What's in your shower head? Don't wanna know, do you?
Too late, you're reading this. It's disease-causing "mycobacteria" microbes stuck in their own slime.
"Microbes are everywhere, so in fact finding them in showers is not a surprise," says Laura Baumgartner of the University of Colorado-Boulder, an author of a new study. "Finding large numbers of mycobacteria was a bit of a surprise, though."
The study, out Monday in the Proceedings of the National Academy of Sciences, tested 45 shower heads in nine cities, including Denver and New York. The researchers expected to find harmless microbes usually seen in tap water. They did find those, but discovered about 20% of the samples contained mycobacterium, at least 100 times more than expected. That's worrisome because strains of the bacteria cause lung disease, and shower heads "aerosolize" bacteria so they're easy to inhale.
Only about 1 in 4,000 people suffer from lung diseases linked to environmental mycobacteria, says lung expert Theodore Marras of the University of Toronto, but infections have doubled in Ontario in the past decade. "Given their ubiquity in the water system, the markedly increasing rates of infection and the extreme difficulty in treating them, I think this is an important problem," he says in an e-mail.
"For the average person, this isn't a concern, but people with immune (system) disease or cystic fibrosis might want to change their shower heads every six months or so," Baumgartner says. "The first burst of the shower head is the most concentrated."
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