Your showerhead is infinitely grosser than you think

Scientists are currently processing data from 800 volunteers on the formation of harmful bacteria inside showerheads.

"We're particularly interested in which of these bacteria can cause infections, rather than harmless bacteria we contact everyday without any negative health effects," says Noah Fierer, an associate professor of ecology and biology at the University of Colorado, Boulder. "Most bacteria we're exposed to in everyday life — though the air, through food, through water, even from your clean bedsheets — are innocuous. Some are even beneficial. But for people with cystic fibrosis or lessened immune systems, some bacteria can be harmful."

Indeed, one nasty pathogenic microbacteria — nontuberculous mycobacterium, or N.T.M. — can cause respiratory ailments, including lung disease in people with weakened immune systems, but it does not necessarily affect people with healthy immune systems. Visually, it looks like a dark-colored slime with a mucus-like layer on top. While they're most often found in pipes and soil, the harmful bacteria have also been found in contaminated showerheads, which provide a rich environment for them to colonize: your shower is warm, wet, and relatively sheltered from passing air.

So where is this bacteria found? Fierer says that one of the early findings of the universities' research initially determined a greater presence of bacteria in homes fed from municipal, or city-supplied, water, versus underground well water sourced on private homes' property.

"The greater harmful bacterial presence in municipal water over well water is partly due to the chlorine in municipal water," says Fierer. "These bacteria can survive chlorine."

Shower Clear inventor Steve Sunshine discovered this firsthand several years ago, after his mother contracted a mysterious skin ailment that no one could diagnose. Her doctor didn't know if it was merely an infection or something more serious, so Sunshine went through a variety of methods to figure out what could be causing the skin disorder. Eventually, his mother's doctor finally suggested unscrewing her showerhead and swabbing it out from the back side.

"Sure enough, what came out was black, gross, and moldy," Sunshine says. "I then cut the showerhead completely open in my shop and found more black mold." It turned out this mold contained harmful bacteria causing his mother's skin disorder. Shortly thereafter, Sunshine obtained several patents and started his own company, Shower Clear, which manufacturers easily cleanable shower heads.

"Most people simply get in the shower and don't look at the shower head," says Sunshine. "Today, you take care of your health in so many ways: you strive to exercise, you stick to a healthy diet. But you can get into a filthy shower and not know it and come down with a nasty reaction or a disease. The chances are remote, but it can happen."

The final findings on harmful bacteria in showerheads will be published in early 2018. But the researchers don't want people to become paranoid when the results are released.

"We're doing this research to locate the problematic bacteria and find their origins," notes Fierer. "We don't want our research to cause panic, because having a severe negative reaction is a remote possibility, though that possibility does exist. If you have an open wound and get exposed to one of these harmful bacteria, you could get an infection or a reaction. And showerheads that open and can be cleaned could be beneficial."