A recent study published in the American Society for Microbiology’s Applied and Environmental Biology journal found empirical evidence of hand dryers contaminating hands with bacteria. This was a small-scale study conducted by a team in 36 bathrooms of University of Connecticut School of Medicine.
The study found that just 30 seconds of hand dryer use resulted in at least 18-60 colonies of potentially harmful bacteria. In comparison, not using the hand dryer resulted in fewer than 1 colony of bacteria even if exposed to the same bathroom air for 2 minutes. The air nozzles were found to be minimally contaminated so opinions are divided whether hand dryers act as reservoirs of bacteria or blowing wind causes more bacteria to stick to hands.
As per reports, the lead author of the study, Peter Setlow, said, “bacteria in bathrooms will come from faeces, which can be aerosolized a bit when toilets, especially lidless toilets, are flushed.” This phenomenon is known as “toilet plume.” Aerosols are fine solid or liquid particles dispersed in air or gas. Hence, it’s only natural that air in a regular public restroom will be teaming with microbes. One way to prevent bacteria in bathroom air is to flush while keeping the lid on the toilet.
Not all bacteria are harmful, in fact a large majority are harmless and some are rather beneficial for humans. However, bacteria from faecal matter in bathrooms can contain dangerous and even drug-resistant strains. The authors of the study said that people with compromised immune systems like the sick or the very old and very young are more susceptible while a normal healthy person may not be affected at all. Some studies have also shown that growing up in too sterile or germ-free environment prevents the immune system from fully developing.
Washing hands before meals and after using the toilets is the best way to prevent a number of dangerous diseases. The study suggests that using paper towels to dry hands may be better than using hand dryers but it’s still too early to tell. The University of Connecticut School of Medicine has started stocking paper towels in all its facilities. The dilemma of using paper towels or hand dryers is of course secondary to the availability of hygienic toilet facilities with clean running water.