Long a staple of our morning routine, showering might actually be bad for your health, according to U.S. researchers who found that nearly one-third of shower heads contain high levels of Mycobacterium avium, a germ that causes lung disease. “If you are getting a face full of water when you first turn your shower on, that means you are probably getting a particularly high load of Mycobacterium avium, which may not be too healthy,” lead researcher Norman Pace, a microbiologist, told the BBC. According to Pace, shower water contains bacteria suspended in droplets that are easily absorbed deep into the lungs. Healthy people should be fine, but those with weakened immune systems (like the elderly or pregnant) could be at risk of developing a lung infection. In fact, showers have also been shown to spread other infectious diseases, including Legionnaires’ disease (a type of pneumonia) and chest infections. Plastic shower heads seem to be worse than metal ones, noted Pace, whose team swabbed and tested 50 shower heads in nine U.S. cities and found that 30 per cent of them posed a potential risk.