Every year the Environmental Working Group releases a report ranking the most pesticide-tainted produce items in the grocery store using test data compiled from the USDA and U.S. Food and Drug Administration (FDA). This year, the report highlighted that of the 47 items tested, nearly 70% of fresh produce contained traces of pesticides. Traditionally, this list contains only fresh fruits and vegetables, but 2020 marks the inaugural year for a processed produced-based product to be added to the ranking.

Known as the “Dirty Dozen,” the Environmental Working Group has released the list annually since 2004 to bring attention to pesticide use in U.S. crop cultivation. Although this year, raisins topped the list, the dried grapes were not officially ranked No. 1 as the list remains dedicated to fresh produce only. The full list includes: Strawberries, spinach, kale, nectarines, apples, grapes, peaches, cherries, pears, tomatoes, celery and potatoes.

While strawberries, nectarines, apples and cherries all tested for at least two pesticides on 90% of samples, it was strawberries, spinach and kale that landed in the top three spots of the “Dirty Dozen.” 

According to the report, the USDA does not test for all pesticides used in crop production, including glyphosate, or Roundup, which is the most widespread and heavily used pesticide in the U.S.

Testing data from the USDA accounted for at-home processing. Produce is washed, peeled or scrubbed according to how it will be used conventionally before pesticide testing is conducted. Similarly, the National Pesticide Information Center notes that washing fruits and vegetables is not 100% effective at removing pesticides. The FDA recommends washing produce in tap water to reduce pesticides on produce.

Even with residual pesticides on produce, a 2015 study from the International Journal of Food Contamination concluded that individuals’ exposure to pesticides are below the levels notable for health concern. The U.S. Environmental Protection Agency (EPA) also sets tolerances for pesticide residue in food at a level that can be used with "reasonable certainty of no harm." The governmental agency sets the guidance using a barometer that measures the toxicity and quantity of an applied pesticide.

The report from the Environmental Working Group indicated that the pesticide DCPA, sold under the brand name Dacthal, was present on kale produced in the U.S. despite its classification as a possible human carcinogen. In 2009, the European unio banned the use of this pesticide. Kale samples had 1.1 to 1.8 times as much pesticide residue by weight than any other crop tested and samples of the crop had 18 different pesticides.

The Environmental Working Group also ranks the cleanest produce items on its “Clean Fifteen” list. Avocados, sweet corn and pineapples were identified as the cleanest produce options with fewer than 2% of avocado and sweet corn samples showing signs of pesticides. Of the 15 cleanest options, 70% of the produce samples not testing positive for pesticide residues. The full list of clean produce includes: Avocados, sweet corn, pineapple, onions, papaya, sweet peas (frozen), eggplants, asparagus, cauliflower, cantaloupes, broccoli, mushrooms, cabbage, honeydew melon and kiwi.