According to health experts, hot-air dryers can suck germs and bacteria present in the loo. This can happen even after flushing faeces. When you use hand dryers, you get prone to infections and allergies. HEALTH HAZARDS: E.coli is the bug that is commonly present in faeces and when you poop, it gets spread in the toilet. As hot-air dryer sucks bacteria, putting your hand under it can make you susceptible to illnesses, like food poisoning.