I see a lot of pro-science people reblogging images like this:

An apple with a caption listing all the chemicals in an apple.

Now, on one hand, I’m sympathetic to this argument. You obviously can’t boycott food made out of “chemicals.” Everything is made out of chemicals. And I am pretty sure having some sort of disordered-eating “detox” diet will not manage to take the toxins out of your system. That is what your kidneys are for. Drinking lots of carrot juice will not help.

But on the other hand, I think that the colloquial use of “chemicals”– and its cousin, “toxins”– actually gets at a concept which is pretty useful and important.

Apples contain chemicals. Pop Tarts also contain chemicals. But apples contain chemicals that have been eaten for millennia, in a combination that has been eaten for millennia. Pop Tarts contain chemicals that were invented in the 1950s. If apples slowly poisoned people, we would be far more likely to know than if Pop Tarts slowly poisoned people.

Think about leaded gasoline. Everyone was assured that the lead in gasoline could not possibly have had effects on the brain. It turns out that this was one of the greatest public health disasters of the 20th century, causing learning disabilities, hyperactivity, and even higher crime rates. Lead alone provides reason enough to be cautious about novel chemicals or chemicals used in novel quantities.

I agree that a lot of times anti-“toxin”/”chemical” writing is gratuitously anti-science. (No, it does not matter if your Subway bread contains a chemical used in yoga mats.) But we shouldn’t go the other way and think that there are no concerns about novel chemicals in our food or our environment, or that it doesn’t make any sense to be suspicious of toxins. The more biodeterminist we are, the more serious concerns that novel chemicals present, and the more worried we ought to be about them.