Hint: the answer is not avocado.

By Liz Steelman
April 12, 2016

Fruits and vegetables are often considered an important component of so-called clean eating—but have you wondered how clean your produce actually is? Well, according to a new report from the Environmental Working Group (EWG), some items like peaches, nectarines, and potatoes might be more contaminated than you realize.

The most contaminated? Strawberries. Of those sampled, 98 percent of strawberries were found to have pesticide residue. Nearly half had residues of 10 or more pesticides and some had traces of as many as 17. For the past five years, apples had been at the top of the list. But now because of high demand for strawberries out of season, farmers are using almost 300 pounds of pesticides per acre to stretch the growing season and yield, some of which leave residue that remains even after washing. Apples moved to number two on the list, followed by nectarines, peaches, and celery.

This finding is part of the EWG’s annual “Dirty Dozen” and “Clean Fifteen” lists, which rank almost 50 varieties of produce for pesticide contamination. This analysis comes from the U.S. Department of Agriculture and Food and Drug Administration testing more than 35,200 samples of fruit and vegetables.

“Fruits and vegetables are important for your health,” Sonya Lunder, EWG senior analyst, said in a statement. “But for those on the Dirty Dozen, we recommend buying the organic versions if you want to avoid pesticides on your food. You can feel confident that conventionally grown fruits and veggies on the Clean Fifteen list have very little pesticide contamination.”

The cleanest item in the produce section? Avocados. Fewer than one percent of samples showed any pesticide residue.

See the full Dirty Dozen and Clean Fifteen lists on the EWG website. Need some help keeping your fruits and veggies clean in the fridge? Here’s how to store fruits and vegetables, according to the USDA, food scientists, and other experts.