Evolution under threat as 'gender bending' chemicals are turning males into females



The soaring number of gender bending chemicals in our food, water and air are triggering an infertility time bomb which could disrupt evolution, scientists are warning.

They say wildlife is being 'feminised' by a host of common man-made pollutants which escape into the environment and mimic the female sex hormone oestrogen.

The chemicals - found in food packaging, cleaning products, plastics, sewage and paint - trigger genital deformities, reduce sperm count and even turn males into females.

Polar bears are among the dozens of species being 'feminised' by man-made pollutants being released into the air

Dozens of species - including polar bears, fish, bald eagles, otters and whales - are suffering, they say.

Although the report, published by the environmental group ChemTrust, only looked at the impact of gender bending chemicals on the animal world, its authors say the findings have disturbing implications for human health.

Gywnne Lyons, a former Government advisor on chemical pollution and author of the report, said: 'Urgent action is needed to control gender bending chemicals and more resources are needed for monitoring wildlife.

'If wildlife populations crash, it will be too late. Unless enough males contribute to the next generation there is a real threat to animal populations in the long term.'

The report looks at the effect of hormone disrupting chemicals - including phthalates added to plastics such as PVC and glues, and bisphenol A used in the linings of food cans, plastics bottles and dental sealants.

'Males of species from each of the main classes of vertebrate animals (including bony fish, amphibians, reptiles, birds and mammals) have been affected by chemicals in the environment,' the report said.



'Feminisation of the males of numerous vertebrate species is now a widespread occurrence.'

Fish have shown signs of developing eggs in their testes

Fish have been badly hit by man-made gender bending chemicals. In one study, half the male fish in British lowland rivers had signs of being feminised - including the development of eggs in their testes.



Some male roaches have changed sex completely after exposure to oestrogen from the Contraceptive pill pouring out of sewage works.



A University of Florida study earlier this year revealed that 40 per cent of male cane toads had become hermaphrodites in a heavily farmed part of the state.



A similar link has been shown between farming and sex changes in northern leopard frogs in Canada, the report says.

Elsewhere in Florida, male snapping turtles have been found with female characteristics, while male alligators have been born with abnormal sexual organs and fertility problems.



A study at Cardiff University found that the brains of male starlings at a sewage plant were altered by a diet of worms contaminated with female hormones. The birds sang longer and more skilful 'female' songs.

In Florida, male alligators have been born with fertility problems

Other studies have found undescended testes in male Sitka black tailed deer in Alaska, fertility problems in male eland in South Africa, hermaphrodite polar bears in the Arctic and reduced testosterone levels in whales.

All vertebrates - or creatures with backbones - have similar sex hormone receptors in their bodies, the report says.

'Therefore, observations in one species may serve to highlight pollution issues of concern for other vertebrates, including humans,' it adds.

Earlier this year, a British study found that people with higher than normal levels of bisphenol A in their blood were more likely to suffer from potentially dangerous heart problems. The chemical - used to make shatter proof plastic - also appeared to raise the risk of diabetes.

And an American study showed that baby boys born to women exposed to gender bending chemicals in pregnancy were at greater risk of being born with genital deformities.



