Article Summary 10: Bathing, but Not Alone

Bathing, but Not Alone. New York Times: Science [Internet]. 2009 Sept 14 [cited 2009 Sept 20]. Available from: http://www.nytimes.com/2009/09/15/health/15shower.html?ref=science

Microbiologists love to tell us about all the bacteria we encounter in our daily lives: we inhale ten thousand bacteria each time we breath in an average office building, and we consume ten million bacteria in each glass of tap water. Researchers at the University of Colorado who study the indoor human environment have now given us another fact that we would rather not consider: every time we take a shower, a cascade of bacteria hit our faces and flow deep into our lungs. Some strains of bacteria, like Mycobacterium avium is related to tuberculosis and can cause chest complaints like lifeguard’s lung, hot tub lung, and Lady Windermere’s syndrome.

Conventional bacteria tests involve growing cultures in laboratories. Since most species cannot be grown in this way, the majority of bacterial species are overlooked. A new method identifies bacteria by examining their genetic material directly, and does not have need for laboratory cultures. Using this new method, scientists are discovering more bacterial strains than they previously believed existed. One scientist alone has turned up over 15 new kinds of bacteria in showers across the country.

What can you do about it? Bacteria get into shower heads from water build-up, so the dose is highest when the shower is first turned on. Run the water for 30 seconds prior to stepping in. Additionally, bacteria tend to prefer plastic shower heads over metal ones.

Mycobacterium avium tends to be a particular problem in water supplies in large cities like New York. The reason is that cities treat their water with chlorine, a poison that kills most bacteria but gives this particular strain a selective advantage. Good news for New Yorkers though: due to the movement of the air, breathing within the subway system may be healthier than your shower’s mist!