Every year the nonprofit Environmental Working Group releases its rankings of the top 48 most popular fruits and vegetables that have the lowest and highest pesticide loads. In order to create the lists, which help families decide when it makes the most sense to buy organic produce, the group analyzes data compiled by the USDA after testing more than 35,200 produce samples.

Topping the list of the Dirty Dozen for the second year in a row are strawberries. Even when rinsed in the field and at home, conventional strawberries contained an average of 7.7 different pesticides per sample, compared to 2.3 per sample in all other tested produce, according to the EWG. Conventional strawberries have been shown to contain chemicals linked to cancer, hormone disruption, and reproductive issues, amongst others.

New to the Dirty Dozen list this year are pears. They have seen an uptick in pesticide use in recent years, bumping them up from the 22nd slot to the sixth. Lastly, non-organic spinach has also seen a rise in pesticide use, taking the number two spot on the list, which is six spots higher than last year’s ranking of eight.

According to Sonya Lunder, a senior analyst at the EWG, “Fruits and vegetables are important for your health, but for those on the Dirty Dozen, we recommend buying the organic version 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.”

* A small amount of sweet corn, papaya and summer squash sold in the United States is produced from genetically modified seeds. Buy organic varieties of these crops if you want to avoid genetically modified produce.

For more information about the Dirty Dozen and Clean Fifteen, and to download the EWG’s free Shopper’s Guide to Pesticides in Produce, visit ewg.org.