Widespread fears over the safety of bisphenol A (BPA) look set to increase after the publication of a study linking the chemical to sperm damage.

The controversial chemical, used in the production of plastics and found in a wide variety of everyday items, has been associated with a host of health problems.

Studies in animals have linked BPA to sperm problems but until now, says John Meeker, human studies have been lacking. Meeker, of the University of Michigan School of Public Health in Ann Arbor, and his team analysed semen quality, sperm DNA damage and BPA in 190 men attending an infertility clinic.

Concentrations of the chemical in urine samples collected on the same day as semen samples showed “suggestive declines” in semen quality and were also associated with DNA damage.

“We found that if we compare somebody in the top quartile of exposure with the lowest quartile of exposure, sperm concentration was on average about 23% lower in men with the highest BPA,” says Meeker (press release).

This is a small study with many potential limitations, not least the fact that infertility clinics are not necessarily the best place to study the impact of chemicals on general fertility. Meeker acknowledges this and notes that this study – published in Reproductive Toxicology – merely shows a “preliminary association”.

However, for a chemical already causing concern, the new study is more ammunition for those pushing for wider restrictions on the use of BPA.

See also – Nature News Feature, The big test for bisphenol A.