Plastics chemical link to male infertility

A chemical which is commonly used to make plastics may be linked to a reduction in sperm quality and sperm concentration in men, a new study has found.

Bisphenol A (BPA) is used to harden plastics and is found in the linings of food and drinks cans, plastic water bottles, mobile phone casings and CDs. Each year more than 6 billion pounds of BPA is manufactured worldwide. Most people are exposed to the chemical through their diet.

Past studies have looked at the potential threat of BPA to pregnant mothers and the developing foetus, but US researchers say more research should focus on how the chemical affects adult health.

The researchers from the universities of Michigan and Harvard tested urine samples from 190 men attending a fertility clinic. BPA was found in 89 per cent of the samples tested.

They also measured sperm concentration, sperm motility, sperm shape and DNA damage in samples taken from the same men. On average, sperm concentration was 23 per cent lower in men with the highest levels of BPA compared to those with the lowest.

Results also suggested a 10 percent increase in sperm DNA damage, the researchers said.

Although past studies have shown adverse effects of the chemical on semen in rodents, none is thought to have reported a similar relationship in humans.

Dr John Meeker, assistant professor of Environmental Health Sciences at the University of Michigan School of Public Health, said: "Much of the focus for BPA is on the exposures in utero or in early life, which is of course extremely important, but this suggests exposure may also be a concern for adults.

"Research should focus on impacts of exposure throughout multiple life stages."

He also added that more research is needed due to the small number of men who took part in the study.

This article was published on Thu 5 August 2010