Findings & Recommendations for the Remediation of Historic Pesticide Contamination - Final Report March 1999
Table of Contents

Addendum 3

Use and Human Health Information for Selected Organochlorine Pesticides

From the EPA Integrated Risk Information System Database and Health Effects Summary Tables

Toxaphene

Toxaphene is an organochlorine pesticide containing over 670 individual chemicals. Toxaphene was developed in 1947 and had the greatest use of any single insecticide in agriculture. Toxaphene was used on cotton and other crops, first in combination with DDT. Then, in 1965, after several major cotton insects became resistant to DDT, toxaphene was formulated with methyl parathion, an organophosphate. It was also used to control insect pests on livestock and to kill unwanted fish in lakes. In 1982, toxaphene was canceled for most uses; and banned for all uses in 1990.

Toxaphene persists in the soil and breaks down very slowly in the environment. The residential cleanup level for toxaphene is 0.6 ppm (EPA), 0.1 ppm (DEP). It is not known whether toxaphene causes cancer in humans due to insufficient information. Breathing, eating, or drinking high levels of toxaphene can damage the lungs, nervous system, and kidneys. There is no information on how low levels affect human health.

Heptachlor/Heptachlor epoxide

Heptachlor is an organochlorine pesticide of the cyclodiene group; heptachlor epoxide is a breakdown product of heptachlor. The epoxide is more likely to be found in the environment.

Heptachlor was registered as a commercial pesticide in 1952 for insects in homes, buildings and on food crops, especially corn and for malarial control programs; after 1960 it was used primarily in soil applications against agricultural pests and termites. Use slowed in the 1970s and stopped in 1988.

Heptachlor and heptachlor epoxide adhere to soil particles and can remain in soil and water for many years. Animals metabolize heptachlor to the epoxide, and plants take up heptachlor from the soils. The residential cleanup level for heptachlor is 0.1 ppm (EPA), 0.15 ppm (DEP) and for heptachlor epoxide 0.07 ppm (EPA). It is not known whether heptachlor or heptachlor epoxide causes cancer in humans due to insufficient information. Heptachlor and heptachlor epoxide mainly disrupt the function of the nervous system in humans.

Methoxychlor

Methoxychlor is a synthetic organochlorine insecticide that is structurally analogous to DDT.

Methoxychlor is used on agricultural crops, livestock, animal feed, grain storage, home gardens and on pets. Methoxychlor adheres strongly to soils and breaks down slowly in air, water, and soils.

The residential cleanup level for methoxychlor is 390 ppm (EPA), 280 ppm (DEP). Human data are unavailable, and animal evidence is inconclusive with regard to cancer causing effects of this pesticide. Methoxychlor is broken down quickly in the body, and not likely to cause neurologic effects unless exposed to very high levels. Little information is available about how methoxychlor affects the health of humans.

BHC

BHC is an organochlorine insecticide that exists in eight chemical forms (isomers). Technical grade BHC is a mixture of several different forms of BHC including the five isomers; alpha, beta, gamma, delta, and epsilon. The gamma isomer (called Lindane) is reportedly the only isomer that has insecticidal properties.

The insecticidal properties of BHC were discovered in 1940 by French and British entomologists. Lindane was used as an insecticide on fruit and vegetable crops (including greenhouse vegetables and tobacco) and forest crops (including Christmas trees). Lindane is still used in ointments for the treatment of head and body lice and scabies. Lindane is also used as an insecticide based seed dressing.

Lindane has not been produced in the United States since 1977, although it is still imported to and formulated in the United States. Lindane's use is restricted by the USEPA and it is applied only by a certified applicator. Technical grade BHC was also used as an insecticide in the United States but has not been produced here since 1983. BHC was withdrawn from the US market due to concerns over its carcinogenicity and ability to cause birth and reproductive effects.

BHC is broken down by algae, fungi, and bacteria in soil, sediments and water. It is unknown how long BHC isomers can remain in the soil. As with other organochlorine pesticides, BHC can be stored in human fat for long periods of time and may be released in breast milk during lactation. Lindane has also been shown to enter the fetus through the placenta.

The residential cleanup level of BHC is:

Alpha-BHC is categorized as a probable human, beta-BHC is categorized as a possible human carcinogen, gamma-BHC is categorized as a probable human carcinogen, technical BHC is categorized as a probable human carcinogen, delta-BHC is not classifiable as to human carcinogenicity. Inadequate human data is available to document the carcinogenicity of BHC in humans; sufficient evidence of carcinogenicity is available in animals.

Chlordane

Technical chlordane is a mixture of at least 23 different compounds including chlordane isomers, other chlorinated hydrocarbons and by-products. Chlordane was used to control insects on a wide variety of crops from 1948 until 1988. Until 1983, chlordane was used on crops like corn and citrus and on home lawns and gardens. Between July 1983 and April 1988, the only permitted use was for the control of termites. Chlordane was canceled in April 1988 due to concerns about cancer risk, evidence of human exposure via accumulation in body fat, persistence in the environment and adverse effects on wildlife. In 1988, EPA banned all uses of the pesticide. Chlordane is persistent in soil. While sunlight may break down a small amount of chlordane, volatilization may be the only major route of removal from soils.

The residential cleanup level for chlordane is 0.5 ppm (EPA), 0.25 ppm (DEP). Chlordane is characterized as a probable human carcinogen. Inadequate human data is available to document the carcinogenicity potential of chlordane in humans. Chlordane is readily absorbed through the skin and is very irritating to the skin and the eyes. Chlordane is stored in human fatty tissue, the kidneys, muscles, liver and the brain. Chlordane has also been found in human breast milk. Excretion of chlordane is relatively slow and can take days to weeks. Chlordane may disrupt the function of the nervous system in humans. Blood disorders, liver and kidney damage may also occur. Since chlordane induces liver enzymes, interactions with medical drugs and the pesticide may occur (such as decreased effectiveness of anticoagulants, steroids and increased activity of thyroxin). Chlordane may cause an acne-like rash following skin contact with the pesticide.

Endrin/Endrin Aldehyde/Endrin Ketone

Endrin is a pesticide used to control insects, rodents and birds. The pesticide has not been produced or sold in the United States for general use since 1986. Endrin aldehyde is an impurity and breakdown product of endrin. Endrin ketone is a breakdown product of endrin when it is exposed to light. Little information is known about the properties of endrin aldehyde or endrin ketone.

While persistence of the pesticide depends on local conditions, the compound has been estimated to remain in the soil for over 10 years. The residential cleanup level for endrin is 23 ppm (EPA), 17 ppm (DEP). The basis for the cleanup level is the non cancer endpoint

Endosulfan (I & II)

Endosulfan is a mixture of two different forms of the same chemical (alpha- and beta- endosulfan). Endosulfan is an insecticide used to control insects on grains, tea, fruits, vegetables, tobacco and cotton. Endosulfan is also used as a wood preservative in the United States. The pesticide has not been produced in the United States since 1982, although it is still used in the United States to produce other chemicals. Endosulfan does not dissolve easily in water and may stay in the soil for several years before it biodegrades. The residential cleanup level for endosulfan is 470 ppm (EPA), 340 ppm (DEP). The basis for cleanup level is non cancer endpoint in animals. Hyperactivity, tremors, decreased respiration and salivation have been noted in people ingesting high concentrations of the pesticide.