Environmental Working Group’s ‘Dirty Dozen’ List Debunked

The Environmental Working Group seems to exist for no other reason than to scare consumers away from the products of modern technology — and to advertise on behalf of the organic food and natural products industries.  Since 1993, the group has been terrorizing America about everything from apples to the zinc-oxide used in some sunscreens, and practically everything in between.  And since 1995, it’s been publishing an annual “Dirty Dozen” list of fruits and vegetables the organization claims have dangerously high levels of pesticides.

When this year’s Dirty Dozen list was published in June, EWG president Ken Cook wrote that:

“Though buying organic is always the best choice, we know that sometimes people do not have access to that produce or cannot afford it.” … “Our guide helps consumers concerned about pesticides to make better choices among conventional produce, and lets them know which fruits and vegetables they may want to buy organic.”

And when last year’s study was published, an EWG press release claimed that “consumers can lower their pesticide consumption by nearly four-fifths by avoiding conventionally grown varieties of the 12 most contaminated fruits and vegetables.”

The fact of the matter is, the mere presence of a substance doesn’t necessarily mean that it’s present at a dangerous level.  Because farmers the world over use pesticides to increase their productivity, there’s going to be trace levels of pesticides in the food we eat. And, frankly, since we don’t live in a Lake Wobegon world, where everything is better than average, some product or another has to measure highest in pesticide residues. Cleverly, EWG rarely says directly that the levels of pesticides they measure are dangerous, but they know they can count on most consumers and the media to infer that conclusion.

Fortunately, a couple of scientists at the University of California, Davis, have conducted their own study that essentially debunks the Dirty Dozen argument.  Carl Winter, a food toxicologist who directs the university’s FoodSafe Program, and PhD student Josh Katz estimated consumers’ exposure to the pesticides “studied” in the EWG report and then compared them with the Environmental Protection Agency’s chronic reference dose (RfD), which estimates the amount of a chemical a person could be exposed to every day over an entire lifetime without an appreciable risk of harm.  What did they find?

All pesticide exposure estimates were well below established chronic reference doses (RfDs). Only one of the 120 exposure estimates exceeded 1% of the RfD (methamidophos on bell peppers at 2% of the RfD), and only seven exposure estimates (5.8 percent) exceeded 0.1% of the RfD. Three quarters of the pesticide/commodity combinations demonstrated exposure estimates below 0.01% of the RfD (corresponding to exposures one million times below chronic No Observable Adverse E?ect Levels from animal toxicology studies), and 40.8% had exposure estimates below 0.001% of the RfD.

Essentially, consumers could eat about 50 times their normal daily amount of the worst food on the EWG Dirty Dozen list, and do that every day for their entire lives, and still not expose themselves to much risk of harm. Winter and Katz concluded by noting that their:

“findings conclusively demonstrate that consumer exposures to the most frequently detected pesticides from commodities on the “Dirty Dozen” list are at negligible levels.” … And “the EWG methodology is not sufficient to allow meaningful ranking among commodities or that substituting organic forms of the commodities on the “Dirty Dozen” list will lead to measurable consumer health benefit.”


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