Home Sweet Home? Bacteria Think So

Ask yourself this question: which room harbors more bacteria, your kitchen or your bathroom? The answer may surprise you -- but it illustrates an important point: ignorance and improper cleaning help spread disease-causing bacteria viruses in the home, a researcher said.

Chuck Gerba, a University of Arizona professor, said surveys have shown that consumers are woefully ill-informed when asked to name the dirtiest place in their house, and that, if better instructed, they could drastically reduce infection risk.

While most people think that toilets and bathroom sinks harbor the worst and greatest numbers of disease-causing microbes, studies by Gerba and others have found otherwise.

Researchers have found more fecal contamination in the kitchen: in 60 percent of sponges, 50 percent of kitchen sinks, and 25 percent of countertops.

"If I was bacteria in my next life, I'd want to live in a sponge -- there's no better place," said Gerba, noting they get food and water there.

To avoid such contamination, Gerba suggested that sponges could be sterilized by 30 seconds in a microwave, or by using them with a bleach-based cleaner.

Surprisingly, bathrooms are usually cleaner than kitchens because Americans properly disinfect sinks and toilets, said Gerba.

In one study, Gerba and students observed 15 houses for four months. They measured pathogen levels in kitchens and bathrooms at the start, and found that kitchens were more heavily contaminated.

The homeowners included in the study were given bleach cleaners and told to follow the label.

As a result, even minimal cleaning reduced germs. With new instructions to clean more often and to target certain pathogen-loaded areas, such as cutting boards and refrigerator handles, there was a 90 to 95 percent reduction in germ levels, Gerba said.

The newest dirty place, Gerba noted, is the laundry room. In studies with hundreds of pounds of soiled clothes, Gerba found that 12 minutes in the wash and 28 minutes of drying were not enough to knock out Hepatitis A, rotavirus, adenovirus or Salmonella bacteria.

Gerba cautioned that people shouldn't believe they are safer in the workplace. In one study, he found that 60 percent of office coffee cups were infected with E. coli, mostly because they were being wiped out with a sponge and then being reused.