The Environmental Working Group reported a list of popular fruits and vegetables with the highest concentration of pesticide residue.

Starting with the highest amounts of pesticide residue, the "Dirty Dozen" list features strawberries, spinach, nectarines, apples, peaches, celery, grapes, pears, cherries, tomatoes, sweet bell peppers and potatoes.

This year, strawberries were listed as the worst offender. The fruit contained at least 20 pesticides.

Produce that had relatively fewer pesticides and lower total concentrations of pesticide residues was placed on the group's "Clean Fifteen" list. This list included, in order, sweet corn (including corn on the cob and frozen corn), avocados, pineapples, cabbage, onions, frozen sweet peas, papaya, asparagus, mangoes, eggplant, honeydew melon, kiwis, cantaloupe, cauliflower and grapefruit.