Conventional vs. Organic

Conventionally grown peaches, apples, and lettuce are marinated in a toxic cocktail of pesticides, which have been shown to cause everything from dizziness to cancer, as well as headaches, rashes, and liver toxicity. But not all fruits and vegetables are affected equally (or receive the same amount of chemical treatment). Bananas, for example, are perfectly safe in their conventional (less expensive) form, thanks to a protective peel.
So which conventional fruits and vegetables are the most toxic? The Environmental Working Group — an environmental research firm in Washington, D.C. — recently tested the pesticide levels of 44 kinds of produce to find out.

10 Most Toxic Conventionally Grown Fruits and Vegetables (in descending order of pesticide toxicity levels):
Peaches
Apples
Sweet Bell Peppers (11 different pesticides found on a single pepper)Celery
Nectarines
Strawberries
Cherries
Lettuce
Grapes
Pears (86 percent of samples tested found with detectable pesticides)

10 Least Toxic Conventionally Grown Fruits and Vegetables (in descending order of pesticide toxicity levels):
Cabbage
Bananas
Kiwi
Asparagus (7 percent of samples tested found with detectable pesticides)
Sweet Peas
Mangoes
Pineapples
Sweet Corn
Avocados
Onions (1 pesticide found on a single onion)

Source: Shopper's Guide to Pesticides in Produce, Fifth Edition, The Environmental Working Group