Ask TreeHugger: Do Hand Sanitizers Work?
by Helen Suh MacIntosh, Cambridge, MA, USA on 04. 3.07
Question: Will a Purell-type hand sanitizer help me avoid getting a cold?
Response: The common cold is caused by a viral infection of the respiratory tract that produces runny nose, sneezing, congestion, and other symptoms. In laboratory tests, alcohol-based hand sanitizers like Purell have been shown to inactivate viruses and make them non-infectious. To be effective, however, the sanitizer has to get to the virus before the virus reaches your nose and begins an infection that leads to a head or chest cold.
There are many types of viruses that can cause an infection that can result in a head or chest cold. You can come into contact with any of these viruses by two routes, by breathing them in through your nose or mouth or by touching the virus and then your nose or mouth with your hands. As you might expect, hand sanitizers work best against viruses that are transferred by your hands rather than through the air.
Scientific studies conducted to date show that head and chest colds happen less frequently (by about 15%) when alcohol-based hand sanitizers are used in schools, day care facilities, and nursing homes. These same benefits, however, have not been shown in homes in the United States. Despite this, you may still want to use alcohol-based hand sanitizers in your home, as they have been shown in the same studies to reduce the spread of “stomach bug” infections that cause diarrhea and upset stomachs by more than 50%.
Regardless, it makes sense to reduce your exposure to viruses and other infectious agents that can cause head or chest colds. Using alcohol-based hand sanitizers seem to be a relatively effective way to do so, and given their ease of use and relative low cost, they may be a good -- if only precautionary -- way for you to reduce your risk of getting a cold. Of course, there are other effective and easy ways to reduce your chance of getting a cold, including hand washing with soap and water, flu shots, and washing toys and other items that are shared among small children.
Previous Ask Treehugger columns can be found here.
Helen Suh MacIntosh is a professor in environmental health at Harvard University and studies how pollution behaves in the environment and how it affects people's health. Please keep in mind that her answers are just her interpretation of available information and should not be taken as the only viewpoint or solution to a problem. Use this column at your own risk. Having said this, please feel free to post any of your environmental health questions to Helen@TreeHugger.com (please use a descriptive email subject line and mention if you want to remain anonymous or not).
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wtf? when did the environmental movement get santized?
between this article and the one about vertical farming, i have to wonder when environmentalism warmed up to the idea of sanitization.
haven't we all heard by now the studies which say allergies are worsened by a lack of exposure to the real world? and isn't it likely this is one sign of a broader dynamic?
j: Nobody's talking about sanitizing *everything*, just a common vector for nuisance communicable diseases. You'll still be exposed to scads of viruses and bacteria no matter what you do... happy?
well, mdpdb, looking at the bigger picture of these posts is something that treehuggers tend to do. I have the same concerns as J in regards to oversanitization. Yes this post only concerns the effectiveness of hand sanitizers, however, this post is on treehugger.com and not a health website.
How long do you think it will take before alcohol resistant bacteria and viruses (supergerms) evolve. Its practically the same issue as antibiotics in milk. If almost all the germs are being killed off by something, the ones that live will be the ones that ere resistant. They then reproduce, creating lots more resistant bacteria.
Good old soap and water work pretty well, too.
Did I miss something in the vertical farming article about sanitization?
Regarding hand sanitizers: Everything in moderation. My dad uses them WAAAAAAY too much, which I'm very nervous about him doing. I use them infrequently when someone is working with me at my desk and I feel like I'm getting something- sort of a health-assist.
Vinegar would likely produce the same exact results, no?
Alex: still don't see merit in j's claims... 'looking at the bigger picture' is important, but so is being able to draw intelligent distinctions and not committing the fallacy of overgeneralization. The fact remains that alcohol-based hand sanitizers are of proven medical benefit, and are very different from "anti-bacterial" soaps and other measures that have an overall deleterious effect on the environment and public health. Nor has it been shown that they lead to immune system deficiencies like j is suggesting.
Since we probably will face continued epidemics like SARS and another flu pandemic in the not too distant future, and with the rise of antibiotic resistant strains of things like Staph and TB, I feel compelled to respond to FUD about techniques and products that may end up saving millions of lives.
I personally just wash my hands. Works even better.
Santizing will just lead to stronger, sanitizing resistant bacteria as we kill the weak ones and the strong ones survive. Haven't we learned any lessons from anti-biotic overuse?