“The Dirty Dozen” – Brief Response to News

(We’ll see if this becomes a regular thing for this blog)

The Environmental Working Group released its annual Dirty Dozen list again. They are a non-scientific group of scaremongers. This list of theirs epitomizes this fact. They take the publicly available USDA data on pesticide residue and then report characteristics like the number of different residues found and the amount of those residues. Then they rank grocery store produce based on these numbers.

What they never do is compare those values to the actual amounts necessary to harm a person. Because if they did, they’d look silly. For instance you’d have to eat 10 kilograms a day of strawberries just to reach the low end of minimum appreciable risk (RfD). (I got the math from here.)

The techniques used to detect pesticide residue are incredibly sensitive. Far more sensitive than necessary for human health. The tiniest amounts can be detected. But those tiny amounts need to be compared to results from toxicology studies to have any meaning.

The Environmental Working Group also asserts, without evidence, that a wider variety of pesticides on a plant is somehow intrinsically more dangerous than just one pesticide. This statement might be true – different chemicals may interact to be more dangerous than toxicology research on a single chemical indicates. But no evidence suggests that it is. And human health is carefully tracked by the CDC.

And even if more chemicals on the plant is more dangerous they fail to take into account the fact that the plant already has thousands of different chemicals inside. At at much higher concentrations than the pesticides. And those plant chemicals include substances evolved to kill other life forms to protect the plant i.e. pesticides. There is more of those pesticides than the ones applied by farmers.

In short, their list has nothing to do with known toxicology information. It is just an attempt to scare people. And CNN and other media swallowed it whole.