Showerheads a Veritable Hotbed of Bacteria: Study

Researchers analyzed roughly 50 showerheads from nine cities in seven states, including New York City, Chicago and Denver. The results would probably prove shocking to most.

About 30% or nearly one-third of the shower heads had significant levels of Mycobacterium aviu. That bacterium has been linked to pulmonary disease which most often infects those with compromised immune systems, but which can occasionally infect healthy people.

CU-Boulder Distinguished Professor Norman Pace was the lead study author. The study appeared in the Sept. 14 online edition of the Proceedings of the National Academy of Sciences. Co-authors of the study included CU-Boulder researchers Leah Feazel, Laura Baumgartner, Kristen Peterson and Daniel Frank and University Colorado Denver pediatrics department Associate Professor Kirk Harris.

You might imagine this would require the showerhead to become really cruddy, but according to the researchers, even those that appeared "normal" to the naked eye could house a significant amount of bacteria.

Past studies on showerheads have used cell cultures, but many bacteria do not grow well in cultures, so in this case, they used scanning electron microscopes to examine areas of the heads. Interstingly, the researchers also found that metal showerheads seem to carry less bacteria than plastic showerheads.

Should people be concerned? According to Pace, no, as long as you don't have a compromised immune system. It's all a risk assessment according to him. After all, just about anything can be toxic if you're given enough of it.