Your fingernails. Washing your hands after you go to the bathroom or change a diaper is par for the course (at least we hope). But are you scrubbing underneath your fingernails? A 2007 study done at Aston University in Britain found that harmful bacteria was lurking on 24 percent of men's nail clippings studied and 15 percent of the women's clippings. According to lead researcher Anthony Hilton, the worst of the bacteria could cause diarrhea and vomiting. It's especially important to scrub under your fingernails after you go to the bathroom and after touching raw meat, which can contain harmful bacteria.
