Dieldrin

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Dieldrin is a organochlorine pesticide that is now banned in most of the world. It is a white powder with a "mild chemical odor." Between the 1950s and 1970, dieldrin was used widely for crops like corn and cotton in the United States. It was banned by the U.S. EPA in 1974 for all uses except termite control. In 1987, the EPA banned all uses. Another pesticide, aldrin, is similar to dieldrin. In the human body and in the environment, aldrin changes to dieldrin.

In the Environment

In the environment, dieldrin binds tightly to soil and slowly evaporates into the air. Dieldrin breaks down in soil and water very slowly. Plants can take in and store dieldrin from the soil. Due to previous widespread use, dieldrin is everywhere in the environment, albeit at very low levels.

In Sewage Sludge

A study in Australia found several banned organochlorine pesticides (aldrin, chlordane, dieldrin, heptachlor, hexachlorbenzene, and DDT) in sewage sludge. Researchers found that in some cases, it takes as long as 15 years after the pesticides were banned for their levels in sewage sludge to drop below detectable levels.

Human Exposure and Health Effects

Humans are exposed to dieldrin by eating contaminated foods, particularly fish or shellfish from contaminated lakes or streams, or contaminated root crops, dairy products, and meat. Humans may be exposed to higher levels from air, surface water, or soil near waste sites, or by living in homes that were once treated with aldrin or dieldrin to control termites. Once ingested, dieldrin is stored in fat, so it leaves the body very slowly.

Ingesting a large amount of dieldrin will make a person suffer convulsions and, if the dose is high enough, die. Ingesting small doses over a long period of time may also result in health effects because dieldrin builds up in the human body. According to the CDC's Agency for Toxic Substances & Disease Registry:

"Some workers exposed to moderate levels in the air for a long time had headaches, dizziness, irritability, vomiting, and uncontrolled muscle movements. Workers removed from the source of exposure rapidly recovered from most of these effects.

"Animals exposed to high amounts of aldrin or dieldrin also had nervous system effects. In animals, oral exposure to lower levels for a long period also affected the liver and decreased their ability to fight infections. We do not know whether aldrin or dieldrin affect the ability of people to fight disease.

"Studies in animals have given conflicting results about whether aldrin and dieldrin affect reproduction in male animals and whether these chemicals may damage the sperm. We do not know whether aldrin or dieldrin affect reproduction in humans."

Aldrin and dieldrin have also caused liver cancer in mice. The EPA classifies aldrin and dieldrin as probable human carcinogens.

Federal Regulations

• Drinking Water: The EPA limits the amount of dieldrin present in drinking water to 0.002 milligrams per liter.

• Workplace Air: OSHA sets a maximum of 0.25 milligrams of dieldrin per cubic meter of air (0.25 mg/m3) in the workplace during an 8-hour shift, 40 hour week. The National Institute for Occupational Safety and Health (NIOSH) also recommends the same limit for up to a 10-hour work day, 40-hour week.

• Raw Food: The FDA limits the amount of dieldrin in raw food, with allowable amounts ranging from 0 to 0.1 part per million, depending on the type of food.

Articles and resources

Related SourceWatch articles

• Biosolids
• Sewage sludge
• Food Rights Network

External resources

Pesticide Action Network Database Listing for Dieldrin