March 29, 2002

 

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-34239B – Lindane Revised Risk Assessments

 

The purpose of this letter is to comment on EPA’s Revised Risk Assessments for lindane.  These risk assessments were made available for public comment on January 31, 2002 (67 FR 4714).  The County Sanitation Districts of Los Angeles County’s (Sanitation Districts’) are concerned that the Revised Risk Assessments set dangerous precedents regarding pesticides and water quality.  In particular, the Sanitation Districts are concerned about discrepancies in water quality standards within the EPA, about EPA’s refusal to consider all uses of pesticides when conducting their risk assessments, and EPA’s lack of interaction with the Food and Drug Administration (FDA) regarding areas of overlapping responsibility.

 

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.

 

            The Sanitation Districts are concerned about discharges of lindane from their wastewater treatment plants.  Water quality standards for California’s inland surface waters and enclosed bays and estuaries were promulgated by the Environmental Protection Agency in May 2000^[1].  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 established a criterion of 19 ppt lindane for protection of human health via consumption of water and aquatic organisms.  This 19 ppt criterion for lindane is also EPA’s legally adopted national water quality criteria for waterbodies that are existing or potential municipal drinking water sources.^[2]

 

            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^[3].  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 took effect January 1, 2002.  However, the Sanitation Districts continue to see detectable amounts of lindane entering their sewers.  The continuing lindane loadings may be coming from pharmacies that are not aware of the ban on sales and from lindane lice and scabies products that have entered 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 Revised Risk Assessments for lindane follow.  Each comment begins with the specific document, page, and language upon which comments are being made.

 

1.      Agency Response to Phase III Comments on Lindane, p. B6.   “Public Comment: The County Sanitation District of LA and others noted that the California Toxics Rule (CTR) establishes a criterion of 19 ppt lindane for protection of human health via consumption of water and aquatic organisms. Based on this criterion, both monitoring data and EPA’s model generated EECs [estimated environmental concentrations] exceed the level of concern set by the CTR.   HED Response: The Maximum Contaminant Level Goal (MCLG) for lindane established by EPA’s Office of Water is 0.2 ppb (200 ppt). An MCLG is defined as the level of contamination in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety and are non-enforceable public health goals. OW’s Maximum Contaminant Level (MCL) for lindane is also 0.2 ppb. The MCL is an enforceable standard. The MCLG for lindane is based on EPA’s assessment that short term exposure to lindane at levels above the MCLG potentially cause nervous system effects and chronic exposures above the MCLG have the potential to cause liver and kidney damage.  It is EPA’s understanding that 19 ppt criterion established under the CTR is set based on potential lifetime cancer risk from long term exposure to lindane (www.epa.gov/fedrgstr/EPA-WATER/ 2000/May/Day-18/w11106.htm). Based on a recent review of the data, the Office of Pesticide Programs Health Effects Division (HED) has classified lindane into the category “Suggestive evidence of carcinogenicity, but not sufficient to assess human carcinogenic potential” because lindane caused an increased incidence of benign lung tumors in female mice only. HED’s Cancer Assessment Review Committee (CARC) therefore recommended that human cancer risk not be quantified. EPA’s Office of Water has similarly determined that there is inadequate evidence to state whether or not lindane has the potential to cause cancer from lifetime exposures in drinking water. Therefore, EPA believes that the Office of Water’s MCLG of 0.2 ppm is the appropriate health based standard for lindane in drinking water sources.”  EPA’s Office of Pesticide Programs should recognize that the EPA itself developed and adopted the CTR.  It is based on national water quality criteria that were also developed by EPA.  In particular, the 19 ppt standard for lindane in the CTR is the same as in EPA’s national water quality criteria.  The Office of Pesticide Programs needs to be aware that water quality standards for surface water bodies that are drinking water sources are based not only on drinking water from a waterbody but upon consumption of fish and other organisms living in the waterbody.  Therefore, some water quality standards for surface waters are more stringent than drinking water limitations.

 

An issue that is particularly worrisome to the Sanitation Districts is the use of different water quality criteria by different branches of the EPA. The Sanitation Districts are surprised that EPA would reject its own legally adopted surface water quality standards.  Publicly owned treatment works (POTWs) have to meet surface water quality standards for a variety of pollutants, including pesticides.  Meeting such standards for pesticides could become very difficult if EPA’s Office of Pesticide Programs chooses to ignore them in determining which pesticide uses are likely to cause water quality problems.  Before taking further action on the lindane reregistration, it is essential that the Office of Pesticide Programs and the Office of Water agree on appropriate water quality standards.

 

The Sanitation Districts were also surprised to read that “EPA’s Office of Water has similarly determined that there is inadequate evidence to state whether or not lindane has the potential to cause cancer from lifetime exposures in drinking water.”   The State of California and other states around the nation are currently basing water quality decisions on EPA’s surface water quality criterion for lindane, which is based on carcinogenic risk.  If EPA’s Office of Water is indeed considering revising their human health water quality criterion for lindane, such a revision has not yet been proposed nor received public comment and therefore should not be the basis for decision making.

 

2.      Overview of Lindane Risk Assessment, p. 6.  “The highest EECs for lindane in surface water (0.67 ppb, from GENEEC) and in groundwater (0.011 ppb, from SCI-GROW) are less than the acute DWLOCs [drinking water levels of concern] for all sub-populations (lowest acute DWLOC = 170 ppb) indicating that acute aggregate exposure to lindane in food and water does not exceed the Agency’s level of concern.” The EEC for surface water of 0.67 ppb is thirty-five times greater than EPA’s legally promulgated 0.019 ppb lindane human health criterion for waterbodies that are existing or potential drinking water sources.  The EEC for surface water is also expected to be higher when the risks from lice and scabies are considered.  The medical literature indicates that lindane has been used to treat scabies over 24 million times in the past 17 years.  This averages out to 1.41 million applications per year which amounts to 1320 pounds of active ingredient per year or 3.63 pounds per day.  Spread evenly among the 287 million residents of the United States and the average 100 gallons per day of sewage they produce, that is enough lindane to cause lindane concentrations in sewage to become 0.015 ppb.  If a similar amount of lindane is used in lice and scabies treatments, the 0.030 ppb of lindane from the pharmaceutical uses alone is enough to exceed EPA’s 0.019 ppb standard.  Note that pharmaceutical uses of lindane have a direct pathway to water, as pharmaceutical lindane is disposed to water in normal usage.

 

3.      Overview of Environmental Fate and Effects Division Integrated Environmental Risk Assessment for Lindane, p.3.  “Even considering lindane’s very low use rate under the current use restriction to seed treatment (maximum of 0.05 lb a.i./acre), lindane concentrations may be expected to reach water resources at environmentally significant levels.  Modeling studies showed that lindane concentrations in both surface and ground waters may reach environmentally significant levels (>MCL), even when lindane is restricted to seed-treatment uses only.  This conclusion is based solely on lindane’s use as a seed treatment and does not consider past uses of lindane.  However, note that lindane continues to persist in the environment from past uses.”  Projected lindane concentrations in water resources are likely to be even higher when lice and scabies treatments are considered, particularly as these treatments are disposed to water bodies.

 

4.      Overview of Environmental Fate and Effects Division Integrated Environmental Risk Assessment for Lindane, p.2-3.  When only seed treatment uses of lindane were evaluated, the following were found:  “Restricted use and endangered species LOC’s [levels of concern] are exceeded (RQ=0.40) for freshwater fish…. The acute endangered species LOC is slightly exceeded (RQ=0.07) for freshwater invertebrates…Acute, restricted use and endangered species LOC’s were exceeded (RQ=8.7) for estuarine/marine invertebrates…. Chronic risk to estuarine/marine invertebrates could not be assessed due to a lack of toxicity data.” [Note: RQ stands for risk quotient and is the ratio of estimated environmental concentrations to generally the most toxic ecotoxicity value (acute) or no-effect level (chronic) for that group of organisms.]  While these exceedances are worrisome, they likely to be more severe when lice and scabies treatments are considered, particularly as these treatments are disposed of in water.

 

5.      Agency Response to Phase III Comments on Lindane, p. A2.  “Public Comment:  Numerous commentors stated that EPA’s risk assessment of lindane would be incomplete without the inclusion of the pharmaceutical use of lindane as a lice and scabies treatment….  Response:  The Agency acknowledges this concern for the pharmaceutical use of lindane.  However, the Agency is still exploring this issue.”  The EPA still has not offered any explanation as to why it is neglecting to consider lice and scabies in its risk assessment, in the face of over a thousand requests to do so and in consideration of its statutory responsibilities and specific obligations as expressed in the Food Quality Protection Act (FQPA).  The lack of Agency consideration of pharmaceutical uses of lindane in the current version of the risk assessments does not relieve EPA of its statutory responsibility to ensure that pesticides are safe and effective for their intended uses and to prevent unreasonable adverse affects to man, other animals, and the environment from their usage (7 U.S.C. §136(bb), §136a(a), §136a(d)(2), §136d(b)).

 

EPA’s refusal to consider pharmaceutical uses of lindane in this risk assessment sets a worrisome precedent.  Other pesticides also have pharmaceutical uses.  The most notable is permethrin, which is used in lice and scabies treatments and has an extremely high aquatic toxicity.  When EPA conducts its reregistration of permethrin, it is essential for the protection of aquatic organisms that pharmaceutical uses of this pesticide are considered.

 

6.      Overview of Lindane Risk Assessment, p. 7.  “There are no residential or other non-occupational (e.g., golf course) pesticidal uses of lindane regulated by EPA.  However, there is a pharmaceutical use of lindane for head lice and scabies treatment, which is not included in this risk assessment at this time.”  It is irresponsible of EPA to undertake such an important risk assessment without considering these pesticidal uses of lindane that have a direct route to the waters of the United States.  It appears that EPA may feel uncomfortable about including risks from pharmaceutical uses of lindane in its risk assessment due to its current division of regulatory responsibilities with the Food and Drug Administration (FDA), as FDA is currently regulating pharmaceutical pesticides. If this is the case, EPA should implement a memorandum of understanding (MOU) with the FDA that would transfer responsibility for evaluating the environmental impacts of pharmaceutical pesticides to EPA.  Such information could then be shared with FDA for use in FDA’s decision-making processes.  Note that FDA has existing statutory authority under the Federal Food, Drug, and Cosmetic Act (FFDCA) and the Public Health Service Act to require a pharmaceutical manufacturer to submit additional environmental information on an existing FDA approval.^[4]  Under the MOU, FDA could obtain the necessary environmental information and EPA could evaluate the information.  It makes sense for all environmental information related to pesticide use to be evaluated by a single regulatory agency, to ensure consistency and fair treatment.

 

The Sanitation Districts strongly recommend that EPA and FDA immediately convene a working group to discuss the feasibility of developing an MOU or some other means of ensuring that the environmental impacts of pharmaceutical pesticides be adequately considered as EPA performs its reregistration processes.  Development of a formal MOU may be too time-consuming for the lindane reregistration process given its tight time constraints.  If so, such an MOU should still be pursued because of other pharmaceutical pesticides but in the meantime FDA should use its own environmental staff within its Center for Drug Evaluation and Research to work with EPA on performing a parallel risk assessment.

 

7.      Agency Response to Phase III Comments on Lindane, p. B6.  “Public Comment:  A number of commentors raised concerns that the EPA did not include a quantitative assessment of risks from exposure of children to lindane from direct application of the pesticide to their scalp or body for treatment of head lice or scabies.  Commenters stated that the FQPA requires that this source of exposure be taken into account.  HED Response:  The risk assessment does not at this time include an assessment of risks from exposure to lindane from uses other than seed treatment.”  The Sanitation Districts are looking forward to reviewing a version of the risk assessment that does take into account such risks.

 

8.      Agency Response to Phase III Comments on Lindane, p. A3.  “Public Comment:  Several commentors also expressed concern about the potential human health and environmental impacts from the disposal of lice and scabies treatments.  These treatments are rinsed off (disposed of) into municipal sewers that do not effectively remove lindane before discharging their effluent into surface waters.   Response:  … Nevertheless, the Agency has funded two pollution prevention projects (in Region II and Region IX) to see if the pharmaceutical uses of lindane can be altered or replaced with other treatments that are less persistent and/or less toxic to the environment.”  The Sanitation Districts were the lead agency for the Region IX pollution prevention project.  The purpose of the project was not to determine if the pharmaceutical use of lindane can be replaced with other treatment that are less toxic, as such replacement is widely accepted and well-documented in the medical literature.  The purpose of the project was to encourage the use of less toxic treatments among affected populations.  The project led to a ban on pharmaceutical use of lindane in California that took effect on January 1, 2002.  In the three months since the ban’s inception, there have been no known reports of problems with the lindane restriction.

 

9.      Revised Human Health Risk Assessment for 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, although they are also pharmaceutical 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.

 

10.  Revised Human Health Risk Assessment for 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.”  Any aggregate exposure assessment must include risks posed by lindane in lice and scabies treatments.

 

Contact Information

 

The Sanitation Districts appreciate your consideration of our comments.  If you have any questions about this letter or require additional information, please contact Ann Heil of the Sanitation Districts’ Industrial Waste Section by phone at 562/699-7411, extension 2950, or by e-mail at aheil@lacsd.org.

 

Very truly yours,

 

James F. Stahl

 

Paul C. Martyn

Head, Industrial Waste Section