DDT (Dichlorodiphenyl-trichloroethane)

Posted: 21 August 2000

A chlorinated hydrocarbon once widely used as a broad-spectrum insecticide. Introduced during the Second World War as a delousing agent, it proved very effective against diseases such as malaria, yellow fever and typhus, which were spread by insects. Over the longer term, serious side affects became apparent. Being a broad-spectrum product, it killed beneficial insects as well pests and could accumulate in the environment for perhaps 20 years. Although not soluable in water, it was soluable in fat, which allowed it to migrate up the food chain, where it accumulated in the body tissue of the predators. In birds it caused the thinning of eggshells, seriously reducing the breeding success of some species. By the mid-1960s, DDT was found to be widespread in the fatty tissue of the human population, passed on from mother to child through breast milk. Although the link between DDT concentration and human health was not clear, its potential to cause serious ecological disruption was recognised, and it was eventually banned or had its use severely restricted in the developed world.