What's the top contamination hazard in your kitchen?

Hand towels are the top contamination hazard in the kitchen, according to a new study.

Cellphones are another potential source of kitchen cross-contamination, the researchers found. Cross-contamination refers to the accidental transfer of potentially hazardous germs from one surface to another.

Kansas State University researchers asked 123 people to prepare a recipe using either raw ground beef or chicken, along with a ready-to-eat fruit salad. The participants did the food preparation in a kitchen set up on the campus.

A harmless type of bacteria was placed in the raw beef and chicken in order to trace levels of meat-associated contamination spread during meal preparation.

"First, participants were observed frequently handling towels, including paper towels, even when not using them for drying. Towels were determined to be the most contaminated of all the contact surfaces tested," lead researcher and food safety specialist Jeannie Sneed said in a university news release.

Many participants touched towels before washing their hands or used them after inadequate washing of their hands, she said. Even after they washed their hands properly, the participants reused the towels and re-contaminated their hands, according to the study in the journal Food Protection Trends.

Cloth towels can easily become contaminated with germs that can cause foodborne illnesses, the researchers said. They added that previous studies found that bacteria commonly found in raw meat and poultry grows on cloth towels stored overnight, even when they are washed and rinsed in the sink.

Wash cloth towels after using them while preparing a meal, or use paper towels and throw them away after each use, Sneed advised.

Her team found that more than 90 percent of the fruit salads prepared by the participants were contaminated with the tracer bacteria. This shows that if the tracer had been a harmful germ such as salmonella, there was a high risk of foodborne illness.

Four out of five participants also left raw meat contamination on the sink faucet, refrigerator, oven and trash container, the study found.

Moreover, many participants used cellphones during meal preparation and didn't clean them properly.

"We often take our cellphones and tablets into the kitchen," Sneed said, "but what about all the other places we take them? Think of how many times you see someone talking on their cellphone in places like the bathroom, where microorganisms such as norovirus and E. coli are commonly found."

If these devices are used in the kitchen, Sneed recommended wiping their surfaces with a disinfectant.