Between 1989 and 2005, average sperm counts fell by a third in the study of 26,000 men, increasing their risk of infertility. The amount of healthy sperm was also reduced, by a similar proportion.
The findings confirm research over the past 20 years that has shown sperm counts declining in many countries across the world. Reasons ranging from tight underwear to toxins in the environment have been advanced to explain the fall, but still no definitive cause has been found.
The decline occurred progressively hroughout the 17-year period, suggesting that it could be continuing.
The latest research was conducted in France but British experts say it has global implications. The scientists said the results constituted a “serious public health warning” and that the link with the environment “particularly needs to be determined”.
The worldwide fall in sperm counts has been accompanied by a rise in testicular cancer – rates have doubled in the last 30 years – and in other male sexual disorders such as undescended testes, which are indicative of a “worrying pattern”, scientists say.
There is an urgent need to establish the causes so measures can be taken to prevent further damage, they add.
Richard Sharpe, professor of reproductive health at the University of Edinburgh and an international expert on toxins in the environment, said the study was “hugely impressive” and answered sceptics who doubted whether the global decline was real.
“Now, there can be little doubt that it is real, so it is a time for action. Something in our modern lifestyle, diet or environment is causing this and it is getting progressively worse.
( via independent.co.uk)