Since 1993, the Environmental Working Group (EWG) has been on a mission to protect public health and the environment by pushing for national policy change. Recently, this nonprofit organization once again released information about pesticide residue in produce. 

Many scientific studies show pesticides are linked to a variety of health concerns, including cancer and brain damage, especially when they’re consumed in large amounts on a consistent basis.

Here is the EWG’s 2012 Dirty Dozen list of fruits and vegetables that contain unacceptable pesticide residues (with the worst offenders at the top of the list):

1. Apples
2. Celery
3. Sweet bell peppers
4. Peaches
5. Strawberries
6. Nectarines
7. Grapes
8. Spinach
9. Lettuce
10. Cucumbers
11. Blueberries
12. Potatoes

You can avoid pesticide residue by choosing produce that is certified organic by the U.S. Department of Agriculture. USDA regulations prohibit use of chemical pesticides, herbicides, insecticides or fertilizers on organic crops. But organic produce often carries a price premium, making the EWG’s list a handy guide if you’re on a budget.

“When making the choice between organic and nonorganic produce,” explains Mary Mulry, PhD, who is a food scientist and Wellness Times editorial advisor, “use the Dirty Dozen list as your guide to what to always purchase organic.”

The fruits and vegetables that had the lowest amount of pesticide residue made it to the 2012 Clean Fifteen list compiled by the EWG:

1. Onions
2. Sweet corn
3. Pineapples
4. Avocado
5. Cabbage
6. Sweet peas
7. Asparagus
8. Mangoes
9. Eggplant
10. Kiwi
11. Cantaloupe
12. Sweet potatoes
13. Grapefruit
14. Watermelon
15. Mushrooms

The EWG says that some of the Clean Fifteen do have detectable levels of pesticides, but those levels are the lowest of all the foods tested.  Some of the fruits and vegetables on the list have no detectable pesticide levels. 

The EWG also tested prepared baby food and found that 92 percent had at least one form of pesticide residue. Green beans tested positive for five different pesticides, while sweet potatoes were the cleanest.  

“Consumers should choose organic whenever possible, but especially for their children,” said Mulry. “Because children have a smaller body size, pesticide exposure can be more harmful to them.”