May 8, 2000
The Honorable Carol M. Browner
Administrator
U.S. Environmental Protection Agency
401 M Street, SW
Washington, DC 20460
Dear Administrator Browner:
The Committee on Science received the Environmental Protection Agency's
(EPA) response to our letter of May 10, 1999, regarding EPA's maximum
contaminant level goal MCL (G) for fluoride in drinking water and
we would like to ask further questions to clarify or expand on some
of EPA's responses. Similar questions are being sent to other federal
government agencies. Please respond to this letter by June 1, 2000.
1. On November 18, 1998, two EPA scientists, Drs. James Murphy
and William Hirzy, wrote a memorandum to Dr. Oscar Hernandez, Director
of the Risk Assessment Division, Office of Pollution Prevention and
Toxics (OPPT) on the subject of the then pending Children's Health
Test Rule. Drs. Murphy and Hirzy cited six recent studies that indicated
that fluoride might pose a risk of neurotoxicity for children. They
also pointed out that a Reference Dose (calculated using standard
EPA methodology) and the cited studies would have a range of 0.000007
mg/kg-day to 0.003mg/kg-day. They noted that no chronic studies of
any kind appear to have been conducted on hydrofluosilicic acid or
its sodium salt -- which are used in around 90% of water fluoridation
systems in the U.S. -- and that the potential for those substances
to form complexes with heavy metals (such as lead) has not been studied.
Given the extremely wide-spread exposure of millions of American children
to fluoride, and in particular to hydrofluosilicic acid and its sodium
salt, along with the Administration's concern for the health of children
and these two scientists' positions at EPA, surely EPA has responded
to their November 18, 1998, memorandum. Please provide a copy of EPA's
response, and what action EPA has taken to deal with the concerns
raised in the November 18, 1998, memorandum. 2.
Given that normal, healthy teeth do not display fluorosis, does EPA
consider the appearance of dental fluorosis as a sign of too much
exposure to fluoride? If not, why not? If so, at what incidence level
would EPA consider that the population is receiving too much exposure
to fluoride? 3. What regulations does EPA
have -- either promulgated, under development or under consideration
-- to control fluoride emissions to the air, water or soil? Regarding
emissions of hydrofluosilicic acid, which EPA has characterized as
a water and air pollutant, how does EPA explain its willingness to
allow this substance to be bled into drinking water systems (especially
in the absence of any chronic toxicity studies on it) -- as long as
the fluoride level does not exceed 4 mg/L? Is it EPA's policy that
the "solution to pollution is dilution" as long as the pollutant
is applied directly into drinking water systems and not into fresh
surface water? 4. What has EPA done to investigate
the charges of science
fraud made in the amicus curia brief submitted by your headquarters
professionals union in 1986 in the NRDC v. EPA lawsuit over drinking
water standards that was filed in that year (and subsequently reiterated
by Drs. Robert Carton and William Hirzy of the union in a 1998 National
Association of Environmental Professionals publication)?
5. What has EPA done to investigate charges made
by Office of Ground Water and Drinking Water Senior Science Advisor
Dr. William Marcus that data were tampered
with and conclusions improperly down-graded in the National Toxicology
Program (NTP) cancer study on sodium fluoride? Regarding the NTP study,
mandated by Congress in 1977 to specifically exclude the Public Health
Service and the National Institutes of Health from involvement with
it (because they would not be unbiased), how is it that EPA did not
challenge the down-grading of the study conclusions? 6.
What disciplinary action has been taken against the EPA employees
involved in firing Dr. Marcus (and thereby incurring unwarranted expenses
to the taxpayers)? What personnel actions have been taken against
those involved including promotions, awards, transfers, demotions,
firing, etc?
7. Fluoride is well recognized as a general enzyme poison
(arising from its powerful hydrogen-bonding propensity that disrupts
protein [and DNA/RNA] structures) and it displays high acute toxicity
(ca. 5 mg/kg as threshold lethal dose), ranking as an acute toxicant
lying between lead and arsenic. A host of chronic toxic effects of
lead and arsenic are acknowledged by EPA (e.g. hematopoietic effects,
cardiovascular effects, neurologic effects, carcinogenicity, etc.).
The EPA view of fluoride toxicity appears to be that ingested fluoride
strengthens teeth, or will kill, or will inflict skeletal fluorosis,
but it has no other chronic toxic effects as its neighbors arsenic
and lead do. How does EPA explain this unique toxicological behavior
of fluoride, especially in light of its known effect on enzymes?
8. How many individuals in the nation does EPA
estimate fall into the category depicted as "unusually susceptible"
in the Toxicological Profile for Fluorides, Hydrogen Fluoride,
and Fluoride, published by the Agency for Toxic Substances and
Disease Registry? What measures does EPA recommend for these unusually
susceptible individuals who live in fluoridated communities or communities
whose water contains fluoride at the MCL (G)? 9.
Do you interpret Section 101(b)(4) of the Safe Drinking Water Act
of 1996 as requiring EPA to set its MCL(G)s at a level that protects
all persons, including sensitive subpopulations, such as infants,
children, people who drink 4 or more liters of water per day, people
with allergies or hypersensitivity to fluoride, and people with renal
disease? 10. Is the EPA satisfied that fluoride
doses delivered to the public via drinking water under an MCL(G) of
4 milligrams/liter (mg/l) when added to the fluoride intake from dental
products, pesticide residues, food and beverages will not cause adverse
health effects? 11. What is the margin of
safety for infants who consume drinking water containing 4 mg/l of
fluoride? 12. What is the margin of safety
for persons receiving kidney dialysis treatment, diabetics or those
who have a hypersensitivity or allergy to fluoride who consume drinking
water containing 4 mg/l of fluoride? 13.
Does the incidence of dental fluorosis among at least an estimated
22% of American children indicate that, at least among these children,
an overdosing is occurring? 14. What steps
has the Agency taken to address the hazards identified with fluoride
exposure in the following publications that appeared since the EPA
reaffirmed its drinking water standards for fluoride? These publications
include:
(a) Neurotoxicity of sodium fluoride in rats
Mullenix, P.J., Denbesten, P.K., Schunior, A. and Kernan,
W.J. Neurotoxicology and Teratology 17 169-177 (1995);
(b) Influence of chronic fluorosis on membrane
lipids in rat brain. Z.Z. Guan, Y.N. Wang, K.Q. Xiao, D.Y Dai,
Y.H. Chen, J.L. Liu, P. Sindelar and G. Dallner, Neurotoxicology
and Teratology 20 537-542 (1998);
(c) Chronic administration of aluminum-fluroide
or sodium-fluoride to rats in drinking water: alterations in neuronal
and cerebrovascular integrity. Varner, J.A., Jensen, K.F., Horvath,
W., and Isaacson, R.L. Brain Research 784 284-298 (1998);
(d) Effect of high fluoride water supply on children?s
intelligence. Zhao, L.B., Liang, G.H., Wu, X.R. Fluoride
29 190-192 (1996);
(e) Effect of fluoride exposure on intelligence
in children. Li, X.S., Zhi, J.L., and Gao, R.O., Fluoride
28 (1995);
(f) Effect of fluoride on the physiology of the
pineal gland. Luke, J.A. Caries Research 28 204 (1994).
15. Please provide copies of any risk assessment
documents in EPA files that pertain to fluorine-bearing pesticides,
such as cryolite.
16. Have any studies on hydrofluosilicic acid or
silicofluorides been submitted to EPA under claimed Confidential
Business Information protection?
17. Does the EPA support the recommendations made
in the draft report of the Joint Science Advisory Board-Scientific
Advisory Panel Subcommittee on Data From Testing of Human Subjects
that states, "... in no case should developing humans be exposed
to neurotoxic chemicals."
18. Has the so-called "10x factor" been
considered or applied in any way for fluorine-bearing pesticides
under the FQPA?
19. Has the final rule and resulting risk assessment
found in FR, Vol. 62, No. 234, Friday, December 5, 1997, "Fluoride
has been identified as the residue of toxicological concern in cryolite
and synthetic fluoride and the available data show that these compounds
which are approximately 52.8% fluoride, act as free fluoride"
been applied to any other substances?
20. What is the Water Quality Criterion under the
Clean Water Act for protection of aquatic life (and for protection
of human health) for fluoride?
Please provide the committee with copies of any EPA publications,
studies, reports, memos, or any other correspondence relating to
the fluoride MCL(G) and water fluoridation.
I respectfully request your response to our concerns. Thank you
for your attention to this matter.
Sincerely,
KEN CALVERT
Chairman
Subcommittee on Energy and Environment
enc.
KC/tjv |