Your Showerhead Is Really Gross—and It Might Make You Sick

If the ick factor alone doesn't motivate you to clean your shower regularly, the results of new research published in the journal mBio may change your mind. As IFL Science reports, your showerhead is a hotbed of microorganisms, some of which could pose a threat to your health.

For the study, citizen scientists from Europe and the U.S. swabbed their showerheads and submitted the samples to researchers. After sequencing the DNA of the more than 650 samples, the Showerhead Microbiome Project team found worlds of microbes thriving on the very things we use to bathe ourselves with each day.

While most of these organisms aren't harmful, the researchers did detect some types of nontuberculous mycobacteria (NTM), which can cause lung infections. When water vapor fills your shower, mycobacteria become aerosolized and therefore easier to breathe. While NTM doesn't lead to illness when inhaled in most cases, infections can bring about shortness of breath, fatigue, and weight loss, especially in people with weak immune systems. Researchers found that areas with the highest concentrations of showerhead mycobacteria—Florida, New York, and Southern California—are also "hot spots" of NTM lung disease.

Mycobacteria live in biofilm, a.k.a. the scum that coats the front of your showerhead. The study found that the microbes are more likely to grow on metal showerheads than plastic ones—likely because the chemicals in plastic support more diverse microbial communities that stop any one bacteria from taking over. The mycobacteria were also most common in U.S. households that use municipal water supplies. The water in these showers is usually chlorinated, and because mycobacteria are somewhat resistant to the disinfectant, those microbes tend to spread in place of the bacteria that are killed off.

The study's data could be used by doctors and public health officials to better understand the causes of NTM. In the meantime, set aside a few minutes to wipe the slime off your showerhead.