Eating is so easy in the summer: Once a week I stop off at my local CSA, Taliaferro Farms in New Paltz, and pick up bags of freshly picked organic spinach, raspberries, and carrots. I buy eggs laid by free-range chickens that spend their days feasting on tomato and melon scraps, and I purchase yogurt, milk, and meats from local organic farms. For six months of the year, I am practically pesticide-free.

But I'm no purist. When the Hudson Valley growing season ends, I'm back to shopping at supermarkets. I shop where it's convenient, and a lot of times my decisions are based on habit, price, or mood. I often buy organic when it's available, but I won't make a special trip if it isn't. At stores that carry both organic and nonorganic foods, I choose my purchases on a whim. But when mixing and matching in the fruit and vegetable aisle, I've learned, there some items I should absolutely avoid-and some that can be downright dangerous. According to the Shopper's Guide to Pesticides in Produce, a new list created by the Environmental Working Group (EWG), some fruits and vegetables are so likely to be contaminated with pesticides you should always buy them organic. The guide reflects the results of nearly 43,000 tests for pesticides on produce conducted by the Department of Agriculture and the Food and Drug Administration between 2000 and 2004. Peaches, apples, sweet bell peppers, and celery top the dirty list.

Richard Wiles, senior vice president of the EWG, explains how these three fruits and one vegetable found themselves crowning the list of the 43 commonly consumed produce: "These fruits and veggies are the most likely to have pesticides on them after washing and peeling. They have higher levels, more different chemicals, a higher percentage of the crop with detectable residues, and, overall, a greater number of different pesticides on the crop," says Wiles. He stresses that the tests were conducted after washing and preparing for normal consumption, so shoppers should not fool themselves into thinking that washing an apple will remove it from the most-contaminated to the least-contaminated list.

The EWG also posits that eating the 12 nonorganic fruits and vegetables at the top of the contaminated list will expose a person to about 15 pesticides a day. The safe list is topped by onions, avocados, frozen sweet corn, and pineapples. Eating the 12 least-contaminated items will expose a person to fewer than two pesticides a day. In fact, if consumers avoid the most-contaminated produce and instead eat the least contaminated, they could cut their pesticide exposure by almost 90 percent.

It is also particularly important to minimize pesticide exposure in children under the age of 3-ages when we are most vulnerable to the toxic effects of pesticides and chemicals.  However, Wiles says, "parents of small children should do all that they can to buy organic or choose the least-contaminated fruits and vegetables."

For those who feel they simply can't afford to buy organic, Wiles suggests eating as many on the least-contaminated list as possible-as even when they are not organic, they have very few pesticides. He ends by stating, "Adults should eat more fruits and vegetables, period. First, they should choose organic, or the least contaminated, but if the option is between another burger or a salad, eat the salad."

For a full report on the Environmental Working Group's Dirty Dozen and Cleanest 12, visit www.foodnews.org.