I recently addressed a class of 6th graders on the topics of germs and hygiene. As you can imagine, we spent much of the time discussing the importance of hand washing, which in turn led to the subjects of soap, water, and antibacterial cleaners. What’s new in the scientific literature?
Hygiene plays a significant role in how frequently we get sick. The data is rather depressing regarding hand washing after using a public toilet. Studies show that women are better at it than are men: roughly 62% of women wash after using the bathroom, while only 40% of men do. Even worse, only 5% of all people wash correctly. I’ll get back to that.
A recent study out of the University of Maryland looked at hand sanitizers vs. soap and water. The hands of participants were deliberately exposed to E. coli. Then, one of the following was used for cleansing: alcohol-based hand sanitizer, non-alcohol based hand sanitizer, plain bar soap, or liquid antibacterial soap. Twenty seconds were counted out for each washing (note that most people spend five seconds with their hands underwater – if they wash at all).
The results? Alcohol-based hand sanitizers worked better than those without alcohol. Antibacterial soap worked only slightly better than regular soap. Washing with soap and water is the first choice, however, especially if the dirt on your hands is visible. Sanitizers do not actually remove the dirt. However, hand sanitizers are indeed more effective than soap and water in eliminating germs. The bottom line is that technique is actually more important than which product is used.
Just to make it more complex, however, note that the overuse of hand sanitizers and antibacterial soap is not a good thing, as not all germs are bad - many are protective. The overuse of antibacterial products can encourage bacterial resistance, making it more difficult to fight the harmful germs when we really need to.
To properly wash hands with soap and water:
Wet the hands with running water (the temperature makes little difference), and add soap.
Rub the hands together, making a soapy lather. Wash the fronts and backs of the hands, between the fingers, under the nails, and around the wrists for at least 20 seconds (the “ABC” song, or two rounds of “Happy Birthday”).
Rinse the hands well under running water.
Dry the hands thoroughly with a clean towel or air dryer.
Turn off the water with a clean paper towel or an elbow.
Soap and water are not always available or convenient. To properly use hand sanitizers:
Apply the hand sanitizer to the palm of one hand
Rub the hands together, spreading it over all surfaces of the hands and fingers until dry.
Always wash hands before preparing food or eating, treating wounds, dispensing medicine, caring for a sick person, inserting contact lenses, or touching your eyes, nose or mouth. Wash your hands after using the toilet, preparing food (particularly raw meats), changing a diaper, touching an animal, blowing your nose, coughing or sneezing into your hands, treating wounds or caring for the sick, handling garbage, household or garden chemicals, handling dirty towels, or shaking hands with others.
My talk to the 6th grade class was a good reminder to me and to the parents in attendance, as well as to my target audience. Germs are all around us. Some of the germs can cause illness. Please pay attention to your cleansing routine. Until your hands are truly clean, keep them away from your eyes, nose and mouth…and from everyone else.