A Germ-Zapper's Guide to Clean

By Megan Voelkel
Thursday, July 24, 2008; 12:48 PM

Ever just rinse the kitchen cutting board in between uses? Or wash a load of linens in cold water? Think twice before calling either squeaky clean. Germs, the pesky microbes that cause maladies such as the common cold and stomach flu, among others, aren't so easily washed away. And despite being microscopic, these buggers always have the potential of becoming a very big deal.

"Anytime you take a chance on getting ill [from exposure to pathogens], you have a chance of getting really sick," says Charles Gerba, an environmental microbiologist at the University of Arizona who has studied germs' domestic dabbles for more than 30 years.

Which means you shouldn't rely on theories that say a lapse in germ defense will boost your immune system or that the spare use of sanitizing agents will somehow thwart antibioticresistant super-bugs. Both are scientifically shaky, and neither should get in the way of preventing infections, Gerba says.

Bacteria can survive for a few hours to a couple of days or more on surfaces such as the kitchen countertop, and viruses can linger up to a couple of weeks. We spend less time cleaning than we used to, despite having more vehicles for germs on gadgetry like cellphones and remote controls.

The bottom line: to "not live in a bubble, but to understand the dynamics of how germs are transferred and to maintain good hygiene practices," says Philip Tierno, author of "The Secret Life of Germs" and director of clinical microbiology and diagnostic immunology at New York University Medical Center.

The key to picking these battles is awareness. We talked to germ experts for the lowdown on some of the home's most pathogenpopular (and just plain dirty) destinations and strategies to keep those areas clean.

Kitchen Sponge


Call it the mother ship. The hot zone. Germ HQ. The kitchen sponge (or dishcloth) consistently reigns as the dirtiest item in the home, decisively out-pathogenizing more infamous culprits, such as the toilet.

According to a new study by the Hygiene Council, an international group of infectious-disease specialists, 75 percent of sponges tested in U.S. homes were heavily contaminated. Think of it this way: One drop from the sponge equals millions of bacteria. The council's study was sponsored by Lysol.

In Gerba's research, which was sponsored by Clorox, the kitchen sponge was crowned the germiest, especially when used for food prep and cleanup. A cutting board, for example, was found to have 200 times more fecal bacteria than the toilet seat.


Soak the sponge or dish cloth in a disinfectant or bleach for a few minutes at least three times a week before letting it air-dry. For a quick fix, you can nuke the sponge in the microwave on high for 30 seconds, or throw it in the dishwasher.

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