The study conducted by Safe Home tested shower curtains and surveyed over 500 people. The shower curtain analysis detected over 60 times more microbial life on the shower curtains than on toilet seats; the strains of bacteria present included gram negative rods and gram positive rods.
Findings suggest that shower curtains may be the dirtiest surfaces in the bathroom. According to the researchers the majority of gram negative rods are harmful to humans, and they can be resistant to antibiotics.
According to this study Americans are not just cleaning in the shower as participants reported doing other activities: 81% of men and 73% of women reported urinating; 61% reported having sex; 65% reported shaving; and 33% reported brushing their teeth. There is no strong evidence to support any of these activities causing higher levels of bacteria on shower curtains, but it is suggested that they do undoubtedly add to the reasons supporting regular cleaning of the shower/tub and curtains/enclosures.
Bacteria from fecal matter can also spread from the toilet through the plume spray float radius to reach the shower, and this plume spray may also be reaching your toothbrush according to experts. Once any germs collect on the shower curtain the different bacteria within the plume can begin to multiply in the hot, humid, and often dark environment of the shower. This is why it is ever so important to keep the toilet seat closed when you are flushing it to help prevent the spread of germs from plumes.
Some experts suggest that bacteria can survive and even thrive on organic compounds that are released from our bodies via sneezing, talking, burping, coughing, and other bodily functions. Bathroom bacteria has not been very well studied, it also has not been associated with well documented risks in a healthy person, regardless it is still gross and should be a good motivation to do what you can to prevent it.
According to Charles P. Gerba, PhD, a microbiologist and professor at the University of Arizona, “Some opportunistic pathogens have been detected, but for healthy persons, it should not be a problem,” he said.
Some of the commonly found opportunistic pathogens that have been found in a bathroom include sphingomonas and methylobacterium, and these organisms can infect wounds and exacerbate an illness in those with compromised immune systems.
A study published in the journal Applied and Environmental Biology showed that 80% of the bacteria on a shower curtain came from 2 types of bacteria. But these types of bacteria differed from those that were most recently found.
“One [strain] typically only causes infection in very rare cases and, even then, it tends to be in people admitted to the hospital with a compromised immune system,” said Dr. Jeffrey Brown, a family medicine specialist at the Cleveland Clinic. “For example, those being treated for things like cancer, autoimmune diseases, or HIV.”
“The other bacteria is the one responsible for body odor. Although it may not be desirable, it’s certainly not harmful,” Brown added, going on to note that “there were small amounts of E. coli, which causes diarrhea. It’s still very unlikely you would catch an E. coli infection from the shower curtain as it needs to be ingested,” Brown said.
“Mold seems to be the major problem,” Gerba said. “I think most of the risk is from mold allergies and sharing the shower among family members.”
Bacteria and mold are not the same, and should not be confused, but they can both similarly thrive in washroom environments. Mold exposure is associated with health concerns such as eye irritation, chronic coughs, skin rashes, and sore throat according to the National Institute of Environmental Health Sciences. Those with compromised immune systems, children, and older adults are more vulnerable to the risk.
To prevent bacteria and mold growth the shower curtains or enclosure should be cleaned with regular frequency, but the exact cleaning will depend on your household shower habits. At minimum in an active shower the curtains should be cleaned monthly according to some experts.
Fabric shower curtains help to make this an easier task as they can be laundered and they will dry quicker than a traditional plastic or PVC curtain. Plastic or vinyl curtains can also be more prone to accumulating biofilms layers of microbial life. Home mold typically appears to be blackish, bright red or green, and mildew is grayish-white or even yellowish in appearance.
Another tip some experts recommend is to close the shower curtain after use so that it does not bunch up and can fully dry. Misting the shower surfaces with a cleaner between deep cleaning can also help. If you can’t remember how old your shower curtain is, it may be time to get a new one and start a cleaning schedule using a new fresh shower curtain.
“If you don’t wash your shower curtain for several months, you’re likely going to get mildew that could cause some health issues,” says Jennifer Rodriguez from Pro Housekeepers.
“If there is mold or mildew on your shower curtain, toss it out,” said Becky Rapinchuk, author of The Clean Mama “If the material is worn or breaking down, toss it.”
“When you see nasty grime buildup that doesn’t go away, the best practice is [to replace your curtain] once per year,” Rodriguez said. “Some people like to alternate shower curtains throughout the seasons, and this helps them last much longer.”
