The Environmental Working Group provides this list of vetetables and fruit that are both highest and lowest in pesticide residues. With the Dirty Dozen -- those containing the most pesticides -- buy organic. The Clean 15 are the lowest in pesticide residues.
The Dirty Dozen (buy these organic)
1. Celery
2. Peaches
3. Strawberries
4. Apples
5. Blueberries
6. Nectarines
7. Bell peppers
8. Spinach
9. Cherries
10. Kale/Collards
11. Potatoes
12. Grapes (imported)
The Clean 15
1. Onions
2. Avocado
3. Sweet corn
4. Mangoes
5. Pineapple
6. Sweet peas
7. Asparagus
8. Kiwi
9. Cabbage
10. Eggplant
11. Cantaloupe
12. Watermelon
13. Grapefruit
14. Sweet potato
15. Honeydew melon