October 22, 2001
Public Information and Records Integrity
Branch (PIRIB)
Information Resources and Services Division
(7502C)
Office of Pesticide Programs (OPP)
Environmental Protection Agency
1200 Pennsylvania Avenue, NW
Washington, DC 20640
Docket Control Number OPP-34239 –
Lindane Preliminary Risk Assessments
The purpose of this letter is
to comment on EPA’s Preliminary Risk Assessments for lindane. These risk assessments were made available
for public comment on August 29, 2001 (66 FR 45677). The County Sanitation Districts of Los Angeles County’s
(Sanitation Districts’) primary concern with the proposed risk assessments is
that they are deficient since they fail to take into account the environmental
and human health risks associated with the use of lindane in lice and scabies
treatments. Without inclusion of these
risks, the risk assessments are essentially meaningless. The Sanitation Districts also have comments
on EPA’s interpretation of the potential adverse water quality impacts of
lindane usage as a seed treatment.
Background
The Sanitation
Districts are a confederation of 26 independent special districts that serve
the water pollution control and solid waste management needs of over five
million people in Los Angeles County, California. Fifteen of the districts have collectively constructed an
extensive regional sewerage system known as the Joint Outfall System (JOS),
which conveys and treats approximately 450 million gallons per day (MGD) of
wastewater from 72 cities and unincorporated county areas. The JOS consists of seven treatment/water
reclamation plants and 1,200 miles of large diameter trunk sewers, that form a
network connecting the treatment plants and ocean outfalls off Whites Point on
the Palos Verdes Peninsula. The
Districts also operate four water reclamation plants in northern Los Angeles
County serving the communities in and around the cities of Santa Clarita,
Lancaster and Palmdale. On an annual
basis, over 50 MGD of reclaimed water is reused for applications including
groundwater recharge, landscape irrigation and industrial uses. The remainder is discharged to inland
surface waters that are effluent dependent water bodies. The beneficial uses of the receiving waters
are diverse and include municipal and industrial water supply, groundwater
recharge, water recreation, warm fresh water habitat, wildlife habitat,
commercial and sport fishing, and rare, threatened or endangered species
spawning, reproduction, and early development.
Solid material removed during treatment is digested and dewatered. The resulting biosolids are either
landfilled or beneficially reused for agricultural land application.
Wastewater
discharged from the Sanitation Districts’ treatment plants contains 20 to 30
parts per trillion (ppt) of lindane.
While this has been acceptable in the past, water quality standards for
California’s inland surface waters and enclosed bays and estuaries were
promulgated by the Environmental Protection Agency in May 2000. These standards are known as the California
Toxics Rule and establish water quality criteria for the protection of aquatic
life and human health. In the latter
case, the criteria are intended to minimize the adverse human health effects
due to substances in ambient water. The
California Toxics Rule establishes a criterion of 19 ppt lindane for protection
of human health via consumption of water and aquatic organisms. This 19 ppt criterion for lindane was also
included in EPA’s 1998 national compilation of recommended water quality
criteria.
Since
most receiving waters in Southern California are effluent-dominated, the 19 ppt
criterion will be applied directly as an effluent limit for most of the
Sanitation Districts’ treatment plants.
It is also important to note that even though mixing zones are available
for some POTWs, the EPA has begun a campaign for nationwide elimination of
mixing zones for bioaccumulative toxic pollutants, such as lindane. Thus most POTWs across the country can
expect that, at some future date, water quality criteria for bioaccumulative
toxic pollutants such as lindane will be applied as end-of-pipe water quality
based effluent limits.
Because
lindane is a highly regulated pesticide, the routes for it to enter the
sewerage system are extremely limited, particularly in urban areas such as
Southern California. The main pathway
is from human treatments for lice and scabies with lindane-containing
products. Lice are insects that live on
human bodies in hairy areas. A one
percent lindane shampoo is available with a physician’s prescription to control
lice. After use, shampoo is washed into
the sewer system. Similarly, scabies is
a mite that lives in the human skin. A
one percent lindane lotion available with a physician’s prescription can be
applied to the skin to control scabies, with the lotion washed to the sewer
system following application. A typical
lice or scabies treatment uses one to two ounces of the one percent lotion, or
approximately 0.015 ounces of the lindane active ingredient. That is enough lindane to pollute 6 million
gallons of water to the 19 ppt standard.
In the past 17 years, lindane has been applied more than 24 million
times to treat scabies. These treatments contained enough lindane to
pollute 144 trillion (144,000,000,000,000) gallons of water.
In order
to reduce lindane loadings to the Sanitation Districts’ system, the Sanitation
Districts actively pursued a ban on the sale and use of lindane-containing lice
and scabies prescriptions in California that will take effect January 1,
2002. However, the Sanitation Districts
are concerned that lindane lice and scabies products will continue to enter
California from out-of-state. As a single
lice or scabies treatment contains enough lindane to pollute six million gallons
of water to the 19 ppt standard, a single treatment could cause a discharge
violation at a smaller POTW. Therefore,
even small amounts of lindane entering California from out-of-state are of
concern.
Specific Comments
Specific
comments on the Preliminary Risk Assessments for lindane follow. Each comment begins with the specific
document, page, and language upon which comments are being made.
1. Overview of Lindane Risk Assessment, p.
6. “ The chronic EECs [estimated
environmental concentrations] for Lindane in surface water (0.67 ppb, from
GENEEC) and in groundwater (0.011 ppb, from SCI-GROW) are less than the chronic
DWLOC [drinking water level of comparison] (14 ppb), indicating that chronic
exposure to lindane in food and water only is less than the agency’s level of
concern.” The chronic EEC for lindane in surface water of 0.67 ppb is
thirty-five times EPA’s allowable criterion of 0.019 ppb for the protection of
human health via consumption of water and aquatic organisms. If surface water
containing 0.67 ppb of lindane was distributed in the Sanitation Districts’
service area, we would expect a similar amount of lindane to be present in
wastewater entering our treatment plants.
A number of our treatment plants are facing possible discharge limits of
0.019 ppb under the California Toxics Rule.
Since lindane is not removed well in conventional or tertiary wastewater
treatment plants, it would be impossible to meet the 0.019 ppb discharge
limitation if water entering the plants had lindane concentrations approaching
0.67 ppb.
2. Overview of Lindane Risk Assessment, p.
6-7. “In the USGS NAWQA study, lindane was detected in 2.58% of surface
water samples (0.67% at levels greater than 0.05 ppb, maximum concentration
reported was 0.13 ppb)… Although these long-term monitoring programs have
detected lindane in various water bodies, the Agency determined that these data
are not suitable for risk assessment, because there is no correlation of
monitoring with actual lindane use.
Therefore, these data are presented here solely for informational
purposes.” 2.58% of surface water
samples represents one in thirty-eight samples, a significant degree of
contamination for the nation’s surface water bodies. As lindane does not naturally occur in the environment,
these environmental concentrations are coming from lindane usage in some
form. As lindane is only used as a
pesticide, the contamination must be coming from lindane pest treatments. It is not clear why the data should be
considered “not suitable for risk assessment.”
3. Overview of Lindane Risk Assessment, p.
7. “There
are no residential or other non-agricultural FIFRA [Federal Insecticide,
Fungicide, and Rodenticide Act] uses of Lindane.” Lindane is widely used as a pesticide to treat lice and scabies
in humans. Although these uses are not
currently subject to regulation under the FIFRA, they were subject to such
regulation until 1979. Since lindane lice and scabies products are considered
to be drugs, they have also been subject to the Federal Food, Drug and Cosmetic
Act (FFDCA). On November 5, 1979 (44
Federal Register, 63749), EPA decided to exempt lindane lice and scabies
products from the requirements of the FIFRA.
The regulation of these products under both the FIFRA and the FFDCA was
felt to be duplicative, as stated in the announcement of the exemption, “EPA
and FDA concluded that the dual review of pesticide/new drug products offered
solely for human use represents an expensive duplication of time and resources
for both the Agencies and the sponsors of these products without any
significant increase in benefits to public health and/or the environment. It is further concluded that regulations of
these products solely by FDA under the FFDCA would adequately serve the intent
of FIFRA.”
Regulation under the FIFRA
and the FFDCA is no longer duplicative.
Since 1979, the degree of regulation under FIFRA has changed
considerably, most notably with passage of the Food Quality and Protection Act
of 1996 (FQPA). This statute requires
EPA to review all pesticide registrations on at least a fifteen-year cycle (7
U.S.C. §136a(g)(1)(A)). The goal of
this requirement is to ensure that all pesticides continue to meet up-to-date
standards for safety, public health, and environmental protection. EPA has the
authority to require data and take action if needed between registration cycles
(7 U.S.C. §136a(c)(2)(B); §136a-1(d)(3)).
No similar provisions exist under the FFDCA. Additionally, EPA has emergency suspension authority, which means
a pesticide registration can be canceled immediately if there is an emergency,
imminent threat to public health or the environment (7 U.S.C. §136d(c)). This
appears to be a much more direct and powerful tool to regulate pesticides when
compared to the FDA’s authority to simply require an Environmental Assessment
in such circumstances.
It
is the Sanitation Districts’ position that EPA should reassert its control over
lice and scabies treatments under the FIFRA.
Because such action is beyond the scope of the action EPA is currently
considering, EPA should, at minimum, consider the human health and
environmental impacts of these treatments in its current risk assessments. As lindane lice and scabies products
dominate the human health and environmental risks of lindane, the risk assessments
are essentially meaningless without them.
Under the FIFRA, EPA has a statutory responsibility to ensure that
pesticides are safe and effective for their intended uses and to prevent
unreasonable adverse effects to man, other animals, and the environment from
their usage (7 U.S.C. §136(bb), §136a(a), §136a(d)(2); §136d(b)). By ignoring the risks posed by lindane lice
and scabies treatments, EPA is not fulfilling its statutory responsibility.
4. Overview of Lindane Risk Assessment, p.
7. “The
aggregate risk assessment for lindane examines the combined risk from exposure
through food and drinking water only since there are no residential or other
non-agricultural uses of Lindane.” As discussed in Comment Five, there is significant usage of lindane in
the residential setting, from lice and scabies treatments. The Cancer Prevention Coalition has reported
that there were 2.3 million retail lindane prescriptions filled in 1992. It should be recognized that there are
satisfactory alternatives to lindane for both lice and scabies treatment. These alternatives are effective and widely
used.
5. Overview of Lindane Risk Assessment, p.
7. “The
DWLOC was calculated based only on dietary exposures. As noted above neither acute nor chronic, surface water or groundwater
EECs exceed the DWLOC and therefore do not exceed the Agency’s level of
concern.” The EEC for surface water
significantly exceeds EPA’s 0.019 ppb lindane human health criterion for
waterbodies.
6. Overview of Lindane Risk Assessment, p.
9. “..lindane and its isomers have been
detected in areas of non use (e.g., the Arctic), indicating global atmospheric
transport may occur. The source of
these lindane detections is unclear but may be the result of a combination of
lindane’s past widespread use and its extreme persistence.” It may also be the result on on-going usage
of lindane in lice and scabies treatments, as these treatments are rinsed into
sewer systems after use and thus indirectly enter surface water bodies.
7. Overview of Lindane Risk Assessment, p.
9. “Currently,
U.S. uses of lindane are restricted to (agricultural) seed treatments at
relatively low application rates.” This statement misrepresents lindane
usage inasmuch as lindane is also used for lice and scabies treatments in the
U.S.
8. Overview of Lindane Risk Assessment, p.
9. “At
current application rates used on major crops, acute high risk and restricted
use levels of concern are exceeded for both freshwater and estuarine/marine
organisms.” These levels are likely
to be even higher if lice and scabies treatments are considered, particularly
as these treatments are released indirectly to water bodies.
9. Environmental Fate and Ecological Risk
Assessment: Seed Treatment, p. 2. “At
present, there is only one agricultural use (seed treatment) that might affect
the environment.” This risk
assessment should also take into account aggregate ecological risk posed by the
use of lindane in lice and scabies treatments.
10. Environmental Fate and Ecological Risk
Assessment: Seed Treatment, p. 11. “Based on a screening level assessment,
both surface and ground water simulations show that lindane concentrations in
water resulting from seed treatments may reach levels of environmental concern
and may exceed the MCL for drinking water (0.2 ppb).” This assessment is incomplete. It fails to acknowledge lindane
contributions from lindane prescriptions for lice and scabies treatment. It also fails to acknowledge that the
resulting concentrations in water could exceed recommended water quality
criteria and, in California, adopted water quality standards.
11. Environmental Fate and Ecological Risk
Assessment: Seed Treatment, p. 14. “Agriculture run-off is likely the major
contamination route of lindane and other HCH isomers to surface water.” This assessment is incomplete. It fails to acknowledge that in urban areas,
as agricultural and structural uses of lindane have become more highly
restricted, contamination of water bodies is likely to be caused by lice and
scabies treatments.
12. Human Health Risk Assessment Lindane, p.
7. “No residential exposure scenarios have been identified for
pesticide uses of lindane and therefore no risk estimates will be presented in
this document for non-occupational exposure to lindane.” This conclusion is patently
incorrect. Uses of lindane to treat
lice and scabies are definitely pesticide uses. These uses involve direct application of lindane to humans and
thus a very high level of human exposure. These exposures must be considered when
doing an aggregate risk assessment for lindane.
13. Human Health Risk Assessment Lindane, p.
8. “The
Agency considered aggregate exposure and risk estimates for residents who might
be exposed to lindane from multiple sources, such as residential use, food, and
water. Since no residential exposure is
expected, an aggregate risk estimate was not calculated.” See Comment Fourteen. Any aggregate exposure assessment must
include risks posed by lindane in lice and scabies treatments.
14. Occupational and Residential Exposure
Assessment and Recommendations for the Reregistration Eligibility Decision
Document for Lindane, p.4. “There are no current registered uses for
recreational, residential or other public (non-occupational) settings.” Although not currently registered under
FIFRA, lindane usage in lice and scabies treatments must be considered in
properly assessing residential risks from lindane.
Contact Information
The Sanitation Districts would like to be added to
the stakeholder’s list for the lindane reregistration process. Our contact on lindane issues is Ann Heil of
the Sanitation Districts’ Industrial Waste Section. She can be reached by phone at 562/699-7411, extension 2950, or
by e-mail at aheil@lacsd.org. Ms. Heil
should also be contacted if you have any questions about this letter or require
additional information.
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Very truly yours,
James F. Stahl
Paul C. Martyn
Head, Industrial Waste Section
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