Lather, Rinse, Disinfect the Showerhead

The showerheads of America are crawling with bacteria that can cause pulmonary disease in people with weakened immune systems, LiveScience reports. Around 20% of showerheads tested for a new study held significant levels of Mycobacterium avium, which can be suspended in air when water flows and be inhaled deep into the lungs. Biofilms that coat the interior of the heads contain that bacterium and other pathogens.

The study also found the bacteria present in concentrations 100 times the levels found in municipal water supplies that feed the showers tested. The authors suggest routinely replacing the heads, because cleaning the interiors is difficult, and even bleach can’t eradicate M. avium. But don’t freak out and neglect your personal hygiene, the lead author says. “It's like anything else," he says of the shower. "There is a risk associated with it.” (More bacteria stories.)