A study has found that sunscreen can render a man infertile by disrupting human sperm cells.
Nearly all ingredients present in sunscreen, meant to block out ultra-violet light, mimic the effects of the female hormone progesterone, which typically stops sperm cells functioning normally, causing infertility.
Niels Skakkebaek, a professor at the University of Copenhagen said the findings were worrying. ‘These results are of concern and might explain in part why unexplained infertility is so prevalent,’ he added.
The scientists placed the sperm in a solution that resembled the conditions in female fallopian tubes, in order to test the theory further. They found a specific channel in a sperm cell which is a receptor for the female hormone progesterone.
This can stop them effectively fertilising an egg.
Professor Shakkebaek said : ‘Our study suggests that regulatory agencies should have a closer look at the effects of UV filters on fertility before approval.’
Some of the chemicals which have regulatory approval but have been found to disrupt sperm include: avobenzone – considered as one of the most important UV filters, homosalate, meradimate, octisalate (also known as octyl salicylate), octinoxate (or octyl methoxycinnamate), octocrylene, oxybenzone (also called benzophenone-3 or BP-3) and padimate.
As well as being common in sunscreens and sunblock they are also used in sunscreen-containing personal care products, such as makeup, moisturisers and lip balms.
Although the purpose of the chemical UV filters is to reduce the amount of the sun’s UV rays getting through the skin by absorbing UV, some UV filters are rapidly absorbed through the skin, Skakkebaek said.
UV filter chemicals reportedly have been found in human blood samples and in 95 percent of urine samples in the U.S., Denmark and other countries.
Previous research has found that oxybenzone, a common ingredient in sunscreens, is toxic to coral reefs.