What is the Dirty Dozen List?

Close-up of strawberries growing
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If you watch the TV news, you probably know that once a year, there's a report called the "Dirty Dozen," put out by an organization called the Environmental Working Group, purporting to show the 12 types of conventionally grown produce with the highest levels of pesticide contamination. Foods like apples, strawberries and kale routinely top the list of the so-called "dirtiest" foods, and the news media breathlessly reports it.

Well here's the thing about the Dirty Dozen list: It's completely wrong. It's not based on any type of science, it's not peer reviewed, and it's been criticized as false and misleading by the scientific community.

Who is the EWG?

The Environmental Working Group is a Washington, D.C.-based political lobbying group funded by big organic companies like Organic Valley and Stonyfield Farms, and its goal is to promote organic produce. Which is fine as far as that goes—it's perfectly legal for industry to fund research and lobbying.

But it's worth noting that the EWG is also responsible for promoting the long-debunked but still pervasive notion that vaccines cause autism. Right. That was them.

According to Activist Facts, which compiles and reports on the activities of lobbying groups,

“[T]he Environmental Working Group is a cauldron where many of the worst pseudoscience smear campaigns are cooked up. It preys on the public’s distrust of polysyllabic scientific jargon—and reporters’ ignorance of the same—to make it sound as if everyday items with complicated names are, in fact, deadly dangerous.”

Here's an example: The USDA studies 20 types of produce and finds that over 99 percent of the pesticide residue on that produce was below the tolerance level set by the EPA (in other words, the threshold, for each chemical, above which that chemical is considered harmful to humans). Indeed, more than half the detections were 100 times lower than the threshold. 

The EWG then takes that same data and says: "99 percent of produce is contaminated with pesticides!"

In other words, the USDA reports that apples are safe to eat, and the EWG takes that same report and twists its findings around to say the exact opposite. 

When surveyed, 79 percent of members of the Society of Toxicology said that the EWG misrepresented the risk of pesticides on produce. Some referred to it as the Environmental Worrying Group. 

And despite this, the EWG goes ahead and publishes a new list every year, and every year the media reports it without criticism.

Another fact the EWG doesn't make clear in their annual press release is that organic produce is also treated with pesticides. This is not to say that organic produce is bad for you, but the implication that conventional produce is dripping with pesticides and organic is somehow "clean" is also just plain wrong.

For instance: One of the chemicals that is permitted as a pesticide on organic produce is chlorine. Examples: calcium hypochlorite, chlorine dioxide, hypochlorous acid and sodium hypochlorite. And yes, chlorine is the same chemical used in making bleach, and it's also a toxic gas that's been used as a weapon during war. And yet the National Organic Program allows it to be used on organic produce

But the amounts of chlorine used in organic farming are minuscule. It would be totally unfair to assert that organic farmers are using toxic gas on their produce. And yet that is exactly the sort of scaremongering nonscience that the EWG routinely uses in promoting its Dirty Dozen list.

This is not to say that organic produce is bad. It's not. It's just that it's not any better, or safer, than ordinary produce. 

Another problem with the Dirty Dozen list is that it tends to discourage people from eating fruits and vegetables, a decision with far worse health consequences than any health risk resulting from the minuscule amount of pesticides on the produce. And it also encourages families, some of whom can't afford it, to purchase a more expensive product—a product that just happens to be sold by the companies that fund the EWG.

The Upshot?

Eat fresh vegetables and fruits, whether organic or conventional, whatever your preference, without fear of pesticide contamination. And if you hear claims that fruits and vegetables are bad for you, it's a good idea to consider the source.