Negligible, because all that paper gives up its CO[sub]2[/sub] when it decomposes. Some paper can last a long time in a landfill, but compared to carbon sequestration in coal, oil or limestone, even that is not very long.
Velly intervesting. They take into account the energy it takes to produce the paper towels. But do they take into account the energy it takes to produce the hand driers? Think about what it takes to make the plastic and the electric motors. The driers might come out ahead since their construction is a one-time cost, but the paper towels are being manufactured continually.
Yes, I took into account the energy to manufacture the hand dryers, the energy to transport the dryers to the site, and the energy to discard the hand dryers when they died. On the paper side, I took into account transport energy for the paper towels to the site, as well as disposal energy to the landfill. I also looked at the energy to manufacture the paper towel dispenser, although that was not significant for the analysis.
FTR I did not look hard at cost, although from my surveys it appeared that on that standpoint, the hand dryers were a slam-dunk favourite.
That I did not analyze, other than the direct impact of the energy consumption. I did see a large number of assumptions for what would happen to the paper towels in the landfill - that is, what is the total carbon sequestration involved. Depending upon how much you assume ends up as methane, you could end up with a large difference in the possible net greenhouse gas impact. The assumptions would also depend upon several things, such as the renewable energy use of the mills (paper mills use a lot of renewable energy), the transport use, etc.
Another factor which was brought to my attention was the possible impact of heating up an air-conditioned space by the hand dryers, but due to discussions with HVAC folks, and learning that many buildings exhaust via the bathrooms anyways (for obvious reasons), this impact seemed too difficult to quantify.
My major problem with air dryers in bathrooms is that there are times when you need to wipe something off your hands. And I’m not talking about something that got on them while I was in the stall. On several occasions I have somehow gotten grease or tar on my hand, gone into the bathroom to clean it off, and found it did not have any paper towels. Have you ever tried to scrub your hands with wet toilet tissue?
Something that’s related to the paper towel / electric dryer choice (though not directly to the environmental impact) is the germ factor. I remember going to a demonstration of a new hand washing technology (isn’t my life fabulous?) wherein people would stick their hands into these spinning cylinders that sprayed them down and got them “operating room clean” in about 10 seconds (allegedly). Anyway, they had paper towels to dry off with, because they said that electric hand dryers actually cover your hands with a thick layer of all the bacteria that’s hanging out in the bathroom air. Makes sense to me - I haven’t used one since. Any comments?
Nice job, Unca Cecil and Una. But there must have been a million variables and I’d guess you had to make nearly as many assumptions, however well-informed, to arrive at your conclusions. I still favor paper towels: you can dry your hands with them faster, and more completely, than with even the strongest air dryers in the same amount of time. And as LurkMeister pointed out, if you have something you want to get off your hands, there’s no comparison.
And what’s up with those old-fashioned continuous-loop cloth towel dispensers, anyway? As Cecil wrote, those always seemed broken or gross, or both. Would the same length of towel be in one dispenser forever, or would a laundry service come by every now and then and replace it with a new one? Was there some kind of cleaning mechanism in the box itself? Seems unlikely. Haven’t seen one in a long time, come to think of it.
More actually than symbolically, although pulp mills have given me a decent living over the years. I do like the smell of the kraft process, but try to stay upwind of the effluent treatment facilities, and the neutral sulfite semi-chemical process burns my nose, but there aren’t many facilities still using that.
There are a lot of wood sugars in the black liquor, mainly hemicellulose based, arabinose, xylose, galactose and mannose, with rather a lot of glucose from the peeling reaction in cellulose. That much sugar gives it almost a mollasses like undertone. On top of that you’ll have some hydrogen sulfides and methyl mercaptans, which nobody likes the smell of. In softwood facilities the alpha-pinene and beta-pinenes show up too. I kind of like the smell of turpentine, but some don’t.
Of course all of these, while over the odor threshold are well below any harmful or regulatory limit.
There is one near the Southeast corner of Oklahoma, actually in Arkansas, IIRC, but anyway, we could smell it from 6000 feet and 20 miles certain days when flying near there. It was our signal that we were getting close to Texarkana…
I did grad school just north of Lewston, Idaho where the Potlatch paper mill operated. To get there, you took several switchbacks down into a valley. The smell was very noticeable–(I would go so far as to call it a stench reminiscent of sauerkraut—and I like sauerkraut). Most residents of Lewiston that I talked to would admit that the smell was pretty bad but, yes, they had gotten used to it.
I knew a girl that interned there for two years. She liked first year, testing water quality by spending the summer rowing around in boat. The second year spent measuring levels in the plant’s internal sewer didn’t have the same fond memories.