Perhaps you already know about the Dirty Dozen, the Environmental Working Group's (EWG) list of the most pesticide-contaminated fruits and vegetables.  Every single one of them is grown in the Boston area, and according to the EWG, "People who eat five fruits and vegetables a day from the Dirty Dozen list consume an average of ten pesticides a day."  

Buying organic produce from a Boston-area farmer's market, Boston Organics, or a Boston-area grocery store is one way to avoid eating all those pesticides.However, as one reader notes in her recent message to me, that can get expensive, and many have to consider alternatives:

"I buy organic for the dirty dozen and anything else on my list that is reasonably priced organic. The rest I buy conventional."  She goes on to wonder, "Do the Dirty Dozen rules hold for frozen/dried foods? I buy lots of frozen and freeze dried fruits for [my son]. Should I be buying organic for those for apples, berries, etc., or are they far enough removed from the field at that point that it doesn't make much difference?"

The answer is yes, the Dirty Dozen definitely includes frozen, canned, and otherwise prepared foods.  Processing them doesn't change what they've been exposed to in the field.  That means that if you're buying dried or frozen produce from the Dirty Dozen list, it is safer to choose organic products.

My reader goes on to ask about whether peeling Dirty Dozen items before eating them is an effective way of reducing the amount of pesticide one consumes.  She says, "Potatoes, for instance. They're a dirty dozen item, but I never cook potatoes with the skin on. I've never liked the skin. Does removing the skin from potatoes, apples, peaches, etc. before eating them remove most of the pesticides, making them roughly equivalent to conventional? Or does the skin get permeated enough that it's still better to buy organic?"

This is a much more complex issue.  It's important to note that the EWG tested foods the way people generally eat them - washed for foods that are eaten with the skin, and peeled for foods that are not.   For items that were tested with the peel on, that doesn't necessarily mean that peeling the item would reduce pesticide exposure.  It depends on the particular vegetable/fruit, because some have much more permeable skins than others. Peaches are very thin-skinned. Apples are less so, but pesticides still permeate.  When in doubt, peeling is "safer," but in most cases it won't yield the equivalent of an organic food.  Also, edible peels often contain valuable nutrients, which are a shame to toss in the trash.

The moral of the story is to buy organic versions of the Dirty Dozen when possible, and to think carefully about whether  to sacrifice nutrients by peeling or avoid their non-organic counterparts.  The EWG recommends eating a varied diet, thereby increasing the kinds of nutrients you consume, and hopefully spreading your risk of pesticide ingestion a little bit thinner.