How dirty are grocery shopping carts? A lot dirtier than you probably think. According to Professor Charles Gerba, a University of Arizona researcher, half of those shopping carts you grab have E. coli bacteria on them and nearly three-fourths (72%) have fecal bacteria. Gerba swabbed the handles of 85 grocery carts in four states for bacterial contamination to come up with his finding.

If that sounds like a lot of fecal matter to you, you’d be correct. That is more fecal matter than you would typically find in a bathroom because bathrooms get cleaned and disinfected more often than grocery carts. After reading that, you shouldn’t be able to look at a grocery cart quite the same way again.

The lesson to be learned here? It’s important to realize that most grocery stores will not wash and/or disinfect their grocery carts on a regular basis, so it’s best to assume that the grocery cart’s handle is filthy, and you’ll be the one that needs to make sure that it’s clean. If your store offers disinfecting wipes at the entrance of the store, be sure to take advantage of them. If not, it is worthwhile for you own health (and your kids — previous studies have found that children who touch the grocery cart handles are more likely than other children to get infected with bacteria like salmonella) to invest in a tub of them and place it in your car so that you can have the wipes available each time you go grocery shopping.

In addition, Gerba notes that if you shop with reusable shopping bags when grocery shopping, you should wash your bags on a regular basis because these can easily become a “bacterial swamp” in not washed.