By Brierley Wright, M.S., R.D. , April 29, 2010 - 12:54pm
When I shop for fruits and vegetables I always consult the Environmental Working Group’s (EWG) pocket-size Shopper’s Guide to Pesticides, which identifies fruits and vegetables that have the highest and lowest pesticide residues. So I’m pleased that EWG, a nonprofit organization, is updating the list again this year. Their 2010 update is based on new data from the USDA and FDA on pesticide residues in produce. Three new foods made the “Dirty Dozen,” the 12 fruits and vegetables that are most likely to be contaminated with pesticide residues , and three new foods were added to the “Clean 15,” which are least likely to be contaminated with pesticide residues .
As a registered dietitian and nutrition editor at EatingWell magazine, I know there are health benefits (beyond vitamins and fiber) to eating a diet rich in a variety of fruits and vegetables . But pesticides can be absorbed into fruits and vegetables and, although you can remove some pesticide residues with washing, long-term exposure to pesticides has been associated with cancer, infertility and neurologic conditions, such as Parkinson’s . I don’t buy everything organic, because it would add to our grocery bills , so I use this list while I shop. (Find recipes for 7 quick healthy weeknight dinners that cost $3 or less per serving. )
The full updated list won’t be released until mid May on the EWG website foodnews.org. But the folks at EWG e-mailed their members an exclusive first look at the list (see below)—and also answered a few questions for EatingWell.
What’s different on the updated Dirty Dozen list? Blueberries , potatoes  and spinach  are all new to the list. “This is our sixth installment of the guide. For the past two installments blueberries weren’t anywhere on the list because we didn’t have the necessary data from the USDA and FDA to evaluate them,” says Leann Brown, a spokesperson for EWG I talked with.
Carrots, lettuce and pears were previously on the list and aren’t anymore. “We’ve been surprised by the movement of certain fruits and vegetables on the list,” says Brown, who couldn’t elaborate on why pesticide levels change. “Unfortunately, there aren’t any common trends, so we can’t make recommendations, such as buy all berries organic.”
That said, EWG ranks pesticide contamination for popular fruits and vegetables from nearly 96,000 tests from the USDA and FDA. So carrots, lettuce and pears may end up somewhere in between the Dirty Dozen and the Clean 15 lists, but we won’t know for sure until the full list is released in mid May. That in-between category is one where, if your budget allows, you should try to buy organic.
What’s different on the Clean 15 list? Cantaloupe, grapefruit and honeydew melon are all new to the Clean 15 list. Previously on the list of produce lowest in pesticides, but no longer, are broccoli , papaya and tomatoes —so, again, if your budget allows, consider buying them organic too.
The EWG found that eating 5 fruits and vegetables a day from the Dirty Dozen list will expose a person to about 10 pesticides per day, on average. Eating the Clean 15 will expose a person to fewer than 2 pesticides per day). Experts say that some pesticides wreak their damage by operating as free radicals, compounds that damage tissues in ways that can lead to the development of cancer and other diseases. (Here are 4 more ways to reduce your exposure to pesticides.) 
Minimizing your exposure to pesticides will reduce this free-radical damage, but so will consuming more antioxidants found in fruits and vegetables, which mop up free radicals. Many of the pesticides stay in the peel, so discarding the skin can reduce residues significantly—by up to 98 percent, according to a 2008 Journal of Agricultural and Food Chemistry study. But ditch the peel and you lose out on a lot of fiber and many of the antioxidants. So if you can’t afford to buy organic, keep in mind that eating lots of fresh fruits and vegetables in general is the point.
And while health considerations are important, there’s another reason to consider buying organic: the environment. Organic produce is healthier for the environment because it requires more sustainable farming practices and helps to reduce the amount of chemicals that leach into our soil and water.
You can find a detailed description of the criteria EWG used to develop these rankings and the complete list of fruits and vegetables tested at foodnews.org.
What influences your choices about what to buy organic and what to buy conventional? What makes the cut and why? Tell us what you think below.