Sperm counts are falling dramatically across Britain and the rest of industrialised world, and scientists are increasingly convinced that pollution is to blame.
Studies around the world have shown that average sperm counts in men have dropped by more than half over the past 50 years – from about 160 million per millilitre of semen to 66 million.
The Medical Research Council reports that the fertility of Scottish men born since 1970 was 25 per cent less than those born in the 1950s, with sperm counts continuing to drop by two per cent a year.
Other research by the US Government's Environmental Protection Agency shows that, proportionately, a man now produce only about a third as much sperm as a hamster.
Scientists increasingly blame a whole class of hormone-disrupting chemicals. Evidence suggests that they cause cancer and damage the immune system, as well as impairing fertility. And they are ever more ubiquitous.
DDT and other pesticides disrupt hormones, as do PCBs, used in countless products worldwide, from plastics and paint to electrical equipment.
Other components of plastics have been found to leach hormone-disrupters including phthalates, which have been found in a wide range of foods including baby milk.
Furthermore, an investigation by the BBC's Countryfile and The Independent on Sunday has revealed research, to be published this month, that shows that artificial oestrogens, used in contraceptive pills and emitted through sewage works, appear to be changing the sex of half the fish in Britain's lowland rivers.
Scientists and environmentalists fear that the powerful chemicals are getting into drinking water and affecting human fertility. One third of Britain's drinking water comes from rivers; most of it is taken from below sewage works.
The Environment Agency denies that there is any danger. Water UK, which represents the water companies, says that no hormone-disrupting chemical has ever been detected in British drinking water, and that fish placed in the water to test it did not become feminised.
But some scientists say that the chemicals may not have been detected, because there is no routine testing for them in drinking water, and because the equipment used in Britain is not sensitive enough.
Research at the University of Ulm, in West Germany, using more sophisticated techniques, found small amounts in four out of every 10 samples tested. And environmentalists fear that effects in people may occur over much longer periods than those used to test the fish.
Dr Susan Jobling of Brunel University, who led the research, says: "Unlike in fish, it is going to take 20 years to see if my children have been affected by developmental exposure to this same cocktail of chemicals."
Half of all the male fish in lowland rivers are changing sex as a result of pollution, alarming new official research suggests. The findings raise serious questions as to whether the pollution is getting into drinking water and affecting human fertility.
The research – to be published by the Environment Agency this month – shows that male fish are developing female characteristics in rivers all over the country. In some stretches all the male fish have been feminised.
Scientists conducting the research blame a particularly powerful form of oestrogen in urine from the contraceptive pill, which is flushed through sewage works into the rivers. Some fear that the "exquisitely potent" chemical may be contaminating part of the one third of all of the country's drinking water that is taken from rivers.
The water industry and the agency strongly deny that this situation – revealed by a joint investigation by The Independent on Sunday and BBC TV's Countryfile – could damage health. But environmentalists fear that the fertility of some men could be affected by years of drinking the water. Sperm counts have been falling dramatically in Britain over the past half-century. Yesterday Peter Ainsworth, the shadow environment secretary, said: "Danger to human fertility cannot be ruled out" and called for an urgent programme of research on the threat. The agency said that it was taking the pollution "very seriously" and would unveil an action programme later this month.
The research, financed by the Department of Environment Food and Rural Affairs and the official Natural Environment Research Council, has examined roach from 10 rivers over the past five years. They found feminised "intersex" males in all of them – the rivers Lea in Hertfordshire (from which London takes much of its drinking water), Blackwater in Essex, Arun in West Sussex, Avon in Bristol, Rea in Shropshire, Wreake in Leicestershire, Nene in the East Midlands, Ouse in North Yorkshire and Aire and Calder in West Yorkshire.
It found that, on average, just under 50 per cent of the male fish had developed eggs in their testes, and/or female reproductive ducts – a finding they believe is likely to be typical of roach and other species of fish all over the country. In stretches of the Aire and Nene all the male fish were affected in this way: even in relatively unpolluted waters 7 to 8 per cent were affected.
The fish did not change back after being put into clean water, suggesting that the changes were permanent. About one tenth of male fish were sterile, and about another quarter had damaged sperm.
The research suggests that the main culprit is ethanol oestradiol, a synthetic oestrogen used in the contraceptive pill which the scientists say can feminise fish at levels of as low as one part per billion. Conventional sewage treatment is ineffective at removing it from water.
Professor Charles Tyler of Exeter University, one of the leaders of the research, says that it is "so exquisitely potent that some of the very concentrations where we are seeing effects on fish are below the detection limit that is presently in place for testing our drinking water. So we cannot be sure that some of these compounds, albeit at very low concentrations, aren't getting into our drinking water".
|
If you have come to this page from an outside location click here to get back to mindfully.org |