Bacteria in shower heads may cause lung disease

Professor Norman Pace, a molecular biologist at the University of Colorado at Boulder, who led the study, said, “If you are getting a face full of water when you first turn your shower on, that means you are probably getting a particularly high load of Mycobacterium avium, which may not be too healthy.”

A team of scientists tested water before and after it passed through showerheads in nine cities across the nation and found high levels of pathogenic bacteria growing inside showerheads. The main microbe detected was a tuberculosis relative known as mycobacterium avium.

According to the researchers the bacteria multiplies in the dark warm confines of the shower heads and clings as slimy residue known as biofilms. The level of bacteria detected was more than 100 times higher than found in tap water.

Bacteria a potential risk for the vulnerable
What is a cause for concern is that the shower heads spray tiny droplets laden with bacteria that can be inhaled into the lungs. This in turn can cause fever, weight loss, respiratory problems and fatigue.

The researchers stated that although showering was unlikely to harm healthy people, they could pose risks to HIV sufferers, cystic fibrosis patients, those on steroid medication, and people with underlying health issues like chronic lung disease vulnerable immune systems.

Laura Baumgartner, co-author of the study stated, "It's no more dangerous for the average person than getting out of bed in the morning, but if you're immune-suppressed, with diseases like cystic fibrosis or AIDS, it could be worrisome.”

Minimization of risk
The scientists state that the risk can be minimized by avoiding standing under the shower for the first 30 seconds, so that the bacteria can be flushed out.

Another alternative is to change the shower heads two to four times a year. Or better still, the researchers recommend switching to metal shower heads instead of plastic ones which breed more bacteria.

Scientists behind the study state that the increase in the incidence of lung disease may be related to the popularity for showers over baths in the developed world.

Pace said, “There are a lot of people walking around out there that have this disease. How many people do you know that have a chronic shallow cough? I know a lot.

“Indeed, mycobacterium avium pulmonary disease is more common in this country, at this time, than is tuberculosis.”

The study was supported by the Alfred P. Sloan Foundation and is published in the journal, Proceedings of the National Academy of Sciences.