A fishy tale?

A new culprit for the decline in male fertility in Britain may have been identified. Scientists have claimed that chemicals that are known to have been responsible for causing male fish to change sex could also affect human fertility if they find their way into drinking water.

Research undertaken by the UK Government's Environment Agency shows that artificial oestrogens - from contraceptive pills, for example - pass through sewage works and into rivers, where they have had a drastic effect on male fish. Male fish have been found to have developed eggs or female reproductive ducts, many have become sterile and others produced defective sperm.

Scientists and environment campaigners are concerned that the oestrogens and other chemicals may also be getting into drinking water and, consequently, may affect human fertility. It is estimated that one third of Britain's drinking water comes from rivers. Dr Susan Jobling, who carried out the research said that humans should be warned, adding 'the issue is not just about fish. Everything that we eat, put on our skin, throw down the drain, ends up in the sewage treatment works and ultimately in the river'.

The Environment Agency claims that there is no danger and that drinking water is tested, including by putting fish in it to see if they become feminised. However, some scientists say that the equipment used is not sensitive enough to detect small amounts of the chemicals and that there is no routine testing. Scientists from the University of Ulm in Germany, using more sophisticated detection devices, found that four out of every ten samples tested were affected.