Image: Benjah-bmm27/Wikimedia Commons

Throw aside your politics for a bit. Government scientists at the EPA concluded that a pesticide sprayed on crops was toxic. A few months later, a new guy comes into the agency, looks at the agency’s petition to ban the substance, and denies it—he decides that, although the substance is poisonous, he’d rather keep spraying crops with it.

This should make you mad, but it’s a much more complex issue than that. It should also make you think.

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On Wednesday, EPA-head Scott Pruitt denied a petition first filed in 2007 by the Pesticide Action Network North America (PANNA) and the Natural Resources Defense Council to ban chlorpyrifos, a common pesticide used on crops today. President Obama recommended to ban the chemical back in 2015, after determining that the best science available conclusively pointed to chlorpyrifos’ toxicity. Now, Pruitt is saying the science isn’t sound, and that it won’t be reviewed again for another five years.

Chlorpyrifos is an organophosphate pesticide that we’ve been using since 1965. It’s a white crystalline solid that’s highly toxic to fish, and moderately toxic to birds and honeybees. At high levels, it can cause convulsions, nosebleeds, loss of nervous system control, and involuntary shitting and pissing your pants, according to a fact sheet I found on the University of Kentucky website. But no worries, at least it’s not a carcinogen!

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Also, if “organophosphate” sounds familiar, that’s because we wrote about another organophosphate recently—VX, the nerve agent. Let’s just think about Kim Jong-nam shitting his pants for a second.

Anyway, Pruitt calls this a return to sound science-based decision making, according to the New York Times. Ignoring the fact that the EPA itself recommended we not use this chemical, one thing that’s sound is that organophosphate pesticides are bad. A review of organophosphates in the journal NeuroToxicology couldn’t find a metric to compare studies on these pesticides, but found that 26 out of 27 studies demonstrated the chemicals had negative effects on childrens’ brain development. Here’s one about chlorpyrifos specifically.

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But CNN reports that many chlorpyrifos studies demonstrate correlation, not causation. There are other factors that could be causing neurological effects that the studies might not have taken into account. Nonetheless, the EPA still found in a November 2016 report that chlorpyrifos levels in food were higher than it considered safe. Sheryl H Kinickis, director of the Office of Pest Management Policy at the USDA, said in a comment on the report that the USDA had “grave concerns” about this EPA analysis, and that the EPA had released several different health assessments in the span of two years, casting “severe doubts about the validity of the scientific conclusions.” In other words, another federal agency isn’t sure the EPA’s conclusions about the toxicity of chlorpyrifos are robust, either.

I couldn’t find up-to-date information on the chemical’s toxicity in humans, but one old EPA study found that the lowest level of the chemical to produce an adverse effect is around .3mg per kilogram of body weight per day—so a 150 pound human exposed to around 21 milligrams of the stuff per day would start to feel the negative effects. The amount of chlorpyrifos the EPA lets on an apple is around 1.5 micrograms according to a quick calculation I did, so you’d need to eat 14,000 apples a day if you’re planning on poisoning yourself. Other studies show that even tiny amounts can lead to birth defects in children, according to the AP, like studies that compared the chemical levels in umbilical cords before and after the EPA’s regulation changes in 2000.

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The EPA has taken lots of steps to reduce the amount of chlorpyrifos we come into contact with. It hasn’t been allowed in home products since 2000. The agency began limiting its use on crops since then in 2000, then again in 2002, and again 2012. They also created “buffer zones” near homes and public spaces where farmers couldn’t spray.

But there are farmers who actually need to use this stuff every day to spray their crops, who are likely getting exposed to a whole lot more, even if they take all the precautionary measures. Additionally, runoff can cause it to get into the water supply.

So really, what we know that organophosphate pesticides are generally bad, chlorpyrifos is an organophosphate and definitely poisonous at high levels, there are associations between the molecule and bad health outcomes in children, and biased people who work with pesticides or in business say the science isn’t sound. Other biased people, environmental activists, basically want to ban all chemicals like this, regardless. The issue is rife with disagreement because it’s full of people with something to gain, as well as people with something to lose. Honestly, toxicology is a really hard science to make “sound.” And that’s because it’s hard to find a robust correlation between something that exists in the environment and its effects on regular people, amidst all of the confounding factors.

So, all that being said, this is really more of a political issue than anything. Yes, Scott Pruitt wants to continue spraying a nerve agent-like chemical onto your food. Yes, that last sentence made it sound a lot worse than it probably is. My personal view is that we should ban it, but that’s because I just reported on it and don’t want to increase my risk of shitting my pants. So at the end of the day, if this is an issue that upsets you, it’s something you should be talking to your representative about.