Hot-air hand dryers in public bathrooms ‘suck in’ bacteria from flushing toilets, new research suggests.
Previous studies show such dryers can disperse germs from people’s hands on to surrounding surfaces, however, the new findings imply less powerful versions actually bathe hands in bacteria circulating in bathrooms.
When Petri dishes containing ‘bacteria food’ are kept in bathrooms without hand dryers, just six pathogen colonies grow within 18 hours compared to up to 254 after being blasted with such air for just 30 seconds, a study found.
These bacteria can include Staphylococcus aureus, which is resistant to the antibiotic methicillin and can cause life-threatening sepsis, pneumonia or toxic shock syndrome.
Due to hand dryers’ abilities to transmit spores, they could potentially spread Clostridium difficile, according to the scientists, which causes watery diarrhea that can lead to severe dehydration.
They wrote: ‘This suggests another means of C.difficile transmission and one that may not be interrupted by either hand washing or traditional surface decontamination methods.’
Filters reduce dryers’ bacteria levels by four times
Results further suggest hand dryers can spread the bacteria Bacillus subtilis strain PS533.
Although this is generally harmless, the finding shows dryers’ abilities to spread spore-forming bacteria, according to the researchers.
They wrote: ‘The facile dispersion of one bacterial strain throughout a research facility should probably be a concern to risk assessors and risk managers when the dispersion of potentially pathogenic bacteria is considered’.
The researchers add hot-air dryers’ potential to transmit C.difficile should be investigated further.
Findings also imply when dryers are fitted with high-efficiency particulate air filters, which remove 99.97 percent of particles larger than 0.0003mm, their bacteria counts are reduced by around four times.
How the research was carried out
The researchers, from the University of Connecticut, analyzed hot-air hand dryers in multiple men’s and women’s public bathrooms in an academic health center.
The dryers were screened for their total bacteria and PS533 spore counts.
Petri dishes containing ‘bacteria food’ were placed around the bathrooms, away from the direct blast of dryers, to determine where pathogens come from.
The findings were published in the Journal of Applied and Environmental Microbiology.
Deadly bacteria can lurk in dishwashers
This comes after research released last January suggested life-threatening bacteria may be lurking in people’s dishwashers.
The kitchen staple can contain everything from E.coli, which causes life-threatening food poisoning, to other pathogens linked to infections of the urinary tract, skin, and inner heart lining, a study by the University of Ljubljana, in Slovenia, found.
Although usually harmless, these bacteria can be fatal in people with reduced immune systems, such as those undergoing chemotherapy or organ transplants.
Bacteria and fungi are thought to enter dishwashers via the tap water that supplies them, as well as through contaminated food, the research adds.
Researchers recommend people reduce their risk of infection by allowing dishwashers to cool before opening them and wiping their rubber seals after every use.
If you know someone who might like this, please click “Share!”