That being said, you might want to think twice before purchasing conventionally grown strawberries, spinach, or kale. According to a new report from the Environmental Working Group (EWG), these foods are the most likely to be contaminated with synthetic pesticide residue—and nearly 70 percent of the fresh produce sold in the U.S. contains residues of these chemicals. “Many crops contain potentially harmful pesticides, even after washing, peeling or scrubbing, which the USDA does before testing each item,” states the EWG’s Shopper’s Guide to Pesticides in Produce. “Since pesticide contamination varies by crop, it is important to understand which items are most or least contaminated.” The findings are part of the EWG’s 2020 “Dirty Dozen” and “Clean Fifteen,” an annual list of the most and least pesticide-ridden foods. To compile the ranking, the EWG analyzed tests conducted by the U.S. Department of Agriculture of 47 different types of conventionally grown produce. Alongside the results of the Dirty Dozen and Clean Fifteen lists, perhaps the most surprising piece of this year’s findings involves a popular dried fruit: raisins. The EWG typically examines just fresh fruits and vegetables, but chose to include raisins in its 2020 research (the USDA tested raisins last year for the first time since 2007). “Almost every sample of non-organic raisins tested—99 percent—had residues of at least two pesticides,” it reports. If included in the 2020 Dirty Dozen list, raisins would rank worst of all fruits tested. This includes strawberries, nectarines, apples, and cherries, which all had residues of two or more pesticides on at least 90 percent of samples. Aside from raisins, the EWG found that strawberries were the most contaminated fruit for the fifth year in a row. Kale made its way onto the list’s top 10 for the first time in over a decade last year, thanks to new data that suggested pesticide residues on this leafy green included traces of DCPA. “The Environmental Protection Agency classifies DCPA as a possible human carcinogen, and in 2009 the European Union banned it,” reports the EWG. Despite their robust health benefits, conventionally-grown leafy greens appear to contain more pesicides than most other types of produce: multiple samples of kale showed 18 different pesticides, and on average, kale and spinach samples both had 1.1 to 1.8 times as much pesticide residue by weight than any other crop tested. So what conventionally grown produce is safest to purchase? Avocados (#blessed). According to the EWG, fewer than 2 percent of samples of both avocados and the second cleanest type of produce, sweet corn, showed any detectable pesticides. More good news: save for cabbage, all other products on the Clean Fifteen tested positive for four or fewer pesticides, and nearly 70 percent of Clean Fifteen fruit and vegetable samples had no pesticide residue at all. “Multiple pesticide residues are extremely rare on Clean Fifteen vegetables. Only 7 percent of Clean Fifteen fruit and vegetable samples had two or more pesticides,” states the EWG report. The EWG lists, which started in 1993, have gained a reputation among many notable doctors and health organizations, including the American Academy of Pediatrics, for reducing pesticide exposure in diets. But the Dirty Dozen list has also attracted some criticism for focusing on quantity of pesticides rather than actual toxicity, or for failing to acknowledge that organic produce may also contain pesticides. According to Sonya Lunder, EWG senior analyst, the group has taken to highlighting crops, like hot peppers this year, as the “Dirty Dozen Plus.” These produce picks don’t meet the traditional criteria, but have been found to have residue of highly toxic pesticides on them. Additionally, some critics have pointed out that the levels of pesticide residue found on the food in this list, though higher than other fruits and vegetables, are generally still well below EPA tolerance levels. Remember: fruits and vegetables are highly critical components of a healthy diet, whether conventionally grown or organic. See the full Dirty Dozen and Clean Fifteen lists below, as well as the complete rankings of over 50 varieties of produce on the EWG website.
The Dirty Dozen:
- Strawberries
- Spinach
- Kale
- Nectarines
- Apples
- Grapes
- Peaches
- Cherries
- Pears
- Tomatoes
- Celery
- Potatoes
The Clean Fifteen:
- Avocados
- Sweet corn
- Pineapple
- Onions
- Papaya
- Sweet peas (frozen)
- Eggplant
- Asparagus
- Cauliflower
- Cantaloupe
- Broccoli
- Mushrooms
- Cabbage
- Honeydew Melon
- Kiwi Want to keep your produce clean at home? Get expert tips from the USDA, food scientists, and other experts on how to store fruits and veggies.
