When men can't be fathers [June 05, 2004]

This is what might be called a feedback loop--one of nature's ways of ensuring sustainability. Environmental pollution caused by man is leading to low sperm counts in a growing number of men, supressing the birth rate.

In almost 40 per cent of couples who present to fertility clinics, it is the men who are infertile.

Causes of infertility include sperm production problems such as low sperm count and low sperm mobility, to the blockage of sperm from the testes and, in some cases, hormonal problems where the brain does not produce adequate hormones to stimulate sperm production.

Low sperm production is the most common of these causes, affecting 60 out of 100 men who are diagnosed. ...

Professor John Aitken is a bio-chemist at Newcastle University in NSW who believes that increases in testicular cancer are just one of the signs that pollutants are playing havoc on male fertility and the health of babies.

"Oxidated stress from environmental pollutants are damaging the health and fertility of men. Smoking is a leading factor," Professor Aitken explains.

"Oxidated stress means the sperm can be unable to fuse with the egg but it also means that the sperm that do fuse may contain damaged DNA.

"The children of these men are four times more likely to have childhood cancer."

Overseas research also points the finger at environmental pollutants.

Studies in Florida swamplands in the US have shown that male alligators' external genitals are changing due to exposure to DDT, a chemical used to control mosquito populations.

And last year a study in Italy, published in Fertility and Sterility, showed a decreased sperm count in men who collected tolls on major roadways.

While this may be a personal tragedy to the men involved, it is a necessity if a sustainable society is to be achieved. Unfortunately, low fertility rates may be too little and to late to avoid much more seriour "feedback loops" such as starvation and disease from bringing the human population back to sustainable levels.