Sunday, February 22, 2009

An airy conundrum

I am a fan, ahem, of hot-air hand dryers. I think they do a good job of drying ones hands if you follow the directions. (You know, the ones that usually direct us to "Push Button" and rub hands briskly.) The use electricity but do use less overall resources than paper towels. Further the paper towels here at UW are akin to tissue paper and become sopping wet and torn before your hands are dry. Then there is the waste.

There is a recent "study" concerning certain characteristics of drying ones hands. (A second hand report of the study is listed here, I have not found the original.) They basically claim that the paper towel is a better hand dryer for several reasons, which would almost be expected since the research study was funded by the European Tissue Symposium, a marketing group for paper towel manufacturers.

They did 4 studies. The most interesting of them were the drying effectiveness and the bacteria count. Of course paper towels did better in both. Their claim was paper towels dried your hands more effectively. (10 seconds of paper towel use versus 50 some seconds of hand drying)
This is contrary to my recent experience but I can accept the results. Basically because I have no idea what the conditions of the experiment were. The same holds for the second experiment. Their claim here is that a warm-air hand dryer increases the bacteria count on your hands, palms and finger pads, by up to 254 and 194 percent respectively. A paper towel increases it a mere 77 and 76 percent, respectively. Again, I have to wonder what the conditions of the experiment were. And I have to wonder what the condition of the dryer is.

Much like any science, we can interpret results or set up experiments so that we get the results that we want to see if we are not careful to be fully objective. Our methodology is almost more important than the results and full disclosure, which I suspect I would get if I found the original report, must include all of the assumptions that went into the interpretation. A nice lesson for those who try to interpret, and report, on things such as climate change. Here the methodologies and assumptions not to mention the facts are broad and hard to truly understand by lay persons. We have to be careful in our secondary readings because they could lead to misinterpretations which are again misinterpreted by others.

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