UV chemicals that harm male fertility
The study was designed to look at chemicals that humans encounter in their day to day environment. It looked at data from 501 couples who did not have any prior fertility problems. The couples provided urine samples and written journals on their attempts
at conception, keeping those journals up until they had conceived, or until 12 months had elapsed.
Study authors found that those couples who took the longest to conceive, or who did not conceive, had a common thread: the male partner's urine showed a high-concentration of two chemicals, BP-2 and 4OH-BP, found in sunscreens and in sunblocks. There are other products, for example some moisturizers and shampoos, that also contain those two UV blocking chemicals.
“In our study, male fecundity seems to be more susceptible to these chemicals than female fecundity," one of the
study's authors, Dr. Germaine Louis wrote in a press release. "The women participants actually had greater exposure to the UV filters overall, but their exposure wasn’t associated with any significant pregnancy delays.”
Dr. Louis, the director of Population Health Research at the Eunice Kennedy Shriver National Institute of Child Health and Human Development in Bethesda, Maryland, said that while the chemicals may work for blocking UV rays, she questions if they work for overall health. They do not know, she said, why the chemicals are having such an affect on male fertility.
"Our next step is to figure out how these particular chemicals may be affecting couple fecundity or time to pregnancy," she said. "Whether it’s by diminishing sperm quality or inhibiting reproduction some other way.”
If you do use these products, some scientists suggest you wash yourself thoroughly afterwards.