Study Finds Third Of Male Fish In Rivers Changing Sex

July 20, 2006 2:15 p.m. EST

London, England (AHN)-Alarming new research shows that a third of male fish in English rivers are changing sex due to the so-called "gender-bending" pollution.

Experts say female hormones from the contraceptive pill and HRT are being washed into the rivers and causing male fish to produce eggs, raising fears that the pollutants could also be contaminating drinking water-and even be affecting the fertility of men.

The Environment Agency study looked at the health of more than 1600 roach found in 51 rivers and streams around the country, finding that a third of the male fish were between sexes. However, in one waterway, near a particularly heavy discharge of treated sewage more than 80 percent had female characteristics.

Tests showed the males developed female sex organs and were producing eggs. Such fish also produce less sperm and the sperm that is produced is of low quality. Females may also be affected, producing abnormal eggs.

Research Professor Charles Tyler tells the Daily Mail that the fish are swimming in a soup of estrogen-like compounds, found in the Pill and in HRT, saying, "There is a soup of estrogen compounds, all with different degrees of potency and they are interactive in their effects-if you add them together, you add there are additional effects. This soup of estrogen is responsible for causing these changes to the fish. It is abnormal. These fish should be male or female. The fact that we have got such a large proportion right across the country is not right."

Although there is no conclusive proof, it is thought the hormone, which has similar actions in fish and humans, could be partly to blame for falling sperm counts in men. British men's sperm counts dropped by almost a third between 1989 and 2002, and one in six couples now have difficulty conceiving.

Meanwhile, the Environment Agency is looking at ways of improving the sewage treatment process, to either remove estrogen during the process or reduce the amount that is discharged into our waterways.