Endocrine disrupters: DDT

By 5. March 2013Blog, Health, Risk Management

Dichlorodiphenyltrichloroethane (DDT) is an organochlorine pesticide, first discovered in 1874, that became a major pesticide during World War II after it was found to have pesticidal properties. It was used to control typhus, malaria and dengue fever. After the war, it became available commercially as was used to control a wide variety of insect pests such as the Colorado potato beetle, coddling moth and corn earworm.

Then people started voicing concerns about the indiscriminate use of DDT and the possible effects it was having on wildlife and the environment. It all came to a head in 1962 with the publication of the book “Silent Spring”. The book was a best seller and is cited as being responsible for the start of the environmental movement in the US. President Kennedy asked his advisors to look into the claims of the book and they came back recommending a phase out of persistent toxic pesticides.

That is the problem with DDT, it is fat soluble, meaning it is stored in the fat of the animals that consume it. They are then eaten by bigger animals who absorb this DDT and it accumulates up the food chain in a process known as biomagification.

It is suspected that bald eagles, for instance, nearly became extinct due to DDT (or more precisely DDE) causing the egg shells to be thinner than normal. This meant the parent birds were crushing the eggs they were trying to incubate as the thinner than normal shells could not support their weight.

DDT is an endocrine disrupter and interferes with reproductive development. It has been shown to reduce fertility in both men and women.

DDT was banned in most countries in the 70’s and 80’s and in 2004 several persistent organic pollutants including DDT were outlawed at the Stockholm Convention, which has been ratified by more than 170 countries. Its use as a vector control is still permitted.

Read the story on Wikipedia.