Celery has no protective skin, which makes it almost impossible to wash off the chemicals (64 of them!) that are used on crops. Buy organic celery, or choose alternatives like broccoli, radishes, and onions.
Multiple pesticides (as many as 62 of them) are regularly applied to these delicately skinned fruits in conventional orchards. Can't find organic? Safer alternatives include watermelon, tangerines, oranges, and grapefruit.
If you buy strawberries, especially out of season, they're most likely imported from countries that have less-stringent regulations for pesticide use. 59 pesticides have been detected in residue on strawberries. Can't find organic? Safer alternatives include kiwi and pineapples.
Like peaches, apples are typically grown with poisons to kill a variety of pests, from fungi to insects. Tests have found 42 different pesticides as residue on apples. Scrubbing and peeling doesn't eliminate chemical residue completely, so it's best to buy organic when it comes to apples. Peeling a fruit or vegetable also strips away many of their beneficial nutrients. Can't find organic? Safer alternatives include watermelon, bananas, and tangerines.
New on the Dirty Dozen list in 2010, blueberries are treated with as many as 52 pesticides, making them one of the dirtiest berries on the market.
With 33 different types of pesticides found on nectarines, they rank up there with apples and peaches among the dirtiest tree fruit. Can't find organic? Safer alternatives include, watermelon, papaya, and mango.
7. Bell peppers
Peppers have thin skins that don't offer much of a barrier to pesticides. They're often heavily sprayed with insecticides. (Tests have found 49 different pesticides on sweet bell peppers.) Can't find organic? Safer alternatives include green peas, broccoli, and cabbage.
New on the list for 2010, spinach can be laced with as many as 48 different pesticides, making it one of the most contaminated green leafy vegetable.
Traditionally, kale is known as a hardier vegetable that rarely suffers from pests and disease, but it was found to have high amounts of pesticide residue when tested this year. Can't find organic? Safer alternatives include cabbage, asparagus, and broccoli.
Even locally grown cherries are not necessarily safe. In fact, in one survey in recent years, cherries grown in the U.S. were found to have three times more pesticide residue then imported cherries. Government testing has found 42 different pesticides on cherries. Can't find organic? Safer alternatives include raspberries and cranberries.
America's popular spud reappears on the 2010 Dirty Dozen list, after a year hiatus. America's favorite vegetable can be laced with as many as 37 different pesticides. Can't find organic? Safer alternatives include eggplant, cabbage, and earthy mushrooms.
Imported grapes run a much greater risk of contamination than those grown domestically. Only imported grapes make the 2010 Dirty Dozen list. Vineyards can be sprayed with different pesticides during different growth periods of the grape, and no amount of washing or peeling will eliminate contamination because of the grape's thin skin. Remember, wine is made from grapes, which testing shows can harbor as many as 34 different pesticides. Can't find organic? Safer alternatives include kiwi and raspberries.