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Thursday, 4 May, 2000, 18:00 GMT 19:00 UK
Young Danes' sperm count dips
Denmark's males face a new challenge
By environment correspondent Alex Kirby

Almost half of 700 Danish army recruits have been found to have sperm counts low enough to make it hard for them to father children.

The recruits, aged from 18 to 20, had significantly lower counts than men in another sample born about 10 years earlier.

While the researchers describe their findings as "difficult to explain", environmentalists believe exposure to one group of chemicals is a factor.

The research is significant because it is the first study of sperm counts in a random sample of healthy young men.

It is published in Human Reproduction, the journal of the European Society of Human Reproduction and Embryology.

The research, conducted between 1996 and 1998, tested 708 men reporting for a compulsory military medical examination.

General deterioration

It found that 43% of them had sperm counts low enough to lead to decreased fertility - in other words, to make it difficult for them to reproduce.

The authors, all from Denmark, say there is published evidence "that male reproductive function seems to have deteriorated considerably in the past four to five decades".
polar bear cub
Polar bear cubs are affected by hormone disrupters
But clinical studies on semen quality have dealt with selected groups: candidates for vasectomy, semen donors, infertility patients, and volunteers.

"Studies of semen quality, reproductive hormones and testicular size in unselected populations of young males have not previously been reported."

They describe the sperm concentrations they found in the sample as "surprisingly low", and are at a loss to explain them.

"It remains to be seen whether these findings are generally applicable to populations of young men in the industrialised countries. Denmark seems to have relatively high rates of male reproductive abnormalities."

The World Wide Fund for Nature says it believes that a factor in the low sperm counts is exposure to endocrine-disrupting chemicals.

Low dose effects

These are chemicals which can interfere with the normal functioning of the body's hormonal control systems and seriously affect health.

They do so by mimicking naturally occurring hormones, or by activating or blocking hormone receptors or hormone production. And they can take effect at very low doses.

Known disrupters include some phthalates (used in many plastic goods, including toys), Bisphenol A (used in plastic bottles, the plastic lining of food cans, and elsewhere), and TBT, an anti-fouling paint for boats.

Elizabeth Salter, the head of WWF's European toxics programme, said the Danish study "proves that reduced sperm production is real and common".
tin cans
The chemicals are found in tin cans
"Before the 1930s there were very few man-made chemicals. Today everyone in Europe is exposed constantly to a cocktail of hundreds of man-made chemicals.

"This study is a wake-up call to the European Union, which must act now to reduce human exposure to chemicals that are known to interfere with hormones."

WWF has criticised the European Commission's plan to concentrate research on about 30 or 40 endocrine disrupters as inadequate.

Dr Rob Taalman, of CEFIC (the Chemical Industry Council of Europe) told BBC News Online: "I think the Danish finding is very odd.

"There must be an explanation, but I can't think of one, unless Denmark has some peculiar regional factor.

"We take this problem very seriously, and we do want to understand it. But studies suggesting both a decrease and an increase in sperm counts seem to be in balance."

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