A chemical found in some common plastics may be linked to reduced fertility in men, according to a new report. A US study found that men with the highest levels of Bisphenol A (BPA) in their urine had a sperm count 23 per cent lower on average than those with the lowest BPA levels.
Although the study is small and in need of replication, these preliminary results add to growing concerns over the effects of BPA on health.
The study was led by Professor John Meeker from the University of Michigan in conjunction with the Harvard School of Public Health. 190 men were recruited to the study through a fertility clinic and 90 per cent tested positive for BPA in their urine.
Researchers looked for correlations between the level of BPA and sperm quality and quantity. In addition to the decrease in sperm count, men with the highest BPA levels also tended to have more sperm DNA damage – increasing on average by ten per cent compared to those with the lowest BPA levels.
BPA is widely used in the hardening of plastics and can be found in various food and drinks containers, baby bottles and CD boxes. There has been much debate over the safety of the chemical, with particular concerns over its effect on unborn babies and young children. This is because BPA, once inside the body, mimics key hormones involved in development - including the female sex hormone, oestrogen.
This has led Canada and three US states to ban the chemical in food and drinks containers used by newborns and infants, with Denmark becoming the first EU country to follow suit earlier this year.
Professor Meeker said: 'Much of the focus for BPA is on the exposures in utero (in the womb) or in early life, which is of course extremely important, but this suggests exposure may also be a concern for adults'.
Some studies in animals have previously linked BPA with fertility problems, as well as with breast cancer, diabetes and obesity. However, other animal studies have found no such links and this study is the first to report adverse effects of BPA on sperm count and quality in humans.
Dr Allan Pacey, a fertility expert at Sheffield University, said: 'This survey needs to be followed up. The inference is it’s not good for fertility but it's also not good for any fetus'.
The Food Standards Agency (FSA) stresses that human exposure to BPA through plastics is 'well below levels considered harmful'.
The study was published in Reproductive Toxicology.