Lakes and rivers around the world are polluted with synthetic hormones that have negative effects on wildlife, causing male fish, for instance, to become feminized and produce eggs. The synthetic hormones get into municipal wastewater because millions of women around the world take synthetic hormones via birth control pills or hormone replacement therapies. So far wastewater treatment facilities are not able to completely remove these hormones before they head to rivers and seas. A team of U.S. and British scientists now think they may have hit upon a solution based on a common household chemical — hydrogen peroxide.