Chlordecone

Synonyms and Trade Names (partial list): GC 1189, Kepone, Merex
CAS No.: 143-50-5; molecular formula: C10Cl10O
Appearance: An odorless tan-white crystalline solid.
Properties: Molar mass 490.64 g/mol, Density 1.6 g/cm3, log KOW: 4.50 – 6.00.

Chlordecone was used as an insecticide on tobacco, ornamental shrubs, bananas, citrus trees, and in ant and roach traps. Structurally, chlordecone is very similar to mirex and therefore these chemicals share main characteristics.

Chlordecone breaks down slowly in the environment, and it may stay for years in soil and water. It also does not evaporate to any great extent from surface water or surface soil. Chlordecone does not dissolve easily in water, but will preferentially bind to soil and sediment particles. In soils, Chlordecone is fairly immobile and is unlikely to migrate far through soil or in groundwater. Like Mirex and other POPs, Chlordecone can bioaccumulate in fish or other organisms that live in contaminated water or that eat other contaminated animals.

The mechanism of toxicity to humans is not well understood. However, workers who were exposed to high levels of Chlordecone over a long period (more than one year) showed harmful effects on the nervous system, skin, liver, and male reproductive system. These workers were likely exposed primarily through touching Chlordecone, although they may have inhaled or ingested some as well.

Animal studies with Chlordecone have shown effects similar to those seen in people, as well as harmful kidney effects, developmental effects, and effects on the ability of females to reproduce. It is not known if these last three effects also occur in people. Animal studies have shown that ingesting high levels of Mirex can harm the stomach, intestine, liver, kidneys, eyes, thyroid, and nervous and reproductive systems.

The U.S. Department of Health and Human Services (DHHS) has determined that Chlordecone may reasonably be anticipated to be a carcinogen. There are no studies available on whether Chlordecone is carcinogenic to humans. However, studies in mice and rats have shown that ingesting Chlordecone can cause liver, adrenal gland and kidney tumors.

For more information:

Adapted from Tox Facts; Toxicological Profile for Mirex and Chlordecone. (US Department of Health and Human Services, Public Health Service 1995).

Chemical structure of Chlordecone
Source: UNEP
Hatfield Consultants The World Bank funded by the Canadian POPs Trust Fund through the      
Canadian International Development Agency
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