British and other researchers have identified changes in testosterone levels in men exposed to bisphenol A, a chemical used in food and drink containers.

Researchers at the Peninsula College of Medicine and Dentistry and the University of Exeter, both in England, and colleagues linked higher BPA exposure with small increases in levels of testosterone in the blood.

The large population study, published in Environmental Health Perspectives, found the average BPA daily of more 5 micrograms per day exposure in the European study population was slightly higher than recent comparable estimates for the U.S. population.

"This is the first big study of BPA from a European country and confirms that 'routine' exposures in the population are not negligible," David Melzer of Peninsula Medical School said in a statement. "This finding is consistent with the evidence from laboratory experiments. However, this is just the first step in proving that at 'ordinary' exposure levels, BPA might be active in the human body. This new evidence does justify proper human safety studies to clarify the effects of BPA in people."

Melzer and colleagues analyzed data on BPA excreted per day in urine samples and sex hormone levels in an Italian population sample of 715 adults ages 20-74.