Deposits in the shower head can lead to dangerous illnesses

What health hazard is caused by our showerheads??

Most people shower several times a week to improve their personal hygiene. For many, it will be surprising that contaminants in the shower heads can also transmit harmful bacteria to the users, which may then lead to various illnesses.

Researchers at the University of Colorado found in their current research that people in their showers are sometimes exposed to lethal bacteria. The experts published the results of their study in the English-language journal "mBio".

Medical professionals examined the bacteria in our showerheads

The researchers examined the bacteria in our showerheads for their study. Most of the microbes are harmless, but there are some dangerous exceptions, says study author Noah Fierer of the University of Colorado. Particularly interesting for the experts were the microbes of the genus Mycobacterium. For example, this group of bacteria can cause leprosy and tuberculosis. In addition, the studied bacteria also included nearly 200 other species that are common in our environment. These bacteria are found in soil, dust and tap water. Together they are called non-tuberculous mycobacteria (NTM). Such bacteria grow in colonies in a slimy, mold-like manner. As a result, NTM could lurk in the dirtiest areas of your bathroom, such as the edges of the sink and shower head.

DNA from 656 shower biofilm samples was examined

It is important to understand the pathways of mycobacterial exposure, especially in the home, says study author Matt Gebert of the University of Colorado. To do so, the scientists examined the DNA of 656 biofilm samples from household showers and basic water chemistry data for each source. As they suspected, there was no shortage of NTM in their analysis, although large differences emerged, depending on the region in which the samples were collected and the sources of water used.

Genus Mycobacterium has been found most frequently

The analyzes revealed that the genus Mycobacterium was consistently the most abundant genus of bacteria discovered in shower heads of homes. Mycobacteria were more prevalent in US households than in European households. The experts suspect that this is due to differences in the chemicals used to clean the water. Chlorine is more commonly used in the US, but NTMs tend to become resistant to this type of disinfectant.

Metal shower heads were more heavily contaminated

Strangely enough, more NTMs were found in metal showerheads, while plastic showerheads contained a more diverse microbiome. This may be due to chemicals in the plastic that hold the mycobacteria in check, explain the researchers. The team discovered that in regions of the US where so-called NTM lung disease was most prevalent, showerhead microbiomes also contained more NTM. For now, however, the team's results show only a correlation and no causal relationship. Further investigations now have to deal with this topic. (As)