoride s effects on bone because so much of the chemical is stored there. Studies have shown that high doses of fluoride can stimulate the proliferation ofbone-building osteo- Pedosteum Marrow blast cells, raising fears that the chemical may induce malignanttumors.Fluoridealsoappears - .___.,~,._._,_ to alter the « ystalline structure ofbone, possibly increasing the risk of fractures. Osteoblasts forming new bone Exlstina bone • Normal Bone Formation Proliferation of Layer of new osteoblasts weak bone tals. As a crystal matrix forms, the amelogenins break down and are removed from the matur- ingenamel. But when some children consume high doses of fluoride, which is absorbed through the digestive tract and delivered by the bloodstream to the developing teeth, the bio- chemical signaling goes awry and the proteins remain inside the budding [ooth longer than usual, thereby creating gaps in the crystalline enamel structure. As a result, when a fluorosed tooth finally erupts it is often unevenly colored, with some por[ions whiter than others-a visu- aleffect caused by light refracting off the po- rous enamel. In more severe cases, the surface of [he tooth is pitted and the s[ains are brown. Nutrition and genetics can influence the risk of fluorosis, but the most important factor by far is the amount of fluoride ingested. With grant money from the National Insti- tu[e ofDental and Craniofacial Research, Levy set out to determine how much fluoride children consume and how it affects their teeth and bones. There is no universally accepted optimal level for daily intake offluoride-that is, a level that maximizes protection against tooth decay while minimizing other risks-but the range most often cited by researchers is 0.05 to 0.07 milligram of fluoride per kilogram of body weight per day. In the early 1990s, when the children in Levy's study were infants, he found that more than a third of them were ingesting enough fluoride-mostly via wa[er-based infant formula, baby foods and juice drinks-to put them at a high risk of developing mild fluorosis in [heir permanen[ teeth. That fraction dropped only slightly as xheir dice changed during their toddler years-a critical period for enamel for- mation in preemergenr xeeth. Typical fluoride ingestion stayed high during the toddler years, in part because roothpaste replaced formula as a key source. Although both children and adults are supposed to spit out their toothpaste after brushing, Levy had found in an earlier study that toddlers on average ac[ually swallowed more than half of their toothpaste. By [he time the Iowa children were nine years old and their permanent front teeth had emerged, it was obvious that the earlier expo- sures to fluoride had literally left their mark. The front teeth of children who had been in the high-intake group as infants and toddlers were more than twice as likely to show the telltale staining of fluorosis than the teeth of children who had ingested less fluoride when they were younger. And as their die[ broadened, so did their sources of fluoride: Tests performed in S{' 7$ SCIENTIFIC AMERICAN Jenuaty 2008 • Effects of Excessive Fluoride i f l Levy's lab found, for example, that many kinds of juice drinks and soda pop contain enough fluoride (generally about 0.6 mg/L) so that drinking a little more than a liter a day would put a typical three-year-old at the optimal in- take level, without counting any other daily sources. Dozens of Eood items tested by Levy's team contained even higher concentrations of fluo- ride: anaverage of 0.73 mg/L in cranberry-juice cocktail; 0.71 mg/L in ice pops, 0.99 mg/L in beef gravy and 2.10 mg/L in canned crabmeat, for example. In mosx cases, the fluoride came from waur added during processing, although higher levels also got into grapes and raisins via pesticides, into processed chicken products via ground-up bone, and into tea leaves via absorp- tion from soil and water. Levy found that exposure to fluoridated drinking water was an even more impo[tan[ risk factor for fluorosis. Iowa children who lived in communities where the water was fluoridated were 50 percent more likely to have mild fluoro- sis on atleast two of their eight permanent front teeth at nine years of age than children living in nonfluoridated areas of the state ([here was a 33 percent prevalence in the former versus 22 per- cent in.the latter). Similar results appeared in the NRC report, which found that infants and coddlers in fluoridated communities ingest about twice as much fluoride as they should. Furthermore, the committee noted that adults who drink above-average amounts of water, in- cludingathletes and laborers, are also exceed- ing the optimal level for fluoride intake. But enamel fluorosis, except in the severest cases, has no'health impact beyond lowered self-esteem:'the tooth marks are unattractive and do not go away (although there are mask- ing treatments). The much more important question is whether fluoride's effects extend be- yond altering the biochemistry of tooth enamel formation. Says longtime fluoride researcher Pamela DenBesten of the University of Califor- nia,San Francisco, School of Dentistry: "We certainly can see that fluoride impacts the way proteins interact with mineralized tissue, so what effect is it having elsewhere at the cello lar level? Fluoride is very powerful, and it needs to be treated respectfully.° Fluoride and Bane Bone is an obvious place to look fox fluoride's fingerprints because so much fluoride is stored there. What is more, studies of patients with www.SciAm.com osteoporosis-a bone disease that increases the risk of frac[ures-have shown tha[ high doses of fluoride can stimulate the prolifera[ion of bone-building osteoblast cells, even in elderly patients. The exact mechanism is still unknown, but fluoride appears [o achieve this by increas- ing [he concentrations of tyrosine-phosphory- lated proteins, which are involved in biochemi- cal signaling to osteoblas[s. As witb'[oo[h enamel, however, fluoride not only stimulates bone mineralization, italso appears [o ulcer the crys[alline structure of bone-and in this case, the effects are not merely aesthetic. Although fluoride may increase bone volume, the strength of the bone apparently declines. Epidemiologi- calstudies and tests on lab animals sugges[ [hat high fluoride exposure increases the risk of bone fracture, especially in vulnerable populations such as the elderly and diabetics. Although [hose studies are still somewhat controversial, nine of the 12 members of the NRC panel con- cluded that a lifetime of exposure [o drinking water fluoridated at 4 mg/L or higher does indeed raise the risk of fracture. The committee noted [hat lower fluoridation levels may also increase the risk, but the evidence is murkier. As the Iowa children in his study enter ado- lescence, Levy hopes that analyses of the strength of their spine, hips and overall skeleton will point to possible connections between fluo- rideintake and bone health. He presenxed some preliminary data in 2007, finding little differ- ence in the mineral con[ent of the bones of lI- year-olds based on how much fluoride [hey had ingested as youngthildren. As they go through adolescence, however, Levy thinks that trends may emerge. The even bigger question looming over the fluoride debate is whether these known cellular effects in bones and teeth are clues that fluoride is affecting other organs and triggering other diseases besides fluorosis. The biggest current debate is over osceosar- coma-the most common form of bone can- cer and the sixth most prevalent cancer in children. Because fluoride stimulates the pro- duction of osteoblasts, several researchers have suggested that it might induce malignant tumors in the expanding cell population. A 1990 study conducted by the U.S. govern- ment's National Toxicology Program found a positive dose-response relation for os[eo- sarcoma incidence in male rats exposed to different amounts offluoride in dritking wa-' ter (all rhose amounts, as is typical for ani- When young children consume large amounts of fluoride, the chemical can disrupt the develop- ment of their permanent teeth. When the teeth emerge, their enamel may he discolored (top) or, fn more severe cases, disfig- ured (bottom). Researchers have found that this condition, called dental fluorosis, is more common in communities where the drink- ingwater isfluoridated. SCIENTIFIC AMERICAN 79 mal studies, were far above the actual expo- mechanism: the formation of aluminum fluo- sures found in fluoridated communities). But ride completes-smallinorganic molecules that other animal studies as well almost epidemio- mimic the structure of phosphates and thus in- logicalstudies inhuman populations have been fluence enzyme activity in the brain. There is ambiguousatbest. alsosomeevidrncethatthesilicofluoridesused ~~~~®~~~~~~~~ The latest dustup over fluoride and osteosar- in water fluoridation may enhance [he uptake The optimal rangefor dally intake coma was instigated by a young researcher of lead into the brain. otfluoride-the level that maxi- named Elise B. Bassin of the Harvard School of The endocrine system is yet another area mites protection against tooth Dental Medicine. Bassin collected information where some evidence exists that fluoride can deraybut minimizes other risks- about fluoride exposures among 103 os[eosar- have an impact. The NRC contmit[ee conclud- isgenerallyconsideredtahe0.05 comapa[ientsand215matchedcontrolsubjects edthatfluoridecansubtlyal[erendocrinefunc- to 0.07 milligram for each kilo- gram of bodyweight. Consuming and concluded that fluoride is a risk factor for xion, especially in the thyroid-the gland that foods and beverages with large the cancer among boys (the results were ambig- produces hormones regulating growth and me- amountsoffluoridecanputadiet uousforgiris).Bassin'srepor[appearedin2006 [abolism.Althoughresearchersdono[know above thisrange. Belowaretypi- in the journal Cancer Causes and Control; in how fluoride consumption can influence the cal trace levels of fluorlde, mea• however, her dissertation advis- the same issue thyroid, the effects appear to be strongly influ- sured inparts per million (ppm), found in foods and drinks tested , er at Harvard, Chestu Douglass, wrote a tom- enced by diet and gene[ics. Says John Doull, at the university of Iowa College mentary warning readers to be "especially cau• professor emeritus of pharmacology and toxi, of Dentistry. tious" in interpreting her findings because, he cology at the University ofKansas Medical Cen- better data, still unpublished, contradict said [er,whochairedtheNRCcommittee:"Thethy- 3.73 ppm Brewed black tea , them. Antifluoridationists and some envi- told changes do worry me. There are some 2.3~ppm Baisins- rorimental groups quickly rushed to things there that need to be explored." 2.O2 ppin White wine Basin's defense, demanding that Har- vard investigate Douglass, professor The Cantraversy Continues ppm Apple- ® 1.0g and chair of epidemiology at the den- The release of the NRC reporthas nonriggered flavored juice drink tal school, for allegedly misrepresent- a public stampede against fluoridation, nor has ing Basin's work and for having aeon- it prompted the EPA to quickly lower its fluoride ® 9~ ppm Brewed flice of interest because he is editor in limit of 4 mg/L (the agency says it is still study- coffee chief of a newslet[er Eor dentists Funded by ing the issue). Water suppliers who add fluoride 0.71 ppm Tap water Colgate. The university's investigation of Doug- typically keep levels between 0.7 to 1.2 mg/L, (U5: wide lass, completed in 2006, concluded that there far below the EPA limi[. About 200,000 Ameri- average) was no misconduct or conflict of interest. cans-and several million people in China, 0.61 ppm Chicken soup Clashesoverthepossibleneurologicaleffects India, [he Middle East, Africa and Southeast broth of fluoride have been just as intense. Phyllis Asia-drink concentrations higherthanthelim- 0.60 ppm Diet Coke Muflenix, then at the Forsyth Institute in Bos- it, but their excess fluoride comes from natural- (U.S: wide ton, set off a firestorm in the early 1990s ly occurring runoff from fluoride-containing average) ~ when she reported that experiments on rocks and soils near water sources. O.Q8 ppm Not dog lab rats showed that sodium Fluoride The repot[ is, however, prompting some re- 0.46ppmGrapefruit can accumulate in brain tissue and af- searchers to wonderwhetherevenlmg/Lis too juice fec[ animal behavior. Prenatal expo- much in drinking water, in light of the growing 0.45 ppm Beer - ~., sores, she reported, correlated with hy- recognition that Eood, beverages and dental - peractivity in young rats, especially products are also major sources of Fluoridq es- 0.45 ppm Baked russet males, whereas exposures afterbirth had pecially for young children. The NRC commi[- potatoes .~~ -. the opposite effect, turning female rats tee did not formally address the question, but 0.35 ppm Cheddar cheese!" ~~, '" into what Mullenix later described as its analyses suggest that lower water fluorida- 0.33 ppm flour ~ "couch potatoesY Although her research cion levels may pose risks, too. "Wha[ the com- tortillas was even[ually published in Neurotoxicology mittee found is [hat we've gone with the status 32 ppm Creamed corn 0 and Teratology, i[ was attacked by other quo regarding fluoride fot many years-for Coo . (baby food) scieansts who said that her methodolo- long, realty-and now we need to cake a fresh m Chocolate 23 0 gywasflawedandthatshehadusedun- look,"Doullsays. "In the scientificcommumty, h h l d [ pp . realistically high dosages. Since then, mean,w e e . peoplexeadtothinkthisissett ice cream - ;, however, a series of epidemiological theU.S.surgeongeneralcomesoutandsaysth~ 0.13 ppm Brewed `. studies in China have associated high is one of the 10 greases[ achievements of [he chamomile tea Fluoride exposures with lower IQ, and 20th century, that's a hard hurdle to get over. 0.03 ppm Milk (2%) - research has also suggested a possible But when we looked at the studies that have $~ SCIENTITIC AMERICAN January 2008 as Colorado Browh3tairi. McKay discovered that th there did not. They tiypdtl ehamel faced the highest uhkhawn cbmpo0nd ihtl ~dB~ae®~~ first been done, we found chat many of these ques- tionsare unsettled and we have much less infor- mation than we should, considering how long this [fluoridation] has been going on. I think that's why fluoridation is still being challenged so many years after it began. In the face of igno- rance, controversy is rampant." Some longtime fluoride researchers, however, remain unimpressed by the evidence of effects beyond teeth and bones, and they continue to push for an expansion of water fluoridation in the U.S. and elsewhere. Their view remains the official position of the American Dental Asso- ciationand the U.S. Public Health Service. "We feel there are enough communities out there with high caries rates to justify additional fluo- ridation," says Jayanth V. Kumar, director of oral health surveillance and research attheNew York State Department of Health and a member of the NRC panel who dissented from some of www.SciAm.com its findings. He acknowledges, however, that the argument for water fluoridation is not as strong in affluent areas with good nutrition and dental care. "Today it depends on what the car- ies level is in the community. If the disease is low, the return on investment [for fluoridation] may not be all that great " Opponents of fluoridation, meanwhile, have been emboldened by the NRC report. "What the committee did was very, very important, be- cause it's the first time a truly balanced panel has looked at this and raised important ques- tions,"says Paul Connect, a chemistry professor at St. Lawrence University and the executive di- rector oEthe Fluoride Action Network, one of the most active antifluoridation groups world- wide. "I absolutely believe it's a scientific turn- ingpoint because now everything's on the table. Fluoride is the most consumed drug in the U:S., and it's [ime we talked about it." ^ Patterns of Fluoride Intake from Birth to 36 Months. Steven M. Levy, John 1. Warren, Charles S. Davis, H. Lester Kirchner, Michael 1. Kanellis and lames S. Wefel in Jour- nal of Public Health Dentistry, Vol. 61, No. 2, pages 70-77; June 2007. Pattemz of Fluoride Intake from 36 to 72 Months of Age. Steven M. Levy, John 1. Warren and Barbara Broffit[ in Journal of Public Nealth Dentistry, Vo1.63, No. 4, pages 211- 220;December2003. Timing of fluoride Intake in Rela- tion to Development of Fluorosis on Maxillary Central Incisors. Liang Hong, Steven M. Levy, Barbara Broffitt, John 1. Warren, Michael 1. Kanellis, lames S. Wefel and Deborah V. Dawson inCommu- nltyDentistryandOial Epidemiology, VoI.34, No.4, pages 299-309; August 2006. Age-SpedRc Fluoride Exposure in Drinking Water and Osteosarco- ma. Elise e. Bassin, David Wypij, Roger B. Davisand Murray A. Mittleman in Cancer Causes and Con- trol, Vol. 17, No.4, pages 421-428; May 2006. Caution Needed In Fluoride and Osteosarcoma Study. Chester W. Douglass and Kaumudi loshipura in CancerCauses and Convol, Vo1.17, No.4, pages 481-482; May 2006. Fluoride in Drinking Water: , A SCientiflc Review of EPA's Sa Standards. National Academy of Sciences, 2006. Available at www.nap.edu/catalog. php?record_id=11571 SCIENTIFIC AM ERICAN $1 i -. The cause remained a mystery anti 'staining in Bauxite; a company town o6 minum might tie blamed, Akoa4 ~ilef thing McKayhad neversuspected: high pe<t water supplies and found that wh) -:" fir CDA Position Statement: Fluoridation The Colorado Dental Association (CDA) has long supported community water fluoridation as a safe, effective and economical contributor to the dental health of all Coloradans. A dentist in Colorado Springs discovered the decay-preventive properties of fluoride in the eazly 20th Century. Community water fluoridation began 60 years ago to bring a significant reduction - 20% or more - in dental caries (tooth decay) in the general population. There are numerous scientific studies about fluoride and community water fluoridation. None have ever found any sound evidence of a health risk being caused or even exacerbated by fluoridation. The safety, effectiveness and economic benefit of community water fluoridation has led the Centers for Disease Control and Prevention to label it as one of the "10 great public health achievements of the 20th Century," a conclusion with which we unreservedly agree. STATEMENTS FROM SIX LEADING HEALTH AUTHORITIES REGARDING COMMUNITY WATER FLUORIDATION American Dental Association (ADA) "The Association endorses community water fluoridation as a safe, beneficial and cost-effective public health measure for preventing dental caries. This support has been the Association's policy since 1950." --ADA Operational Policies and Recommendations Regarding Community Water Fluoridation (Trans.1997:673). Centers for Disease Control and Prevention (CDC) "During the 20`h century, the health and life expectancy of persons residing in the United States improved dramatically. To highlight these advances, MMWR will profile 10 public health achievements in a series of reports published through December 1999 (Fluoridation of drinking water was chosen as one of these achievements and profiled in the October 22, 1999 MMWR). Fluoridation safely and inexpensively benefits both children and adults by effectively preventing tooth decay, regardless of socioeconomic status or access to care. Fluoridation has played an important role in the reductions in tooth decay (40%- 70% in children) and of tooth loss in adults (40%-60%)." --CDC, Morbidity and Mortality Weekly Report. "Ten Great Public Health Achievements-United States 1900-1999" April 1999. American Medical Association (AMA) "The AMA recognizes the important public health benefits of drinking properly fluoridated water and encourages its member physicians and medical societies to work with local and state health departments, dental societies, and concerned citizens to assure the optimal Fluoridation of community drinking water supplies." -AMA Letter to the American Dental Association, March 10, 1995. U.S. Surgeon General "A significant advantage of water fluoridation is that all residents of a community can enjoy its protective benefit - at home, work, school or play -simply by drinking fluoridated water or beverages and foods prepared with it....Water fluoridation is a powerful strategy in our efforts to eliminate differences in health among people and is consistent with my emphasis on the importance of prevention... Fluoridation is the single most effective public health measure to prevent tooth decay and improve oral health over a lifetime, for both children and adults. While we can be pleased with what has already been accomplished, it is clear that there is much yet to be done. Policymakers, community leaders, private industry, health professionals, the media, and the public should affirm that oral health is essential to general health and well being and take action to make ourselves, our families, and our communities healthier. t join previous Surgeons General in acknowledging the continuing public health role for community water fluoridation in enhancing the oral health of all Americans." --Surgeon General Richard H. Carmona, Statement on Community Water Fluoridation, July 28, 2004. National Institute of Dental &Craniofacial Research (NIDCR) "The National Institute of Dental and Craniofacial Research continues to support water fluoridation as a safe and effectve method of preventing tooth decay in people of all ages. Community water fluoridation is a public health effort that benefits millions of Americans. For more than half a century, water fluoridation has helped improve the quality of life in the U.S. through reduced pain and suffering related to tooth decay, reduced tooth loss, reduced time lost from school and work, and less money spent on dental care." --NIDCR: Statement on Water Fluoridation, June 2000. World Health Organization (WHO) "Most recently, efforts have been made to summarize the extensive database (on fluorides) through systematic reviews. Such reviews conclude that water fluoridation and use of fluoride toothpastes and mouthrinses significantly reduce the prevalence of dental caries....Waterfiuoridation, where technically feasible and culturally acceptable, has substantial advantages in public health..." --WHO Effective use of fluorides for the prevention of dental caries in the 21 s` century; the WHO approach." Community Dentistry and Oral Epidemiology 2004;32:319-21 li { ~%~ Licwsure ~`~+"' Larzlo9 ~ i ,~L Nember Direemry ~ ~ Lonrac Us ~ ~~ ~.:, 11~/f "a:Go:gk A-Z Tapirs Advocacy Education & Testing Events & Meetings Member Centel PutjEications & Resources :N~a?aw rs minti.~sa~ u5n'~5 ~Kc31'i,'LBfr6?'r, T~Y1.S:5 voowl~afv9tzss ADA Curzent Polities ADA Positions 8 Statements Research Agenda SrumnR~s UE?lTAL PROFESSIOPLALS , THE AOA YOUR OPAL HEALTH AOA POSITIONS 8 STATEMENTS AMERICAN DENTAL ASSOCIATION SUPPORTS FLUORIDATION The American Dental Assodation umeservadly endorses Ma fluoridation d commuriily water supplies as safe, effective and necessary in preventing toots dewy. This support has been the Asaodation's position since policy was friar adopted in 1950. Fluoridation of Water 6uppiiea (Trens.1860:224) Resolvetl, that in the interest d public health, the American Dental Association recommends Me fluoridation d munidpal water supplies when the fluoridation precedure is approved by the local dental sodery end uWaed in accordance with Me standards established by the responsible heaflh authority, end be it fuller Resolved, that the American Dental Association recommends the continuation of contrdled studies d the benefits derived fmm the fluoridation of water supplies. In 1993, Me Assodation marked the 50th anniversary of wmmunhy water fluoridation. 69th Anniversary of Community Water Fluoridation (Trcns.i993:692) Resolved, that the American DenW Association dedare the 60M Anniversary of Fluoridatbn in Grand Rapids, Michigan to be of national signiflmnce in the history d preventive dentistry, and be rt fuller Resolved, that the Association identity appmpriata opportunities to be visibly assodated wdh this commemaretive event You gt Since the inception d water fluoridation, the Ameriran Dental Assodation has carefully monitoretl scentifc research YOUP Practice regarding safety and efficacy. Based on Mat roview, the Assocation has continually rcafirmed waterfluoridation as Ue most affective pudic health measure (« Me prevention of dental ceries and sbongly urges that its benefits be eMended to Mole served by communal water systems. In 7997, the ADA House of Delegates confirmed its support for fluoridation by setting farih a comprehensive poky sfatemerit Operadonel Poflcles entl Recommentlatlons RegaMing Commun{ry Water Fluoritlafion (Trans.1987:673) 1. The Assodation endorses community water fluoridation as a safe, benefidal and cest- effeotiva pubec hea1M meawro f« preventing tl•nml nriec. 2. The Assocation supports Me position Mat dl communal water supplies Mat are beknv Me optimum fluoride level recemmended by the U.S. Pubec Heeah Service (a range from 9.7 - t.2 parts per mglionj should be adjusted M an optimum level. 3. The Assocation urges MdNitluaf tlentiats and dental sodeties to e>ierdse leadership in ell phases d acfiuity which lead to the initiation and rastinuation of mmmunlty water fluoridation, inducting making scientific knowledge entl resources availade to Me community and collaborating with stele end local agendas. 4. The Assocation eneouages individual tlerrtists and tletdal sodaties to utikze Assocation materiels on the community organization and public adoration aspects of fluardation. 5. -^:e Assodalio.^, encurages states to ualiu Me caps d evperts in the area of fluoritles and fluoridation Mat is meliYSined t.irough app Pr_ - ~ a "-•-~ -~- •- pmmofe Me safely, benerns and rnslaffectiveness d fluoridaton. 6. The Association encourages governmental agcndes and philaMMOpic organizations to make funding ava0able to rammunides scatting tc adjust Me fluoride content of the .un•v s :vaHr n~,::.n., ...... is rFlt «ida0on entl iisLLinfrastrudure -. ~. ~ .. .... ..~.. - ...... .._ s ~c.c • allocsLan ofneeded resources t oP•oodeic spa au iov _ a-~u a:~ .,. ...~ fluoridation infrastructure', entl • otsarvance of the Certc ~ `~ .''.'.coat C."^ ~ - .r. i...-~. aii s~~L S. pA -~ Licemure ~ Casiod I ~`,~ Memhe~ Oire aY ~ ~ Contact Us I ~~' DEt~JTAL PRDFESSIQFIALS ' ti9E ALFA yitol6t ORAL 4TEALT4 A-2 3Dpics ADA PDSITIONS & STATEfl7ENTS ADA STATEMENT ON THE EFFECTIVENESS OF COMMUNITY WATER FLUORIDATION Advocacy The effectiveness of water fluortdalion has been dowmemed in sdenfific lilereture for well over 55 years. Even before fhe first wmmunily fluoridation program began in 1945, EdUCatIDR & TestlD J data from the 19306 and 19406 revealed 5U-60%Iower toots decay rates in children wnsuming naturally occuning, optimally fluoridated water compared to chldren wnsuming fluodde-0efidanl water. Since that lime, numerous studies have been EVe{7t5 $ (4}ei?tiDgS published malting fluoddation one of the most widely sWtlietl public healM measures in history. Studies prove water fluoridation wntinues to be effective in redudng troth decay by 2040%, even in en era with widespread availabAity of fluodde from other I. _' :~eFil~72f-E[1Re-~~ fOllfCes a ~F ~e flUOndGI00tfIp831P Publications In April 1999, the Cemerc far Disease Control and Prevention (CDC) Drodaimed wmmuniry water fluoridation es one of 10 great public health achievements of the 20th & Resources cemury. The list of achievements, which also indudes vawinations and wnhol of infecdous tliseases, was developatl to highlight signi0cent contributions Net impact the ~~ m, health and well being of Me public Additionally, in 2001, the CDC restated, ?nr.P .ha-r.~i5 'Community waterfluoridafbn is a safe, efiedive end inexpensive way to prevent denW ~.irq~rc~~"~~ cedes.' The CDC not only rewmmended wntinuation of fluoddation but also celled for . its adoption in addNOnal U.S. wmmunities. ~,, t _ In August 2002, the U.S. Task Force on Community Preventive Services wnUUded [hat aL/~5 the evidence for Me effectiveness o(fluoddatiw is strong based on the number and PDaIZU[FaW3110tS quality of studies that have hem done, the magniNde of observed benefits and the ?.pA Cunent Policies wnsistency of the findings. The Task Force issued a strong rewmmendation that water fluoddation be induded as part of a wmprehensive population-based strategy to prevent x ADA Positlons 8 Statements or wntrol troth dewy in wmmunifies. Research Agentla ::u L5 The Amedwn Derital Association (ADA) wntinues to endorse fluoddation of wmmunity water supplies as safe and eRectlve for preventing tooth dewy. This support YDU ~t has been the AssoUation's posMon since pdicy was first adopted in 1950. Based on darn for 2000, approximately t62 million people (two-thirds of the population) in the Untied Your Practice States arc served by pudic water systems that are fluoddated. The ADA, along wdh state end local demal wdeties, wntinues to work with federal, state, and local agendas to increase the number of wmmunitles beneFNng from water fluoddation. For more iMarmation regarding fluodde and fluoridation, visit ttra Amedwn Denial Assodation's'Fluodde end Fluoridation' Web sfle at htlp;i/www:ada;org/gptoMuodde. January 2004 f F,prmore informationabout FluonGe and fluogdaiipn, Please malt the YOUr Oral yealth area of ADA_grg For more topics related to the needs ofpa6ents~see;" ! _- .. Oral Health Tops A-Z ~oPVrrenaeszooe a.mErinw, oEr-ai AEwtia5Je. 3EPrJd -Jl "2P~'~I:v'c"~J~:trulY Pteh S1 C\Vi~hJUl:~nJrV IItE.~PermlESien, __-- cy P w Gpi tl GIH4r0a) snd n ., ar the ' g I In`,Jrn\af]n ~1 _ x Jeans in s=i.ara;e a+noJ.:. Fecu -J 'or a\avn t Jsae.Ed. http://www.ada.org/prof/resources/positions/statements/fluoride_community_effective.asp 6/22/2008 A YF .?. R-Z Topics AEfYOCaCtf E(iuca#iDn & Testing Events & Meetknc~s Member ~2diYer -- Member Directory I ~ Gontect Us I E}EF,iTAL PPt7FESSIt3FkAL5 ' THE ADA ADA POSITIOHS ~ STATE6~ENTS ADA STATEMENT ON THE SAFETY OF COMMUNITY WATER FLUORIDATION O E~ YQUR ORRL HEALTH Fluordaton of community water supplies is safe. This has been fire American Dental Assodation'a (ADA) pdiry since 1950. The ADA's pdidea regarding commundy water fluordatlon ere based on the overwhelming w'eigM of credide scentific evidence. This body of knowledge U based on the efforts of nationally recognized sdeMists who have conducted research using the scenfific method, have drawn appropriate balanced conclusions based on their research findings end have published the'e results in refereed (peerteviewed) professiowl journals that are widely held or circdated such as The Journal d the American Medical Assotiation and the American Jeumal of Pudic Heahh. Studiesshowing Me_safety_of Ovate[fluoridation have been confirmed b~ independent _ _ __. sdarM' tc studies. Publ4Ca#lOr1s Fluoride is nature's wvdy fighter occurring naturally in the eaM's crust in cembina0on 8r Re$aurCes with other minerals found in soil and rocks. Small amouMS of fluoride occur naturally in all water sources. Waterfluoridation is the process d adjusting the natural level of aaaue~:fty fluoride to a concentrafion su~cienl to protect against tooth decay (0.7 fo 1.2 parts per ;4xP,g.:[rrm'aS million). Fluoride in these low concentrafions is not toxic or hamdul. i Y3 vTP _ C 4R.~i E 5 f3 °J K61J~-ntW3v Throughout more than 55 years of research and p2diwl experience, the overwhelming 1nP :~e~STCwvTSr?.; weight of credible scientific evidence has consistently indicated that fluoridatlon of community water supplies is sate. The possibility of any adverse health effects from ~~'s confinuous low-level consumption of fluoride has been and continues to be extensively ODARgxSaFCStr)S studied. Of the hundreds of credible sdentdic sWdiea on fluoridation, none has shown health problems assodated with the consumption d optimally fluoridated water. ADA Current Polities '~~ ADA Positions & Statements In 2000, the U.S. Surgeon General David Satcherwrote in his repoq Orel Haelth in ~4esearch Agenda Ameriw,'Communhy waferfluondadon is safe antl eftecfiva in prevenfing dental canes sra~:DS in both children and adults. Weterfluoridadon benefits ell residents served by community water supplies regardless of their nodal or economic status.' Additionally, the Centers ror Disease Conbol and Prevention and the Natlonal Institute d Dental and YUU ~ Creniofadal Research continue to support waterfluoridadon as a safe method of Your Prac#ice prevenfing tooth dewy in people of all ages. Hassel on dam for 2000, approximately 162 million people (two-thirds d the population) in the United States are served by pudic water systems tltat are fluoridated. The ADA, along wflh stele and local dental societies, continues to work with federal, state, and local agencies to inueex the number of communfies benefiting tram wafer fluoridation. For more inmrmagon regarding fluoride and fluoddatlon, visit the Americen Dental Assodation's'Fluoride and Fluoridation' Web site al httpJM~ww,atla_prg/go(o/fluoride. 1/04 t For more _nformelion shoal fluoride and fluondadpn~please visit the.Your 021 Health area of ADA org„ ~ For more toples relatedto the needs ofpahepts see 027 Hea1N Topics A-.; J...GVr 1 43 JOB ¢ f -.'. 3' I Lank P p2 :¢ . d =ePro~~Car r Wb':~u. s _ICOmn b'. .. .vliho~.il Pnorv t Pop p31 ~k. tlcb saCl?G. oaz Pr v_.)PO'cj fJPtab., .31C;-.S~antl T=~ms c`_sz'ot Zzlyl nam~¢tioa ®, Psember only con:¢r~n http://www.ada.org/prof/resources/positions/statements/fluoride_community_safety.asp 6/22/2008 Excerpted from ADA Fluoridation Facts Copyright 2005 Available at htto://www.ada.ora/public/topics/fluoridelfacts/fluoridation facts odf Question 46. Does the process of water fluoridation present unusual safety concerns for water systems and water operators? Answer. No. With proper planning, maintenance and monitoring, water fluoridation is a safe process. Fact. Water plant facilities and water plant personnel perform a valuable public service by carefully adjusting the level of fluoride in-water fo improve the oral health of the community. Facilities and personnel are subject to a number of regulations designed to ensure safety. The Occupational Safety and Health Administration provides guidelines for the safety of employees in the workplace.eo,s,s Additionally, the American Water Works Association publishes detailed guidance on safety and safe working conditions for water plant personnel. Furthermore, the Centers for Disease Control and Prevention has established safety procedures designed specifically for water plant operators in charge of implementing fluoridation.35 Adherence to these guidelines helps to ensure continuous levels of optimally fluoridated drinking water while maintaining water operator safety. As part of the safety procedures, water plant personnel receive training on the management of the chemicals/additives in water plants. While the optimal fluoride concentration found in drinking water has been proven safe, water plant operators and engineers may be exposed to much higher fluoride levels when handling Fluoride additives at the water treatment facility.36 Fluoride additives present comparable risks as other chemicals/additives in common use at water treatment facilities, such as hypochloride, quick-lime, aluminum sulfate, sodium hydroxide and ferrous sulfate. In fact, the fluoride additives are much less dangerous than chlorine gas commonly used in water plant operations. Today's equipment allows water treatment personnel to easily monitor and maintain the desired fluoride concentration. Automatic monitoring technology is available that can help to ensure that the fluoride concentration of the water remains within the recommended range. It is important that the water treatment operators responsible for monitoring the addition of fluoride to the water supply be appropriately trained and that the equipment used for this process is adequately maintained.35 As with any mechanical equipment, water fluoridation equipment should be tested, maintained and replaced as needed. With over 60 years of experience and thousands of water systems in operation, there have been remarkably few untoward incidents. Excerpted from the National Research Council's Report in Brief FLUORIDE IN DRINKING WATER A SCIENTIFIC REVIEW OF EPA'S STANDARDS March 2006 A majority of the report's authoring committee also concluded that people who drink water containing 4 mg/L or more of fluoride over a lifetime are likely at increased risk for bone fractures. Overall, there was consensus among the committee that there is scientific evidence that under certain conditions fluoride can weaken bone and increase the risk of fractures. The majority of the committee concluded that lifetime exposure to fluoride at drinking water concentrations of 4 mg/L or higher is likely to increase fracture rates in the population, particularly in some demographic subgroups that are prone to accumulate fluoride into their bones (e.g., people with renal disease). However, three of the 12 members judged that the evidence only supported a conclusion that the EPA standard (MCLG) might not be protective against bone fracture, and that more evidence is needed that bone fractures occur at an increased frequency in human populations exposed to fluoride at 4 mg/L before drawing a conclusion that the EPA standard likely poses a risk of increased bone fracture. There were few studies to assess risks of bone fracture in populations exposed to fluoride at 2 mg/L in drinking water. The best available study suggested an increased rate of hip fracture in populations exposed to fluoride at concentrations above 1.5 mg/L. However, this study alone is not sufficient to judge fracture risk for people exposed to fluoride at 2 mg/L. Thus, no conclusions could be drawn about fracture risks at 2 mg/L. The committee did not evaluate the risks or benefits of the lower fluoride concentrations (0.7 to 1.2 mg/L) used in water fluoridation. Therefore, the committee's conclusions regarding the potential for adverse effects from fluoride at 2 to 4 mg/L in drinking water do not apply at the lower water fluoride levels commonly experienced by most U.S. citizens. From the full published report, page 157, regarding bone fractures: "The U-shaped exposure-response curve for all fractures combined (but not hip fractures) for this population of individuals provides an interesting and potentially important finding. Whereas the trend for fractures appears to increase from 1.00 to 4.00 mg/L, it must be appreciated that the fracture rate in the 1.00 to 1.06 mg/L category was lower than the rate in the category with the lowest intake." 1tFWYL ~~ Fluoride in Drinking Water: A Scientific Review of EPA's Standards ADA Responses to the Report As of 3/22106 On March 22, 2006, the National Academies' National Research Council released a report following a review of studies and data relating to fluoride in drinking water that has been published since 1993. Does this resort question the safety of community water fluoridation? No. Community water fluoridation remains the model for dental disease prevention, saving Americans billions of dollars and untold suffering every year. In fact, community water fluoridation was not part of the committee's charge. This report deals with the EPA's maximum goal of 4 parts per million (ppm) of naturally occurring fluoride in drinking water, as compared to the optimal fluoride levels of 0.7-1.2 ppm in fluoridated community water systems. Has the ADA's Position on community water fluoridation chaneed? No. The American Dental Association supports community water fluoridation as a safe, beneficial and cost-effective way to prevent tooth decay. Past comprehensive reviews of the safety and effectiveness of fluoride in water have concluded that water fluoridation is safe and the most cost-effective way to prevent tooth decay among populations living in areas with adequate community water supply systems. In fact, the Centers for Disease Control and Prevention (CDC) proclaimed community water fluoridation one of 10 great public health achievements of the 20`h century. Then, why was this report necessary? This new report was prompted as part of a routine, periodic review by the Environmental Protection Agency (EPA). EPA, the federal agency with authority to regulate public water supplies, determined that enough new scientific studies had been published since 1993 to warrant a thorough review. EPA contracted with the National Research Council (NRC) for the review. What did the report examine? The NRC was asked to examine whether the amount of naturally occurring fluoride allowed in drinking water poses a health risk. What conclusion did the report make? The report concludes that the EPA's maximum level goal for naturally occurring fluoride in drinking water should be lowered. •tn I ~ ~~i 114TJj0 /~,a111A. t.~IKT+~51 ~~EIf1t1A ~K$~ ~ 21i71~ a~lt~.tn~~~ What led to this conclusion? The report cites severe dental fluorosis, also known as enamel fluorosis, as one of the reasons for the new recommendation. Severe fluorosis, where teeth appear discolored and sometimes pitted is found in about 10 percent of children in communities with water fluoride concentrations at or near 4ppm, according to the report. That concentration of fluoride is nearly four times the optimum amount recommended by the U.S. Public Health Service, CDC and ADA to prevent tooth decay. The report says that if the EPA's maximum level goal for naturally occurring fluoride in drinking water is lowered from 4ppm to 2ppm, it would eliminate severe dental fluorosis. The report also indicated that lowering the EPA's maximum fluoride goal will reduce the risk of bone fracture and possibly skeletal fluorosis in certain at risk patients who have excessively high water sources over long periods of time. What action will be taken on the report's recommendations? The report and recommendations will be considered by the EPA. The EPA may decide that no action is necessary at this time. If the EPA decides a change in the current regulations is necessary, the agency will initiate the process on the proposed changes. That usually includes publishing the proposed changes for public comment, possibly holding public hearings and publishing final rule changes. If EPA eventually lowers its maximum recommended fluoride level to 2ppm, this new level would hove no effect on the optimal amount of fluoride that the ADA and other public health agencies recommend to prevent tooth decay. What are ADA's next steps? As a science based organization, the ADA welcomes this opportunity to review the science sun•ounding fluoride in drinking water. The ADA will carefully review the approximately 500-page report and its recommendations and provide additional information to the public and the dental profession. The ADA will also monitor the EPA's review of the report. What is imaortant to remember about the resort? This report is limited to a review of the level of naturally occurring fluoride currently recommended in drinking water - a level many (2 to 5) times higher than the level of fluoride used in optimally fluoridated community water systems. Nothing in this report calls into question the optimal levels of 0.7-1.2 parts per million in fluoridated community water systems. 241 F'.al C:hxalg, Asmir.::l,xav,~,, a Ilhrm~ qWY i 2b96 A~ tlGiYiILL S10Wi[111A1 ~~ What h~loful advice can we give? The ADA continues to support the optimal levels of 0.7-1.2ppm in fluoridated community water systems and its contributions in preventing tooth decay. One part per million is the equivalent to about one cent in $10,000. Everyone deserves optimal levels of fluoride in drinking water. Everyone deserves optimal oral health. You can learn about the level of fluoride in your water by contacting your water supplier. If you use a private well, contact your local health department to team where to get your water tested. Health professionals use this information when considering the use of dietary supplements. While too much of any good thing has the potential to have unintended results, there are simple, effective ways to help insure children do not ingest too much fluoride. The good news is that parents and other caregivers can monitor the use of all fluoride-containing products by children younger than 6 years by placing only apea-sized amount of fluoride toothpaste on a young child's toothbrush at each brushing. Young children should be supervised while brushing or using a mouthrinse so they learn to spit, and not to swallow. Before the age of two, children should not be allowed to use a fluoride toothpaste for brushing. Additional information will appear on ada.ore after the report has been reviewed. 2i 1 ra3 t:MUpo Mm~¢. l:hxapo. Ilhrxan L+IM7 3 ?fi?d March 2006 FLUORIDE IN DRINKING WATER REPORT Z A SCIENTIFIC REVIEW OF EPA'S STANDARDS After reviewing research on various health effects from exposure to fluoride, including studies conducted in the last 10 years, this report concludes that EPA's drinking water standard for fluoride-a maxi- mum of 4 milligrams of fluoride per liter of water (4 mg/L)--does not protect against adverse health effects..lust over 200,000 Americans live in communities where fluoride levels in drinking water arc 4 mg/L or higher. Children in those communities are at risk of developing severe tooth enamel fluorosis, a condition that can cause tooth enamel loss and pitting. A majority of the report's authoring committee also concluded that people who drink water containing 4 mg/L or more of fluoride over a lifetime are likely at increased risk for bone fractures. THE NATIONAL ACADEMIES Advisers M Me Nofian on Srkrrcq Engineering, andMedirine W m National Academy of Sciences • National Academy of Engineering • Institute of Medicine • National Research Council preventing tooth decay in communities where natural fluoride levels are low. The "optimal" concentration range offluoride in drinking-water for preventing tooth decay was set at a range of 0.7 to 1.2 mg/L more than 40 years ago by the U.S. Public Health Service. In 2000, it was estimated that approximately 162 million people had artificially fluoridated water. The recommended range for artificial fluoridation is below the EPA standards and was designed for a different purpose, so it is important to note that the safety and effectiveness of the practice of water fluoridation was outside the scope of this report and is not evaluated. This report only evaluates EPA's standards. A ] 993 report from the National Research Coun- cil had concluded that the EPA standard of 4 mg/L was an appropriate interim standard until more research could be conducted. However, following a compre- hensive review ofthe research conducted since 1993, this report concludes the EPA standard is not protec- tive of health because fluoride exposure at 4 mg/L puts children at risk of developing severe enamel fluorosis that ca~i compromise tooth enamel function and appearance. Fluoride exposure at 4 mg,~L could also weaken bone and increase the risk of fractures. Exposure to Fluoride Water and water-based beverages are the largest contributors to an individual's total exposure to fluo- ride, although there aze other sources of exposure. For the average person, depending on age, drinking water accowtts for 57% to 90% of total fluoride exposure at concentrations of 2 mg/L and accounts for 72% to 94% of total fluoride exposure at concentrations of 4 and L. Non-beverage food sources containing vari- ous concentrations offluoride are the second largest contributor to fluoride exposure. The greatest source of nondietary fluoride is dental products, primarily toothpastes. The public is also exposed to fluoride from background air concentrations and from some pesticide residues. Other sources include some phar- maceuticalsand consumer products. EPA based its standards on the assumption that adults consume 2 liters of water-based beverages per day. People who are exposed to higher concentrations include those who live where there are high concen- trations offluoride in drinking water; those who drink unusually large volumes of water, such as athletes or people with certain medical conditions; and those who are exposed to other important sources offluoride such as from occupational exposures. On a per-body- weight basis, infants and young children have approx- imately three to four times greater exposure than do adults. Dental-care products are also a special consid- eration for children, because many tend to use more toothpaste than is advised and may swallow some. Dental Effects Exposure to fluoride can cause a condition known as enamel fluorosis. Depending on the amount offluoride exposure (the dose) and the period of tooth development at which the exposure occurs, the effects of enamel fluorosis can range from mild discoloration of the tooth surface to severe staining, enamel loss, and pitting. The condition is permanent after it de- velops in children during tooth formation (from birth until about the age of 8). Severe enamel fluorosis oc- curs at an appreciable frequency, approximately 10% . on average, among children in U.S. communities with water fluoride concentrations at or near the current allowable concentration of 4 mg/L. The prevelance of severe enamel fluorosis is very low below about 2 mg/L of fluoride in drinking water. The biggest debate concerning enamel fluorosis, particularly the moderate to severe forms, is whether to consider it an adverse health effect or a cosmetic effect. Previous assessments considered all forms of enamel fluorosis to be aesthetically displeasing, but not adverse to health. This view has been based large- ly on the lack of direct evidence that severe enamel fluorosis results in tooth loss, loss of tooth function, or psychological, behavioral, or social problems. There was suggestive but inconclusive evidence that severe enamel fluorosis increased the risk of cavi- ties. It is known that restorative dental treatment is often considered for children with the enamel pitting that characterizes this condition. The committee concludes that the current EPA standard does not protect against severe enamel fluo- rosis. All members of the committee agreed that the condition damages the tooth and that the EPA standard should prevent the occurrence of this unwanted condi- tion. The majority of the memhers judged the condi- tion to be an adverse health effect because enamel loss and pitting can compromise the ability of the tooth enamel to protect the dentin and, ultimately, the pulp from decay and infection. Two of the 12 members of the committee did not agree that enamel defects alone are sufficient to consider severe enamel fluorosis an adverse health effect, as opposed to a cosmetic one. Studies relied upon by EPA indicated that the prevalence of moderate enamel fluorosis, which causes staining but not pitting of teeth, at 2 mg/L could be as high as !5%. A 1997 report from the Institute of Medicine recommended tolerable upper intake levels for children of different ages intended to protect against moderate enamel fluorosis. At EPA's current secondary maximum contaminant level of 2 mg/L, between 25% and 50% of infants up to one year of age in EPA's 2004 water intake survey consumed enough water to exceed the tolerable upper intakes for their age groups. Skeletal Effects of Fluoride Fluoride is readily incorporated into the crystalline structure of bone, and will accumulate over time. Con- cerns about fluoride's effects on the musculoskeletal sys- tem aze focused on a condition called skeletal fluorosis and also on increased risks of bone fracture. Models that estimate the accumulation of fluoride into bone (pharma- cokineticmodels) have been developed that are usefid in understanding fluoride's effect on bone. Skeletal fluorosis is a bone and joint condition associated with prolonged expostue to high concentra- tions of fluoride. Fluoride increases bone density and causes changes in the bone that lead to joint stiffness and pain. The condition is categorized into a preclini- cal stage and stage I, 11, and III, the last of which is sometimes referred to as the "crippling" stage because mobility is affected. At stage It, mobility is not sig- nificantly affected, but it is characterized by sporadic pain, stiffness of joints, and osteosclerosis (bone thickening) of the pelvis and spine. The commit- tee concluded that both stage tI and stage lil skeletal fluorosis should be considered adverse. There are very few Known clinical cases of skeletal fluorosis in the United States. Pharmacoki- netic models show that bone fluoride concentrations resulting from lifetime exposure to fluoride in drink- ing water at 2 mg/L or 4 mg/L fall within or exceed the ranges historically associated with stage 11 and stage Ill skeletal fluorosis. However, this evidence is not conclusive because the levels at which skeletal fluorosis occurs vary widely, and because it appears to be rare in the United States. The effects of fluoride exposure on bone strength and risk of bone fracture have been studied in animals. The weight of evidence indicates that, although fluoride might increase bone volume, fluoride affects the quality of the bone such that there is less strength per unit volume. Evidence for this effect in humans was found in several new studies of populations exposed to fluoride in their drinking water at 4 mg/L, as well as studies of fluoride as a therapeutic agent, which collectively showed an increased risk of bone fracture. Overall, there was consensus among the com- mittee that there is scientific evidence that under cer- tainconditions fluoride can weaken bone and increase the risk of fractures. The majority of the committee concluded that lifetime exposure to fluoride at drink- ing water concentrations of 4 mg/L or higher is likely to increase fracture rates in the population, particu- larly in some demographic subgroups that are prone to accumulate fluoride into their bones (e.g., people with renal disease). However, three of the 12 members judged that the evidence only supported a conclusion that the EPA standard (MCLG) might not be protec- tive against bone fracture, and that more evidence is needed that bone fractures occur at an increased frequency in human populations exposed to fluoride at 4 mg/L before drawing a conclusion that the EPA standard likely poses a risk of increased bone fracture. There were few studies to assess risks of bone fracture in populations exposed to fluoride at 2 mg/L in drinking water. The best available study suggested an increased rate of hip fracture in populations exposed to fluoride at concentrations above I.5 mglL. However, this study alone is not sufficient to judge fracture risk for people exposed to fluoride at 2 mg/L. Thus, no con- clusions could be drawn about fracture risks at 2 mg/L. Studies of Fluoride and Cancer Whether fluoride might be associated with bone cancer has been a subject of debate. Animal studies have suggested the possibility of increased risk of osteosarcoma (a bone cancer) in male rats, but no new animal bioassays have been performed to evaluate this further. Several new population studies investigating cancer in relation to fluoride exposure are now avail- able. Some of those studies had significant meth- odological limitations that make it difficult to draw conclusions. Overall, the results were mixed, with some studies reporting a positive association and oth- ers no association. The committee concluded that the evidence to date is tentative and mixed as to whether fluoride has the potential to initiate or promote can- cers, particularly of the bone. A relatively large hospital-based case-control study of osteosazcoma and fluoride exposure is under way at the Harvard School of Dental Medi- cine and is expected to be published in the summer of 2006. The results of that study m fight help to identify what future research will be most useful in elucidating fluoride's carcinogenic potential. Implications for EPA's Drinking Water Standards In light of the collective evidence on adverse health effects and total exposure to fluoride, the committee concludes that EPA's drinking water standard of 4 mg/L is not adequately protective of health. Lowering itwill prevent children from developing severe enamel fluorosis and will reduce the lifetime accumulation of fluoride into bone that the majority of the committee concludes is likely to put individuals at increased risk of bone fracture and possibly skeletal fluorosis, which are particular concerns for those of the public who are prone to accumulating fluoride in their bones. To develop a standard that is protective against severe enamel fluorosis, clinical stage 11 skeletal fluorosis, and bone fractures, EPA should update its risk assessment of fluoride to include new data on health risks and better estimates of total exposure (relative source contribution) for individuals. EPA should use current approaches for quantifying risk, considering susceptible sub- populations, and characterizing uncertainties and variability. From a cosmetic standpoint, EPA's standard for cosmetic effects of 2 mgi'L does not completely prevent the occurrence of moderate enamel fluorosis. EPA has indicated that the standard was intended to reduce the severity and occurrence of the condition to l5% or Tess of the exposed population. Recent EPA water intake survey data indicate that substantial proportions of children in communities with fluoride at 2 mg/L consume enough water to exceed the age-specific tolerable upper intake levels recommended by the Institute of Medicine. The degree to which moderate enamel fluorosis might go beyond a cosmetic effect to create an adverse psychological effect or an adverse effect on social functioning on children or their parents is not known. The committee did not evaluate the risks or benefits of the lower fluoride concentrations (0.7 to 1.2 mg/L) used th water fluoridation. Therefore, the committee's conclusions regazding the potential for adverse effects from fluoride at 2 to 4 mg/L in drink- ingwater do not apply at the lower water fluoride levels commonly experienced by most U.S. citizens. Recommended Research As noted above, gaps in the information on fluoride prevented the committee from making some judgments about the safety or the risks of fluoride at concentrations between 2 and 4 mg/L and below. The report makes several recommenda- tions for future research to fill those gaps, as well as recommendations to pursue lines of evidence on other potential health risk (e.g., endocrine effects and brain function). Recommendations include exposure assessment at the individual level rather than the community level; population studies of moderate and severe enamel fluorosis in relation to tooth decay and to psychological, behavioral, or social effects; studies designed to clarify the relationship between fluoride ingestion, fluoride concentration in bone, and clinical symptoms of skeletal fluorosis; and more studies of bone fracture rates in people exposed to high. concentrations of fluoride in drinking water. Committee on Fluoride in Drinking Water: John Doull (Chair), University Kansas Medical Center, Kansas City; Kim Boekelheide, Brown University, Providence, RI; Barbara G. Farishian, Washington, DC; Robert L. Isaacson, Binghamton University, Binghamton, NY; Judith B. Klotz, University of Medicine and Dentistry of New Jersey, Piscataway, NJ; Jayanth V. Kumar, New York State Department of Health, Albany; Hardy Lime- back, University of Toronto, Ontario, CANADA; Charles Poole, University of North Cazolina at Chapel Hill, Chapel Hill; J. Edward Puzas, University of Rochester, Rochester, NY; Nu-May Ruby Reed, California En- vironmental Protection Agency, Sacramento, CA; Kathleen M. Thiessen, SENES Oak Ridge, lnc., Oak Ridge, TN; Thomas F. Webster, Boston University School of Public Health, Boston, MA; Susan N. J. Martel, (Project Director), National Research Council. This report brief was prepared by the National Research Council based on the committee's report. For more information, contact the Board on Environmental Studies and Toxicology at (202) 334-3060 or visit http://dels.nas.edu/best. Fluoride in Drinking Water is available from the National Academies Press, 500 Fifth Street, NW, Washington, D.C. 20001; (800) 624-6242; www.nap.edu. 2006 The National Academy of Sciences ( Water Fluoridation and the Environment: Current Perspective in the United States HOWARD f. POLLICK, BDS, MPH Evidence of water fluoridation's effects on plants, ani- mals, and humans is considered based on reviews by sci- entiflc groups and individual communities, including Fort Collins, CO, Por[ Angeles, WA, and Tacoma-Pierce County, WA. The potential for corrosion of pipes and the use of fluoridation chemicals, particularly fluoro- silidc add, aze considered, as is the debate about whether fluoridation increases lead in water, with [he conclusion that there is no such increase. The argu- ments of anti-fluoridationists and fluoridation propo- Hants are examined with respect to the politics of the issue. Key words: fluoridation; environment; toxicology. INT J OCCUP ENVIRON HEALTH 2004;10:343-350 as in toothpaste, have signifitandy reduced the preva- lence of dental caries in the United States.t Eazly investigations into the physiologic effects of flu- oride in drinking water predated the fast community field trials.°-r Since I950, opponents of fluoridation have claimed it increases the risks for cancer, Down's syndrome, heazt disease, osteoporosis and bone fiac- mre, acquired immunodefldency syndrome, low intelli- gence, Alzheimer disease, allergic reactions, and other health conditions a The safety and effectiveness of water fluoridation have been recv4luated frequently, and no credible evidence supports an assodation between fluoridation and any of these condidons.g•1p P riot to 1945, epidemiologic and laboratory studies confirrned [he association between [he environ- ment (naturallyoccurring fluoride in water sup- plies) and the health and cosmetic appearance of [eeth.t Where fluoride levels were low, prevalences and severity of dental terries were high among lifetime residents, yet where fluoride levels were high, the prevalences and severity of dental caries were low, but dental fluorosis occurred with high prevalence and severity. This led to the concept of creating an ideal environment for opti- mal dental health through adjusting the naturally occur- ringfluoride level m about 1 mg/L (1 part per million). In 1986, the U.S. Environmental Protection Agency (EPA) set the maximtun contaminant level (MCL) for naturallyoccurring fluoride in public drinking water at 4 mg/L, with a secondazy standard at 2 mg/L.P Water fluoridation, then, is the controlled adjust- ment of fluoride concentrations of community water systems to opfimal ]evels to minimize the inddence of dental caries (tooth decay) and dental fluorosis (enamel mottling). From initial efforts begun as com- munity trials in 1945, water is now fluoridated in thou- sands of public water systems and reaches two thirds of the U.S. population served by such syscems.s Commu- nitywater fluoridation and other uses of fluorides, such Remived from the Department of Pmendve and Restorative Dental Sciences, Schoo] of Dentisvy, Univeniry of California San Francsco, San Francisco, California. Address correspondence and reprint requesrs to: Howard Pollick, Department of Preventive and Restorative Dental Sciences, 707 Par- nassus Avenue, San E tancisco CA 9414E-075S. The Environment Environmental concerns have been investigated in liter- ature reviews for the Tacoma-Pierce County Health Department, Washington (August 2002); t and the City of Port Angeles, Washington (October 2003); z and no negative impact of water fluoridation on the environ- ment has been established. Issues related to discharge to water; emissions to air; production, storage, or release of toxic or hazardous substances; or production of noise have been found to be nonsignificant Emil sions of fluoride into the air aze no[ released outside the well houses. Fluoride concentrations in rivers dovvn- stream of the discharges increase by less than 0.01 mg/L due to adding fluoride to the water supply system. Fluoridated water losses during use, dilution of sewage by rain and groundwater infiltrate, fluoride removal during secondary sewage treatment, and tfif- fusion dynamics at effluent outfall combine to elimi- nate fluoridation related environmental effects. In a literature review, Osterman found no instance of municipal water fluoridation causing recommended environmental concentrations to be exceeded, although excesses occurred in several cases of severe industrial water pollution not related to water fluorida- tion. is Osterman found that overall river fluoride con- centrations theoretically would be raised by 0.001-0.002 mg/i, a value not measurable by current analytic tech- niques. All resulting concentrations would be well below those recommended for environmental safety. A study conducted in Phoenix, Arizona, to test the efficary of soil aquifer treatment systems indicated that fluoride concentrations decline as water travels under- 343 ground. This study suggests [hat 40-50`yo of the fluo- ride discharged [o groundwater is removed as the water [revels through the soil and aquifer. Thus, fluoride does not concrntrate in groundwater." PLANTS AND ANIMALS The concentration of fluoride in the treated water does not reach levels that could harm any plant or animal species.tr•t~ A report of the effect of industrial pollu- don,from an aluminum plant on salmon indicated [hat the usual fluoride concentration of the river was 0.1 mg/L, and when the concentration was raised experi- mentally to 0.5 mg/L, there was an effect on the salmon.ts Since rivers and streams are not fluoridated and the increase in the fluoride concentration of a river as a result of runoff from fluoridated water would be insufficient to raise the level to even 0.2 mg/L, fluoridation of water can have no effect on salmon. There is no evidence that fluoridated water has any effect on gazdens, lawns, or plants. Although silver fluo- ride is not used in water fluoridation, silver fluoride at 1 mg/L used as a disinfectant had no effect on growth of wheat_'s There is evidence that very high concentra- tions offluoride have no toxic effect on plants in ponds: The fate of fluoride in a simulated accidental release into an experimental pond was observed for 30 days m Grenoble, France. The components investigated were water, sediments, plants, algae, molluscs, and fish. Twenty-four hoots after the relcasc, most (99.83'0) of the fluoride was distributed in the physical compo- nents (water and sediments), and the biological agents contained only 0.23'0 of the fluoride released. Despite an exposure m hot spots of 5,000 ppm at the beginning of the accidents] release, no visible toxic effects were observed on the biological components such as plants, algae, molluscs, and fish.'r There is evidence that ladyfinger (okra) ran withstand up to 120 mg/L fluoride. The consumption by people of this plant grown with fluoridated water at 1 mg/L would be 02 mg per kg: Because of suggestions that food is a rich source of flrr oride to humans and the absence of permissible and upper limits of fluoride for urigaton water, plant uptake studies were conducted using fluoride-rich irri- gationwater. Ladyfmger was grown in sand and soil cub tares for 18 wk aztd the accumulation of fluoride in var- ious plant parrs was studied. The potential for ingestion of fluoride by humans through this route was also considered. The percentage uptake was greater in sandtultured plants than in soiltultured plants. The root accumulates most of the fluoride supplied through irrigation water and the fruit accumulates the least Up to 120 mg/L fluoride of irrigation water did not harm the plants. The ingestion of fluoride by humans from planu irrigated with water containing 10 mg/L fluoride would be 0.20 mg per 100 g ladyfinger.rs HUMANS The Institute of Medicine, Food and Nutrition Board has estimated that the tolerable upper limit for human daily intake of fluoride is 10 mg per day for adults and children over 8 years of age.19 Ten independent U.S. and Canadian studies published from 1958 to 1987 showed that dietary fluoride intakes by adults ranged from 1.4 to 3.4 mg/day in areas where the water fluo- ride concentration was 1.0 mg/L. Where the water con- centration was less than 0.3 mg/L, daily intakes ranged from 0.3 to 1.0 mg/day.1e Several municipal or tcrrimrial reviews of the water fluoride issue have concluded that available informa- tion indicates [hat there is no significant adverse health impact associated with water fluoridation. The Fort Collins reviews9 included reviews from other communi- ties, including Brisbane, Australia (1997)?r Natick, Massachusetts (1997)?Y Calgazy, Alberta, Canada (1998),YS Ontario, Canada (1999)?~ and Fscambia County Utilities Authority, Florida (2000) g Addition- ally, the Fort Collins review considered several 'Tier One" reviews, including reviews by or for the Centers for Disease Convol and Prevrntion,t the Institute of Medicine (1999),19 the World Health Organization (1994),% the National Reseazch Council (1993)? the U.S. Public Health Service (1991)?r the International Programme on Chemical Safety (1984)?s the Medical Reseazch Council, US (2002)?9 the Agency for Toxic Substances and Disease Registry, U.S. Public Health Ser- vice (2001 draft and 1993) 90 and York, U.R. (2000) 31 The Fort Collins report found [hat The weight of the evidence suggests that there is caries (cavities) reduction in populations exposed to water fluoridation at or neaz an optimal level Likely [oral exposure values for children older than six months living in communities with water fluori- dated at up to 1.2 mg/L (ppm) do not exceed the upper limit set to be protective of moderate dental fluorosis by the Institute of Medicine. Total dietary exposures of fluoride can exceed this threshold amount (0.7mg/day) in infants fed formula recon- stitutedwith optimally fluoridated water. There is no consistent evidence from human or animal studies that exposure to optimally fluori- dated drinking water and other sources causes any form of cancer in humans, including bone and joint cancer The FTSG agrees with the conclusion of the Medical Reseazch Council of Great Britain that states, 'The possibility of an effect on the risk of hip fracture is the most important in public health terms. The available evidence on this suggests no effect, but cannot rule out the possibility of a small percentage change (either an increase or a decrease) in hip fractures." (Medical Research Council 2002, page 3] 744 Po15ck www.Iloeh.com • IM J OCCUP ENVIRON HEALTH At the concentrations of fluoride provided in Fort Collins water including exposures from all sources over a Iffetime, skeletal fluorosis caused by drinking water exposure is not likely to be a health issue. At the concentrations of fluoride provided in Fort Collins water, in combination with other sources of fluoride, as many as one in four children under age 8 may develop very mild to mild dental fluorosis. This degree of fluorosis may or may not be detectable by the layperson. With oral health as the goal, this degree of dental fluorosis is considered an acceptable adverse effect given the benefits of caries prevention. In the li[erarure reviewed, doses appropriate For caries reduction were not shown to negatively impact thyroid function. Studies in which humans received doses significandy higher than the opti- mum fluorid° intake for long periods of time showed no negative impact on thyroid function. Overall, evidence is lacking that exposure to fluoride through drinking water causes any problems to the human immune system.40 In general, there is no credible evidence indicating a cause-and~ffect relationship between water fluorida- tion and increased health risks. CORROSION According to the U.S. Environmental Protection Agency and the National Association of Corrosion Engi- neers, corrosion is not related to fluoride 9s Corrosion by potable water is primarily caused by dissolved oxygen, pH, water temperature, alkalinity, hazdness, sal4 hydrogen sulfide, and certain bacteria. Fluoride, at concentrations found in potable water, does not cause corrosion. A small increase in the corrosivity of potable water that is already corrosive may occur after treatment with alum, chlorine, fluorosilicic acid, or sodium silico- fluoride, which decreases pH. This may occur in some potable water sources with little buffeting capacity; it can easily be resolved by adjusting the pH upward.tt,tz,ss CHEMICALS USED FOR FLUORIDATION Flttororikcates Urbansky reviewed available information on fluorosili- ca[es, with three objectives: (1) to enumerate unresolved chemical issues ger- mane munderstanding fluoridation and ascertaining the fate of fluoride and fluorospecies, (2) m critically review what is known or reported, and (3) to assemble a knowledge base to provide a starting point for future study.'' Urbansky states: Since [1962], [oxiclry and adverse health impacts have tested fluoride rather than fluosilicates. As a recent example, in 2001, the FDA reported [hat Americans' exposure m fluoride had increased from dentifrices, and i[ demonstrated that any increases did not produce observable health effects in rats. Flu- oride salts were continually tested instead of fluorosil- icates because the complete and fast dissociation- hydrolysis (eq 1) of fluorosilicates m fluoride and (hydr)oxosilicateswa' generally accepted as a chemi- cal fact. Accordingly, no reason was apparent to test fluorosilitates separately. HsStFs(aq) + 4HY0(I) ~ 6HF(aq) +Si(OH)4(aq) (eq 1) all the rate data suggest that equilibrium should have been achieved by the time the water reaches the con- sumer's tap if not by the time it leaves the waternorks plant.... The most common fluoridating agents used by American waterworks aze sodium fluoride (NaF), fluorosilicic acid (HrSiFs), and sodium fluorosilicate (NaQSiF~ (see table below). TABI.Es4 Sodium Sodium Fluorosilicic Fluoride Fluorositicate Arid (a) Number of Utilities 249] ]635 5876 (b) People served 1],700,000 36,100,000 80,000,000 'Data for the United States from the CDC'' 1992 Fluorida- tion Csruudu: (a) Number of udlitits using specific additives as reported by those that fluoridate their water, (b) Popula- tions served by specific additives (millions of people) of those drinking supplemenrally fluoridated water (does not include vraters with naturally occurring fluoride). Although 25% of the utilities repotted using NaF, this corresponds to only 9.29,1 of the U.S. population drinking fluoridesupplemented tap water. The ease in handling NaF rather than fluorosilicates accounts for the disproportionate use of NaF by utilities serving smaller populations. On the other hand, the cost sav- ings in using fluorosilicates result in lazge systems using those additives instead. The reduced cost of lazge volume offsets [he costs associated with han- dling concentrated stocks of the fluorosilicates, which require accommodations shnilaz to hydrochloric acid, which is sometimes used to adjust pH. In acidic solu- tion, the dissociation and hydrolysis of fluorosilidc acid, which occurs upon dilution, is given by eq 1. In drinking water, pH is adjusted with the addition of base (e.g., NaOH, NaI-ICOs). HgSiFs(aq) +4HP0(I) 6HF(aq) +Si(OH)4(aq) (eql) ~' While there maybe evidence of toxicity of these sub- stances when workers involved in their production aze not protected, there is no credible evidence of toxidty when they are diluted for use in fluoridated water. Fluorosilicic acid is diluted with water from an initial aqueous concentration of about 23-24`yo by about 1:250,000-1:300,000 when used for fluoridating VOL 70/NO 3, JUUSEP 2004 . www.iloeh.com Water FluoddaHon and Envlronmenl 345 waters This produces the final concentration of between 0.7-1.2 mg/L, the specific level set according to CI)C guidelinessr Concerns have been raised about arsenic and lead in fluorosilidc-acid-vested water.~~ However, there is no credible evidence [hat this is of concern'0 Urbansky and Schock add: The vast preponderance of the lead(IIj in neazly till tap waters originates from the plumbing materials located between the water distribution mains and the end of the faucet used by the consumer. Arsenic and lead may be present at minute unde- tectable concentrations, well below all current (50 ppb) and proposed (10 ppb) EPA standards. Following dilution with water, the calculated range of arsenic concentrations in the finished water contributed by fluorosilicic acid feed is 0.10 to 0.24 pg/L (parts per billion, ppb) ~ The analytic detection limit for arsenic is 2 pg/L, so the amount added by the fluorosilicic acid would not be detected.ss In Fort Collins, the concen- tration of lead in the source waters was below the detec- tion limit for lead in [he department's laboratory of 1.0 pg/liter (ppb). Because lead levels are below the detec- tion limits both before and afrer the addition of flea rosilicic acid, the actual changes in lead concentrations were not measunble.% Masters and Coplan have alarmed the public with their reports linking fluoridation, increased lead levels and crime.~~*t Urbansky and Schock tziticize the con- clusion reached by Masters and Coplan by stating: Interestingly, the bibliographies of the Masters and Coplan study most strongly asserting the adverse effects of silicofluoride shows only a single reference related m sampling of drinking water or the convo] of lead or other metals by water vestment, so the level of awareness in the design of the studies and inter- pretation of the data is highly questionable. By no[ measuring or statistically testing numerous other water and plumbing characteristics that could corre- late with lead(fI) levels with equal to or greater static deal significance than those relationships that were pus forth, the studies of [Reference 2] are intention- ally biased towards what appears to be a preconceived conclusion. Even simple analyzes that are known to affect lead mobility, such as pH or alkabniry, or ana- lyzes known to play important dietary roles in health, such as caldum, sodium or magnesium, were no[ reported to be measured in their study, so possible confounding variables are conspicuously excluded from evaluation. ...Recent reports [41, 39] that purport to link ter rain water fluoridating agents, such as fluorosilicic add and sodium fluorosilicate, m human lead uptake are inconsistent with accepted scientific knowledge. The authors of those reports fail [o identify or account for these inconsistencies, and mainly argue on the basis of speculation stated without proof as fact. The sampling scheme employed in the studies is entirely unrelated to any credible statistically-based study design [o identify drinking water lead and flux ride exposure as a significant source of blood lead in the individuals. The authors use aggregated data unrelated in space and time and then attempt to selectively apply gross statistical techniques that do not inc]ude any of thousands of other possible rater quality or exposure variables which could show simi- lar levels of correlation utterly by accident. Many of the chemical assumptions are scientifically unjusti- fied, are contradicted by known chemistry data and principles, and alternate explanations (such as multi- ple roues of PbII exposure) have not bern aatisfacto- rily addressed. The choice in water fluoridation approach is ofren made for economic, commercial or engineering reasons that may have a regional wmpo- Went that could also be related to various community socioeconomic measures, and so should not be con- sidered to be a purely independent variable without investigation. At present, the highly-promoted studies asserting enhanced lead uptake from drinking water and increased neurotoxiciry stiff provide no credible evidence to suggest that the common practice of fluoridating drinking water has any untoward health impacts via effects on lead(II) when done properly under established guidelines so as m maintain total water quality. Our conclusion supports current EPA and PHS/CDC policies on water fluoridabon.40 Nevertheless, concerns have been raised about the acidity of drinking water that may be created by fluori- dation. According to Urbansky and Schock, "one cannot demonstrate that an increase in blood lead(H) ion levels can be linked to acidity from SiFs s- hydroly- sis any more than one can demonstrate it results from consuming soft drinks." Additionally thry state: `Note that the species PbSiFfi is present at such low concen- trations that we would expect to find only one molecule of this complex in more than 1, 000 liters of tap rooter at pH 6, which of course, faz exceeds the volume possible for water consumption and the human stomach.` A critique of this review was included in "Comments on The April 17, 2002 ICCEC Approach to Silicofluo- rides Study" by Coplan'= The ICCEC is the U.S. Public Health Service National Toxicology Program (NTP) Interagency Committee for Chemical Evaluation and Coordination. Coplan states his concerns about the way in which Urbansky and the EPA and CDC have investi- gated silicofluorides. For example, he provides the fol- lowing headings in his review: "EPA's acknowledged ignorance about a position they have adamantly held"; "EPA's continued effort at misdirection"; °Why Urbansky and Schock cannot be trusted"; "Why the CDC cannot be vested"; A substantial body of evidence has been submitted to the NTP dearly supporting the need for a comprehensive program of animal testing for health effects from chronic ingestion of SiF treated water. This S46 Polfick www.ljoah.com . IM J OCCUP ENVIRON HEALTH is true now and would remain true no mater what the EPA may learn about dissociation chemistry from a con- tractor selected by EPA employees whose objectivity and sdentific integrity aze less than impeccable." Coplan's comments are in keeping with his stance as an anti-fluoridadonist (one who is strongly opposed to the fluoridation of public waur supplies) as It should be poiaud out that Urbansky and Schock have been highly critical of the work of Masters and Coplan. It appears that the main thrust of conumporary anti- fluoridadon tactics is to assert that the chemicals used in fluoridation aze causing problems of one sort or another. Such tactics have emanated from the work of Masuts and Coplan. The toxicology of sodium fluorosilicau and fluoro- silicic acid has been reviewed for the EPA.44 The authors of that review state: In waur, the compound (sodium fluorosilicate) read- ily dissociates to sodium ions and fluosilicau ions and then to hydrogen gas, fluoride ions, and hydraud silica. At the pH of drinking waur (6.5-8.5) and at the roncentmtion usually used for fluoridation (1 mg flu- oride/L), the degree of hydrolysis is essentially 100tyo. ...Like its salt, its (fluorosilicic acid) degree of hydrol- ysis is essentially 100% in drinking water. At equibb- rium, the fluorosilicate remaining in drinking water is estimaud to be «1 part per trillion.10 In addition, exposure to impurities in the fluoridating agent is judged to be of low health risk when properly veaud water is ingested. For example, in fluorosilicic acid, iron and iodine are usually below the IeveLs considered useful as a dietary supplement; the phosphorus level is reported m be insignificant and silver is usually <4 parrs per septillion in the fluoridated wateru The Colorado City of Fort Collins has been fluoridating tvith fluorosilidc acid and has responded to concerns raised about that chemical.sa The Report of the Fort Collins 2003 Fluoride Technical Study Group, April 2003, provides a comprehensive review that includes "The Pountia] for Increased Contaminant Levels Due to the Use of Hydrofluorosilicic Acid." The FTSG's review identified three potential con- cerns associaud with hydrofluoros0icit acid (HFS). 1) cotontamination (i.e., arsenic and lead), 2) decreased pH leading to increased lead solubility or exposure, and 3) potential mxicological effects from incompleu dissociation products of HFS. The FTSG used [he raw and finished water quality data for the City of Fort Collins m determine whether the addi- tion of HFS was responsible for the potential addition of contaminants such as heavy metals [o the city's drinking waur There was no evidence [hat [he addi- tion of HFS increased the concentmdons of copper, manganese, zinc, cadmium, nickel, or molybdenum. The concentrations of arsenic and lead were below the detection limit for the Fort Collins Water Quality Control Laboratory in both the source water and the finished water and below the maximum contaminant level (MCL) for these naturally occurring elements. There was no evidence that the introduction of HFS changed the pH of the wazer appreoably. Concern that HFS incompletely disassociates may be unfounded when the fundamental chemical facts are considered. Therefore, it is unlikely that Community water fluoridation poses a health risk from the expo- sure to any of these chemicals present in the water as it ]eaves the plant. Further studies related to the health effects of HFS are in progress.% Reeves (fluoridation engineer at the CDC) oudined the process by which the safety of fluoridation chemi- cals is assured: Concern has been raised about the impurities in the fluoride chemicals. The Amermn Water Works Asso- ciation (AW WA), a well-respecud waur supply indus- vy association, sets standards for all chemicals used in the waur treatment plant, including fluoride chemi- cals. The AW WA standards are ANSI/AW WA B701-99 (sodium fluoride), ANSI/AWWA B702-99 (sodium fluorosilicau) and ANSI/AWWA B703-00 (fluorosili- cic acid). The National Sanftadon Foundation (NSF) also sets standards and does product certification for products used in the water industry, including fluo- ride chemicals. ANSI/NSF Standard 60 sets standards for purity and provides testing and certification for the fluoride chemicals. Standard 60 was developed by NSF and a consortium of associations, including the AWSNA and the American National Standards Insti- mu (ANSI). This standard provides for product qual- ity and safety assuranm to prevent the addition of harmful levels of contaminants from water treatment chemicals. More than 40 stasis have laws or regula- tionsrequiring product compliance with Standard 60. NSF tests the fluoride chemicals for the 11 regulated metal compounds that have an EPA MCL. In order for a product [for example, fluorosilicic acid] m meet certification standards, regulaud metal contaminants must be present at the tap [in the home] at a con- centration of leas than ten percent of the MCL when added to drinking water at the recommended maxi- mum use level. The EPA has not set any MCL for the sibcaus as there is no known health Concerns, but Standard 60 has a Maximum Allowable Level (MAL) of 16 mg/L for sodium silicates as corrosion control agents primarily for turbidity reasons. NSF lists have shown the silicates in the water samples from public water sysums to be well below these levels46 Sources ojFluoride Pollution Unrelated to WoterFluoredatiou The principal sources of fluoride pollution are indus- tries, particularly phosphau ore production and use as well az aluminum manufacture, mining, and coal burn- ing.~•47•'s In the absence of adequate emission control in such settings environmental pollution can be a prob• tem. Such pollution has been a problem in the past in VOL 10/NO 3, JUL/SEP 2004 . www.fjoeh.com Wafer FluorltlaHOn antl Environment 347 industrialized countries, and the WHO warns that unless proper environmental safeguards are adhered m, there is a danger of its occurring in developing countries with increasing industrialization. Fluoride pollution is therefore recognized as an industrial hazard; however water fluoridation is not considered a potential source of fluoride pollution.as Arguments olOpponents and Proponents Whereas anti-fluoridationists try to prevent the unnec- essaryexposure of living things to fluoride, often in the misguided belief that any amount of fluoride is toxic, pro-fluoridationisis try to reduce tooth decay through the judiilous use of fluoride, with the understanding that there is an optimum amount, appropriately deliv- ered, that is both beneficial and safe. This distinction leads to a difference in interpretation of the scentiflc and popular literature on this topic, whether related to the effects of water fluoridation on ceeth or other organs of the body, or the effects on the environment. Similarly, there are those who may judge water fluori- dation on political or philosophical grounds, such as being supportive or opposed to what government agen- cies may advocate. Some may have personal or anec- dotal experience that is counter to what opponents or proponents recommend. Newbrun has chazacterized the fluoridation debate as a religious argumentas While opponents of fluoridation are not without their supporters and supporting groups,50 almost every reputable, recognized, competent scientific and/or public health organization or government unit endorses fluoridation of drinking water as safe and effective 51~s2 Furthermore, community water fluorida- tion has been heralded as one of the ten great public health measures of the 20th centtrry.ss Proponents of fluoridation assert that the dose of fluoride determines whether it is benefidal or toxic, and that there are threshold levels that must be exceeded before there aze toxic effects. This is a basic principle of toxicology and is true of every chemical approved for use in treating drinking water. "All sub- stances are poisons: [here is none which is not a poison. The right dose differentiates a poison and a remedy." Patacelsus (14931541) sa While there has been considerable scientific study of the effects of fluorides on health and the environment, there will alruays be the need for more reseazch.~ How- ever, proponents argue that it is not rational that the gains made from water fluoridation should be tmdone because not all the research has been completed. Fur- ther, it is strongly recommended that those communi- ties that have not yet fluoridated their water supplies should do so to protect the dental health of their cw- rent and future residcnrs.ss Both sides use arguments related to freedom of choice. Those supporting fluoridation argue that the public water supply is designed to protect public health and it is more important to protect people's health than to protect some people's concern for their free- dom to use unfluoddated waterss~sr Additionally, pro- fluoridationists invoke the ethical principle of nodal justice arguing that the safe public health measure is socioeconomically equitable, providing greater benefit to the disadvantaged.] Current anti-fluoridation tactics have focused on chemicals used to fluoridate water supplies. As has been shown above, there is no txedible evidence to sup- port the notion that the chemicals are unsafe. In the past, tactic have focused on studies that purported to show that fluoridation was linked to cancer and myriad other health problems 48 However, such assertions were based on improper silence, and numerous subsequent studies found no assodation between fluoridation and cancer.ss CONCLUSION Scientific evidence supports the fluoridation of public water supplies as safe for the environment and benefr dal to people. Reports at the local, national, and inter- national levels have continued m support this most important public health measure. There appears m be no concern about the environmental aspects of water fluoridation among those experts who have investi- gated the matter. Furthermore, since the chemicals used for water fluoridation aze co-products of the man- ufacture of phosphate fertflizets, and the taw material used is a namral resource (rocks excavated for their mineral content), water fluoridation could accurately be described as environmentally friendly, as it tttaxi- mizes the use made of these natural resources, and reduces waste.59 Nola In the uxt, the term "8uorosilicit hat been substituted for fluosilicic, hydrofluorosilitic, and hexafluorosiliric (all being synony- mous); similarly, "fluoroailica[e' for fluosilicate, hexafluorosilicate, and silicofluoride. However, the original terms in all rcfercncea have not been substituted. Rejerenrer 1. Centers for Disease Control and Prevention (CDC). Achievo- menu in public health, 1900-1999: fluoridation of drinking water to prevent dental caries. MMWR. 1999;48:933+10. <h ttp://wwwcdc.gov/mmwr/preview/mmwrhwl/mm4841a1. htm>. 2. U.S. Environmental Protection Agency. Crotmd Water and Drinking Water. Drinking Water Conumi»ants (Online Y003) <h ttp://www.epa.gov/safewater/hfazta.htmMlnotganio. 3. (:enters for Diseaac Control and Prevention (CDC). Popula- tions rccciving optimally Ruotidated public drittldng water - United States, 2000. MMWR. 8002;51:144.7. ~Ftttp://wwwcde gov/mmwr/preview/mmwrhtinl/mm5107aY.htm>. 4. McClure E7. A review of fluorine and its physiological effecn. Physiol Rev. 1935;13:Y77-300. 5. McClure F7. Fluoride domestic waters and systemic eHecn. I. Relation to bone-Cracture experience, height, and weight of high school boys and young selectees of the Armed Forces of the United Sra¢s. Public Health Rep. 1944;59:1543-58. 348 Pollitdc www.ijoeh.com • INT J OCCUP ENVIRON HEALIH 6. McClure FJ, Kinzer CA Fluoride domestic waters and rystemic effects. H. Fluorine content of urine in relation to fluorine in drinking water. Public Health R<p. 1944; 59:1575A1. 7. McClure FJ, Mitchell HH, Hamilton TS, Kinser CA. Balances of Fluorine ingested From various Sources in food and water by flvc young men (ez¢etion of fluorine through the skin).] Ind Hyg Toxicol. 1945;27:159-70. 8. Hodge HC. Evaluation of some objections to water fluoridation. In: Newbrun E (ed). Fluorides and Dental Caries. 3rd ed. Springfield, IL Charles C Thomaz, 1986:221-55. 9. National Reuazch Council. Health Effects of ingested fluoride. Washington, DC: National Academy Press, 1993. <h[tp:// atills.nap.cdu/books/OS0904975X/h tml>. 10. Mrponagh MS, Whiting PF, Wilson PM, et al. Systematic review oftvacer fluoridation. BMj. 2000;321:855A. Il. Tacoma-Pierce County Health Department. Tacoma-Pierce County Health Department Fluoridation Resolution. WAC 197- ]tA60 Environmental Checklist. August 2002. <hup://www. tpchd.org/NEWS/RELEASES/FluorideSEPAhtm>. 12. City of Por[ Angeles Public Works and Utllities, Washington. SEPA Fluoridation Checklist. October 2005. <h«p://www.ci. port-angeles.wa:ss/men us/planning.h un>. 13. Osterman J4V. 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Univeniry of Toronm, Toronto, ON, Canada: Community of DrnW Health Services Reuarch Uni[, Faculty of Denfisuy, 1999. <http://www.gov.on.ca/MOH/english/pub/miniavy/ fluoridation/fluocpdfS. 25. Lepo JE, Snyder RA Impact of fluoridation of the munidpal drinking water supply, review o[ the Bterawrc. Prepared for the Escambia County Utilities Authority. The Center for Environ- mental Diagnostics and Bioremediation. University of West Florida, 2000. <http://fluoride.oralhealih.org/papers/2001/ IeposnydcruwCcscambia.hvn>. 26. World Health Organnation. WHO Technical Report Series #846: Report of a WHO Expert Committee on Oral Health Slaws and Fluoride Uu. Geneva, Switzerland: World Health Organization, 1994. 27. Report of [he subcommittee on fluoride of the Commitue to Coordinate Environmental Health and Related Programs, USPHS. Review of fluoride: benefits and risks. Public Health Sceice: Department of Health and Human Services. 1991. <h ap: //www.heal th.gov/environment/ReviewotFluoride/ defaulthun>. Y8. [n[crnational Rogrammc on Chemical Safety ([PCS) Task Group on EnvironmenW Health Criteria for Fluorine and Flu- orides. EnvironmenW Health Criteria 36. Huorine and Fluo- tides. Geneva, Switzerland: World Health Organization, 1964. chop://wwwinchem.org/dtscumenfs/ehc/ehc/ehc36.htm>. 29. Medical Reuarch Council. Medical Reuarch Council working group rcpott: Water fluoridation and health. September 2002. <h «p://www.mrcac. uk/prn/index/public-interest/public- ncws/public-fluoridation report-Y.htm>. 30. Agency For Toxic Substances and Diuau Registry, U.S Public Heald[ Service. Toxicological profile for fluorides, hydrogen fluoride, and fluorine (2001 tits[[ and 1993). cht[p://www. atsdr.cdc.gov/tozproBles/tpl l.htmb and cht[p://www.atsdr. cdc.gov/toxprofiles/phsl Lhunl>. 31. NHS Cenue for Reviews and Dissemination, University of York. A Systematic Review of Public Water Fluoridation. York, U.R: York Publishing Services Ltd. 2000. <http://wtsw.york.ac.uk/ irut/ad/fluores.hvn>. 32. U.S. Department of Health and Human Services, Centers for Diuaze Control, DrnW Diuase Prevention Activity. WatcrFlu- oridation: AManual for Engineers and Technioans. Adanta, GA, CDC, September 1986. 33. American Dental Association. Fluoridation Facss. Question 33: Does Fluoridation present difficult engineering problems? (online 2003). <h[[p://www.ada.org/public/topin/fluoride/ fscts/saFeryasp>. 34. Urbansky ET Fate of fluorosilica[e drinking watt/ additives. Chem Rev. 2002;102:2837-54. 35. Cemen for Disease Control and Prevention. Fluoridation Censuz 1992. Atlanta, GA U.S. Department of Health and Human Services, Public Health Service, CDC, September 1993. 36. Fluoridation Technid $wdy Group Ciry of Fort Collins, Coo orado. Report of [he Fort Collins Fluoride Technical Swdy Caoup. Finding #4-The Potendni Cor Insxeased Contaminant Levels Due [o the Uu of Hydrofluorosilicic Acid. <http:// fcgov.tom/utilit[es/fluoriderepor[.php> and <h[tp://fcgov. tom/utilities/pdF/fluoride-report030903.pdb. 37. Centers For Diuau Cono-ol and Prevention. Engineering and administrative recommendations For water fluoridation, 1995. MMWR Rccomm Rep. 1995 Sep 29;44(RR-13):140. chap:// www.cdcgov/mmwr/preview/mmwrhtml/00039178.htm#0000 1289.htm>. 38. klasters RD, Coplan MJ, Horst BT, Dykes JE. Aswciation of sili- cofluoride vested tvater with elevaud blood lead. Neuromxico4 ogy.2000;2l:1097-100. <lt«p://homepage.tinet.ie/-Buoridefree/ netuotox.him>. 39. Masters RD, Coplan M. Water veatmen[with silicofluorides and lead toxicity. Inc J Environ Swdies. 1999:56:43549. 40. Ilrbansky ET, Schock MR Can fluoridation affect lead(B) in potable water? Hezafluorosilicate and fluoride equilibria in aqueous solution. Inc j Environ Studies. Y000;57:597I>S7. <h up://fluoride.oralhealth.org/papers/pdUurbanakgpd6. 41. Mazurs RD and Coplan M. Brain biochemistry and the violrnce epidemic: toward a '[vin-win' strategy for reducing crime. In: Nagel SE (ed), Super-0ptimizing Ezampks: Across Public Policy Problems. New York: Nova Science PubBshers, 1999. VOL 10/NO 3. JUL/SEP 2004 vnw/.ijoeh.com Woler Fluoridnflon and Environment 349 i 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. Commenu on The April 17, 2002 ICCEC Approazh to Silicoflu- orides Study by MJ Coplan. chop://216.239.33.100/starch?q= cacti r.5FsS1UaEae kC: n cp-se rve r. n i ehs. n i h. gu v/Meetings/ 4002/Coplan 081504.pdf+2002+ICCEC+Approach+to+Silico fluorides+Smdy&h1=en&ie=UTF$>. The American Heritage Dicdonary of Ne English Language. 4th ed. 4000. Haneke RE, Carson BL. Prepared for Scot Masten, PhD, National Insdr.:te of Environmental Health Sciences. Contratt No. N01•ES65402. Tozicologinl Summary for Sodium Hexa- Buorosilia[e [16893A5A] and Huorosilicic Acid [16961-834], October 2001. <http://ntp-server.niehs.nih.gov/htdocs/ Chem Background/EzBttmPDF/Fluorosilica[es.pd6. Colorado Springs Dental Society fluoride informadon page Y001 [ott-Line]. <http://www.csds.org/feature_arucle Buoride_ bodyh[mNBuotide_silicoEluotide fa<ts>. Reeves TG. Current technology on the engineering aspccn of rater Buoridadon. Paper presented at National Fluoridadon Summit, September 8, 2000 Sacramento, CA. ch[[p://fluoride. oralheal[h.otg/papers/pdf/rcevesnsLPDF>. Expett Committee on Oral Health Status and Fluoride Use. Flu- orides and oral health. WHO Technical Report Series No. 846. Ceneva, Swiverland: World Health Organization, 1994. Intemadonal Programme on Chemical Safety (IPCS) Environ- mental health criteria, No. 227. Fluorides. Grneva, Switzerland: World Health Organizadon, 2002. <h[tp://www.inchem.org/ documents/eh</ehc/ehc227.htm>. Newbrun E. The fluoridadon war: a sciendfic dispute or a relF gious argument? J Public Health Dent.1996;56(5 Spec No):24G 52. Review. [Abstraz[] <hop://www.ncbi.nlm.nih.gov/envez/ query.ftgi?cmd=retrieve&db=pubmedHais[ uids=9034969&dop t=Abwaco. Fluoride Action Network [online 2003]. chap://wwwfluoride alertorg/about-fan.hun>. American Water Works Association [online]. Fact Sheeu. Fluo- ridation. 2003. chap://www.awtva.org/Adwmry/presuoom/ ^uoride.cfm>. 52. American Dental Association. Fluoridadon Facts. Nadonal and In[ernadonal Organizations that Recognize the Public Health Benefiv of Community Water Fluordadon for Preventing Dental Detay [on-line 2003]. chop;//www.adaorg/public/ topics/fluoride/facts/compendium asp>. 53. Center For Diseau Convol and Prevention (CDC). Ten great public health achievements-United States, 19041999. MMWR. ]999;48:241-3. <ht[p://www.cdc.gov/mmwr/Preview/ mmwrhunl/00056796.hun>. 54. Society of Toxicology. Some Basic Prinriples of Toxicology: Teacher's Notea. [Online 4003] <http://www.mxicologyorg/ publicouveach/Education Outreach/prinnote.htmb. 55. ('zn[en for Disease Convol and Prevention (CDC). Recom- mendations for Using Fluoride m Prevent and Control DenW Caries in the United States. MMWR. 2001;50(RR l4):1~12. <h «p: //wrvw. cdc.gov/mmwr/preview/mmwrhtml/rr5014a1. htm>. 56. Pratt E Jr, Rawson RD, Rubin M. fluoridation az fifty. what have the Itarned2 J law Med Ethica. 200Y;30(3 suppl):117-41. chop://www.f ndarucles.tom/d_dls/mODPE/3_30/95843945 /pl/article jhtml?tcrm=>. 57. Fielding JE, Marks JS, Myers BW, Nolan PA, Rawson RD, Toomty KE. How do we translate adence into public health polity and law? J Law Med Ethics. 200Y;30(3 suppl):Y2-3Y. <http://www.findardcles.com/cf dls/mODPE/3_30/9584393D /pl/ardcle;jhtml>. 58. National Cancer Institute. Cancer Fazts. fluoridated Wa[cr. [Online reviewed 2000] <http://fluoride.onlhealth.org/ papers/2001 /ncicancerfactal O] OOO.hmu. 59. Bridsh Fluoridation Society. The enduonmental aspects ofwater fluoridation. [Online 2003] <http://www.livacuk/bfa/em'von brieLhtm>. 350 Pdllck vnvw.goeh.com IM J OCCUP ENVIRON HEALTH TABLE 5-2 CHEMICALS COMMONLY USED IN A WATER TREATMENT PLANT NAME USE * I. Ammonia (anhydrous) Disinfection * 2. Hydroxide ammonium Disinfection 3. Ammonium sulfate Disinfection 4. Bromine Disinfection * 5. Chlorine (gas) Disinfection, oxidation agent 6. Chlorine dioxide Disinfection 7. Hydrochlorites -Calcium hypochlorite (HTH) Disinfection - Sodium hypochlorite (household bleach) Disinfection -Lithium hypochlorite Disinfection * 8. Ozone Disinfection 9. Silver nitrate Disinfection -home units 10. Ultraviolet light Disinfection 11. Activated carbon Absorption material 12. Charcoal (carbon) Absorption material 13. Aluminum ammonium sulfate A Metal coagulant, dechlorinator 14. Sulfur dioxide Dechlorination agent 15. Sodium sulfite Dechlorination agent 16. Sodium bisulfate Dechlorination agent 17. Sodium thiosulfate Dechlorination agent 18. Ion -exchange resins Water softener media 19. Sodium chloride (salt) Water softener media 20. Glauconite (greensand) Water softener media 21. Silica sand Filter media 22. Anthracite coal Filter media 23. Aluminum sulfate (alum) A Metal coagulant 24. Ferric sulfate A Metal coagulant 25. Fen~~us sulfate A Metal coagulant * 26. Ferric chloride Coagulant 27. Sodium aluminate Coagulant, pH control 28. Aluminum potassium sulfate Coagulant * 29. Calcium oxide (quick lime) pH control, coagulant 30. Calcium hydroxide (hydrated lime) pH control, coagulant 31. Clay (Bentonite) Coagulant aid 32. Calcium carbonate Coagulant aid, pH control 33. Activated silica Coagulant aid 34. Sodium silicate Coagulant aid 35. Sodium carbonate (soda ash) pH control, coagulant 36. Carbon dioxide (gas) pH control * 37. Hydrochloric acid pH control * 38. Sodium hydroxide pH control, corrosion control * 39. Sulfuric acid pH control 40. Potassium permanganate Disinfection, remove color, oxident 41. Polyelectrolytes Coagulant aid 42. Polyphospates - Calcium polyphosphate Corrosion control, Iron control - Zinc polyphosphate Corrosion control, Iron control - Soilium tri-polyphosphate Corrosion control - Sodium hexa-metaphosphate Corrosion control 43. Sodium fluoride Fluoridation 44. Sodium silicofluoride Fluoridation * 45. Hydrofluosilicic acid Fluoridation 46. Copper sulfate Algae control * Very hazardous material for plant operator Source: U.S. Department of Health and Human Services, Centers for Disease Control, Dental Disease Prevention Activity. Water Fluoridation: A Manual for Engineers and Technicians. Atlanta; September 1986:98. Cancer Causes Control (2006) 17:48162 M1I 10.1007/s10552-006-0008-8 Caution needed in fluoride and osteosarcoma study Chester W. Douglass • Kaumudi Joshipura Received: 3 7anuary 2006/Accepted: I2 January 200fi © Springer 2006 This issue of Cancer Causes and Controls includes a paper with results from an analysis of a subset of participants in our ongoing study of fluoride and osteosarcoma. The paper, "Age-specific fluoride exposure in drinking water and osteosazcoma", presents a partial view of this ongoing study. We would like to advise the readers to be especially cautious when interpreting the findings of this paper for several reasons. The authors themselves have already raised a flag of caution in their final paragraph with the note that they are aware of additional findings from other inci- dent cases that appear not to replicate the findings from the cases presented in their paper. The Harvard School of Dental Medicine study of fluo- ride and osteosarcoma has been a 15-year collaboration among NIEHS, NCI, NIDCR, and Harvard. Two sets of cases have been collected each with their own control groups. The study started in 1992. The first set of cases was recruited from existing cases between 1989 and 1992, and the second set of cases was recruited from new incident cases between 1993 and 2000. The Bassin et al paper reports age-specific results among only the cases from 1989 [0 1992. We are also finding some positive associations between fluoride and osteosarcoma in the overall (not age- specific) analysis of the first set of cases. However, our preliminary findings from [he overall analysis of the second set of cases (1993-2000) do not appear to replicate the overall findings from the first part of the study. Our find- ings currently being prepared for publication, do not sug- gest an overall association between fluoride and osteosarcoma. This seems particularly important since [he cases had been accrued essentially from the same hospitals within the same orthopedic departments with the same providers, and the same pathology departments making the diagnosis of the osteosarcoma and also using similar methods of fluoride exposure. In addition to fluoride intake history, many of the cases and controls that were accrued in the 1993-2000 time period agreed to provide bone specimens. The cases pro- vided bone that was obtained proximal to the osteosarcoma lesion as well as from their contra lateral hip. The control group of non-osteosarcoma cancer patients provided bone specimens. Our preliminary analysis of the fluoride content of the bone specimens suggests [hat the fluoride level within the bone is not associated with excess risk of oste- osarcoma. We aze grateful to Dr. Bassin and her coauthors for mentioning at the end of their paper that we are not finding a positive association from the bone specimens in the second set of cases. Obtaining and analyzing sufficient numbers of bone specimens has been a laborious and a time consuming effort by many people throughout the hospitals and research teams. The analysis of these specimens has included quality convol procedures on laboratory tech- niques, pilot studies to test reliability, many rvns of small batches of specimens, the double checking of specimen transport procedures, and the preparation of data sets for analysis. We are now in the possession of [he complete analytic data sets and are pursuing previously planned analysis and comparisons with the earlier set of collected cases. We C. W. Douglass (®) ~ K. Joshipura Harvard School of Dental Medicine, Boston, MA, USA; Harvard School of Public Health, Boston, MA, USA e-mail: Chester_douglass@hsdm.harvard.edu Tel.: +I-617432-1456 Fax: +1-617-032-0047 K. Joshipura University of Puerto Rico, Medical Sciences Campus, San Ivan, Puerto Rico ~ Springer 482 have delayed publication of all the major findings until we found replication or lack of replication of the earlier po- sitive findings. Our role model in this process has been Sir Richard Doll, whose first publication associating smoking with illness was rejected for publication until it could be replicated (New York Times, July 26, 2005). I[ was too important and too unexpected to be published on its own. Professor Doll did replicate his initial findings; we appar- ently have not and the bone specimens seem [o corroborate the lack of an association between the fluoride content in drinking water and osteosarcoma in [he new cases. Inter- estingly, the NIEHS replication of their own earlier study that found excess osteosarcoma in male rats was recently presented on [he NIEHS web site [l]. The findings of their second study do no[ replicate their original widely quoted National Toxicology Program study [2]. Drinking water with very high fluuride content was not found to be asso- ciated with osteosarcoma in either male or female rats. Cancer Causes ConVOI (2006) 17:48182 A parallel analysis of age-specific exposure to fluoride, especially during growth periods, is also being pursued by our study team in the second se[ of cases of our study. Accordingly, readers aze cautioned not to generalize and over-interpret the results of the Bassin et al. paper and to await the publications from the full study, before making conclusions, and especially before influencing any related policy decisions. References I. T'he National Toxicology Program (NTP). Supplemental 2-year study of sodium fluoride in male F344 mts (CAS No. 7681~91t) 2. National Tozicology Program (1990) Toxicology and carcino- genesis of sodium fluoride in P344 1'N rats and B 6C3FL mice. Technical Report Services 393, NIH Publication No. 90-2848 Pn Springer Cancer Causes Control (2006) 17:42128 DOI 10.1007/s 10$52-005-0500-6 Age-specific fluoride exposure in drinking water and osteosarcoma (United States) Elise B. Bassin • David Wypij • Roger B. Davis Murray A. Mittleman Received: 24 July 2005/Accepted: 7 November 2005 © Springer 2006 Abstract Objective We explored age-specific and gender-specific effects of fluoride level in drinking water and the incidence of osteosarcoma. Methods We used data from a matched case-control study conducted through 11 hospitals in the United States that included a complete residential history for each pa- tient and type of drinking water (public, private well, bottled) used at each address. Our analysis was limited to cases less than 20 years old. We standardized fluoride exposure estimates based on CDC-recommended target levels that take climate into account. We categorized exposure into three groups (<30%, 30-99%, >99% of target) and used conditional logistic regression to estimate odds ratios. Results Analysis is based on 103 cases under the age of 20 and 215 matched controls. For males, the unadjusted odds ratios for higher exposures were greater than I.0 at each exposure age, reaching a peak of 4.07 (95% CI 1.43, 11.56) at age 7 years for the highest exposure. Adjusting for potential confounders produced similaz results with an adjusted odds ratio for males of 5.46 (9S% CI I.50, 19.90) at age 7 years. This association was not appazent among females. Conclusions Our exploratory analysis found an associ- ation between fluoride exposure in drinking water during childhood and the incidence of osteosarcoma among males but not consistently among females. Further re- search is required to confirm or refute this observation. Keywords Osteosarcoma ~ Fluoride ~ Fluoridation Case~ontrol E. B. Bassin Department of Oral Health Policy and Epidemiology, Harvard School of Denlal Medicine, USA e-mail: elise_bassin@post.harvard.edu D. w'YPiJ Departrnent of Pediatrics, Harvard Medical School, USA and Clinical Research Program, Children's Hospital, USA R. B. Davis ~ D. Wypij Department of Biostaristics, Harvard School of Public Health, USA R. B. Davis (®) Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215, USA M. A. Mitdeman Department of Epidemiology, Harvard School of Public Henlth, USA and Cardiovascular Epidemiology Research Unit, Beth Israel Deaconess Medical Center. USA Introduction Osteosazcoma is a very raze primary malignant tumor of bone. Although uncommon, primary malignant bone tu- mors comprise the sixth most common group of malignant tumors in children and [he third most common malignant tumor for adolescents, with an annual incidence rate of 5.6 per million for Caucasian children under 15 years old [1]. Osteosazcoma is the most common tumor of bone and for patients less than 20 years old more than 80% of these tumors tend [o occur in the long bones of the appendicular skeleton which are undergoing rapid growth [2J. The incidence of osteosarcoma is slightly higher in males than females with an annual incidence rate of approximately 3.5 per million for males and 2.9 per million for females under the age of 24 years [3]. Springer 422 Cancer Causes Control (2006) 17:42128 The etiology of osteosarcoma is lazgely unknown [l, 4]. In humans, ionizing radiation is the only environmental agent known [o cause bone cancer and is thought to have an effect in approximately 3% of cases from either external high-dose irradiation used in cancer therapy or internal bone-seeking radioisotopes from occupational or medical use [l, 5, 6]. Alkylating agents used in chemotherapy are thought to increase the risk for osteosarcoma and evidence for other etiologic factors including viruses, antecedent trauma, or radium in drinking water has been suggested but inconclusive [I, 5, 7, 8]. Certain pre-existing bone defects including Paget's disease have been found more frequently in patients who subsequently developed bone cancers [l, 4, 5]. Also, a genetic predisposition for osteosarcoma has been described, specifically for patients with a hereditary form of re[inoblastoma or those with familial Li-Fraumeni cancer syndrome [1, 5, 6]. The age-incidence distribution of osteosarcoma is bimo- dal, raising the possibility of different risk factors contrib- uting tothe incidence of osteosarcoma at different ages. The first and larger peak in incidence occurs in the second decade of life and a subsequent peak occurs in males in the eighth decade of life [Z, 4, 5, 9]. Evidence suggests that osteosar- coma is associated with skeletal growth, patticularly for patients diagnosed during adolescence [l, 9-I1]. Since fluoride may act as a mitogen (increasing the proliferation of os[eoblasts) and its uptake in bone increases when skeletal growth is more rapid [l2, 13], it is biologically plausible that fluoride exposure during growth is associated with the sub- sequent development of osteosarcoma, and fluoride could either increase or decrease the rate of osteosarcoma. There are conflicting data regarding the association between fluoride exposure and the incidence of osteosar- coma. Several antmal studies have been conducted, but only one found evidence that fluoride exposure may in- crease osteosarcoma formation, specifically in male rats [14]. Human studies also show conflicting results. The majority of epidemiologic studies found no association between fluoride and osteosarcoma [I 5-21 ]. However, two studies found evidence of an association in males under age 20, but not in females [22, 23]. Furthermore, prior studies have primarily evaluated fluoride exposure at the time of diagnosis or as an average lifetime exposure and have not evaluated exposure at specific ages during growth and development when cell division is occurring rapidly. Therefore, we use data from the Harvard Fluoride Oste- osarcomaStudy [24] to explore age-specific and sex-specific effects and evaluate exposure to fluoride in drinking water from birth through eazly adolescence. Specifically, based on prior studies suggesting an effect of fluoride limited to males under age 20, we limited our analysis to the first two decades of life and evaluated effects in males and females separately. Materials and methods We used data from ahospital-based, matched case~ontrol study which evaluated lifetime exposure to fluoride from drinking water and self-administered fluoride products [24]. Subjects were identified through the orthopedic departments at ll teaching hospitals across the United States. Cases had histologically confirmed osteosarcoma diagnosed between November 1989 and November 1992. Exclusion criteria were: age 40 yeazs or older, any history of radiation therapy or a history of renal dialysis. Controls were patients of the same hospital's orthopedics depart- ment, seen within ±6 months of [he case's diagnosis and matched with cases on age (±5 yeazs), gender, distance from hospital, with the same exclusion criteria applied to cases. Telephone interviews were conducted between January 1992 and January 1995 with the parent or subject (over 18 years old) or with a proxy if subjects were de- ceased or incapacitated. Interviewers collected informa- tion which included a complete residential history, use of fluoride supplements and mouth rinses. Study procedures were approved by the Harvard Medical School Committee on Human Studies and each of the participating institu- tions. Data on a total of 419 subjects, 139 cases and their 280 matched controls, were available based on eligibility criteria, matching criteria and a completed interview. However, we limit the current analysis to 103 cases less than 20 yeazs old and 215 convols matched to these cases. Fluoride level in drinking water was the primazy expo- sure of interest. The interview obtained the usual type of [he subject's drinking water (municipal, private well, bot- tled) and the subject's age(s) while at each address. From these data, we estimated the level of fluoride in drinking water for each subject a[ each age, and explored the effects of fluoride during their growth and development. To esti- mate fluoride concentration for public water supplies, we obtained preliminary data from the 1985 CDC Fluoridation Census [25] and the 1992 CDC Fluoridation Census [26]. We then contacted state agencies (State Dental D'irector's Office. State EPA Office of Drinking Water, Water Administrators Office) and local sources (county health departments, the town or city clerk's office and specific water systems) to confirm and supplement the CDC data [27]. For subjects who drank well water, a sample was obtained from current or former residents for the specific appropriate addresses. Fluoride concentrations were measured at Harvard School of Dental Medicine using a Colorimeter (Model 41100-21, Hach Company, Ames, IA). Subjects who used bottled water as their usual source of drinking water were identified, but information about specific brand was not collected. We estimated fluoride Springer Cancer Causes Control (2006) 17:42128 423 levels to be 0.1 parts per million (ppm) in bottled water based on the weighted average of fluoride concentration in leading brands [28]. Since subjects who used bottled water were also likely to consume fluoride from tap water in food and beverage prepazation and use outside the home (e.g., school), we used the mean of fluoride estimates for bottled water (i.e., 0.1 ppm) and municipal water for these resi- dences. Since water consumption may vazy based on cli- mate, we standardized fluoride exposure estimates based on CDC recommendations for optimal target levels of fluoride [29j. For example, for locations in warmer climates where the target fluoride level is 0.7 ppm, we divided fluoride levels by 0.7, while for locations in colder climates where the target fluoride level is 1.2 ppm we divided by 1.2. The standardization of fluoride exposure was done for all three types of drinking water. We created a proxy measure for socioeconomic status (SES) by linking zip code at the time of diagnosis with data from the Census Bureau that provide 1989 median family income for each zip code. Median family income was categorized into quartiles based on the distribution for controls. We also used data from the Census Bureau to determine the 1990 population of the county where sub- jects resided at the time of diagnosis, categorized by approximate tertiles. We examined type of drinking water by including indicators for use of bottled water or well water at any time up to the exposure age. Since age matching allowed for a difference as large as 5 years, we included age (at diagnosis for cases and at time of hospital veatment for controls) as a covariate. Lastly, since infor- mation was collected for use of self-administered fluoride products a[ home or in school-based programs, we included an indicator for any use of these products as an additional covariate. We used conditional logistic regression to estimate the odds ratio for the association between fluoride exposure and osteosarcoma, taking into account the matching between cases and controls. The dependent variable was an indicator identifying cases and the primary independent variables were measures of fluoride exposure. We fit two basic models. The first model included only the exposure mea- sures as independt:n[ variables. T'he second model also in- cluded age, a proxy for SES, county population, use of private well water or bottled water, and any use of fluoride supplements or mouth rinses as covariates. In [his analysis, our a priori hypothesis was that fluoride exposure may have sex-specific differential effects on osteosarcoma risk based on age at exposure. The models we employed therefore do not assess the question of average induction time or latency. We report the mean and standard deviation of fluoride levels in ppm and percent of target for each specific age. To examine the association between osteosarcoma and fluo- ride exposure at specific ages, we fit separate models for each exposure age up to the age of diagnosis for each case and the same age for the matched controls. Each model included the age-specific fluoride level and asex-fluoride interaction term. In [his analysis we expect substantial correlation in exposure to fluoride in drinking water from year to year, limiting our ability to identify age-specific effects precisely. For our primary analysis we categorized climate-standardized fluoride exposure into three catego- ries (<30%, 30-99%, >99% of target fluoride content) cotresponding to approximate tertiles based on the distri- bution among controls. We plot sex-specific estimates of the odds ratio and 95% confidence intervals as a function of exposure age. We also fit a model using fluoride exposure categorized without standardization by climate into three groups (<0.3, 0.3-0.69, and ?0.7 ppm). We performed a sensitivity analysis on our assumption that the fluoride content of bottled water is 0.1 ppm by fitting models using values as high as 0.5 ppm fot bottled water (assuming that bottled water and municipal water each contributed half of the consumption for subjects who used bottled water). In addition, we conducted a sensitivity analysis evaluating the age-specific and sex-specific effects of fluoride in drinking water among subjects who reported never having used any fluoride supplements or fluoride mouth rinses. Results A total of 157 cases diagnosed before age 20 were iden- tified at the participating hospitals. No interviews were completed for 13 of the cases (did not attempt to contact, could not contact, or respondent refused). Eleven cases used well water for which no sample was obtained and 12 cases lived outside [he United States for more than 6 months. An additional 18 cases with interview data were excluded due to lack of appropriately matched controls (nine had no eligible matches identified or successfully interviewed, seven whose only matches used well water for which no sample was obtained and two whose matches lived outside the United States >6 months). Characteristics of the remaining 103 cases and their 215 matched controls are presented in Table 1. Cases were diagnosed at a median age of 14 years (range 6-19, interquar[ile range 11-17). Residential histories for six participants, five cases and one control, were provided by proxies (grandparents, step- parent, sibling, aunt, neighbor). The 1989 median family income for zip code of residence was lower for cases than controls (P=0.01, Student's t-test) and a larger proportion of controls used bottled water (P=0.002, chi-square test). Table 2 shows the average fluoride level and percent of climate-specific target level in drinking water at each age for cases and controls. Springer 424 Cancer Causes Control (2006) 17:421-428 Table 1 Characteristics of study population' Cases Controls Number 103 21S Age (years) 13.7 ± 3.5 14.5 ± 3.9 Gender Male 60 (S89e) 122 (5T-o) Female 43 (4290) 93 (43%) Se!( reporred race White 81 (7990) 180 (8490) Black 16 (1690) 23 (1190) Asian 3 (390) 2 (1%) Other 3 (390) 9 (490) Number of residences 2.5 ± 1.7 2.6 t 1.7 1989 Median family income` $41,458 ± 15,146 $46,841 t 19,319 County population` <250,000 37 (3790) 69 (329x) 250,000-999,999 44 (4490) 86 (409x) 1,000,000+ 19 (19%) 60 (2890) Hospital MGH 17 (17%) 27 (1390) CH, Boston IS (IS%) 45 (21%) Creighton 5 (590) I I (S9o) CH, DC I I (11%) 20 (9%) MSKCC 7 (790) 14 (790) U Chicago 8 (8%) 16 (79o) Rush 3 (3%) 6 (39n) U Florida 12 (1290) 19 (9%n) UCLA 14 (1490) 32 (1690) Cleveland clinic 8 (890) 19 (99a) CWRU 3 (390) 6 (3%) Ever well water use 29 (2890) 44 (2090) Ever bottled water use 8 (8%) 46 (2190) Fluoride Products Rinses 3 (390) 19 (9'&) School program 17 (1790) 30 (14%) Tablets 10 (10%) 28 (1390) Drops 9 (990) 19 (99n) Any of above 27 (2690) 77 (36%) ° Values reported aze mean ± standard deviation or n (90) "Race not available for one control ` 1989 Median family income and county population data not avail- able for three cases Figure 1 shows the odds ratio, relative to the lowest exposure group, of osteosarcoma for the climate-stan- dardized fluoride level at each exposure age from 0 to 14 years, estimated using the conditional logistic regres- sion models unadjusted for other covariates. Among males, exposure to fluoride at or above the target level was associated with an increased risk of developing osteosar- coma (Fig. la). The association was most apparent be- tween ages 4 and 12 with a peak at 6-8 years of age. The odds ratio for the high exposure group was 4.07 at 7 years of age with a 95% confidence interval of 1.43-11.56. Among females less than 20 years old, no association between fluoride in drinking water and osteosazcoma was apparent at any age (Fig. lb). Next we fit models with all the covariates. As an example, Table 3 shows the model for subjects at 7 years Ta41e 2 Fluoride level for drinking water' F level in ppm Cases Controls Percent of target Cases Controls Age (Years) 0 0.63±0.40 0.60±0.41 6690±4]% 629ot419o I 0.63 f 0.40 0.60 1 0.40 6590 ± 41% 6190 ±4090 2 0.64 ± 0.40 0.61 ± 0.40 6790 t 4190 639a ± 4090 3 0.67 t 0.39 0.63 ± 0.39 6990 ± 4090 64% ± 399a 4 0.70 ± 0.40 0.62 t 0.39 73% t 4190 63% ± 3990 5 0.69 t 0.40 0.63 ± 0.39 72% t 4190 65% t 3890 6 0.70 t 0.40 0,62 ± 0.39 7490 ± 4190 6390 ± 3990 7 0.70 t 0.38 0.61 ± 0.39 7590 t 4090 63% ± 399a 8 0.69±0.38 0.61±0.39 73%±g09o 63%±3890 9 0.68 t 0.39 0.63 ± 0.38 7390 f 41% 65%± 3890 10 0.67 t 0.39 0.61 ± 0.39 7190 ± 4190 6390 ± 39% I I 0.70 f 0.56 0.60 ± 0.39 74% ± 65% 6290 ± 3990 12 0.69 ± 0.56 0.59 t 0.39 75% ± 6690 61% t 39% 13 0.68 t 0.39 0.61 ± 0.39 71% t 41% 62% ± 3890 14 0.65 t 0.41 0.59 ± 0.39 699a t 4390 6190 t 3890 ° When bottled water was used, the esdma[e was 0.1 ppm for bottled water and it was assumed that bottled water and municipal supply each accounted for 50% of consumption (a) 64 3z ° 16 B a 4 z v 1 a 0 5 a6 .tzs 0 1 2 3 4 6 6 7 6 9 10 11 12 13 14 Exposure A g e Fluoride --- 100%+ • •'• 30-99% (h) 64 32 ° 16 8 N ¢ 4 z a 1 o s as .1zs 0 1 2 3 4 6 6 7 6 9 10 11 12 13 14 Exposure Age Fluoride --'-100%+ "^•30-99% Fig. 1 Odds ratios and 969o confidence intervals relative to fluoride levels less than 3090 of target are shown for males (panel a) and for females (panel b). The dashed line shows the odds ratios for the intermediate exposure category (30-99% of target fluoride level) and [he solid line shows the odds mhos for the high exposure category (10090 of target or greater) Springer Cancer Causes Control (2006) 17:42128 Table 3 Sez-specific associations between fluoride exposure a[ age 7 years and osteosamoma, estimated by conditional logistic regression Fluoride ezposure at age 7 years Odds ratio (95% C.IJ' Males Less than 30% of target L00 30.99% of tazget 3.36 (0.99, 1 I.42) At least 100% of target 5.46 (L50, 19.90) Females Less than 30% of target 1.00 30-99% of target 1.39 (0.41, 4.76) At least 100% of tazget 1.75 (0.48. 6.35) 'Adjusted for age, zip code median income, county population, use of well water by age 7, use of bottled water by age 7, any use of fluoride supplements of age. Figure 2 shows a similar effect of fluoride level in drinking water after adjusting for income by zip code, county population, ever use of bottled or well water, age, and any use of self-administered fluoride products. For males, the odds ratio for the high exposure group was 5.46 at 7 years of age with a 95% confidence interval of 1.50- 19.90. Sensitivity analyses, which assumed that the fluoride (a) 6a 32 ° 76 a W 4 e 2 v 1 o s .726 (b) sa 3z ° 16 0 1 2 3 9 5 6 7 B 9 70 11 12 73 14 Exposure Age Fluoride -'--100%+ ""^30-99% a m a e 2 9 7 o s 25 .tu 0 7 2 3 4 6 6 7 B 9 10 11 72 73 14 E zp osure Age Fluod~ -'-- 700%+ ° "• 30-99% Fig. 2 Odds ratios and 95% confidence intervals relative to fluoride levels less than 30% of tazget are shown for males (panel a) and for females (panel b). The dashed line shows [he odds ratios for [he intettnediate exposure category (30.9990 of target fluoride level) and the solid line shows [he odds ratios for the high exposure category (]0090 of target or greater). Estimates are adjusted for age, zip code median income, county population, prior use of well water, prior use of bottled water, and any use of fluoride supplements 425 728 64 o ~ 16 a g 4 a 9 2 a 7 O .6 zs 126 0 1 2 3 4 5 6 1 6 9 10 11 12 13 14 Exp os ure Age Fluadtle ---100%+ w«•30_gg% Fig. 3 Odds ratios and 95% confidence intervals relative to fluoride levels less than 30% of target are shown for the subset of male participants who never used fluoride supplements or rinses. The dashed Tine shows the odds ratios for the intermediate ezposure category (30.99% of tazget fluoride level) and the solid line shows the odds ratios for the high exposure category (100% of target or greater) content of bottled was as low as 0.1 ppm or as high as 0.5 ppm, yielded essentially identical results. A sensitivity analysis that categorized fluoride exposure based on the absolute fluoride concentration, without standardizing for climate-specific target fluoride level, also showed essen- tially the same results (unadjusted OR=3.77; 95% CI 1.41, 10.05, and adjusted OR=5.55; 95% CI 1.60, 19.24 for 0.7 ppm or greater relative to less than 0.3 ppm). To avoid potential confounding by fluoride supplementation or fluoride rinses, we conducted a sensitivity analysis resuicting our population to subjects who reported that they did not use supplements or rinses. This substantially reduced the sample size limiting us to unadjusted analyses for males. The results were consistent (Fig. 3). Discussion Our exploratory analysis described the association of fluoride level in drinking water at specific ages and the incidence of osteosarcoma. We observed that for males diagnosed before the age of 20 years, fluoride level in drinking water during growth was associated with an in- creased risk of osteosarcoma, demonstrating a peak in the odds ratios from 6 to 8 years of age. All of our models were remarkably robust in showing this effect, which coincides with the mid-childhood growth spurt [30-33]. For females, no clear association between fluoride in drinking water during growth and osteosarcoma emerged. We found similar effect magnitudes in the intermediate and high exposure levels, as opposed to adore-response gradient. This may be due to misclassification of the pri- mary exposure for some artificially fluoridated systems. Springer 426 Cancer Causes ConWl (2006) 17:42128 Reeves [34] reported that only 65% of fluoridated water systems routinely have target levels of fluoride maintained in the drinking water, which may result in our misclassi- fying up to 35% of the adjusted water systems, categorizing [hem in the highest group (100% of target or greater) when some truly belong in the middle group (30-99% of target). While non-differential misclassification of exposure results in bias towards the null for a dichotomous exposure, Birkett [35] has shown that with three levels of exposure, the estimated odds ratio for the highest exposure level is biased towards the null, but for the intermediate category the estimate can be biased in either direction. Hence, in our study [he misclassification might mask an effect that in- creases with dose. Our results azc consistent with a pattern seen in [he National Toxicology Program (NTP) animal study and two ecological studies. The NTP animal study, which reported "equivocal evidence" for an association between fluoride and osteosarcoma, found a positive association for male rats, but no association for female rats or mice of either gender [14]. Using data from [he Surveillance, Epidemi- ology and End Results (SEER), Hoover et al. found an unexplained increase in osteosarcoma in males less than 20 years of age in fluoridated versus non-fluoridated areas. However, atime-trend analysis which took into account the duration of fluoride exposure failed to demonstrate a higher incidence among males exposed [o fluoridated water their entire lives than among those exposed less than half their lives [22]. A similar, but smaller study examining osteo- sarcoma in New Jersey also showed an increase in inci- dence rates for males less than 20 years old who lived in fluoridated areas compared to those living in non-fluori- da[ed azeas [23]. A number of other case-control studies did not find an association between fluoride in drinking water and osteo- sarcoma [18-21]. In addition, preliminary analyses of an ongoing case~ontrol study of the determinants of osteo- sarcoma conducted at [he same network of hospitals that participated in the present study and recruited cases during their initial hospitalization, found no overall association between lifetime exposure to fluoride or fluoride content in bone biopsies, a marker of cumulative exposure, and osteosarcoma (personal communication, Chester Douglass, D.M.D., Ph.D.). This lack of agreement may be related to the bimodal age-incidence distribution of osteosarcoma [2, 4, 5, 9]. When there are two distinct peaks in an age- incidence distribution, two distinct sets of component causes should be considered [36]. McGuire et al. []9] and Moss et al. [20] included cases up to age 40 years and 84 years, respectively, and if fluoride exhibits a different effect according a the age-specific distribution, detecting an effect would be unlikely. Operskalski et al. [ 18] selected friends and neighbors of the cases as controls, which might have been optimal for some exposures of interest, but re- sulted in inadvertently matching on drinking water fluoride level. The evaluation of age-specific effects distinguishes ow study from the other investigations. Rothman [37] has warned that failure to identify the appropriate time window for exposure may result in misclassification which can adversely affect the ability [o detect an association. This might explain why the study by Gelberg et al. [21] did not find an association between fluoride in drinking water and osteosarcoma since age-specific effects were not evaluated. I[ is biologically plausible that fluoride affects the incidence rate of osteosarcoma, and that [his effect would be strongest during periods of growth, particulazly in males. First, approximately 99010 of fluoride in the human body is contained in the skeleton with about 50% of the daily ingested fluoride being deposited directly into calci- fied [issue (bone or dentition) [13]. Second, fluoride acts as a mi[ogen, increasing the proliferation of osteoblasts [12, 38] and its uptake in bone increases during periods of rapid skeletal growth [13j. In the young, the hydroxyapatite structure of bone mineral exists as many extremely small crystals each surrounded by an ion-rich hydration shell, providing a greater surface area for fluoride exchange to occur [39, l3]. Also, osteosarcoma, for the ages we con- sidered, generally originates in the me[aphyseal azeas of long bones [2] and the pattern of the blood supply [o the metaphyses and epiphyses, where growth of long bones takes place, differs from that of the dpaphyses because of the special circulation to the epiphyseal growth plate in the young which in turn disappears when growth is complete [40, 41]. Lastly, the amount of fluoride present in bone depends on gender and intake [39] and intake, on average, is greater for males than females for all ages over 1 year [42]. There are several limitations to our study. First, our estimates of fluoride in drinking water at each residence do not reflect actual consumption by subjects and the study did not obtain biologic markers for fluoride uptake in bone. However, dietary sources of fluoride comprise the majority of human exposure [l3], and for individuals living in fluoridated communities, the fluoride in drinking water is estimated to contribute two-thirds of the total dietary intake [39]. Also, when we added use of self-administered (home- or school-based) products as a covariate in the model, there was no substantial change in results. The halo or diffusion effect, described in the dental literature, refers to people in non-fluoridated communities receiving fluoride from food and beverages processed in fluoridated communities and vice versa [43]. We would expect this type of measurement error to result in a bias towards underestimating any tme effect that might exist. Because cases and controls moved razely up to [he age at diagnosis (an average of 1.5 times) leading to essentially ~'] Springer Cancer Causes Control (2006) 17:421 X28 collineaz exposure from year to year, we were unable to apply statistical models that assess the effect of age-spe- cific exposure while simultaneously adjusting for exposure a[ other ages such as distributed lag models. Residential histories were obtained fmm proxies more often among cases than controls, however the absolute number was small and [he proxies were generally close relatives. The estimation of fluoride concentration a[ each resi- dence is subject to several sources of measurement error. Monitoring guidelines for fluoridated water systems permit actual fluoride levels to vary. For example, if the target fluoride concentration for a specific water system is I.0 ppm, guidelines may consider values between 0.8 and ].3 ppm acceptable. Also, natural fluoride levels may vary over time, but they are unlikely [o do so for the length of time subjects lived at their respective address unless [he water source changed. For bottled-water users, we did no[ know the specific brands consumed and a small proportion of brands on the market do have substantial levels of fluoride. However, analysis of the leading national brands makes a value of 0.1 ppm a reasonable estimate [28]. Further, we demonstrated [ha[ our findings were not sen- sitive to this assumption. The lack of d.tta available for other potential con- founders is also a limitation. Fluoride may not be the causative agent; instead there may be another factor in drinking water correlated with the presence of fluoride. Data to assess fluoride exposure in diet, industrial fluoride exposure or other fluoride exposures (e.g., pesticides) were not available. Instead, by including type of drinking water subjects used (ever well, ever bottled) as a covariate, we may have partially controlled for some of the "other un- known factors" such as contaminants or carcinogens sub- jects might have been exposed to irrespective of fluoride concentration in these natural sources or products. Another limitation is the possibility of selection bias. In our case-conVOl study, the secondary study base is defined by the cases and in order for the results [o be valid the exposure distribution for controls must repre- sent the exposure distribution in this theoretical popula- tion. Referral patterns to [he participating hospitals may differ for cases and controls because the participating hospitals were primary referral centers for osteosarcoma for lazge regions but the controls likely represented a more proximate population. Further, for some of the hospitals the referral base for controls could represent different socioeconomic populations than for cases. Distance from hospitals was used as a matching factor, to limit selection bias. This matching factor could also result in some overmatching on exposure, resulting in possible underestimation of the effect. Additionally, we included the 1989 median family income and county population as covariates. 427 For this study, cases of osteosarcoma that were diag- nosed at participating hospitals between November 1989 and November 1992 were identified. However, case and convol interviews took place later, between January 1992 and January 1995. Although efforts were made to inter- view aparent or proxy respondent if the subject was deceased or incapacitated, it is possible that cases with more favorable prognosis may have been over-sampled. If this occurred, an alternative explanation for our observa- tion is that boys exposed to higher levels of fluoride who subsequently develop osteosarcoma have a better prog- nosis than boys exposed to lower levels. While we cannot mle out this possibility, the magnitude of the protective effect that would be required to explain the observed association is unlikely. Differential recall of exposure information between cases and controls is unlikely in the current study because respondents did not provide information about the fluoride level in their drinking water but rather a complete resi- dential history. For other covariates, such as date of birth, sex, or zip code at time of diagnosis, information was obtained by medical record review. Reporting of [he type of water used or the use of self-administered fluotide products could be affected by recall bias. In summary, this exploratory analysis found an associ- ation between exposure to fluoride in drinking water and [he incidence of osteosarcoma, demonstrating a peak in the odds ratio for exposure at ages 6-8 yeazs among males diagnosed less than 20 yeazs old, but no consistent asso- ciation among females. Future studies would benefit from the inclusion of biomarkers of fluoride exposure and assessment of potential gene~nvironment interactions. Such studies with larger numbers of osteosarcoma patients, with incidence under age 20, that examine age-specific and sex-specific associations are required [o confirm or refute the findings of [he current study. Acknowledgements The authors acknowledge Manuela Orjuela, MD, ScM, for her contributions on a preliminary analysis. This work was supported by the National tnstimtes of Health Crant number 5- ROl FS06000. Dr Bassin was supported by National Research Service Award grant T32 DE07151-13. References I. Link MP, Eilber F (1997) Osteosarcoma. In: Pizzo PA, Poplack DG (eds) Principles and practice of oediatric oncology, 3rd edn. Lippincott-Raven Co., Philadelphia, pp 889-920 2. Dorfman EiD, Czemiak B (1995) Bone cancers. Cancer 75(Sup- plcment):203-210 3. Homa DM, Sowers MFR, Schwartz AG (1991) Incidence and survival rates of children and young adults with osteogenic sar- coma. Cancer 67:2219-2223 FL_I Springer ~~~~ Catalog ~ '1 Find a Dentist ~ ~ Seal Program ~ ®Contact Us ~ ~ ~~ a \ e ".`F~t?Pg lf". y DEf~1TALPROFE551DNA45 ~ THE ADA _ YdURQRALHEALTN~_~~, NEWS RELEASES Att#ttatiats & G~rteS __. _ _.. _ __ _._...__.. °'~ --~ ---~~- -~---~ -. Current Releases ^a'. Sign Up: Media E-mail List B.~ Careers I'n Dertti5try °' Arcnive Edttcatars Contact Information: ~~ & Students Telephone: 312-440-2806 E-mail: medlarelatons@ada.org (Journalists) or Contact ADA (All Others) En Espanol ~' ~ _. l`l` " " - `" Events -_. --~~- _~ ADA Reaffirms Support of Water Fluoridation ~ CHICAGO, A ril 7, 2006-After reviewin a recent! P g y published paper on a possible association ' ~', Manage Ynur ~' between fluoride in water and osteosarcoma (a rare form of bone cancer), the ADA remains Dral Health ' confident that community water fluoridation is a safe, effective public health measure for . ___., .. __.... preventing tooth decay. ' Media 1655 Rt7nln ' M~t4vf~ ~ The ADA agrees with the paper s authors that their work constitutes an "exploratory analysis° that will require scientific confirmation to conf nn or refute the findings. The data in this paper is nEVt5ReFnSES simply one piece of a much more comprehensive 15-year study by the Harvard School of Pt2ESSIQIS Dental Medicine scheduled for publication later this summer. The principal investigator of the larger Harvard study has advised against drawing conclusions before seeing the full study, TOpiC5 & RCSbUrteS which will not suggest an overall association between fluoride and osteosarcoma, he states. ° - Further, an "association" found in one, limited study, falls far below any scientific standard needed to establish accuse-and-effect relationship. In fad, after more than 60 years of rigorous scientific study of water fluoddation, the overwhelming weight of scientific evidences does not show an association with osteosarcoma. Bottom line: Nothing in this study should deter the public from continuing to enjoy the proven health benefits of optimally fluoridated water. About the American Dental Association The not-for-profit ADA is the nation's largest dental association, representing more than 155,000 dentist members. The premier source of oral health information, the ADA has advocated for the public's health and promoted the art and science of dentistry since 1859. The ADA's state-of-the-art research facildies develop and test dental products and materials that have advanced the practice of dentistry and made the patient experience more positive. The ADA Seal of Acceptance long has been a valuable and respected guide to consumer and professional products. http://www.ada.prg Return to Top ~ ADA Positions & Statements. ~ OraLHealth.TOpics '~ Video News Release;._Oral Can..cer Copyright 1995-2007 Amercan Dental Association. ~ Lnk opens in separate window. Reproduction or republicatior• strictly prohibited without prior wriHen permission. Pop-up Blocker may need to be disabled. See Privacy Polity (Updated 03!14(05) and Terms of Use for funher legal information. ® tdember only content. http://www.ada.org/public/media/releases/O604_release02.asp 6/8/2007 N » m° D ~~3na 5\n..a c°3 o w ~ ° n' T m > > m , . w o a °. m ~ ~ ~ O m ~ ~ N ~ W ~ N ep j'<m ma ~ ~ ~ ~ 0 O o Rv c ~~ n ~~m~ mm' c m m^e 0 0 0 a m a d ' , o ~ D~ a p m n n ` J ~ ~ 4 m ~Fd yCO p'9 C O C O ~ J, ~ F N T O O' ~ i p n O d O o"ep a £ °-' ~ w' 7 o u ~ 2 m 30a mom' n m' " ~' o =w ~ m N O A S i t~ a`; oe xsu>~.vNc ., ```fik ~9p i r, '~ O -p en. T ~ O T `~ (7 ~ 'O ~ ~ eD ~ m o y in< map a"'~».3 m N3 3~ ^.<~m°~ 3 C O ~QJ o O m C iC Q ~ O J l .~ ~ ~. A a j n ~ ~ T ~~ ~ ~ ~ O (p N < o m m ~ n N~ °' ~p n o d m m ^ ~ ~ R 3 d_n m D~ m Q J J ~ <., c J w o n o N G ~_Oi., A ~. d i d 3 m ~ < ~ " m ry J m ~-< 01 m m a 3° 3 N J ~ O .~+ a 3 a~ o y y ~ -w m O J O y~ O d m -p G om~a .mom ~ > o '~ o'0 3 m o- ~g5 J m-o m ~3'v a m_m m m ~oj.o~.o.°i3 ~ ~ ~ ? y o' ~ n n j C - 0 O m~ <3 n 0 m m 3 0~ o n n n ~ J o D `D o~~°~mm <3 y ~ W ., ~~ ° m J 3 m c ~ . a , . ~ ~ c `° °'~ 3 ~ ~ ;~ m 'zSO O. Vic- 0 7 rt '~ ~ O~ N~ .. m J J ~ o m ~ o ~ y S . o d `, D a S -^ ry N m S ~° o ~, m a m f/~1 ^ pOj O y i (D ~'O ~ N N J ~ ~ Q J ~ M m o p " N O. 3 - J' ~ '~ ma ~ °- ~J ~ o .. - ~ . s ~ ' 3 » o ' m J m n d n <o < N ~ o C ~ ~ N d d ° m J o m o _. ~ _ a3 J 5- d m o = ` a~~ya m o m n m " a m o ~ ~ v 3' ~ ~ o m J O //'~~L~ lL ~' O ' 1 A~` r z v C G C (D 7 e-i 3 0 h fU O a m ~ c ~ ' ° ° = ° » v o - O o ~ ~ ~ ~ a m ~ c m m a m o c °' 1 1 N N~ Q C O m~ C O. m a.0 J N~ C V 0 3~ 3 0 C (D O ~ C N m m H1 X, N O << Ji N C O G ti` d m N O m° O. ~. S O. ~ Lp O . m H m a m 0 i. ~ J m N S O m J O O_ N -°i. a<~ d 3 O. d N ~ N O :~ - ' a- 0 m ° D m y 3 .C N d 0 m d~ - +~ ~ N N C N ~ d~ J d ~ C m m Nd C 3 J a a F `m< p O O O ry 3 0 ». m N N y m `G < ~ . 0 ~ J V O ~ ^ n ~ 0 < C m N 3° C m J A N ~' m O YL~ a ~~ O a 3 m 7 <° a? O. c 3 S m~ m ~ N<~ m a g ~, ~ .. ° ' o o m 0 3 m F x m m- m a m o ? c ~ O J J J d .< , m y 3 y ~, d J E O ~ F J ~ N tp J S° j 2 ~ . . -~ C ° ~ m m ^ '< m - ~O fD m J w c ~ _ J a m tO ~ v , N o a o n o °- ~ ~ ~ .. ~ C ~ m c ~ d ~ ~ ~ ° ~ °J' ~ o ' ~ ~ 0 5 ~ 0 3 3 °• ~ m ' o ' - ° w ~ ' ~ a0 ~O m ., °i m° a y O C o "~ t<0 ~p ~. N a m m m m ~ a m "~ ~ ~° m u a m ~ o ~ y ~ s m< ~ ~° ' m a d a a 3- d 3? m a ~~ m ~ o m °- m w ~ v 5 ~ o .° m N N S ~ S ~. < S O N~ J » O J ° O J d m < O J 0 ~+ ~o ' _ J' .~ 3 S j N 3 ~O m N ~{ 1 O -I O a 7 O d fA fA T O' O O. d S T N 6 0 -I O C O S ~ 5 0~ m m- W O O D j N C? y~ C O N ~, ~ O S ^ O Q ~ ~ m °c ~ ~. °. m m, o N c ~ m n ~. N -~ ~-~ 5 c ~ d 3 m 3 ~ m 0 O O .~G y C ~~ ran d tp N m A~ N Q N V1 w O d .a0 Om O ~~ N~ ?. N (JD~ ?, <~ J m N d N ~ O N a J~~ N N am y V' ~. < t° ~°{ N t4 d 5 n 7 d Of O° m C 7 J J J O N N m?~_< N n d d d J O~ J J N d ~ (D m O N lP J° M S~ °- a V m R ~' .~ < d w N J d~ rt C d N m '* V O° O m y° O d d N n O~~ umi p nOi O O W ~. O O j 0 ~. 0 6 m a 3 m ~ 0~ ~ rJii ° ° 3 m 3 < ° °. x °, m ? < '_ _' d ~ m ~ a 3 N $ °m m ~ °-' van ~ o 'c' ° ~ 3 a `° 3 ,~°, c d~ m m <' ~ ~o ° c s a c' J i m x ?. a m < ,~ Q J °. N O I ,~ W J. - m d- d O J< m 3~ N _. a N m J < N 3 Q i ~ ~ y ~ 3 0~ 3 3 o o a r ~ m m d ^. ~<< a~ a N N ~ m ~ o ~ m ~ ° m~»~ d m m 3 3°~ m <a m `~ ~ ?~ m 2 ~~ 3 Z. -^ m [J .Ci N N N' W 'r' S y G p C C J m m G N C 3< N N A N° m m i C m n m a „~ 0 3 a a 'o m~~ »' `° m m °: o° 3 m F d a~ J ''' v a 3 ~ 3 m g o y o m m `~ °~° m m ~' o ~~ 3 m' m~ 3 ~ °. ~° w ^. m m< 3~ o m~ ~ N° o. a °1 m J d d- n O 2 0. ° 3 ~~ < m 'm 5 m m c~ s ~, d 3 3 3 ~ m d o? m o~ ~ ,°, n a 3 ~_ m a< w - o _a m o o ~n~ O m m j m°? c o p1 w m° n m `° m m m m in J o c ~~ m a x- m ° ~~~~~ American Dental Assoaation www.ada.or8 ADA Statement Commemorating the 60~" Anniversary of Community Water Fluoridation Sixty years ago, Grand Rapids, Michigan became the world's first city to adjust the level of fluoride in its water supply. Since that time, fluoridation has dramatically improved the oral health of tens of millions of Americans. Community water fluoridation is the single most effective public health measure to prevent tooth decay. Additionally, the Centers for Disease Control and Prevention proclaimed community water fluoridation as one of ] 0 great public health achievements of the 20`h century. Fluoridation of community water supplies is simply the precise adjustment of the existing naturally occurring fluoride levels in drinking water to an optimal fluoride level recommended by the U.S. Public Health Service (0.7 - 1.2 parts per million) for the prevention of dental decay. Based on data from 2002, approximately 170 million people (or over two-thirds of the population) in the United States are served by public water systems that are fluoridated. Studies conducted throughout the past 60 years have consistently indicated that fluoridation of community water supplies is safe and effective in preventing dental decay in both children and adults. It is the most efficient way to prevent one of the most common childhood diseases -tooth decay (5 times as common as asthma and 7 times as common as hay fever in 5- tol l-year-olds). Early studies, such as those conducted in Grand Rapids, showed that water fluoridation reduced the amount of cavities children get in their baby teeth by as much as 60% and reduced tooth decay in permanent adult teeth nearly 35%. Today, studies prove water fluoridation continues to be effective in reducing tooth decay by 20-40%, even in an era with widespread availability of fluoride from other sources, such as fluoride toothpaste. The average cost for a community to fluoridate its water is estimated to range from approximately $0.50 a year per person in large communities to approximately $3.00 a year per person in small communities. For most cities, every $I invested in water fluoridation saves $38 in dental treatment costs. The Americana Dental Association continues to endorse fluoridation of community water supplies as safe and effective for preventing tooth decay. This support has been the Association's position since policy was first adopted in 1950. The ADA's policies regarding community water fluoridation are based on the overwhelming weight of peer- reviewed, credible scientific evidence. The ADA, along with state and local dental societies, continues to work with federal, state, local agencies and community coalitions to increase the number of communities benefiting from water fluoridation. 2005 211 Eesl Chicago Avrnue Chicago, Illinois 6061 I-2676 p 312-040-2500 f i 12-040-]494