Two sunscreen chemicals may damage men's fertility - Study

The chemicals known as Benzophenone-2 (BP-2) and 4OH-BP may cause a 30 percent reduction in fecundity, a biological ability to reproduce, said researchers from the National Institutes of Health (NIH) and the New York state Department of Health's Wadsworth Centre.

This is because the chemicals, upon being absorbed by the skin, can interfere with the body's hormones and endocrine system processes.

Lower fecundity may result in a longer time to achieve pregnancy, the researchers reported in the American Journal of Epidemiology.

BP-2 and 4OH-BP belong to the group of compounds called BP-type ultraviolet filters, which comprise a class of about 29 chemicals commonly used in sunscreens and other personal care products to protect skin and hair from sun damage.

The researchers studied 501 couples who were trying to conceive a child up until pregnancy or up to one year of trying to record the time it took for the women to become pregnant.

They tested participants' urine samples and measured concentrations of five selected UV filters associated with endocrine-disrupting activity.

Women participants ranged from 18 to 44 years of age and the men were over 18. None had a medical diagnosis of infertility.

Their findings suggested that some but not all UV filters may be associated with diminished fertility in men, independent of their partners' exposure.

The researchers observed effects among men with the highest exposure to UV filters BP-2 or 4OH-BP.

"In our study, male fecundity seems to be more susceptible to these chemicals than female fecundity. The women participants actually had greater exposure to the UV filters overall, but their exposure wasn't associated with any significant pregnancy delays," said study author Germaine Louis of National Institute of Child Health and Human Development.

Louis said people are still encouraged to continue using sunscreen to avoid skin cancer but men who are concerned about fertility may try other ways to reduce their exposure to benzophenone UV filters, such as washing after returning indoors.