If you live in a big city, we've got great news: It’s super unlikely riding the subway will make you sick. Public transportation isn't all that clean, but a new study found the microbes you come in contact with aren't usually the kind that cause illness. (There are more pathogens in our guts than on trains and buses.) Most of the bacteria researchers found were leftover from normal skin contact, so it's basically like shaking hands with a lot of people you'll never meet. We know that visual may be enough to make you want to wash your hands.