A summary of the
Petition calling on the U.S. Environmental Protection Agency to ban the
fluoridation of the public drinking water under provisions in the Toxic
Substances Control Act.
THIS
PETITION WAS SUBMITTED BY THE FOLLOWING ORGANIZATIONS ON NOV
22,
2016:
Fluoride
Action Network, Food & Water Watch, Organic Consumers Association, American
Academy of Environmental Medicine, International Academy of Oral Medicine and
Toxicology, Moms Against Fluoridation.
OVERVIEW
The
addition of industrial-grade fluoride chemicals to public water supplies for
the pur
pose of
preventing tooth decay is hailed by public health institutions in the U.S., but
has been rejected by most of continental Europe without any demonstrable
adverse effect on childhood caries rates.
Fluoride is not an essential nutrient and does not need to be swallowed
to prevent tooth decay. By contrast, fluoride’s risks to health come from
ingestion, including the spectrum of neurotoxic effects discussed in this
petition.
Petitioners
request that EPA exercise its authority under TSCA, to prohibit the purposeful
addition of fluoridation chemicals to U.S. water supplies. Petitioners make
this request on the grounds that a large body of animal, cellular, and human
research shows that fluoride is neurotoxic at doses within the range now seen
in fluoridated communities.
Using the EPA’s
preferred method for ascertaining a Safe Reference Dose (RfD)
(the
Benchmark Dose method BMD) for a toxic substance, it can be shown that a dose
of 1.4
mg per day could lower the IQ of a child by 5 IQ points. Children drinking two
liters of water at 0.7 mg/liter 0.7 ppm) would reach this dose. If a modest safety factor was applied to
this number (1.4 mg/day) to account for the known wide range of vulnerability
to any toxic substance in a large population, many millions of children in the
USA would be exceeding the computed safe reference dose (RfD) for lowered
IQ(see section IX below for details).
When considering the principles set forth in EPA's
Guidelines for Neurotoxicity Risk Assessment, Petitioners submit that
fluoridation is incompatible with a neurologically safe use of fluoride. Petitioners further make this
request on the grounds that fluoride's predominant role in caries prevention
comes from
topical
contact and thus there is no reasonable justification to expose hundreds of
millions of Americans to the neurotoxic risks of systemic fluoride via water
(and the many processed beverages and foods made therefrom) when topical
fluoride products are now widely available for individual use. Most western nations, including
the vast majority of western Europe, have already rejected water fluoridation.
The EPA is the one federal
agency with the authority to make this happen here in the U.S. We urge EPA to
act accordingly.
II. THE
TOXIC SUBSTANCES CONTROL ACT (TSCA).
The
Toxic Substances Control Act (TSCA) invests EPA with the authority to take
certain actions if it determines that “the manufacture, processing,
distribution in commerce, use, or disposal of a chemical substance . . .
presents an unreasonable risk of injury to health.” In making this
determination, TSCA commands that EPA consider not only risks to the general
public, but to “susceptible subpopulation[s]” as well. Further, TSCA commands that EPA
conduct the risk evaluation “without consideration of costs
or
other non-risk factors.” The
actions that EPA may take include: (1) a c
omplete
prohibition on the manufacture, processing, and distribution of the substance
or (2) a prohibition on a “particular use” of the substance.
EPA’s authority to prohibit
and regulate the use of chemical substances under TSCA encompasses drinking
water additives.
Why TSCA, rather than
SDWA? Although EPA has
certain authorities to regulate fluoride in drinking water under the Safe
Drinking Water Act (SDWA), there
is an important distinction between TSCA and SDWA that permits EPA to take the
requested
action under TSCA in a more targeted, efficient, and less expensive manner than
would be the case under SDWA. Namely, TSCA permits the EPA to differentiate
between fluoride that is added to water versus fluoride that is naturally
occurring. As explained in the petition, prioritizing regulatory action against
fluoridation additives
is
further justified on policy and scientific grounds. It is therefore in the
public interest for EPA to take the requested action under TSCA, instead of
SDWA.
III.
REGULATORY BACKGROUND: FLUORIDE IN DRINKING WATER
In
2003, the EPA asked the National Research Council (NRC) to review the
scientific merits of EPA’s Maximum Contaminant Level Goal (MCLG)of 4 mg/L. for
fluoride.
In
response, the NRC reviewed the existing research on fluoride toxicity and
concluded, in March 2006, that the MCLG is not protective of public health and
should be lowered. The NRC’s conclusion was based on fluoride’s adverse effects
on bone and teeth, but the NRC also raised numerous concerns about the
potential for fluoride to cause other systemic harm, particularly to the
nervous and endocrine systems.
With
respect to the nervous system, the NRC concluded: “On the basis of information
largely derived from histological, chemical, and molecular studies, it is
apparent
that fluorides have the ability to interfere with the functions of the brain.”
This
conclusion by the NRCrested primarily on its review of animal studies, since—
at the
time -fewhuman studies were available.
However,
since the publication of NRC report in 2006 46human studies have been
published
that have found significant relationships between fluoride and adverse
cognitive outcomes. This numberdwarfs the 5 studies that were available to the
NRC in
2006. It has been 10 years since
the NRC concluded that the MCLG for fluoride be lowered, but EPA has yet to do
so. Further, despite the voluminous post-2006 research on neurotoxicity, and
despite the Safe Drinking Water Act’s mandate that EPA protect against “known
or anticipated adverse effects,”EPA’s Office of Water (EPA OW) has indicated
that it will not be considering neurotoxicity as an endpoint of concern when
promulgating the new MCLG. Instead, in December 2010, EPA OW established a
reference dose for fluoride based solely on severe dental fluorosis. EPA OW
justified this decision on the grounds that NRC’s 2006 review did not draw firm
conclusions about the public health relevance of fluoride neurotoxicity. But
nowhere in EPA OW’s risk assessment did it account for the neurotoxicity
research published subsequent to NRC’s review, despite the many studies on
neurotoxicity sent to them.
The cavalier manner in
which EPA’s OW dismissed the evidence of fluoride neurotoxicity stands in stark
contrast to EPA’s own Guidelines for Neurotoxicity Risk
Assessment
that EPA has stated it “will follow in evaluating data on potential
neurotoxicity
associated with exposure to environmental toxicants.”
Petitioners
submit that application of EPA’s Guidelines to the existing database for
fluoride shows that neurotoxicity is a hazard of fluoride exposure, that the
weight of evidence indicates neurotoxicity is a more sensitive endpoint of
fluoride exposure than severe dental fluorosis, and, further, that the
reference dose for fluoride that will protect the public and susceptible
subpopulations against neurotoxicity is
incompatible
with the doses now ingested in fluoridated areas.
IV. THE
RESEARCH DEMONSTRATING FLUORIDE’S NEUROTOXICITY INCLUDES OVER 180 STUDIES
PUBLISHED SINCE THE NRC’S 2006 REVIEW
In
total, Petitioners have identified 196 published studies that have addressed
the neurotoxic effects of fluoride exposure subsequent to the NRC’s review,
including 61 human studies, 115 animal studies, 17 cell studies and three
post-NRC systematic reviews of the literature, including two that address the
human/IQ literature, and one that addresses the animal/cognition literature. Petitioners have attached copies
of over 300 human, animal, and cell studies of fluoride’s neurotoxicity which
include those that have become available since NRC’s review as listed above. The existence of so many human studies
on fluoride neurotoxicity highlights the urgent need for a diligent risk
assessment, per EPA’s Guidelines, to ensure that the general public, and
sensitive subpopulations, are not ingesting neurotoxic levels.
V.
FLUORIDE POSES NEUROTOXIC RISKS AT LEVELS RELEVANT TO U.S. POPULATION
A
frequent claim made by fluoridation promoters is that the doses of fluorid
e
associated with neurotoxicity in humans and animals so vastly exceed the levels
which Americans drinking fluoridated water receive as to be entirely
irrelevant. In support of this claim, proponents often point to the highest
levels that have been linked
to
neurotoxicity, while ignoring the lowest levels (and even the typical levels)
that
have been associated with harm.This focus on the highest levels that cause harm
as the starting point for analysis clashes with standard tenets of risk
assessment, including EPA’s Guidelines, where the starting point for risk
characterization analysis is to determine the Lowest Observable Adverse Effect
Level
(LOAEL) or No Observable Adverse Effect Level (NOAEL)
or a
Benchmark Dose level (BMD).Fluoride Linked to Cognitive Deficits at Levels of
Individual Exposure Seen in Western Fluoridated Populations.
Although the water
fluoride levels associated with IQ reductions are modestly higher than the
levels currently used in artificially water fluoridation programs, it is impo
rtant
to distinguish between the concentration of fluoride in a community’s water
supply and the doseof fluoride that an individual ingests.For example, in rural
China (where most of the IQ studies have been conducted), fluoridated
toothpaste
is
rarely used. By contrast, in the United States, over 95% of toothpastes are
fluoridated and research shows that toothpaste can contribute more fluori
de to a
child’s daily intake than fluoridated water. Available evidence suggests that
(i) the
daily fluoride doses, (ii) urine fluoride levels, (iii) serum fluoride
levels,
and (iv) dental fluorosis levels are all associated with IQ reductions.
Each of
these four metrics of fluoride exposure provide a more direct assessment of
individual fluoride exposure than water fluoride concentration, and are thus
more probative for risk assessment purposes. In the study by Wang,2012the
authors found
a clear
dose response relationship between daily fluoride dose and reduced IQ.
Wang
found that a daily intake of just 2.61 mg F/day was associated with a large,
statistically significant 7.28-point drop in average IQ. Assuming an average weight of32
kg,a daily intake of 2.61 mg would provide a dosage of approximately 0.08
mg/kg/day,
which
is lower than the average daily intake (0.087 mg/kg/day) for non-nursing infants(i.e.
bottle-fed)in the United States, and just two times greater than the average
daily dose for 8-12 year old American children. As with other forms of fluoride toxicity, the potential for
fluoride neurotoxicity is magnified among children with suboptimal nutrient
intake. This is highlighted by the recent study by Das and Mondal which
assessed
the relationship between fluoride intake and IQ among a population with a high
prevalence of underweight children suggestive of an area with pervasive
malnutrition. In
this
population, the authors confirmed a significant correlation between total
fluoride intake and reduced IQ. Notably, these authors found a sharp 15-point
drop in IQ among underweight children with mild dental fluorosis who were
consuming average total daily fluoride exposures of just 0.06 mg/kg/day.). This
is a dose that many infants and children in the U.S. are estimated to exceed.
VI
NEUROTOXIC RISK OF LOW DOSE FLUORIDE IS FURTHER SUPPORTED BY ANIMAL AND CELL
STUDIES
The
studies linking fluoride exposure with neurotoxic effects in humans are
consistent with research on both experimental animals and cell cultures.
VII. RECENT
EPIDEMIOLOGICAL STUDIES CORROBORATE NEUROTOXIC RISK FROM FLUORIDATED WATER IN
WESTERN POPULATIONS
Although
there has been a notable lack of epidemiological research into fluoride’s
neurotoxic effects in the U.S., a 2015 study by Malin and Till found a
statistically significant correlation between the prevalence of water
fluoridation at the state level and Attention-Deficit Hyperactivity Disorder
(ADHD). Another epidemiological
study from 2015, by Peckhamet al., provides further corroborative evidence that
fluoridation can cause neurotoxic effects. Peckham’s study examined the
relationship between
water
fluoride levels and hypothyroidism in the United Kingdom, and found that
fluoride levels > 0.7 mg/L significantly correlated with higher rates of
hypothyroidism. This correlation was strengthened, not weakened, when
controlling for the covariates of age, gender, and index of deprivation. The
correlation between fluoridation and hypothyroidism adds further support for
fluoridation’s neurotoxic potential because, as recognized in EPA’s Guidelines,
“the development of the nervous system is
intimately
associated with the presence of circulating hormones such as thyroid hormone.”
Since
both clinical and subclinical hypothyroidism during pregnancy have been
associated with reduced IQ in offspring the relationship between fluoridation
and hypothyroidism provides a mechanism by which fluoridation can reduce IQ,
even absent a direct neurotoxic effect.
VIII.
SUSCEPTIBLE SUBPOPULATIONS ARE AT HEIGHTENED RISK TO FLUORIDE
NEUROTOXICITY
AND NEED PROTECTION
Recent research in
both humans and animals has specifically demonstrated that nutrient
deficiencies (i.e., iodineand calcium) amplify fluoride’s neurotoxicity. While the full range of individual
susceptibility to fluoride neurotoxicity in the U.S. cannot be precisely
calculated, some subpopulations can be identified as being at elevated risk,
including infants,the elderly,and individuals with (A) deficient nutrient
intake (particularly iodine and calcium),(B) certain COMT gene
polymorphisms,and (C) kidney disease.
Various
factors suggest that African Americans may also suffer disproportionate ris
ks as
well, including elevated use of infant formula,elevated exposure to lead,
depressed
calcium and anti-oxidant intake,and significantly higher rates of dental
fluorosis, including in its moderate and severe forms.Any risk assessment on
the neurotoxicity of fluoride must thus be mindful of the need to protect
susceptible
subpopulations; anything less would be inconsistent with EPA’s
Guidelines.
In fact, even where there is no specific information to indicate differential
susceptibility to a neurotoxin, EPA’s Guidelines state that a margin of safety
(i.e., “uncertainty factor”) should still be incorporated to account for
“potential
differences
in susceptibility.” In the case of fluoride, there is uncontroverted
evidence
indicating substantial differences in susceptibility, and thus the basis for
applying an uncertainty factor is especially strong.
IX. A
REFERENCE DOSE PROTECTIVE AGAINST FLUORIDE NEUROTOXICITY IS INCOMPATIBLE WITH
WATER FLUORIDATION IF STANDARD RISK ASSESSMENT PROCEDURES ARE APPLIED
As
recognized in EPA’s Guidelines, it is standard risk assessment practice to
apply “uncertainty factors” (UF) of 10 when converting a LOAEL, NOAEL, or BMD
(Benchmark Dose) into a safe“reference dose” (RfD) or “reference concentration”
(RfC).
This is
significant because application of even a single UF of 10 to the daily doses/concentrations
of fluoride associated with neurotoxic harm in humans and animals produces an
RfD or RfC that is less than, and thereby incompatible with, the levels of
fluoride added to water for fluoridation (0.7 to 1.2 mg/L). Petitioners recognize that EPA has
a preference for utilizing Benchmark Dose (BMD) methodology for risk
assessments where there is dose-response data that permits the analysis. In the
case of fluoride neurotoxicity, the Xiang dataset is a suitable dataset for
conducting a BMD analysis, as it shows a dose-related reduction in IQ spanning
five dose groups ranging from 0.75 to 4.5 mg F/day without an apparent NOAEL.
(Wang et al. 2012).
Further,
the Xiang dataset benefits from the fact that the study controll
ed for
most of the key confounding factors, including lead, arsenic, iodine, parental
education, and socioeconomic status. (Xiang et al. 2003a,b; Xiang et al. 2013).
If the
BenchMark Response (BMR) is set at 5 IQ points, applying a BMDanalysis to
Xiang’s database results in a BMD of just 1.4 mg F/day(see the following
figure)
This
result can be interpreted as predicting that children exposed to 1.4 mg
fluoride per day will have, on average, 5 less IQ points than children exposed
to no fluoride. The RfD would obviously need to be set at a lower level, since
such a large loss in
IQ is
clearly an adverse effect, and because uncertainty factors would need to be
added to account for variation in sensitivity within a population as large as
the U.S.
X. THE
BROADBENT STUDY DOES NOT ESTABLISH THE SAFETY OF FLUORIDATION
Some
commentators have incorrectly claimed that the recent study by Broadbent et al.
2015 establishes the safety of water fluoridation for neurologic development.
The Broadbent study found no difference in the IQs of children and adults who
spent their first 3 to 5 years of life in fluoridated (0.7 to 1.0 mg/L) vs.
non-fluoridated (0 to 0.3 mg/L) areas of Dunedin, New Zealand. A glaring limitation with the Broadbent
study, however, is that a substantial portion of the “non-fluoridated” control
population used 0.5 mg/day f
luoride
tablets and fluoridated toothpaste, resulting in only a marginal difference in
average total fluoride exposure between the fluoridated and non-fluoridated
populations.
In fact, in response to criticism
on this point, the authors conceded that the
average
difference in total daily intake between the children in the fluoridated and
non-fluoridated
areas would be less than0.3 milligrams per day, while the average intake for
all subjects was 0.9 mg/day.
(Broadbent et al. 2016). At most, therefore, the Br
oadbent
study established that a dose less than 0.3 milligrams of fluoride was not a
sufficiently large enough contrast in daily fluoride exposure to produce a
demonstrable
effect
on average IQ in the study cohort. This does not mean, however, that the
fluoride
exposures in a fluoridated community are safe, since no truly low exposure
comparison group existed in the Broadbent study, and the Broadbent team made no
attempt to study vulnerable subsets of the population (e.g., those with
suboptimal nutritio
n,
genetic polymorphisms, etc). The inherent limitation resulting from the Broadbent
study’s comparison of populations with marginal contrasts in fluoride intake
highlights an important strength of the endemic fluorosis/IQ studies from
China, India, Iran,
and
Mexico. Specifically, the endemic fluorosis studies have generally compared
communities
with clear and stable contrasts in fluoride exposure, thus increasing the power
of these studies to detect fluoride’s effect on IQ. Moreover, unlike
Broadbent’s st
udy,
many of the endemic fluorosis studies have analyzed the relationship between IQ
and individual measures of exposure (e.g., individual urine fluoride levels),
thus overcoming the limitation imposed by Broadbent's ecological (group
level)
estimates of fluoride intake. Although Broadbent and others have criticized the
endemic fluorosis studies for failing to control for potential confounders,
several of these studies did carefully control for confounders and the
association between fluoride and cognitiveimpairment remained intact. Further,
while it’s undisputed that many of the IQ studies used relatively simple study
designs, the consistency of these studies, and their repeated corroboration by
research showing that fluoride impairs learning in rodents
under
carefully controlled laboratory conditions, gives confidence to the conclusion
that fluoride is a neurotoxin that impairs cognition.
XI. THE
BENEFITS OF PREVENTING FLUORIDE NEUROTOXICITY DWARF THE COSTS OF RESTRICTING
FLUORIDE CHEMICALS
EPA’s
authority to act under Section 6 of TSCA is premised on two distinct findings:
(1) a
risk
exists and (2) the risk is unreasonable. Here, in evaluating the preliminary
question of whether a neurotoxic risk exists from use of fluoridation
chemicals, the EPA is duty bound to follow its Guidelines, as the Agency has
stated it “will follow” the Guidelines
when
“evaluating data on potential neurotoxicity associated with exposure to
environmental toxicants.” For
the reasons set forth above, a good faith application of these Guidelines to
the current research on fluoride will show that neurotoxicity is a hazard of
fluoride exposure, and that the doses associated with this hazard overlap the
doses—as reflected by (a) total daily intake, (b) urinary fluoride level, (c)
serum
fluoride
level, and (d) severity of dental fluorosis—
that
U.S. children are exposed to in areas with fluoridated water.
Neurotoxicity
must thus be considered a risk from adding fluoridation chemicals to
drinking
water. Petitioners now turn,
therefore, to the second prong of the inquiry: whether the neurotoxic risk
posed by fluoridation chemicals is an unreasonable one. As
EPA has
stated, the reasonableness inquiry considers the benefits of reducing the risk
with the costs of doing so. In considering these respective benefits and costs
of risk reduction, EPA has stated it will take into account “the extent and
magnitude of
risk
posed; the societal consequences of removing or restricting use of products;
availability and potential hazards of substitutes, and impacts on industry,
employment, and international trade.” There is little question that neurotoxicity is a
serious
insult
to health. In a nation besieged by neurological disorders of poorly understood
etiology, both in young children and the elderly, minimizing exposures to
known
neurotoxic substances should be a public health priority. Because of the
massive
extent of exposure to fluoridation chemicals in the U.S., even small effects on
IQ will
have very substantial economic consequences. Studies have shown that even
a loss
of a single IQ point causes an average drop in lifetime earnings of
$22,250
in current dollars. Since 200
million Americans now live in areas where water is fluoridated, and since
virtually all Americans consume processed foods and beverages made with
fluoridated water, any reduction in IQ from consumption of fluoride-
treated
water stands to have very large economic consequences.
In 2010, there were 74.2
million children under the age of 18 living in the U.S., of which we can
estimate roughly 50 million were living in fluoridated areas. If we apply
Wang’s dose-response data and assume that these 50 million children consumed
between 0.5 to 1 liters of fluoridated water per day during childhood,
fluoridation would have caused a loss of between 62.5 to 125 million IQ points,
resulting in a total loss in lifetime earnings of between $13.9 to 27.8
trillion for this generation. Due to the sheer number of people exposed to
fluoridation chemicals, even if only sentinel or susceptible
populations
in fluoridated areas suffer IQ loss, the economic impacts will still be
substantial. For example, even if
we conservatively assume that only 1 to 5% of children in a fluoridated area
suffer any IQ loss,and even if this IQ loss averaged just 1 IQ point,
this
would still amount to 500,000 to 2,500,000 lost IQ points, with a total loss in
lifetime earnings ranging from $11.1 billion to $55.6 billion for this generation
alone.
XII. IT
IS IN THE PUBLIC INTEREST FOR EPA TO TAKE ACTIONUNDER TSCA
As the above
discussion has indicated there are urgent health and economic reasons why the
EPA should use the provisions in TSCA to ban the purposeful addition of
fluoride to the public drinking water.
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