Researchers from the University of Colorado sampled what they call biofilm from 45 germy showerheads in nine U.S. cities, including New York City, and eight others in Colorado, North Dakota, Illinois, and Tennessee. They analyzed the ribosomal RNA gene sequences from the swab samples to figure out exactly what microorgamisms lurked there. They compared them with swabs from water before it entered the showerhead.
“What we show is the showerhead biofilm contains Mycobacterium avium concentrations relative to other organisms 100-fold higher than in water before it comes out of the shower head,” says Norman R. Pace, the study’s senior author and distinguished professor of molecular, cellular and developmental biology at the University of Colorado, Boulder.
The study is part of a larger effort the team is involved in, focusing on the microbiology of the indoor environment and how it may contribute to illness. The current study received funding from the National Institute of Occupational Safety and Health and the Alfred P. Sloan Foundation.
Researchers do know that infections caused by the Mycobacterium avium complex occur often in patients with conditions that hamper cellular immunity such as AIDS and in patients who have chronic lung disease such as emphysema, according to the Infectious Diseases Society of America.
But the infections are not reported nationally to the CDC, whose researchers suspect the infections are probably environmentally acquired.
Some of the particles coming from shower heads are tiny enough to be inhaled into the airways.
“We conclude that showerheads may present a significant potential exposure to aerosolized microbes, including documented opportunistic pathogens.”
Paces adds that the potential health risk needs more research, particularly in patients with compromised immune or pulmonary systems, such as those with AIDS or emphysema.
His hygiene advice: While a normal, healthy person need not be concerned, he says those with immune system or lung problems may want to take baths instead of showers.
That said, experts agreed that cleaning showerheads regularly is wise step to take.
Here’s how to clean your showerhead:
1. Check the showerhead for mineral deposits build-up. There will be obvious discoloration and build-up on a showerhead that has not been cleaned for a while.
2. Fill the saucepan with enough distilled white vinegar to completely submerge the showerhead.
3. Add the showerhead. Remove the showerhead (it should unscrew) and place it in the saucepan.
4. Boil the showerhead in a saucepan. Allow the showerhead to simmer for a few minutes – the amount of time needed depends on the amount of build-up – keep a close eye on it. Do not boil or turn up the heat too high as the showerhead might melt. Also ensure that it is floating in the vinegar and not sitting on the base of the saucepan.
Another way to do it is to simply soak the showerhead in vinegar for 15-25 minutes, then rinse it off. This should be done regularly.