Gender-bending chemicals putting our future at risk
By David Derbyshire, Last updated at 7:59 AM on 8th December 2008
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The soaring number of gender-bending chemicals in the environment has disturbing fertility implications for humans and wildlife, scientists are warning. They say wild animals are being 'feminised' by a host of common man-made pollutants which mimic the female sex hormone oestrogen and escape into seas, rivers, the earth and air when waste is disposed of. The chemicals - found in food packaging, cleaning products, plastics, sewage and paint - cause genital deformities, reduce sperm count and even turn males into females. Dozens of species - including polar bears, fish, bald eagles, otters and whales - are suffering, according to the environmental group ChemTrust. Its report looked only at the impact of gender-bending chemicals on wildlife. But all vertebrates - or creatures with backbones - have similar sex hormone receptors in their bodies. 'Therefore, observations in one species may serve to highlight pollution issues of concern for other vertebrates, including humans,' the report says.
Its author, Gywnne Lyons, a former government adviser on chemical-pollution, 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.' Some studies have shown that sperm counts in the West have fallen over the past 30 years. Others have shown a rise in boys born with genital deformities.
Communities heavily polluted with hormone-disrupting chemicals in Russia, Canada and Italy have produced twice as many girls as boys. The ChemTrust report draws on more than 250 scientific studies from around the world to look at the effect of hormone-disrupting chemicals - including bisphenol A used in the linings of food cans, plastic bottles and dental sealants, and phthalates added to plastics such as PVC and glues. '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 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 roach changed sex completely after exposure to oestrogen from the contraceptive pill pouring out of sewage works.
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. A University of Florida study revealed that 40 per cent of male cane toads had become hermaphrodites - having both male and female reproductive organs - in a heavily-farmed part of the state. 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.
http://www.dailymail.co.uk/sciencetech/article-1092726/Gender-bending-chemicals-putting-future-risk.html#ixzz0qWU68LWq
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