Pesticides have been associated with everything from cancer and infertility to Gulf War syndrome and eye abnormalities and, in many cases, there is solid evidence to back this up. For this reason, some countries have banned the use of certain pesticides in food and safety levels have been set for others which are deemed to protect the public. However, the jury is still out on the risk of consuming many pesticides on a long-term basis. And there has been a dispute between doctors and environmentalists over calls for a global ban on one of the main pesticides, DDT, which protects against malaria. BBC News Online's health team offers a guide to the ins and outs of pesticides.
Pesticides are poisons, so in themselves they are dangerous.
However, farmers count on the levels used to kill insects being low enough not to affect humans. So the main health fear associated with pesticides is not that someone will eat a sprayed apple and get cancer, but that residues will build up over the years and cause disease to develop slowly. Because such an effect is so long-term, it is difficult to prove it is happening, but many people prefer not to risk exposure to pesticides and opt for organic foods. The September 1999 report from the Working Party on Pesticide Residues found pesticides in many supermarket foods, but only a small proportion breached the limits. However, the approved usage level is set down for adults, potentially putting children at risk.