Pesticides' global threat

Some of the most dangerous environmental pollutants have been found in the some of remotest parts of the world, from the Arctic to the Equator, writes Steve Connor.

A study of 200 samples of tree bark gathered from 90 sites has revealed up to 22 different organochlorines used in pesticides. Some of the pesticides, such as DDT, have been found in countries that have banned them for years. The researchers believe the distribution shows that some are still being transported over vast distances from their original dumping sites.

Staci Simonich and Ronald Hites, of Indiana University, whose analysis is published in the journal Science, said: "Understanding the environmental fate of these compounds is particularly important because some of them are carcinogens and some may be oestrogen [the female hormone that could be responsible for the dramatic fall in male fertility] mimics.''