Organochlorine insecticides are among the oldest, most toxic, and most environmentally destructive synthetic pesticides. First introduced in the 1940s and 1950s, these chemicals were used extensively in agriculture, forestry, and in home pest control until most were banned in the 1970s and 1980s. They target the central nervous system, and many of them are suspected to cause cancer.
Organochlorines like DDT and lindane also tend to be very persistent, breaking down exceedingly slowly once released into the environment. This property made them attractive insecticides, since often just single application would be effective for months. But this also makes them especially dangerous to people and the environment because it means they can be incorporated into ecosystems and food chains where they persist for years.
These persistent pollutants tend to be poorly soluble in water but highly soluble in fat, a combination of properties that causes them to be stored in the fatty tissues of animals, a phenomenon called bioaccumulation. Because of bioaccumulation, the levels of organochlorines in a person can be much higher than levels in the environment or in food.
Today, most organochlorine pesticides have banned, at least in the U.S. Those few that are still in use include:
Endosulfan: Linked to autism, birth defects, and delayed puberty in humans, endosulfan is also extremely to fish, amphibians, and other wildlife. Endosulfan residues are highly mobile and contaminate not only agricultural areas, but also places far from where it's used, like the Florida Everglades and the Alaskan Arctic. In 2010, the EPA announced a ban on endosulfan, but granted it an extended phaseout period that allows some uses to continue until 2016. Find out more on our endosulfan page.
Lindane: An endocrine disruptor and likely carcinogen, agricultural uses of lindane were banned in the U.S. in 2006, and globally in 2010. Incredibly, this acute neurotoxin is still used in lice shampoos in the U.S., despite the availibility of safer and more effective alternatives, and bans on this use in California and more than 50 countries around the world. Read more about lindane here.
Dicofol: This close relative of DDT is an endocrine disruptor and possible carcinogen. Though banned in Europe, it is still used on cotton and fruit crops in the U.S. and other countries.
Organochlorines no longer use in the U.S. include:
DDT: This infamous pesticide has been banned in the U.S. since 1972 but continues to be for malaria control in Africa and parts of Asia. Highly persistent and mobile, DDT and its breakdown products contaminate ecosystems and human bodies around the world, even in remote locales where it's never been used, like the Arctic. Read more about the human health and environmental impact DDT here.
The "drins": aldrin, endrin, dieldrin: Today these extremely toxic insecticides are banned globally under the Stockholm Convention on Persistent Organic Pollutants, but they were used until the mid-1980s in the U.S. Like most organochlorines, they are highly persistent in the environment and bioaccumulate in animals.
Impaired Neurological Development:
Cancer: A significant body of research links organochlorine pesticides to cancer. Organophosphates are associated with non-Hodgkins lymphoma, leukemia, as well as breast, prostate, and testicular cancer. Studies show that prenatal exposure to organochlorine pesticides can increase risk of cancer later in life. For instance girls exposed to DDT before puberty are 5 times more likely to develop breast cancer in middle age, according to the President’s Cancer Panel.
Developmental Effects & Thyroid Disruption:
Autism: New research suggests that children whose mothers lived near applications of the organochlorine pesticides endosulfan and dicofol during the first trimester of pregnancy are at significantly greater risk for developing Autism Spectrum Disorders. See more on environmental factors & autism.
Parkinson's and Alzheimer's Disease:
Humans carry a cocktail of organochlorine pesticides in their bodies, even though the majority of OC's were banned or restricted years ago. Recent CDC biomonitoring found measurable levels of dieldrin, chlordane, heptachlor, and DDT in the blood and urine of people tested.
People are commonly exposed to organochline pesticides on food residues. USDA found DDT breakdown products in 60% of heavy cream samples, 42% of kale greens, 28% of carrots and lower percentages of many other foods. The OC pesticide lindane lingers on common foods such as rice, potatos and green beans. Although human exposure from food is small, organochlorines do not break down easily and can build up in the body over time.