HomeMy WebLinkAboutCOUNCIL - AGENDA ITEM - 07/15/2003 - ITEMS RELATING TO THE FLUORIDATION OF THE CITYS DR AGENDA ITEM SUMMARY ITEM NUMBER: 24
DATE: July 15, 2003
FORT COLLINS CITY COUNCIL FROM: John Fischbach/
Mike Smith
SUBJECT :
Items Relating to the Fluoridation of the City's Drinking Water.
RECOMMENDATION:
The Fort Collins Water Board recommends that the City discontinue water fluoridation. The
Larimer County Board of Health and the Health District of Northern Larimer County recommend
continuing the practice of water fluoridation.
EXECUTIVE SUMMARY:
At the May 27, 2003 City Council study session, information on fluoridation was provided by the
Fluoride Technical Study Group (FTSG), the Fort Collins Water Board, the Health District of
Northern Larimer County and the Larimer County Board of Health.
As a result of the information provided to Council and the subsequent discussion at the meeting, a
majority of Councilmembers expressed an interest in:
1. Continuing, in general, the practice of water fluoridation; and
2. Having the staff research the possibility of reducing the amount of fluoride added to the
water. (Note: This research was completed and it was determined that there is insufficient
justification to lower the level of fluoride below 0.9 parts per million. The present level is
1.0 parts per million.)
Since the time of the meeting, the Council express an interest in taking formal action on the issue
of fluoridation with the consideration of the following two options:
Option A:
Resolution 2003-087 Accepting the Report of the Fort Collins Fluoride Technical Study
Group (April 2003) and Affirming the City's Present Practice of Water Fluoridation.
Option B:
First Reading of Ordinance No. 105, 2003,Amending Section 26-50 of the City Code so as
to Cease Fluoridation of the City's Water Supply.
DATE: July
ITEM NUMBER: 24
BACKGROUND:
In 1954, an ordinance was presented to the voters that would have allowed fluoridation. It failed.
In July, 1966, the City Council adopted a resolution authorizing fluoridation and directing the
Director of Public Works to fluoridate.
In September, 1966, a group of citizens petitioned the Council to adopt an ordinance prohibiting
fluoridation unless the voters approved fluoridation.Later that month,the Council adopted such an
ordinance.
In 1967, the Council submitted to the voters an ordinance authorizing the Council to add fluoride
to the water. The ordinance was approved by the voters. While this voter-approved ordinance
authorized fluoridation, it differed from the previous, Council-adopted ordinance in that it did not
direct the Utility to fluoridate the water.
The Council's authority to fluoridate was later added to the City Code, and the City began
fluoridating its water.
In 1986, as part of a recodification of the Code provisions dealing with water,another sentence was
added to the Code by the Council actually directing the Utility to fluoridate its water to the levels
established by the Colorado State Department of Heath.
Current Situation
In 2001, the Water Board was asked to review the issue of fluoridation of the city water supply and
to make a recommendation to City Council. After the Board's review,it recommended that the City
discontinue fluoridation. This recommendation prompted local public health professionals and local
dental care professionals to express concern about the lack of a scientific review of the health effects
of fluoridation. As a result, the City agreed to work cooperatively with the Health District of
Northern Larimer County (formerly the Poudre Health Services District) to evaluate the available
scientific information about the benefits and risks of water fluoridation. A Technical Study Group
was formed consisting of a variety of experts,advocates for and against fluoridation, and staff from
the City and the Larimer County Board of Health.
For over a year, the Technical Study Group reviewed and evaluated a vast amount of scientific
information regarding the benefits and risks of water fluoridation. The Study Group also conducted
four public meetings as part of its process of soliciting and reviewing information. In early 2003,
the Study Group completed its review and reported its findings to the Fort Collins Water Board,the
Larimer County Board of Health,and the general public. The Executive Summary and Introduction
of the report is attached. In brief, the Study Group found that:
• water fluoridation is an effective mechanism in reducing and preventing dental caries
(cavities);
• there does not appear to be any conclusive evidence of any significant health risks
associated with water fluoridation;
• it appears that the benefits of fluoridation exceed the associated costs; and
DATE: July
ITEM NUMBER: 24
• it does not appear that the contaminants normally found in hydrofluorosilicic acid
(I-1FS) used to fluoridate the city's drinking water pose a health risk to the
community.
As of this date,the Larimer County Board of Health,the Health District of Northern Larimer County
Board and the Fort Collins Water Board have reviewed the Study Group's findings and made
recommendations to the Fort Collins City Council. The Board of Health has recommended that the
City continue with water fluoridation (recommendation attached). The Fort Collins Water Board
has recommended that the City discontinue water fluoridation (recommendation attached). The
Health District of Northern Larimer County Board voted to strongly support the continuation of
water fluoridation (recommendation attached).
. Option "A"
RESOLUTION 2003-087
OF THE COUNCIL OF THE CITY OF FORT COLLINS
ACCEPTING THE REPORT OF THE FLUORIDE TECHNICAL STUDY GROUP
AND AFFIRMING THE CITY'S PRESENT PRACTICE OF WATER FLUORIDATION
WHEREAS, Section 26-50 of the City Code authorizes the City Council to fluoridate the
water supply system of the City and requires fluoridation of such water to the levels established by
the State Department of Public Health and Environment; and
WHEREAS, a question has arisen as to whether such fluoridation is in the best interests of
the City; and
WHEREAS, in order to address this question, the City's Water Board was asked to review
the issue of fluoridation and to make a recommendation to the City Council; and
WHEREAS,the Water Board has recommended that the City discontinue water fluoridation,
which recommendation is based upon considerations of health effects, the cost of fluoridating the
City's water supply, and concerns regarding the use of the City's water system to improve
community dental health; and
WHEREAS, to further study the question of fluoridation, the City, in cooperation with the
Health District of Northem Latimer County, formed a technical study group (the "Study Group")
consisting of a variety of experts,advocates for and against fluoridation,and staff members from the
City and Latimer County Board of Health; and
WHEREAS,the Study Group reviewed and evaluated a vast amount of scientific information
regarding the benefits and risk of water fluoridation and conducted four public meetings to solicit
public input on the subject; and
WHEREAS, in early 2003, the Study Group completed its review and reported its findings
to the Fort Collins Water Board,the Latimer County Board of Health,the general public and the City
Council; and
WHEREAS,the study group concluded that water fluoridation is an effective mechanism in
reducing and preventing dental caries(cavities),there does not appear to be any conclusive evidence
of any significant health risks associated with water fluoridation, it appears that the benefits of
fluoridation exceeded the associated costs, and it does not appear that the contaminants normally
found in hydrofluorosilicic acid(HFS)used to fluoridate the City's drinking water pose a health risk
to the community; and
. WHEREAS, the City Council has reviewed all of the information developed by City staff
and the Study Group in a study session on May 27, 2003; and
WHEREAS,after reviewing all the information,the City believes it to be in the best interest
of the City to continue fluoridation of the City's water supply.
NOW,THEREFORE,BE IT RESOLVED BY THE COUNCIL OF THE CITY OF FORT
COLLINS as follows:
Section 1. That the Council hereby accepts the report and recommendations of the
Fluoride Study Group dated April, 2003.
Section 2. That the Utilities General Manager is hereby directed to continue fluoridation
of the City's water supply at such levels as he may deem appropriate, within the limits established
under Section 26-50 of the City Code.
Passed and adopted at a regular meeting of the Council of the City of Fort Collins held this
15th day of July, A.D. 2003.
Mayor
ATTEST:
City Clerk
2
ORDINANCE NO. 105, 2003 Option `B"
OF THE COUNCIL OF THE CITY OF FORT COLLINS
AMENDING SECTION 26-50 OF THE CITY CODE SO AS
TO CEASE FLUORIDATION OF THE CITY'S WATER SUPPLY
WHEREAS, Section 26-50 of the City Code authorizes the City Council to fluoridate the
water supply system of the City and requires fluoridation of such water to the levels established by
the State Department of Public Health and Environment; and
WHEREAS, a question has arisen as to whether such fluoridation is in the best interests of
the City; and.
WHEREAS, in order to address this question, the City's Water Board was asked to review
the issue of fluoridation and to make a recommendation to the City Council; and
WHEREAS, to further study the question of fluoridation, the City, in cooperation with the
Health District of Northern Larimer County, formed a technical study group (the "Study Group")
consisting of a variety of experts,advocates for and against fluoridation,and staff members from the
City and Larimer County Board of Health; and
WHEREAS,the Study Group reviewed and evaluated a vast amount of scientific information
regarding the benefits and risk of water fluoridation and conducted four public meetings to solicit
public input on the subject; and
WHEREAS, in early 2003, the Study Group completed its review and reported its findings
to the Fort Collins Water Board,the Larimer County Board of Health,the general public and the City
Council; and
WHEREAS, the Study Group concluded that water fluoridation is an effective mechanism
in reducing and preventing dental caries (cavities), there does not appear to be any conclusive
evidence of any significant health risks associated with water fluoridation,it appears that the benefits
of fluoridation exceeded the associated costs,and it does not appear that the contaminants normally
found in hydrofluorosilicic acid(HFS)used to fluoridate the City's drinking water pose a health risk
to the community; and
WHEREAS, notwithstanding the findings of the Study Group, the Water Board has
recommended that the City discontinue water fluoridation,which recommendation is based not only
upon considerations of health effects but also upon the cost of fluoridating the City's water supply
and the Water Board's concerns regarding the use of the City's water system to improve community
dental health; and
WHEREAS, the City Council has reviewed all of the information developed by City staff
and the Study Group in a study session on May 27, 2003; and
WHEREAS, the City Council has concluded that it is in the best interests of the City to
discontinue fluoridation.
NOW,THEREFORE, BE IT ORDAINED BY THE COUNCIL OF THE CITY OF FORT
COLLINS that Section 26-50 of the Code of the City of Fort Collins be amended so as to read in its
entirety as follows:
Sec. 26-50. Fluoridation.
city.The afflity is directed to fluotidate its wate, to the levels established by the state
Department of Pubfic Health and Environment. The City shall not fluoridate the
water supply system of the city.
Introduced,considered favorably on first reading,and ordered published this 15th day of July,
A.D. 2003, and to be presented for final passage on the 19th day of August, A.D. 2003.
Mayor
ATTEST:
City Clerk
Passed and adopted on final reading this 19th day of August, A.D. 2003.
Mayor
ATTEST:
City Clerk
2
Utilities
light & power stormwater • wastewater • water
YAMft
City of Fort Collins
Water Production Department
Memorandum
Dater June 16,2003
To: Michael B. Smith, Utilities General Manager
Brian Janonis,Water Resources and Treatment Manager
Fran Kevin R.Gertig,Water Production Manager��
Rr. Fluoridation Questions
On May 28, 2003, 1 received a request from City Council to respond to three questions
regarding our fluoridation program. The Center for Disease Control Oral Health Program
(CDC)and other sources were consulted for credible information through this process. Data
for attachments are from the Fort Collins Utilities(FCU)laboratory and plant records,and the
• Colorado State University Atmospheric Research Center. Each question is stated as
presented with a response for each area. Graphs and/or data are attached for each question
for ease of interpretation.
1) Is there a level lower than 1.0 mg/L that we could recommend when we consider all of
the other sources of Fluoride?
Answer: The amount of scientific and medical information required to answer this
question is beyond the expertise of Fort Collins Utilities staff. Staff does not have a
recommendation for reduction of fluoride levels given other sources of fluoride.
Note: In evaluating the level of Fluoride, we evaluated the optimal Fluoride levels
based on Center for Disease Controls oral health recommendations. As can be
observed on Attachment A and B, there appears to be a warming trend (1999 —
2002)and this data suggests that we may be able to reduce the level by 0.1 mg/L
and still maintain the optimal level as recommended by CDC. It is important to note
that while we do not feel qualified to reduce the levels per the question stated
(including other sources of Fluoride),we may wish to evaluate the decrease of 0.1
mg/L based on current temperature trends. This would mean our target level
would be 0.9 mg/L verses the current 1.0 mg/L level.
•
4'1b lV. LaPorte Avenue • 1=url Collins, CO W521 • (970) 221-66911 • FAX (970) 21-6736• TDD (11701 224-6003
e-mail: utilities(ici.fort-collins.co.us
6/5/2003 Interoffice Memo: Fluoridation Questions 2
2) How much variation is there from the target level of 1.0 mglL?
Answer. The variation is typically +/- 0.2 mgIL from the target of 1.0 mg/L Data
suggests that FCU tightly controls the level near the 1.0 mg/L target as shown with the
cluster of data on the attachment. Fluoridation monitoring is sent to Colorado
Department of Health and Environment, Oral, Rural, and Primary Care Section
(CDH&E)each month.
See attachments C and D.
3) What is the status of Lead(Pb)in the distribution system?
Answer. The lead levels in the distribution system continue todecr ase over lime. As
to the USEPA action
can be observed, the concentrations are quite low compared
level.
Attachment E shows the trends for raw water. Note that the low levels are below
detection for the raw water as well as water leaving the water treatment facility.
Attachment F shows the trends for the time period from 1992—2002. All data is from
Qualitythe City of Fort Collins Water
Lead and Coppe Rule Survey Results thro throughout e sites shown are for
ut our distributionsystem
Feel free to contact me at extension 6637 if you have further questions regarding these
questions.
KRG(c
Attachments
Cc: File
ATTACHMENT A
Fluoridation Questions
Optimal Fluoride Levels
Based on CDC Recommendations and Fort Collins Air Temperatures
Fen Collins Average Mexpnum Daily Tempaatum(1960.2002)
Ke
Ws
me
uommmded
umide Level 0e.e
.9 m "a
no
n0
ass
no
$1.5
01.0
e0.5
90.0
se.s
0.0
ses
soul
1
(2) TABLE 2. Recommended-optimal-fluoride-levels-for-community public-water supply systems-(31 32)
- ----
Annual average of maximum daily Recomended Recommended control range
air temperatures (8,9) fluoride (mg/L) 0.1-0.5
------------------------------- concentrations -------------------------
F C (mg/L) Below Above
--------- ----- ------------ ----------------
50.0-53.7 10.0-12.0 1.2 1.1 1.7
53.8-58.3 12.1-14.6 1.1 1.0 1.6
58.4-63.8 14.7-17.7 1.0 0.9 1.5
63-.9-70.6 17.8-21.4 0.9 0.8 1.4
70.7-79.2 21.5-26.2 0.8 0.7 1.3
79.3-90.5 26.3-32.5 0.7 0.6 1.2
---------------------------------------------------------------------------------------------------
• Based on temperature data obtained for a minimum of 5 years.
(1) Based on weather data provided by CSU.
(2) Centers for Disease Control and Prevention.Engineering and administrative reoommendatians for water fluoridation,1995.MMWR
1995,44(No.RR-13):page 8,Table 2)
IIIIIIIIIIIIIIIIIIIIII IIIIIIIIIIIII II IIIIIIIIIIII ill �i iiiiliil
2002 Water Fluoride Monthly Averages
In-House Target
1.20
1.00
0.80 ---- •- ---- ---- ----- - ------ - ----- -- - - -- - --• - -- - --- ---- - -- •-- - - --- - --- ---- --- --• - - --- --- ---- --- ------
tm
E
m0.80 ---- -- - - - --• - -- - - --- • ------ - ---- - - • - - •- - - -- - - - - --- • --- - -- - --- • •• - - - • -- -- - - -- - -- - --- - --- ---- --- ---- -
a
0
LL 0.40
0.20
0.00
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
0
tHT Raw —APR Raw m a
Finished Water —in House Target y
1 a
x
tg �7 x
p H
m n
ATTACHMENT D
Fluoridation Questions
• y
Day Mo Yr
1 1.02 595.31 17.145 5 2003
2 0.86 696.21 19.687
3 0.89 696.21 19.651
4 0.89 686.12 19.445 Pounds O Gallons
5 1.01 686.12 19.590 ® Pounds
6 0.99 635.67 18.355 =
7 1.02 615.49 17.522 10.19 mg&
8 1.03 615.49 17.574 IYour dosage•your optimum-your background
9 1.04 615.49 17.252 fluoride level)
10 1.05 615.49 17.392
11 0.95 635.67 18.066
12 1.00 686.12 18.940 H2SiF6 O HaF
13 1.00 827.38 22.853 O Na25F6
14 1.04 827.38 23.115 p H2SF6
• 15 1.05 787.02 21.847
16 1.00 676.03 18.674
17 0.98 665.94 18.734 ISE Electrode
18 1.06 766.841 16 ISE Electrode
19 1 1.041 817.291 O SPADNS Cciorimetric
20 0.89 716.39 19.187
21 0.91 746.66 20.346
22 1.05 998.91 26.788
23 1.01 1019.09 27.088
24 1.00 1009.00 26.994
25 1.00 1019.09 27.454
26 1 1.04 837.47 21.998
27 1.03 746.66 20.142
28 1.02 1220.89 33.222
29 0.98 1301.61 35.500
30 1.01 1099.81 29.794
31 0.90 857.65 1 23.474
Submitted By:
Avo 1 1.001 797."1 21.989
• Email: dan.felzienQstate.co.us
High 1.06 1301.61 35.500 Fluoridation,Co Dept of Public Health
4300 Cherry Creek Dr South
Low 0.89 595.31 17.145 Denver,Co 80z46-ts3o.
FCU WQ Lab data 2001 -2002
Lead Concentrations
16
14
L 12
10
N
8
O
L 6
4
2
a
0
w a
Poudre Raw H.T. Raw Finished (SS#2) MCL N
pa
(IAoRSE7ooTH WA76R) _ CMA%IWUW CONTAW iNANT lC'UFL
N Cj
p: z
ATTACHMENT F
Fluoridation Questions
City of Fort Collins Copper & Lead Survey Results 1992 - 2002
Lead, ppb Copper, ppb
14 ppb= parts per billion
1400
USEPA 90th %tile Action Levels
12 Copper= 1,300 pp 1200
10 Lead = 15 ppb 1000
8 800
6 600
90th %tile highest values of all City results
4 400
2 200
0 0
1990 1992 1994 1996 1998 2000 2002 2004
-W Year vs Lead, ppb
-♦— Year vs Copper, ppb
•
THE FLUORIDE TECHNICAL STUDY GROUP
Executive Summary
The Fluoride Technical Study Group(FTSG)was charged with compiling a report that assesses risks and
benefits of community water fluoridation in order to assist risk managers(The Larimer County Board of
Health,the City of Fort Collins Water Board,and the Fort Collins City Council)to decide whether to
continue, alter or discontinue the City's water fluoridation program.
A more complete discussion of the FTSG's work and a description of the studies and findings are
contained in the attached report. This summary begins with five of the most important considerations
underlying,the report and its findings, and then presents the findings themselves:
These are some of the essential considerations:
The FTSG elected to use a tiered approach to reviewing the existing literature on water fluoridation,
turning first to already conducted and published scientific literature research reviews and
compilations. Only when a gap in the data became evident or when a specific need for more
information was needed did the group turn to and evaluate published,peer-reviewed primary
studies.
2. The FTSG, for the most part, limited consideration to scientific studies of drinking water
fluoridation at or around I milligram per liter(mg/L)or 1 part per million(ppm),because it is the
target amount of fluoride added to the City of Fort Collins water supply(range of 0.7— 1.2 mg/L
with data indicating stringent control at 1.0 mg/L).
3. The levels of fluoride in untreated water range from 0.15 -0.25 mg/L fluoride ion. If the City
were to end its water fluoridation program, the drinking water in Fort Collins would continue to
contain some fluoride.
4. The United States Environmental Protection Agency (EPA),under the Safe Drinking Water Act
(42 USC 300), promulgates the National Primary Drinking Water Regulations. These regulations
set the maximum contaminant levels (MCLs) for chemicals in finished water supplied by public
water systems. The EPA has established an MCL for fluoride of 4.0 mg/L.
5. The FTSG endeavored to create a balanced product for use by decision-makers that took into
account the most current and best available analysis of the weight of the scientific evidence on the
risks and benefits of community water fluoridation.The group also acknowledged that there are
gaps in the knowledge and uncertainties are inherent in the ability to fully understand what may
be subtle,yet important health effects that are yet to be detected via a weighted evidence
approach. Thus,the report includes stated uncertainties and areas where additional research is
needed to better understand the true benefits and risks.
FINDINGS
After considering public concerns and discussion—then focusing—the list of important questions,the
FTSG has developed consensus findings in four categories:
The effectiveness of drinking water fluoridation.
2.The risks of drinking water fluoridation and of cumulative exposure to fluoride from all sources,
including drinking water(over time)with specific attention to cancer,bone fractures, skeletal
fluorosis,dental fluorosis,thyroid function,and immune system effects.
Executive Summary iii
3.The costs and benefits of fluoridating the drinking water supply,and of not fluoridating the
drinking water supply, including assessing the distribution costs and benefits(equity),and
including the costs and benefits of using alternative methods to deliver fluoride.
4.The potential for increased contaminant levels in the drinking water due to the use of
hydrofluorosilicic acid in the fluoridation process.
Finding#1 The Effectiveness of Drinking Water Fluoridation in Preventing Caries(Cavities)
The weight of the evidence suggests that there is caries(cavities)reduction in populations exposed to
water fluoridation at or near an optimal level.The primary mode of action of fluoride in preventing caries
is its topical action on the surface of the teeth; systemic action from ingestion is now thought to play a
minor role. It appears that community water fluoridation is effective in all age groups in preventing dental
caries. This benefit amounts to a relative caries reduction of 25% and an absolute prevalence difference of
1.14 surfaces with caries in primary teeth and 0.5 surfaces with caries in permanent teeth in children
according to the most recent U.S. surveys of schoolchildren.Among the four studies of caries prevention
in adults,the most recent study showed that community water fluoridation reduced surfaces with caries by
0.35 surfaces per year of fluoride exposure. The benefit of drinking water fluoridation decreases as
individuals in the population receive fluoride from other sources(e.g.,toothpastes,dental care,etc.). Even
with the limitations of some of the studies,there appears to be a net benefit in caries reduction from
drinking water fluoridation over and above that from toothpaste and other sources of fluoride. Among the
14 recent studies(completed after 1985)reviewed in which water fluoridation was discontinued,nine
showed an increase in caries rates. Five communities(all of them in other countries)that suspended water
fluoridation did not find that caries rates increased. It is uncertain to what degree changes in oral health
behaviors, introduction of new preventive programs and increased delivery of professional treatments in
response to cessation of fluoridation can account for these findings. Since these studies were conducted in
foreign communities in which there was socialized dental care and school-based oral health programs,
their results may not apply to Fort Collins.
Finding#2—The Risk of Drinking Water Fluoridation
Total Fluoride Exposure
Total fluoride exposure must be considered when evaluating health effects. The amount of total fluoride
ingested will vary between individuals and is not precisely known. The FTSG review of the literature
finds that likely total exposure values for children older than six months living in communities with water
fluoridated 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 reconstituted with optimally fluoridated water.
Cancer
Although a small increase in cancer risk cannot be excluded,there is no consistent evidence from human
or animal studies that exposure to optimally fluoridated drinking water and other sources causes any form
of cancer in humans,including bone and joint cancer.The agreement between the epidemiological and
toxicological literature reduces the uncertainty associated with any one line of evidence finding.
Additional research is needed to address the remaining uncertainty whether community water fluoridation
may cause cancer in humans following long-term exposures of greater than 40 years.
Bone Effects
The FTSG agrees with the conclusion of the Medical Research 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).
iv Report of the Fort Collins Fluoride Technical Study Group—April 2003
•
Skeletal Fluorosis
At the concentrations of fluoride provided in Fort Collins water including exposures from all sources over
a lifetime, skeletal fluorosis caused by drinking water exposure is not likely to be a health issue. The
available data are not consistent with a likelihood of increased human skeletal fluorosis from city water
fluoridation.
Additional research is needed to reduce the remaining uncertainty if cumulative exposure to all sources of
fluoride(including drinking water fluoride at levels of I mg/L)over a lifetime may lead to pre-clinical or
milder forms of skeletal fluorosis in some sensitive populations
Dental Fluorosis
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. Since about 60% of dental fluorosis can be attributed to other sources of fluoride,particularly
toothpaste and other dental products,parental supervision over tooth paste swallowing in their young
children and proper prescribed supplementation in infants will likely reduce development of enamel
fluorosis more than the removal of added fluoride in drinking water.
Thyroid Effects
In the literature reviewed,doses appropriate for caries reduction were not shown to negatively impact
thyroid function. Studies in which humans received doses significantly higher than the optimum fluoride
intake for long periods of time showed no negative impact on thyroid function. For those with
. hypothyroidism,the risks of alteration of thyroid structure or function are very low. The absence of our
finding any conclusive evidence that drinking water fluoride exposures causes increased risk to thyroid
function does not prove that fluoride can not affect thyroid function. The available data are consistent
with a finding of a low likelihood of risk to human thyroid function from water fluoridation.
Immunological Effects
Overall, evidence is lacking that exposure to fluoride through drinking water causes any problems to the
human immune system. The absence of our finding any conclusive evidence that drinking water fluoride
exposures causes increased risk to human immune system function does not prove that fluoride is
harmless to the human immune systems.
Other Health Effects
The potential for other health effects was reviewed by the FTSG. There was not adequate evidence to
consider any of these other potential adverse effects a concern with respect to fluoridation of Fort Collins
water supplies. The absence of our finding any conclusive evidence that drinking water fluoride
exposures causes other potential health effects does not prove that fluoride can not cause other potential
health effects.
Findina #3—Costs and Benefits, Including the Distribution of Costs and Benefits
The research indicates that the public health goal of a reduction in the incidence of caries is better
achieved through community water fluoridation than through individual approaches. It requires minimal
behavioral changes compared to alternative delivery methods. It is effective in reaching people in all
socioeconomic strata.
The FTSG finds that,even in the current situation of widespread use of fluoride toothpaste and lower
baseline caries risk, it is likely that community water fluoridation remains effective and cost saving at
preventing dental caries. Based on best available evidence, suspending fluoridation of water in Fort
Executive Summary v
Collins would yield a net increase in costs of preventing and treating caries of approximately$4.25 per
person per year(range$3.22 -$10.31). The burden of caries is disproportionately home by those with
lower socio-economic status.There is some evidence that water fluoridation reduces this inequality in
oral health.
Not considering the costs of enamel fluorosis or other potential adverse health effects may have led to an
over-estimation of the cost-savings of water fluoridation in Fort Collins.The magnitude of the costs of
adverse effects is likely to fall well below the estimated net savings.
In summary,this cost analysis assumes that there is a significant benefit from community water
fluoridation in preventing caries and that suspending community water fluoridation would result in a
relative increase in caries. It also assumes that potential adverse health effects are not significant. The
analysis also assumes that the city will continue using current fluoride additives(hydrofluorosilicic acid).
Using this set of assumptions,there appears to be a net cost benefit to community water fluoridation. If
any of these assumptions are not valid the cost-benefit picture could change significantly.
The FTSG did not review any study or measure that will achieve the same levels of prevention as water
fluoridation for the same resources.
Finding#4—The Potential for Increased Contaminant Levels Due to the Use of
Hydrohuorosilicic Acid
The FTSG's review identified three potential concerns associated with hydroflumosilicic acid(HFS). 1)
co-contamination(i.e. arsenic and lead),2)decreased pH leading to increased lead solubility or exposure,
and 3)potential toxicological effects from incomplete dissociation products of HFS.The FTSG used the
raw and finished water quality data for the City of Fort Collins to determine whether the addition of HFS
was responsible for the potential addition of contaminants such as heavy metals to the city's drinking
water.There was no evidence that the addition of HFS increased the concentrations 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 water appreciably. 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
exposure to any of these chemicals present in the water as it leaves the plant. Further studies related to the
health effects of HFS are in progress.
vi Report of the Fort Collins Fluoride Technical Study Group—April 2003
Introduction
In response to questions from the public about the risks,benefits and costs of community drinking water
fluoridation,the City of Fort Collins convened the Fluoride Technical Study Group(FTSG)to fulfill the
following responsibility:
• To explore information related to the costs and benefits of community drinking-water
fluoridation;
• To summarize what is known and not known about the risks and benefits of adding fluoride;
• To summarize what is known and not known about the risks and benefits of not adding fluoride;
• To develop and present findings;
• To base findings on the high quality scientific and technical information;
• To work toward consensus findings whenever possible;
• To clarify areas of agreement and of disagreement about the implications of the information;
• To integrate public input into the recommendations;and
• To present data,consensus findings and areas of disagreement to the Board of Health and the
Water Board so that these two boards can offer informed recommendations to the Fort Collins
City Council.
The Fluoride Technical Study Group(FTSG) includes nine community members with an interest in the
questions surrounding community drinking water fluoridation and with specific technical, medical or
scientific capabilities. The FTSG members are:
Ed Carr, DC, MS Gale McGaha Miller,BS
Chiropractor and Wellness Counselor Water Quality Services Manager
Fort Collins Utilities
Bruce Cooper, MD, MSPH
Medical Director Rami Naddy,PhD
Health District of Northern Larimer County Environmental Toxicologist
ENSR International
Greg Evans, DDS Member of City of Fort Collins
Pediatric Dentist Water Board
Kevin Gettig John Reif, DVM,MSc(Med)
Certified Colorado Water Works Professor
Operator A Department of Environmental Health
Water Production Manager Colorado State University
Fort Collins Utilities Water Treatment Plant
Frank Vertucci,PhD, MS
Adrienne LeBailly, MD,MPH * Certified Senior Ecologist
Director, Larimer County ENSR International
Department of Health and Environment Vice President of the
Larimer County Board of Health
*Although Dr. LeBailly's workload necessitated that she withdraw from the review process in Summer 2002,she
was very active in early meetings and helped establish guidelines and review criteria. She has continued to follow
the group's proceedings.
Introduction I
Process
The Fluoride Technical Study Group(FTSG)met monthly as a full group,once each month,between
December 2001 and November 2002. During the report drafting process in the latter half of 2002,smaller
subsets of FTSG members met frequently to draft various sections of this document.The FTSG met three
times in December of 2002 to reach final consensus on the document. In addition,the FTSG held two
public meetings in early 2002 to invite input and advice from the public before beginning its work,and
two in early 2003 to present and discuss report findings.
Throughout the process,the FTSG encouraged ongoing public input.Of particular note is the fact that at
least one-third of the FTSG members examined every technical study,journal article,newspaper article or
videotape submitted by members of the public. All nine members reviewed those public submissions
deemed by any one member to be of significant scientific or technical merit, and therefore worthy of
inclusion in the FTSG deliberations. The technical and scientific information was assembled,reviewed
and distributed to the FTSG by Susan Hewitt of the Health District of Northern Larimer County,who also
assisted in editing and preparing the final draft report.
The FTSG also made efforts to keep the public informed of the work that was being accomplished.All
FTSG meetings were open to the public, although no public comment was taken at these meetings.
Summaries of the public meetings and the FTSG meetings were posted on a website maintained by the
Fort Collins City Utility Department. Additionally,three sets of the reference materials used by the FTSG
were available for review by members of the public at three locations in Fort Collins.
Priorities
In its earliest meetings(and after public meetings that elicited important topics)the FTSG prioritized the
key questions and centered its inquiry on developing findings in response to these priorities.The FTSG
reviewed the scientific and technical literature for information about seven topics, six broad topics and
one specific to a single disease end point:
• The effectiveness of drinking water fluoridation
• The risk of drinking water fluoridation
• The risk of cumulative exposure to fluoride(over time) from all sources, including drinking
water,
• The costs and benefits of not fluoridating the drinking water supply, including assessing the
distribution costs and benefits(equity)
• The effectiveness of alternative methods of delivering fluoride
• The effectiveness of addressing fluoridation as a public health issue and the effectiveness of
addressing fluoridation as an individual choice
• The risk of impacts to thyroid function due to drinking water fluoridation
After generating its initial draft of this report,the FTSG has consolidated its findings into these four
topics:
1. The effectiveness of drinking water fluoridation.
2. The risks of drinking water fluoridation and of cumulative exposure to fluoride from all sources,
including drinking water,over time(with specific attention to cancer,bone fractures,skeletal
fluorosis,dental fluorosis and thyroid function).
3. The costs and benefits of fluoridating the drinking water supply, and of not fluoridating the
drinking water supply,including assessing the distribution costs and benefits(equity),and
including the costs and benefits of using alternative methods to deliver fluoride.
4. The potential for increased contaminant levels in the drinking water due to the use of
hydrofluorosilicic acid in the fluoridation process.
2 Report of the Fort Collins Fluoride Technical Study Group—April 2003
• Technical Study Group Literature Review Method
From the start, it was acknowledged that the published scientific literature base on community water
fluoridation was enormous and that it was beyond the scope of this group to conduct a systematic review
of thousands of primary studies.The FTSG elected to use a tiered approach to reviewing the existing
literature on water fluoridation,turning first to already conducted and published scientific literature
research reviews and compilations. Only when a gap in the data became evident or when a specific need
for more information was needed did the group turn to and evaluate published,peer-reviewed primary
studies. Initially,a half dozen comprehensive literature reviews were located and shared by the FTSG,
with additional studies and compilations located during the process.Ultimately,a tiered arrangement of
the literature utilized by the FTSG was compiled.
• "Tier One" literature were those by well-known,authoritative and unbiased national and
international public health agencies such as the United States Public Health Service,the World
Health Organization,the United States Centers for Disease Control and Prevention,the National
Institutes of Health,the Medical Research Council of Great Britain, and the British National
Health Services Centre for Reviews and Dissemination.
• The next tier included:
• Published literature reviews and meta-analyses.
• Reports of primary studies published in peer-reviewed journals that were used to fill data
gaps or when additional explanation was needed.
• Literature reviews conducted by or contracted by municipal, provincial,or other local
governmental entities that were used for local decision making. These were primarily used to
identify "Tier One"studies and primary literature.
• Other materials considered by the FTSG included editorials,commentary and fact sheets, some of
which were supplied by members of the public.
Concerning"Tier One"and other literature,each of these studies used different search and review
strategies. Some used explicitly stated and highly systematic methods to evaluate the scientific merit of
studies, while others used more implicit and more subjective methods such as relying on an evaluation of
the quality of the literature by subject matter experts.The tiered reference list is provided in Appendix A-
1. Additional information on the search and review strategies of many of the tier one literature and other
documents is presented in Appendix 1.
Study Criteria
The FTSG, for the most part, limited consideration to scientific studies of drinking water fluoridation at
or around I milligram per liter(mg/L)or 1 part per million(ppm),because it is the target amount of
fluoride added to the Fort Collins city water supply(range of 0.7— 1.2 mg/L with data indicating stringent
control at 1.0 mg/L). In some cases,studies where experimental animals were dosed at a higher level or
human epidemiological or pharmacological studies of populations exposed to higher doses of fluoride
were considered by the FTSG to better understand potential cumulative or dose-dependent effects.
Please note the terms part per million(ppm)and milligrams per liter(mg/L)are used interchangeably
throughout this report.They are more or less equivalent and each term is used by the literature cited by
the FTSG. In layman's terms I ppm or I mg/L fluoride represents one"drop"of fluoride in one million
"drops"of water.
Weight of Evidence Approach With Uncertainties
Members of the FTSG used the weight of evidence approach in evaluating scientific studies. The EPA
defines the weight of evidence approach as"Considerations in assessing the interpretation of published
• information about toxicity---quality of testing methods,size and power of study design,consistency of
results across studies,and biological plausibility of exposure-response relationships and statistical
Introduction 3
associations"(htti)://www.el2a.gov/OCEPAterm Thus,all the scientific literature on a topic is
evaluated,with studies categorized into levels of better and lesser studies based on such variables as
degree of measurement accuracy,number of study subjects,how data was collected,control of potential
confounding factors and so on. The best studies get the most weight and the poorer studies less weight or
disqualification if a certain standard is not met. Particular attention is given when multiple studies,by
different researchers,using different methods, in varied population groups reach similar conclusions.
Such findings generally corroborate hypotheses and are particularly useful when looking for subtle health
changes due to the large numbers of subjects measured.The converse is also important, if multiple studies
show contradictory positive or negative effects then no overall effect is discernable and hypotheses may
be refuted before a link is made to potential harm or benefit.The FTSG acknowledged uncertainties are
inherent when scientific literature is evaluated.
Some members advocated for the precautionary principle,defined by the EPA as"When information
about potential risks is incomplete,basing decisions about the best ways to manage or reduce risks on a
preference for avoiding unnecessary health risks instead of on unnecessary economic expenditures"
(http://www.epa.izov/OCEPAterms/). In other words,to assist the risk managers,the weight of evidence is
considered as well as the magnitude of the calamity that a worst-case scenario may produce if the
evidence is flawed or inaccurate.
The FTSG endeavored to create a balanced report for use by decision-makers that took into account the
most current and best available analysis of the weight of the scientific evidence on the risks and benefits
of community water fluoridation. The group also acknowledged that there are gaps in the knowledge and
uncertainties are inherent in the ability to fully understand what may be subtle,yet important health effects
that are yet to be detected via a weight of the evidence approach.Thus,the report includes stated
uncertainties and areas where additional research is needed to better understand the true benefits and risks.
Strengths and Limitations of Epidemiology and Toxicology Approaches
The potential risks of exposure to fluoride among human populations can be evaluated in essentially two
ways. In the first approach, laboratory animals are tested under controlled conditions and exposed to
known quantities of fluoride in water or food for varying lengths of time. Toxicological studies attempt to
derive dose-response relationships between exposure to fluoride and some measure of organismal
response. Measured responses may include mortality,changes in growth, reproductive capacity or the
incidence of cancerous lesions. In some studies, rodents are exposed over their entire lifetime,up to two
years. These studies typically include histologic examination of tissues at the end of the study to detect
microscopic lesions in multiple organs. Doses of fluoride given to animals are often much higher than
doses that would typically be encountered by a person.
Extrapolation of dose-response toxicity tests in animals to the prediction of human risks from drinking
water exposure to fluoride is complicated by many factors. Findings must be extrapolated between the
differences in doses used in animal studies and the range of human exposures associated with the
consumption of Img/1(Ippm)of fluoride in fluoridated drinking water.Animal responses can vary
compared to human responses,and there is always uncertainty associated with extrapolation from test
species like rodents to humans. Absence of a dose-response relationship between a stressor and a response
is considered strong evidence that the stressor is not likely to cause a response.However,the absence of
any observed dose-response relationship between a stressor and a response does not prove that the
stressor cannot cause a response.
The second approach to assessing risk to humans incorporates epidemiologic studies of human
populations.These studies involve comparing the incidence of various potential health effects among
populations exposed or not exposed to fluoride or comparing the frequency of exposure to fluoride among
persons with and without a certain disease. The advantages of the epidemiologic approach are that they
4 Report of the Fort Collins Fluoride Technical Study Group—April 2003
. are conducted in the species of interest(humans),the exposures are at relevant levels and the study is done
by observational,rather than experimental methods under"natural"conditions.
The disadvantages of epidemiologic approaches are that they may make it difficult to accurately assess
exposure over time due to lack of individual level data about diet,water consumption patterns,fluoride
concentrations,etc. These studies are also subject to a variety of biases found in observational research.
Principal sources of bias in epidemiologic studies include 1)confounding-where there may be exposure
to another variable that may be more common among those exposed that is also a risk factor for the
disease,resulting in an over- or under-estimate of the true risk; 2)selection bias due to an inability to
study entire populations, resulting in a biased sample of participants whose exposures or disease patterns
are not representative of the population from which they are drawn; and 3) information bias,where
information about exposures, outcomes or other factors may be inaccurate due to problems with recall,
residential mobility, lack of adequate exposure data and other data inadequacies.
The FTSG reviewed the toxicological and epidemiological studies as independent lines of evidence. The
weight of evidence findings are stronger when the toxicological and epidemiological studies agree.
However,either line of evidence may carry enough weight on its own to be convincing as to the benefits
or risks of a particular substance. In one example,the EPA's recent ruling to lower the maximum
contaminant level for arsenic in drinking water from 50 µg/liter to 10 µg/liter came solely from
epidemiologic studies indicating an increased risk of cancer in exposed human populations. Also in the
cancer arena, toxicological evidence may stand alone if a substance is tested repeatedly in several
experimental test species(such as rats,mice, and hamsters)at suitable doses, and a specific cancer is
detected consistently in a sufficient proportion of test animals.The toxicological evidence is much
stronger when the same substance is also shown, in a variety of genetic test systems,to have DNA-
damaging effects (genotoxicity)that have been associated with cancer in humans.
Risk and Benefit Assessment and Risk Management
The charge of the FTSG was to compile a report that assessed risks and benefits of community
water fluoridation in order to assist the risk managers(i.e.,the Latimer County Board of Health,
the City of Fort Collins Water Board, and the Fort Collins City Council).The FTSG found the
following explanation of risk management by the Medical Research Council of Great Britain to be
particularly useful:
"Once the risks and benefits have been assessed,this information must be set alongside other
considerations, such as the financial cost of the policy or action, and a decision then made
on whether to implement the change. This is not simply a matter of science—it involves
value judgments, and individuals may weight the risks,benefits and attendant uncertainties
differently. If the decision must be taken at the community level(as with water
fluoridation), it often falls to democratically elected representatives and may follow wider
public consultation and debate" Reference cited:Medical Research Council(2002)
Working Group Report: Water Fluoridation and Health. London, U.K.: John Wright, p. 7.
Statutory Authority for Fluoride Used in Community Water Fluoridation
The United States Environmental Protection Agency(EPA),under the Safe Drinking Water Act(42 USC
300),promulgates the National Primary Drinking Water Regulations. These regulations set the maximum
contaminant levels(MCLs)for chemicals in finished water supplied by public water systems. Based on a
report by the National Research Council,the EPA has established an MCL for fluoride of 4.0 mg/L.The
National Sanitation Foundation(NSF)certifies drinking water additives if they are shown to contribute
less than 10%of the MCL to the finished water supply for all drinking water contaminants regulated by
the EPA.As stated above,the level of fluoride in Fort Collins treated water supplies is stringently
controlled at 1.0 ppm(range from 0.7 to 1.2 ppm).The Fort Collins Utilities Water Treatment Program
Introduction 5
complies with all regulations set forth by the EPA for fluoride,uses products that are certified by the NSF,
and meets or exceeds all recommendations set forth by the Colorado Department of Public Health and
Environment(CDPHE)as well as by the United States Centers for Disease Control and Prevention(CDC).
Several individuals at the initial public meetings suggested that fluoride should be treated as a drug that is
added to community water and wondered why the United States Food and Drug Administration(FDA)
does not regulate fluoride in drinking water.The FTSG noted that FDA considers the intended use of
products when determining whether or not an"article" is a drug,as opposed to a cosmetic,a food or
beverage,or none of these.The intended use of the high concentrations of fluoride in toothpaste and other
dental products meets the FDA's definition of a drug, i.e.,drugs are"(A)articles intended for use in the
diagnosis, cure,mitigation,treatment,or prevention of disease and(B)articles(other than food)intended
to affect the structure or any function of the body of man or other animals" [FD&C Act,sec. 201(g)(1)].
Consistent with this definition, when fluoride is added to bottled water,the FDA regulates the product as
a food,because of its intended use. The EPA,rather than the FDA,has the authority in the U.S.to
regulate maximum levels of fluoride in drinking water. In addition,the U.S. Public Health Service and
state public health authorities are charged with issuing recommendations regarding optimal levels of
water fluoridation for purposes of preventing caries,and the decision to fluoridate water is left to the
impacted population's elected officials. The FTSG did not address questions of legal definitions or the
distribution of regulatory authority in investigating the four outlined objectives as previously stated.
Important Background Information Relevant to the Fluoridation of Community Water in
Fort Collins Colorado
History of Fort Collins Water Fluoridation Program
In 1954, an ordinance to fluoridate was presented to Fort Collins voters, but did not receive sufficient
votes to pass. In 1966,the Fort Collins City Council adopted an ordinance prohibiting fluoridation unless
approved by a vote of the public. Citizens voted in 1967 to authorize City Council to add fluoride to Fort
Collins water supply system. That year Fort Collins began adding dry sodium silicofluoride to the treated
drinking water supply at Water Treatment Plant#1. In 1992,the City changed to a liquid form of fluoride
called hydrofluorosilicic acid(H,SiF6). This practice continues to the present.
Natural or Background Levels of Fluoride
The FTSG felt it was important for the decision-makers and the general public to know that the source
waters used by the City of Fort Collins(Cache La Poudre River and Horsetooth Reservoir) contain some
natural amounts of fluoride. The levels in untreated water range from 0.15 - 0.25 mg/L fluoride ion. This
is below the level considered by public health authorities to be"optimal" for caries prevention.Natural
fluoride is not removed during the water treatment process. If the City were to end its water fluoridation
program,the drinking water in Fort Collins would continue to contain some fluoride.
Fort Collins Area Water Providers
In addition to Fort Collins Utilities,there are three additional water utilities serving the Fort Collins area
(East Latimer County Water District, Fort Collins-Loveland Water District and North Weld County
Water District). Currently,Fort Collins Utilities and these districts fluoridate at 1 mg/L.Neighboring
districts sometimes share water. If Fort Collins Utilities ceased to fluoridate the water and some or all of
the other districts continued to do so,some customers served by Fort Collins Utilities would receive
fluoride in the drinking water ranging from 0.2 to 1.0 mg/L.Customers would need to contact their
supplier to determine the level of fluoride in their water.
Review of Water Treatment Process Chemistry
Fort Collins Utilities uses what is termed 'Conventional Treatment' for its two raw water sources.Cache
La Poudre River and Horsetooth Reservoir waters are blended and then treated using several different
6 Report of the Fort Collins Fluoride Technical Study Group—April 2003
chemicals. Each added treatment chemical is defined below and shown,beginning from left to right, on
Figure 1
The water treatment chemicals used at the Fort Collins Water Treatment Facility are purchased or
prepared in highly concentrated forms. Many of these concentrated chemicals are hazardous prior to their
addition to the raw(untreated)water. However,once added to the raw water,these chemicals are diluted
and become harmless, if not helpful. A fundamental concept in toxicology that addresses this
phenomenon was first described in the sixteenth century by Paracelsus, "All substances are poisons;there
is none which is not a poison. The right dose differentiates a poison from a remedy."
Thus,any review of the"safety" of drinking water additives must keep in mind that the dose determines
whether the additive is helpful or poisonous.
The reader should refer to Figure I to review where each of the chemicals described below are added in
the treatment process.
Chlorine Dioxide(OIO,) Polymers (fiocculant aid and filteraid)
Powdered Activated
Carbon Alum(AI�(SO,),H2O)
Lime(Ca(OHz)
Raw Poutlre Carbon Dioxide(co:) Flocculation 8
River Water Flow Blend Coagulation Sedimentation Filtration
Raw Horsetooth
Reservoir Background
Water Fluoride=0.2 mglL
1
Clearvieu sample
Slaton
1
West East
Chlonne Reservoir Reservoir
Lime (Ca(02)
Carbon Dioxide(CO,) Fluoride=1.0 mglL Fluoride=1.0 mg&
Flucrosilics and(HFS)
4 (Added Fluoride=0.8 mg/L)
Fort Collins Water Treatment Facility
Process Schematic LSample
and Station To
2 Distribution
Location of Chemical Feed Points (SS2) System
Figure 1
Chlorine Dioxide(CI02)-used as a pre-oxidant for Horsetooth Reservoir raw water to aid in the removal
of certain contaminants. CI02 is made on site using a highly automated process. Chlorine, sodium
chlorite,and water are blended to form chlorine dioxide solution.The solution varies in strength and
dosage based on raw water quality. C102 is a strong oxidant and requires special handling and feed
equipment. C102 disassociates to chlorite and chlorate ions as well as chorine and hydrogen ions.
Powdered Activated Carbon(PAC)—PAC is used for removing compounds that cause taste and odor.
PAC is added at dosages dependant upon raw water quality conditions. Carbon does not change chemical
• form after addition and is settled out of the process after addition.
Introduction 7
Calcium Hydroxide or Lime [Ca(OH)21—Lime is added to the raw water to adjust the alkalinity of the
raw water prior to coagulation. Alkalinity is a measure of the buffering capacity of the water and is
typically expressed as mg/I of calcium carbonate(CaCO3). When lime is added to water,calcium ions are
released and the alkalinity and pH go up(due to the increase in OH"that is released from the lime).
Dosages vary from 5—35 mg/L. Lime is very basic(pH=> 10.5).
Carbon Dioxide(COD—CO2 gas is used to adjust the pH of the raw water after lime addition(see Lime).
CO2 forms a weak acid when added to water-carbonic acid(1-12CO3).
Aluminum Sulfate or Alum(Al2(SO4)3+ 141-12O)—Alum is added to the water to coagulate the particles
that are present in raw, untreated water. Since alum is positively charged, and most particles are
negatively charged, the particles agglomerate in the flocculation stage,and settle out in the unit process
called sedimentation. Alum is slightly acidic(pH of 1 %solution=3.5). When alum is added to water,
the salts dissociate to their respective trivalent ions,Al"and then form hydroxyl complexes
{AI(H20)6+3}.
Polymers(Cationic and Anionic)-Polymers are added to the process to aid in settling the larger particles
that are formed in the coagulation and flocculation processes. Different types of polymers are utilized
depending on the raw water source and quality. Dosages are applied at very low concentrations(0.01 —
0.2 mg/L). Since polymers are long chained organic compounds,they do not change form and are
removed with the particles that are settled and filtered out of the water.
Chlorine(C12)-Chlorine is added to disinfect the water after filtration.Although chlorine is hazardous as
a gas form,when added to water,C12 disassociates to hypochlorous acid(HOCI")and hydrochloric acid
(HCI).The HOCI- is the form that disinfects the water. Dosages applied are dependant upon many water
quality factors,however regulations require that a minimum of 0.2 mg/L Cl2 remain in the water at the
furthest end of the piping system that delivers water throughout our community.
Lime—Lime is also added at the clearwell to adjust the alkalinity of the finished,potable water'(38—40
mg/L as CaCO3). Alkalinity is a measure of the buffering capacity and is typically expressed as mg/L as
calcium carbonate(CaCO3). Again, when lime is added to the water,calcium ions are released and the pH
goes up(due to the increase in OH-that is released from the lime).
Carbon Dioxide—See above. CO2 is used to adjust the pH of the finished,potable water. CO, forms a
weak acid when added to water-carbonic acid(H,CO3). The final pH target for our community is strictly
controlled(pH 7.8—8.0 units).
Fluorosilicic Acid(HFS or H2SiF6)—Fluoride is added as a liquid with very precise metering and flow
measurement equipment. Liquid HFS is acidic and once added to water,it dissociates and will lower the
pH of the solution. In Fort Collins,both lime and carbon dioxide are added to maintain strict pH targets of
the finished water(see Figure 2).
8 Report of the Fort Collins Fluoride Technical Study Group—April 2003
Raw Poudre
River Water Flow Flocculation 8
Blend Coagulation Sedimentation Filtration
Raw Horsetooth
Reservoir Background
Water Fluoride=0.2 mg/L
cleanvell sample
st,non
1
HFS FEED West East
(Added Reservoir Reservoir
Fluoride
=0.8 mg/L) Fluoride=1.0 mg/L Fluoride=1.0 mg/L
Fort Collins Water Treatment Facility -,::
Process Schematic Sample
Station To
and 2 Distribution
Location of HFS (Fluoride) Feed (sS2) system
Figure 2
When HFS is added to water, hydrofluoric acid(HF)and silicon tetrafluoride (SiF4)are formed. Silica
tetrafluoride is a gas that reacts quickly with water to form silicic acid(H2SiO3)or silica NOD and HE
The HF further dissociates to hydrogen and fluoride ion.The concentration of fluoride is strictly
controlled to a target level of I mg/L as fluoride ion.
Overview of Fluoridation Chemistry
An overview of the chemistry of HFS addition and what happens when it is dissolved in water is
provided. Another overview,written by an independent research group commissioned by the British
Fluoridation Society can be found at: http://www.liv.ac.uk/bfs/wrcreport.t)df. For detailed recent scientific
reviews of this issue, the reader should consult Urbansky and Shock,2000 and Urbansky,2002.
Equilibrium
The equilibrium reaction between the strong acid hexafluorsilicic acid(HFS)and water can be
represented in chemical shorthand as:
SiF62" + 4H2O —. Si(OH)4 +4H' +6F
The dissociation of hexafuorsilicate ion(SiF62)to the products on the right hand side of the above
equation is considered to be complete at equilibrium at the normal pH of municipal water supplies(pH>
7.0). In Fort Collins,the pH is strictly maintained at a range of 7.8—8.0 pH units.Complete dissociation
at equilibrium means chemists would report,based on the most conservative(smallest)equilibrium
constants in the chemical literature,that the ratio of SiOH4/SiF62-at pH 8 and a F-concentration of 1 mg/L
would be about 1 x I OE26.07. That means that for every 1 molecule on non-dissociated SiF62"there are
10,000,000,000,000,000,000,000,000 molecules of Si(OH)4•The resulting concentration of SiF62"at
equilibrium in drinking water supplies where F"is adjusted with HFS to be 1 mg/L would be exceedingly
small (<<< I part per trillion).
Introduction 9
The time to achieve this equilibrium is not precisely known. However, it is known to occur within in
seconds,if not minutes, in complex aqueous chemistry. Since it takes more than six hours for treated
drinking water to reach Fort Collins homes,there is more than ample time for SiF6' to reach equilibrium
(i.e.,to essentially fully dissociate)before any resident ingests the treated water.
Further validation of the dissociation of HFS to F'during Fort Collins water treatment comes from the
chemical mass balance calculations between the known amount of added HFS and the resulting measured
F-ion concentration presented in Appendix A-2. If large amounts of HFS were not dissociated it would
be observed in the mass balance of HFS dosage versus the resulting F ion concentration.
It is important to put the mass balance findings into the context that no more than 66% dissociation was
determined by the Westendorf, 1975 thesis cited by Masters et al 2000(See Finding#4). This thesis
finding is the"experimental evidence"cited to call into question the literature dissociation constants
suggesting nearly 100% dissociation reported by Urbansky and Schock 2000,and Urbansky 2002. Since
the mass balance using the F-ion electrode method(ISE)is balanced within 3%(Mass Balance
Calculations, Appendix A-2),the Fort Collins Water Treatment Facility (FCWTF)monitoring data does
not support the claim that 33%or more of the HFS added is undissociated and remains in the water
supply for Fort Collins. The mass balance reported an error of 3%and hence the analytical result
demonstrates the dissociation of the F- ion. Given the precision in the values used for flow rate,applied
dosage rate,HFS added in pounds per day, and the F- ion concentration,the budget+/-3 %is within
measurement error.The FCWTF data are consistent with the prediction of complete dissociation of HSF
based on chemical equilibrium theory.
10 Report of the Fort Collins Fluoride Technical Study Group—April 2003
cc--. City Council
Mike Smith /khp
Mr. John Fischbach April 17, 2003
City Manager
200 LaPorte Street
Fort Collins, CO 80521 Re: Fluoridation of Fort Collins Water
Cc: Fort Collins Water Board, Board of County Commissioners, Health District of
Northern Larimer County, Fluoride Technical Study Group, Dr. Ned Calonge, Colorado
Dept. of Public Health and Environment
At its meeting on March 27,2003, the Larimer County Board of Health (BOH) heard
public testimony and had the opportunity to question the members of the Fluoride
Technical Study Group (FTSG) about its report. On April 10, 2003, the BOH again met
to consider the FTSG report and the public testimony, and debate the merits of water
fluoridation in order to prepare a recommendation to the City Council. In its own
preparation for these meetings, the BOH had studied the FTSG report, the supporting
documentation, all of the public comment, and other relevant literature.
The BOH found the FTSG report to be complete and balanced, its findings and
conclusions appropriate and fully supported by the evidence presented and the scientific
literature. Moreover, the BOH, on the basis of the report, the literature review mentioned
. above, and the public testimony, finds that fluoridation is a very important public health
measure that is safe and effective in preventing dental disease, is associated with no
known health hazard, and should be continued.
Accordingly, the following motion was proposed, seconded, and approved unanimously
with all members present.
Resolved that the Larimer County Board of Health concurs with and fully supports the
findings and conclusions of the report of the FTSG and in addition, strongly
recommends that the City of Fort Collins continue to fluoridate its water supply within
the range established for optimal dental health benefit and in the manner that it has used
to date.
The following information is provided to support the recommendation of the BOH.
• The weight of more than fifty years of scientific evidence indicates that community
water fluoridation, when maintained within the known safety limits, is both safe and
effective in improving dental health and has not been shown to cause any significant
deleterious health effects.
• The benefits of water fluoridation substantially outweigh any known risk. Optimum
fluoridation of water alone does not cause fluorosis. There is a small risk in babies of
dental fluorosis, a cosmetic rather than a health risk. Dental fluorosis is dose
dependent and affects developing teeth before they emerge as well as after eruption.
Excess fluoride in younger children most often occurs from swallowing fluoride
toothpaste. Since 60% of the total fluoride dose is not associated with community
water fluoridation, other sources, such as ingestion of toothpaste by small children,
should be reduced. For this reason, children under the age of two should not use
fluoride-containing toothpaste.Those between the ages of 2-6 should do so only
under the supervision of an adult in order to prevent excess swallowing of toothpaste
(Tables 2 and 5 on pages 22 and 24 of the FTSG report). In addition, reconstituting
powdered baby formula with fluoridated tap water should be minimized for infants
less than six months of age in order to limit the dose of fluoride ingested by infants
and young (see recommendations below).
• No study has shown any relationship between water fluoridation and significant
diseases such as cancer or bone and joint diseases. It is possible that over the course
of a lifetime some bone fluorosis may occur but this is not of clinical significance in
the United States and can be averted by the intake of a normal diet that contains the
recommended amounts of calcium.
• Therefore, the World Health Organization has stated formally that there is no basis for
altering public health policy regarding fluoridation of water. The BOH endorses this
recommendation. With respect to endorsements of fluoridation by major academic
and public policy groups, the American Dental Association, the National Academy of
Medicine, the American Medical Association, the World Health Organization, and
nearly one hundred other national and international organizations have formally
recognized the public health benefits of water fluoridation and supported its use.
Water fluoridation has been recognized by the Centers for Disease Control as,one of
the ten greatest public health achievements of the 20`n century.
• Optimal water fluoridation results in a reduction of cavities. The primary mode of
action of fluoride is its topical action on the surfaces of the teeth; systemic action
from ingestion plays a minor role except in young children before the teeth have
erupted.The benefit of community water fluoridation was much larger before the
advent of fluoridated toothpaste but still causes a relative caries reduction of 25%. In
communities in the United States where water fluoridation has been discontinued,
tooth decay has increased after one year, and has been shown to revert to earlier
levels when fluoridation was reinstated.These experiments in discontinuing water
fluoridation have been done in other cities and the BOH believes there is no reason to
expose Larimer County children reliant on the municipal water supply of Fort Collins
to this risk.
• The replacement of water fluoridation with topical application of fluoride is not an
alternative since these topical preparations will be costly and require considerable
discipline in their application in order to attain the same degree of effectiveness as
water fluoridation.This would be poor public health policy and result in a significant
increase in dental disease in people who cannot afford these topical agents.
• The cost-benefit relationship for water fluoridation is quite good. The cost of fluoride
per customer has remained stable over the last eight years at around $0.50 per person
2
with an average annual expenditure of about$60,000. This results in an annual cost
savings of over $382,000 for the people of Fort Collins when one considers the
anticipated dental decay rate for the region and the resulting costs to city residents to
care for this. In addition to monetary costs, there are human costs in pain and
suffering associated with dental canes and their treatment that are avoided through
community water fluoridation.
• If one considers the use of fluoride mouth rinses in 26 areas of Colorado without
optimum levels of fluoride in their water, the cost per child is $1.92 per year, about
four times the cost of water fluoridation. Should the water fluoridation program be
discontinued, about 30,000 children would need to be on the mouth rinse program at a
cost of$57,600-almost equal to that of the water fluoridation program yet this would
benefit only one-quarter of the population of Fort Collins.
• There is no evidence that significant amounts of any toxic agent are present as a result
of adding fluoride to the water supply. The water is tested regularly for contaminants
and none has been found at unsafe levels.
• There is no known risk to using hydrofluorosilicic acid (HFS) to fluoridate water in
Fort Collins. The fact that HFS is a byproduct of other industrial processes is
irrelevant. Nevertheless, since some members of the public have raised this issue as a
concern, the BOH has included some recommendations that may allay unfounded
fears (see below).
• Scientific papers have been published that suggest HFS in the water may cause an
increased uptake of lead by the body and bring about chronic lead poisoning (Masters
and Coplan). These papers were mentioned by many in the public comment and,
therefore, should be dealt with here. Both the FTSG and the BOH reviewed the
research and neither group believed it to be of good scientific quality. The reasons are
that the authors used epidemiologic data taken from the work of others and
reorganized it in an attempt to draw conclusions about fluoridation and lead toxicity
even though the original data was not collected for this purpose. Several potentially
confounding variables were not analyzed for their effects on the conclusions, and it
appears clear that those variables probably account for the higher blood lead levels
and that fluoridation played no role.The elevated blood lead levels were more likely
due to the fact that many of the children lived in old homes with lead pipes and lead
paint on the walls.
Moreover, these authors also attempted to support their conclusions with arguments
drawn from the chemistry of HFS.They state that HFS does not completely dissociate
in water. Their statements contradict the known chemistry of this compound and have
been effectively refuted by several scientists well qualified in this field.A mass
balance calculation of the treated water in Fort Collins, before its release in the
distribution system, demonstrates that complete dissociation of added HFS occurs
within the ability of instruments to measure this. Moreover, the chemistry of the
compound makes clear that the dissociation is so complete (hexafluorosilicate ion
3
equal to 10,33 M) that a person would have to drink ten billion liters of water to be
exposed to one hexafluorosilicate ion.Accordingly, the BOH finds that this paper
contains no credible scientific evidence regarding fluoridation and should be
dismissed. The BOH finds that there is no support for the suggestion that the
hexafluorosilicate should be tested for toxicity or that it could in any way influence
the human uptake of lead.
As further evidence of the lack of a relationship between fluoridation and lead
poisoning, a study was done recently in Colorado to compare lead levels in children
with the amount and type of fluoride in the water.The highest prevalence of elevated
blood lead is seen in Adams County (3.7%) where only 11% of the population
receives HFS fluoridated water. Latimer and El Paso counties have the lowest
prevalence of elevated blood lead. El Paso County has high naturally occurring
concentrations of fluoride in the water and most communities do not add fluoride.
Larimer County, similar in many respects to El Paso County, also has a low
prevalence of elevated blood lead levels and provides 94% of its population with
water fluoridated with HFS. Thus, there is a clear lack of relationship between
fluoridation with HFS and blood lead levels. Masters and Coplan's hypothesis is not
supported. There should be no further concern about this.
• The process undertaken by the FTSG in evaluating risks based on the weight of
evidence made it a point to highlight the uncertainty in any findings and to explore
issues raised by the public that were not highlighted in the public health literature.
This facilitates the use of the precautionary principle as applied to the question of
whether or not the BOH should recommend the continuation or cessation of
community water fluoridation. The precautionary principle was applied to risks on
both sides of this issue: the risk of increased prevalence of cavities and the risk of
purported negative health effects.This adds additional validity to the conclusions in
this report.
Recommendations and suggestions to help allay public concerns about water
fluoridation:
• Consider using the lower end of the accepted range of fluoride in the water in order to
reduce total body burden of fluoride over a lifetime. The recommended levels (0.7-1.2
PPM) were made at a time when there were no other methods of providing fluoride.
• Consider making an appropriate climate-related adjustment in the optimal fluoride
concentration based on drinking water ingestion rates likely associated with our dry
climate. Such a change, given the increased frequency of topical exposure of fluoride
ions to tooth surfaces associated with increased water consumption, could be made
without any likely reduction in caries prevention.
• In addition to the downstream testing done for hazardous substances, the water plant
should test each batch of HFS for toxic substances prior to adding HFS to the water
4
. during treatment to insure levels of trace contaminants meet appropriate standards
and specifications.
• If another form of HFS that is not derived as an industrial byproduct becomes
available, consider substituting that for the current product.
• Discontinue the prescribing of fluoride supplements by area dentists to children
drinking city water supplies, in order to help reduce any risk of dental fluorosis.
• Institute an educational program regarding the use of fluoride-containing products in
children under the age of two, who should not use fluoride-containing toothpaste, and
reduce the use of fluoridated water to reconstitute dry baby formula for infants less
than six months old. Those between the ages of 2-6 should use fluoridated toothpaste
only under the supervision of an adult in order to prevent excess swallowing of
toothpaste. This educational program could take the form of signs placed in the
appropriate location in stores that sell fluoridated dental products and dry baby
formula.
• Encourage nutritional programs recommending balanced diets that contain adequate
calcium.
. Thank you for the opportunity to review this issue and provide the City Council with our
recommendations. The BOH has agreed to review this issue every three years.
J. Joseph Marr, MD Frank A. Vertucci, Ph.D. Jane Higgins,MD
President Vice-President Member
c
Uj
aln. G
Teri B. Olson,RN,MSN Blair Trautwein, JD
Member Member
•
5
Utilities
electric • stormwater • wastewater • water
City of Fort Collins
April 30, 2003
Dear Mayor Martinez and City Council Members,
On April 24" 2003, the Fort Collins Water Board voted 9-2 to discontinue fluoridation of our
municipal water supply. This vote was the culmination of more than 2 years of additional
information and public input since our original recommendation to stop fluoridation in March
2001. At that time, our recommendation was not based on any health considerations. Instead, we
based our decision on several other reasons. Besides the large cost for capital improvement
($500k) and annual operating costs ($50-100k/yr), we also considered: less than 1% of the
fluoride we add was ingested, there were plenty of other sources of fluoride available to City
residents, the majority of Europe rejected its use or never used fluoride and it was an extremely
dangerous chemical to handle and transport. We also had problems that the specific substance
we add is a hazardous waste straight from the fertilizer industry and, we wondered, was it
appropriate to deliver a medicine through the drinking water? Since our first vote, none of the
new information from both sides of the issue addressed or repudiated the basis of our original
judgement.
During the discussion preceding our recent vote, health issues were addressed. It was generally
conceded that topical application of fluoride helped prevent dental caries on tooth surfaces,
although how much it would do so for our citizens is not known. The need for fluoride in the
drinking water may have been more important 30 years ago but with so many others sources
available today, keeping fluoride in the water particularly ignoring the more sensitive populations
in the City, does not seem like a good idea. Evidence in a large portion of the research indicates
that there are populations within the City who would be better off if fluoride were not added to
our drinking water, particularly, babies less than 6 months old and older folks with thyroid
conditions.
We are looking forward to the work session May 27'to further discuss the basis for our
recommendation.
Since
Thomas G. ers, PhD, PE, DEE
Chair, Fort Collins Water Board
cc. Mr. Michael Smith, Fort Collins Utilities General Manager
700 Wood St. • PO. Box 580 • Fort Collins, CO 80522-0580 • (970) 221-6700 • FAX (970) 221-6619 • TDD (970) 224-6003
e-mail: utilitiesLfcgov.com • www.fcgov.com/utilities
Health( Distria
. OF NORTHERN LARIMER COUNTY
120 Bristlecone Drive, Fort Collins, CO 80524
May 15, 2003 970.224.5209 fax 970.221.7165
info@healthdistrict.org www.healthdistriet.org
John Fischbach
City Manager
City of Fort Collins
300 LaPorte Avenue
Fort Collins, CO 80521
Re: Fluoridation of Fort Collins Water
Dear Mr. Fischbach:
The Health District of Northern Larimer County has reviewed the issue of fluoridation of the local
water supply and would like to forward its recommendation to you and the City Council. Like the City
Council, the Board of Directors of the Health District deliberately waited until they could review the
published findings of the local Fluoride Technical Study Group (FTSG) before discussing the issue or
taking a stand.
And like the City, the health of the members of our community is of utmost concern to us. In matters of
. public health, when we come to a fork in the road where an important decision is to be made, it is
critical to understand both the health advantages and the health risks that exist for both paths before a
decision is made.
The issue of whether or not to fluoridate is a complex one, with thousands of pages available for those
who choose to review scientific research, conjecture, and opinion. Most of us have neither the time
nor the scientific skills to analyze the quality of the information before us in order to determine which
of those writings are scientifically reliable, which of the theories have basis in fact, and the relative
health outcome for each course of action.
In order that we have a thorough and critical review, our community took the responsible approach of
appointing a technical study group to sort through the information to determine what the evidence tells
us about what health impact either fluoridating or not fluoridating might have on our community.The
FTSG was carefully comprised of representatives from the Water Board, the Health Board, one anti-
fluoridation proponent, one pro-fluoridation proponent, and the remainder of the members were
specifically selected to be neutral expert scientific reviewers.
The FTSG spent months reviewing and discussing the evidence regarding the impact of either
choosing to fluoridate or not to fluoridate on our community. They have delivered a remarkably
thorough and high quality report.
After reviewing the multiple details of the report, the Board of Directors of the Health District of
Northern Larimer County has concluded that there would be a far greater negative impact to the
health of our community were the City of Fort Collins to cease the fluoridation of its public
• water supply than if It were to continue. During its meeting of April 22, the Health District Board
voted to strongly support the continuation of the fluoridation of the local water supply.
creating a healthier community
medical and dental services • mental health services • health promotion • community collaboration
Perhaps the biggest mistake our community could make would be to ignore the extremely significant
health impact that fluoridation is currently having on our population. If we were to stop fluoridating
now, we could expect to see an increase of 67,500 tooth surfaces with cavities in our community over
the next 15 years. Dental disease is a very real and serious disease. It is the most common
preventable disease among children, and the second most common infectious disease among
children. Untreated cavities can lead to abscesses, systemic infection and tooth loss for both children
and adults.
We urge the City Council to carefully review the findings of the Technical Study Group and to fully
understand the relative health impacts of both ending fluoridation and keeping it. To end fluoridation
would certainly mean that thousands of people would suffer unnecessary dental disease each year,
and would be subjected to the cost of treating it. To keep fluoridation does NOT pose a risk for
increase incidence of other serious health concerns.
We have attached the summary analysis our Board used to discuss this issue, which lists both the
arguments for and against fluoridating. A summary of our reasons follows:
1. Dental caries area significant public health problem in every age group that can be reduced by
community water fluoridation.
• Dental caries are an infectious disease that can result in destruction of tooth structure.
Untreated, it can lead to painful abscesses, systemic infection and tooth loss for both
children and adults.
• Every year that we fluoridate, we avoid 4,500 surfaces with cavities in Fort Collins
• Over 50 years of accumulated evidence shows that optimally fluoridated water reduces
caries rates for all age groups.
2. The potential side effects of community water fluoridation are minimal and acceptable.
The Fort Collins Fluoride Technical Study Group's thorough review of scientific literature found:
• Community water fluoridation does not pose a risk for increased incidence of cancer, bone
fractures, skeletal fluorosis, thyroid effects, immunological effects or other serious adverse
health effects.
• The only adverse health effect conclusively associated with water fluoridation is very mild
or mild dental fluorosis. This change in dental enamel is cosmetic in nature and
considered an acceptable risk considering the benefits of reducing dental decay.
• Although the risk of fluorosis (a cosmetic rather than health risk) for infants increases if the
child is fed powdered formula made with fluoridated water, the teeth impacted are the front
teeth and are not likely to be noticed. It would be a relatively simple thing to be certain that
all parents of newborns receive information on this issue.
3. Fluoridation of community water is cost saving and is the most cost-effective fluoride delivery
system for the prevention of caries.
• Fluoridation is one of the few prevention strategies that actually saves more money than it
costs. The net savings for the community served by City of Fort Collins is estimated at
$382,000 in averted dental costs alone every year.
• The average per-person cost of fluoridation in Fort Collins each year is $.71. The average
per person cost of treating the cavities that fluoride is currently preventing would be $4.11.
• When compared to other methods of delivering fluoride (such as school-based mouth rinse
programs and dietary supplements), community water fluoridation reaches more people at
a lower cost.
2
In recommending community water fluoridation, the Health District Board of Directors is joined by:
Larimer County Board of Health
• Larimer County Dental Society
• Colorado Medical Society
Colorado Dental Association
Centers for Disease Control and Prevention
• American Dental Association
• American Medical Association
• World Health Organization
Public health organizations across the United States and the world
American Water Works Association (an association of 50,000 water supply professionals
worldwide)
Dr. C. Everett Koop, former U.S. Surgeon General, labeled fluoridation the "single most important
commitment a community can make to the oral health of its children and future generations."
We urge the City of Fort Collins to continue its commitment to the health and well being of
residents by continuing to fluoridate our community's water.
Sincerely,
0a1w141kz___
Carol Plock
Executive Director
Board of Directors
Wil Huett, President
Tom Linnell, Vice-President
Avie Strand, Secretary/Treasurer
Laurie Steele, Liaison to PVHS
Lee Thielen, Vice-Secretary/Treasurer
cc: Mike Smith, Fort Collins Utilities General Manager
Pro and Con Analysis of Continuation of
City of Fort Collins Water Fluoridation
Health District of Northern Larimer County Board of Directors April 22,2003 Meeting
•
Prepared by Polly Anderson
Background on fluoride
Fluoride is found naturally in water supplies across the United States and the world. Natural levels vary by water source:
untreated water from the City of Fort Collin's two water sources,the Cache La Poudre River and Horsetooth Reservoir,
range from .15 to .25 mg/L.
Fluoride was found to prevent dental caries(cavities)in the early part of the last century. Trials conducted in the 1940s
and subsequent testing found that adding fluoride to municipal water supplies at 1 mg/L(when community water supplies
were not already fluoridated at that level)resulted in a 50-70%reduction in dental caries in children. Following these
findings,community water fluoridation programs grew in the United States and across the developed world.
The prevalence of community fluoridation programs varies by state. According to the Centers for Disease Control and
Prevention,65%of the.US population served by public water systems receive optimally fluoridated water. One of the
Healthy People 2010 objectives for oral health is to increase this percentage to 75%. A sample of states follows below:
Utah—2%
Wyoming—30.3%
Colorado—76.9%
Iowa—91.3%
Washington DC— 100%
In addition to the fluoride naturally found in and added to the City's water supply,local residents may receive fluoride
•through:
• Toothpaste,topical gels,mouth rinses and fluoride supplements
• Foods and beverages with naturally occurring fluoride or made with fluoridated water
Background on the City of Fort Collins fluoridation program
The City of Fort Collins has been adding fluoride to the municipal water supply since 1967. The fluoridation program,
authorized by a citizen vote,utilized dry sodium silicofluoride until 1992, when the City changed to a liquid form of
fluoride called hydrofluorosilicic acid.
The Fort Collins area has three other water utilities:East Larimer County Water District,Fort Collins-Loveland Water
District and the North Weld County Water District. Currently the City of Fort Collins and the other three water utilities
fluoridate at 1 mg/L.
In 2001 the City of Fort Collins Water Board recommended that the City cease its water fluoridation program after what
could be characterized as a limited review of literature about fluoridation. In response,the City of Fort Collins convened
the Fluoride Technical Study Group(FTSG)to explore in depth the costs and benefits of community water fluoridation.
Nine community members were chosen to review existing information and summarize the scientific evidence of the risks
and benefits of community water fluoridation. Included in membership were one representative from the City of Fort
Collins Water Board,one from the Larimer County Board of Health,one pro-fluoridation advocate,one anti-fluoridation
advocate,two representatives from Fort Collins Utilities,and three community members with scientific and medical
expertise.
The study group completed their report in April 2003,titled"Report of the Fort Collins Fluoride Technical Study Group."
This report will be considered by the Board of Health and the Water Board,which will forward recommendations to the
City Council on whether to continue the City's current fluoridation program. The City Council will make the final
•decision.
t
Why is this issue important?
Dental caries are an infectious disease that can result in destruction of tooth structure. According to the Community
Preventive Services Task Force,dental caries remains the most common of chronic childhood disease,five times more
common than asthma. A survey of third grade children conducted in 2002 for the Oral Health Program of CDPHE by
Health District staff found that one in three third graders in schools serving lower income populations had evidence of
untreated caries. Individuals living in poverty are three times more likely to have untreated disease than those who are nw
poor.Dental decay is not a benign condition. Untreated caries can lead to abscess formation,systemic infection and tooth
loss.
Over the past five decades,dental caries incidence has fallen by more than 50% in this country. Since then,many studies
evaluating both the role of fluoridation in'caries prevention and the presence or absence of associated side effects(both
negative and positive)have been completed. Review of this new information is important.
About this analysis
This pro and con analysis was produced by Health District policy staff to assist the Health District Board of Directors in
their consideration of the City's fluoridation program. It was produced both independent of and subsequent to the
Technical Study Group's findings. It should be noted that the FTSG report is quite comprehensive in it's review of
fluoridation;readers of this analysis are encouraged to read the executive summary of the FTSG report or the entire
report.
For a copy of the complete report,visit http://www.ci.fort-collins.co.us/utilities/fluoride-report.php or call the City of Fort
Collins Water Department at(970)416-2486.
The Fort Collins Fluoride Technical Study Group findings
The FTSG developed consensus findings as follows:
1. Drinking water fluoridation is effective in preventing caries. Over fifty years of accumulated evidence from
hundreds of studies shows that optimally fluoridated water reduces caries rates in all age groups. Early studies
showed reductions of 50-60%in children.As background caries rates have decreased,relative differences in
caries rates between fluoridated and non-fluoridated communities have also decreased.More recent studies
estimate differences of about 25%. When communities discontinue fluoridation,caries rates generally increase
relative to continuously fluoridated communities.
2. Drinking water fluoridation risks were evaluated:
a. The FTSG found that community water fluoridation increases the risk for very mild and mild dental
fluorosis. Fluoride ingested from any source during tooth development(infancy to age 8 years)can lead
to visibly detectable changes in enamel opacity broadly called dental fluorosis. Very mild or mild forms
appear as chalklike Iacey markings on the teeth and are not readily apparent even to the affected person.
The rare severe form manifests as brittle,pitted and stained enamel.Even the moderate and severe forms
are considered cosmetic. The severity depends on the dose,duration and timing of fluoride ingestion. 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.
Water fluoridation only accounts for about 40%of dental fluorosis.Other more important risk factors
include young children ingesting toothpaste or inappropriately receiving fluoride supplements.With oral
health as the goal,increasing the prevalence of mild or very mild dental fluorosis is considered an
acceptable adverse effect given the benefits of caries prevention.
b. The FTSG found no consistent evidence of other risks at the level of fluoride provided via community
drinking water including
i. Cancer
ii. Bone fractures
iii. Skeletal fluorosis(thickened bones and skeletal deformity)
iv. Thyroid effects
v. Immunological effects
vi. Other health effects
2
Note: The FTSG notes that the absence of finding conclusive evidence of adverse effects does not prove
that fluoride cannot cause other potential health effects.
3. Community water fluoridation remains effective and cost saving,even in the current situation of widespread use
of fluoride toothpaste and lower baseline caries risk. According to a cost analysis conducted jointly by the FTSG
and an economist from the CDC,community water fluoridation is estimated to save between $3.22—$10.31 per
capita per year(depending on whether least or most favorable estimates of caries incidence and fluoridation
effectiveness were used).
4. There is no credible evidence that the use of hydrofluorosilicic acid(HFS)to fluoridate water introduces
additional hazards. The Fort Collins Water Quality Control Laboratory monitors concentrations of heavy metals
in the finished water.They do not increase after the addition of HSF. Levels of the naturally occurring elements
arsenic and lead are below detection limits(and below the maximum contaminant level)both before and after the
water is treated with BPS. HFS completely dissociates in public drinking water supplies to three ions(fluoride,
hydrogen and silicate)for which there are ample safety data.
Reasons to support continuation of the City's fluoridation program
1. The weight of evidence of fifty years of study shows that there is a significant reduction in dental decay in
populations exposed to fluoridated water at or near the optimal level.
• Children—The most recent US surveys of schoolchildren show a caries reduction of 25% and an
absolute prevalence difference of 1.14 fewer surfaces with caries in primary teeth and a .5 fewer surfaces
with caries in permanent teeth with fluoridated water.
• Adults—Among the four studies of caries prevention in adults,the most recent study showed that
community water fluoridation reduced surfaces with caries by .29 surfaces per year of fluoride exposure.
These reductions translate into thousands of cavities averted every year that the City of Fort Collins
fluoridates its water.
2. The risk associated with water fluoridation is low. There is no conclusive evidence that optimally fluoridated
water causes increases in cancer,bone fractures,dental fluorosis exceeding very mild or mild levels, skeletal
fluorosis,problems with immunity and thyroid function,or other alleged health effects.
3. Community water fluoridation is cost saving. The community served by City of Fort Collins water saves an
estimated$382,000 per year in averted dental costs alone. Fluoridation is one of the few prevention strategies
that actually saves more money than it costs.Routine childhood immunization and influenza immunization in the
elderly are among the rare examples of other prevention strategies that are cost-saving.
4. One of the major advantages of water fluoridation over other fluoride modalities is that it does not require
behavioral changes from its recipients,and that those most likely to benefit from it will do so. There are many
other examples in our society of similar population-based approaches to disease prevention—including folic acid
and iron supplementation of cereals and grains(to prevent neural tube defects and iron deficiency anemia,
respectively)and vitamin D in milk(to prevent rickets).Were one to apply the argument that no additives should
be required in food or water if even a single person could experience an adverse effect,then none of these highly
effective prevention strategies could be supported.
5. Fluoridation is particularly beneficial to populations with lower incomes,who have higher caries rates and less
access to dental care than their higher income counterparts.
6. There is no evidence of a health risk nor is there any credible pathway that would lead one to posit a risk from the
use of hydrofluorosilicic acid or fluorosilicates to fluoridate water. The purity of these products is carefully
controlled and they are fully and rapidly dissociated in water before it leaves the plant.
7. Community water fluoridation has been endorsed by the Center for Disease Control and Prevention,the World
Health Organization,the American Dental Association,the National Academy of Medicine,and almost one-
hundred other national and international governmental agencies,expert bodies and professional associations.
3
Reasons to oppose continuation of the City's fluoridation program:
1. Some argue that with the dramatic decrease in mean caries rates since the early years of fluoridation,it is time to
move from a population-wide prevention approach(community water fluoridation)to an individual approach.
• Although still a cost-saving intervention,the background decrease in caries rates has reduced the net
effectiveness of community water fluoridation.
• There are widely available personal behavior methods to receive fluoride treatments such as toothpastes,
gels, mouth washes and dental treatments.
• Individuals who do not want to consume water with fluoride must undergo personal expense to do so
(utilizing filtration systems or purchasing unfluoridated bottled water).
2. Dental fluorosis is increasing.
• Optimally fluoridated water, in combination with other sources of fluoride can cause dental fluorosis in as
many as one in four children under the age of 8,most of it mild or very mild. This is an increase in
occurrence from the 1930s and 40s when 12-15%of children under age 8 were found to have dental
fluorosis. Although moderate and severe dental fluorosis is extremely rare(and probably not attributable
to community water fluoridation),some may find the increase in mild cases unacceptable.
• Although most cases of dental fluorosis are not of cosmetic concern and therefore don't require treatment,
the FTSG cost benefit analysis did not consider the cost of treating it.
3. Some would say that the current level of uncertainty about the affect of lifelong exposure to fluoride on skeletal
fluorosis,osteosarcoma and bone fractures,however small,suggests that fluoridation should be suspended until
proven completely safe. (This principle is called the precautionary principle.)
4. Both the EPA and the National Toxicology Program have called for further studies of HFS. Using the
precautionary principle,some may suggest that fluoridation programs should cease until this happens. [Note: See
number four of the FTSG's findings on page two for more about this.]
Board position:
The weight of evidence behind water fluoridation for the prevention of dental caries is significant;the potential negative
side effects to fluoridation are both minimal and acceptable;fluoridation is the most cost-effective fluoride delivery
system for the prevention of dental caries. The Health District Board of Directors strongly supports the City of Fort
Collins water fluoridation program due to its significant positive impact on the health of community.
About this Analysis
This analysis was prepared by Health District of Northern Larimer County staff to assist the Health District Board of Directors in
determining whether to take an official stand on various health-related issues. Analyses are based on bills or issues at the time of their
consideration by the Board and are accurate to the best of staff knowledge.To see whether the Health District Board of Directors took
a position on this or other policy issues,please visit www.healthdistrict.org/policy.
About the Health District
The Health District is a special district of the northern two-thirds of Larimer County,Colorado,supported by local property tax dollars
and governed by a publicly elected five-member board. The Health District provides medical,mental health,dental,preventive and
health planning services to the communities it serves.
For more information about this analysis or the Health District,please contact Polly Anderson,community projects coordinator
(970)224-5209 or panderson@healthdistrict.org.
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