With that exciting prelude, I was interested (and the same caveat applies to the use of that word here as above) to read the results of a recent study, sponsored, it should be pointed out, by the European Tissue Symposium, a paper tissue products advocacy group (which begs the question, do paper tissue products really need an advocacy group? I mean, after all, there are certain paper products that will, um, never be replaced by, say, electronic methods, although there are some Web sites that make it tempting to try. Although, I bet if you have a cold, one of their meetings might be the best place to be.) Anyway, about the study:
There were four parts to the study: Part A looked at the drying efficiency of hand drying method; Part B involved counting the number of different types of bacteria on the hands before and after drying; Part C studied the potential contamination of other users and the washroom environment; and Part D took a bacterial sampling of Dyson Airblade dryers in public washrooms.Good! I certainly was in the right all these years. Three guesses, though, who had issues with the study's methodology. Yep, the Dyson Airblade people who said, in essence, that the researchers were full of hot air. So to speak.
Paper towels and the Dyson Airblade were found to be equally efficient at drying hands, each achieving 90% dryness in approximately 10sec. However, the warm air dryer was considerably less efficient, taking 47sec to achieve the same level of dryness.
Twenty subjects (10 male and 10 female) were used in Part B. Three different agar growth media (nutrient, cystine-lactose-electrolyte-deficient and mannitol salt agar) were used to count and identify the bacteria on the fingerpads and palms before and after washing and drying.
Paper towels were found to reduce the number of all types of bacteria on the fingerpads by up to 76% and on the palms by up to 77%. By comparison, the Dyson Airblade increased the numbers of most types of bacteria on the fingerpads by 42% and on the palms by 15%. However, after washing and drying hands under the warm air dryer, the total number of bacteria increased by 194% on the fingerpads and on the palms by 254%.
To be honest, though, when it comes to the unspeakable vileness of public loos the hand-drying method is the least of my worries. Door handles, water taps and knobs, etc., are far more gross. Which is why I really like the trend in public bog design to make everything as touch-free as possible. It's finally getting to the point where I don't have to don my HazMat suit.
One question I do have involves the environmental responsibility of paper towels vs. hot air dryers. Sure, paper requires the cutting of trees and can take up space in landfills, but trees are a renewable natural resource and hot-air dryers run on electricity and likely have some carbon cost associated with them. The answer, perhaps, can be found at The Wild Center, the Natural History Museum of the Adirondacks up in Tupper Lake, NY. They have considered the environmental impact of just about everything, it seems, and pride themselves on their green building(s). And their lavatories do not use air dryers, but rather paper towels made from 100% recycled paper. Q.E.D.