WHEN out in the sun, how often do you apply sunscreen? If it’s anything less than once every 2 hours, you might be better off not using any in the first place.
So says Kerry Hanson, a chemist at the University of California at Riverside. She and her colleagues exposed human skin samples grown in the lab to UV radiation while they were covered with three common UV filters found in sunscreens: benzophenone-3, octocrylene and octylmethoxycinnamate. After just 1 hour, they found each compound had sunk into the skin, meaning its protective effect was greatly reduced. Worse, Hanson’s team found…
