Sunscreen can render a man infertile by disrupting human sperm cells, a study has found. Nearly half of the ingredients commonly used to block out ultra-violet light mimic the effects of the female hormone progesterone, which stops sperm cells functioning normally, researchers said. The sunscreen lotion can enter the blood stream by being absorbed through the skin. 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 said. (Source)