Public Safety Considerations on Lindane

Lindane and Drinking Water Contamination

The Environmental Protection Agency (EPA) has set a conservative target for the amount of lindane allowed in the U.S. water supply, recognizing that more than 99% of lindane use in the U.S. has been for agricultural purposes.1,2 That notwithstanding, extensive sampling of water treatment facilities by the EPA as well as the testing of streams by U.S. Geological Survey teams indicates that lindane levels are well below those considered unsafe.3,4 (See Large-Scale Water Contaminant Test Results for Lindane)

More specifically, “down the drain” estimates by the EPA of lindane in drinking water from pharmaceutical products showed that the amount of lindane reaching public water supplies from the use of prescription medications was “extremely low” and not of concern.1 (See 2006 EPA RED on Agricultural Lindane) Similarly, prescription sales figures and municipal water supply data applied to an unrealistic, worst-case scenario analysis also confirm that the use of lindane medications for the second-line treatment of scabies, head lice and pubic lice does not pose a significant threat to the nation’s drinking water.5,7 (See Unrealistic, Worst-Case Scenario for Pharmaceutical Lindane)

EPA on Lindane Medications and Drinking Water: “[T]he Agency does not have risk concerns for concentrations of lindane in surface water used as a source of drinking water from consumer use for both lice and scabies treatments” 1

There is no evidence of pharmaceutical-grade lindane presenting water safety concerns

Results of large-scale U.S. water contaminant test programs3,4
Sponsor (year)	Water samples tested	Lindane levels
U.S. Geologic Survey (1999 and 2000)	139 streams near large cities and farms across 30 states	Only 5.9% of samples tested positive for lindane; median level just one-tenth of 1991 conservative level* considered safe
EPA (2003)	16,000 water systems serving 100 million people across 16 states	0% at or above 1991 conservative level* considered safe

* “Level” refers to EPA’s maximum contaminant level (MCL)

EPA establishes and monitors guidelines for drinking water contamination

EPA sets Maximum Contaminant Levels (or MCLs) for many water contaminants based on the health effects observed in humans and/or animals8
The MCL is defined as the level at which no known or anticipated adverse health effects will occur
In 1991, EPA set the MCL for lindane at 0.2 µg/L (micrograms per liter), equivalent to 0.2 parts per billion (ppb)3
In 2003, EPA concluded that new data on the health effects of lindane justified raising the MCL to 1.0 ppb—change not implemented for practical reasons:
- States had no apparent difficulty in keeping lindane levels below the more conservative 1991 MCL of 0.2 ppb (see contaminant test program results above)3
- EPA decided that raising the allowable lindane drinking water levels to 1.0 ppb would not provide meaningful cost savings for public water systems or their customers3

Unrealistic worst-case scenario underscores water safety with lindane medications

Analysis by Shayne Gad, Ph.D., D.A.B.T., A.T.S., Adjunct Professor of Toxicology, Duke University Medical Center5

Case: City of Albany, state of NY, 2004 water supply data
Assumption: proportional use of all lindane shampoo and lotion sold in New York State
A worst-case (unrealistic) scenario: assumes 100% of prescribed lindane shampoo and lindane lotion was not washed down the drain (and thus out of the water supply) but was instead poured directly into Albany’s drinking water reservoir
Results: lindane levels would still be well below those considered unsafe—67-times lower than the conservative 1991 MCL and 333-times lower than the 2003 MCL considered safe by the EPA3,5–7 (See Water Calculation)

Unrealistic, worst-case scenario shows lindane water supply levels well below those considered unsafe3,5–7

Putting water supply concerns in context

Chlorine is a chemical added to our water supply as a disinfectant to make it safer to drink; as with lindane, the EPA has set maximum levels of residual chlorine allowed in water, above which toxicity can occur9,10
In general, studies have shown that there is an extremely low likelihood of human health risk originating from low concentrations of pharmaceuticals in drinking water11

Please See Important Safety Information on Lindane

References:

U.S. Environmental Protection Agency (EPA). Lindane Reregistration Eligibility Decision (RED). 2002. Available at: http://www.lindane.com/pdf/lindane_epa_2002.pdf.
Commission for Environmental Cooperation. The North American Regional Action Plan (NARAP) on Lindane and Other Hexachlorocyclohexane (HCH) Isomers. October 5, 2005. Available at: http://www.cec.org/files/PDF/POLLUTANTS/Lindane-NARAP-Public-Comment_en.pdf.
U.S. Environmental Protection Agency (EPA). Announcement of completion of EPA’s review of existing drinking water standards. Federal Register. 68(138): July 18, 2003.
Kolpin DW, Furlong ET, Meyer MT, et al. Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999–2000: A national reconnaissance. Environ Sci Technol. 2002;36(6):1202–1211.
Data on file, Morton Grove Pharmaceuticals, Inc.
City of Albany, NY Department of Water. Annual Drinking Water Quality Report for the Year Ending December 31, 2004. Available at: http://albanyny.gov/Government/Departments/WaterAndWaterSupply/2004AnnualDrinkingWaterQualityReport.aspx .
U.S. Census Bureau. State and County QuickFacts: New York. 2004. Available at: http://quickfacts.census.gov/qfd/states/36000.html.
U.S. Environmental Protection Agency (EPA). Setting Standards for Safe Drinking Water. Last updated February 14, 2005. Available at: http://www.epa.gov/safewater/standard/setting.html.
U.S. Environmental Protection Agency (EPA). Integrated Risk Information System (IRIS) on Chlorine (CASRN 7782-50-5). National Center for Environmental Assessment, Office of Research and Development, Washington, DC. Last updated August 12, 2005. Available at: http://www.epa.gov/iris/subst/0405.htm.
U.S. Environmental Protection Agency (EPA). Ground Water & Drinking Water. List of Drinking Water Contaminants & Their MCLs (EPA 816-F-02-013). Last updated August 12th, 2005. Available at: http://www.epa.gov/safewater/mcl.html#mcls.
Jones OA, Lester JN, Voulvoulis N. Pharmaceuticals: a threat to drinking water? TRENDS in Biotechnol. April 2005;23(4):163–167.