Your showerhead is probably one of the last things to suspect as being potentially harmful, but that’s what a new study shows: showerheads can and do harbor pathogens, which may be making you sick. 30% of the showerheads sampled in a recent study had high levels of Mycobacterium avium, which is linked to pulmonary disease.
Now before you go to sound off about a showerhead epidemic, the researchers caution that M. avium usually affects people with a lowered immune resistance, and “for the average person, it’s not a huge concern”, says Laura Baumgartner, one of the researchers.
The researchers tested about 50 showerheads across seven different states, in nine cities, including New York, Chicago, and Denver. They removed the showerhead from the pipe, took a swabbed sample from the inside, and extracted DNA from the sample.
“We found a fairly high number (of M. avium). It was surprising how consistent it was.” – Baumgartner
The symptoms of an M. avium infection are similar to those of tuberculosis, with a chronic shallow cough, fatigue, and fever. Some experts are warning that M. avium infections are on the rise these days, maybe because more people shower than bathe in a tub. Showering releases the pathogen in an aerosol spray directly at head level.
“We conclude that showerheads may present a significant potential exposure to aerosolized microbes, including documented opportunistic pathogens.”
This study started as a senior level research project, and is part of a larger project looking at the microbiology of human environments, which is funded by the Alfred P. Sloan Foundation. Instead of growing cell cultures, the team used DNA to identify the microbe, using a technology developed by a CU professor, Norman Pace. Previous research has found M. avium residing on shower curtain and soap film in showers.
M. avium infection cannot be spread person-to-person, and only those with immune concerns may have need to replace their showerhead. For those who are concerned, researchers recommend an all-metal showerhead, due to the fact that microbes adhere more easily to plastic. A filter on the showerhead is a plus, as is changing it weekly.
The paper is published online at the Proceedings of the National Academy of Sciences.