Low levels of common industrial chemicals found in a variety of packaging and food products affect the testes and sperm counts of rats, new research has shown.
The two British scientists who co-authored a report on the research, published this month in the American journal Environmental Health Perspectives, were yesterday divided on its implications for human male fertility.
Professor John Sumpter, of Brunel University, in Middlesex, thought the findings could be "extraordinarily significant" in unravelling why human male sperm counts have fallen dramatically in recent decades in the Western world.
But Dr Richard Sharpe, of the Medical Research Council's Reproductive Biology Unit in Edinburgh, played down the link. He issued a statement saying that humans are likely to be exposed to the chemicals at "considerably lower" levels than those used in the study.
The rats were exposed to two man-made chemicals, known as phthalates, which are known to mimic the female sex hormone oestrogen and which are now widely dispersed in the environment at low concentrations.The Edinburgh researchersfound that baby male rats' testes were up to 13 per cent smaller and sperm counts up to 21 per cent lower as a result.
Phthalates are used to impart flexibility in plastics, including food wrappings, and have been found at concentrations above 10mg per kilogram in products as diverse as sandwiches, snacks, sausages, and butter.
Gwynne Lyons, a consultant to the World Wide Fund for Nature on artificial oestrogens, said the research should lead to "urgent action".
"There's not only a threat to human fertility," she said, " but to wild animal species as these substances build up in the wider environment.''Reuse content