The Dirty Little Secret at the Grocery Store

June 9, 2011
Daily Health News
Charles Gerba, PhD

Which of the following surfaces is most likely to be contaminated with dangerous bacteria—a diaper changing table…playground equipment…a shopping cart handle…ATM buttons…or the handrail on an escalator? Most people would have said the changing table…and been wrong. Correct answer: The shopping cart handle, and after you read this, you are going to want to make changes to your shopping habits!


The finding comes from researchers at the Department of Soil, Water and Environmental Science at The University of Arizona in Tucson. Previous studies had shown that seating children in shopping carts increases their risk for infection with Salmonella and Campylobacter bacteria, each of which can lead to abdominal pain and diarrhea that last for a week (or longer in people with weakened immune systems). This time, researchers set out to see just how dirty shopping cart seats and handles really are. To do that, they swabbed the handles and seats of 85 shopping carts randomly selected from parking lots of grocery stores in San Francisco…Los Angeles…Atlanta…Portland, Oregon…and Sioux City, Iowa, and tested the samples they had gathered.

For details on what they found, we turned to Charles Gerba, PhD, professor of environmental microbiology at The University of Tucson and lead researcher on the study. He explained that coliform bacteria (common in soil, on vegetation and in the feces of animals) were present in high amounts on 72% of the carts. Some of the carts were further examined for Escherichia coli (E. coli), a specific species of coliform present in the lower intestines of all warm-blooded mammals and responsible for many serious tainted-food-related illnesses, and it was present on half of them. In fact, the researchers pointed out that bacteria levels on the carts were greater than what is typically found in public restrooms and other public places.


According to the study, the potential causes of contamination are numerous, ranging from contact with contaminated raw foods, such as those found in a supermarket…bird or other animal feces (which may contaminate the carts while they sit in the parking lot)…or contact with feces-contaminated hands (or other body parts) of previous cart users or children in diapers.

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Shopping carts, as it turns out, are one of the objects most contaminated with fecal bacteria that we are likely to come across. Of course, public restrooms are cleaned on a set schedule…your shopping cart, not so much.


The next time you go shopping, don’t disregard the containers of disinfecting wipes now provided by many stores near the carts—give the handle and seat (if you’re planning to use it) a good wipe-down. Though it takes around 10 minutes for the disinfectants in the wipes to work, it’s a good start. Some stores have started providing disposable/recyclable plastic barriers that fit over their cart handles, which are also a good choice. You can buy your own—for instance, Protective Cart Guard made by Health Touch Solutions (877-823-4871, www.HealthTouchSolutions.com). Even if you do use wipes or a barrier on your cart, after shopping, wash your hands (and your child’s hands) before eating anything. When washing isn’t practical, Dr. Gerba said, you can use a hand sanitizer such as Purell, which kills viruses and bacteria in fecal matter. And that’s just what you want. And by all means, don’t ever let a child suck on a shopping cart handle.