Is Using Pesticides an Act of Chemical Warfare? (chlorpyrifos is okay)

By Angela Logomasini of CEI. Excerpt:

"A substance that “belongs to a class of chemicals developed as a nerve gas made by Nazi Germany is now found in food, air and drinking water,” thanks to President Donald Trump according to an article found online. This “neurotoxin” is in “same chemical family as sarin nerve gas,” which has been used as a chemical weapon in Syria, notes another writer.

You might think such outlandish claims come from some looney conspiracy group, but they actually appeared in The New York Times and the Washington Post. These claims are off-the-chart absurd, and they belittle the pain of people who really have suffered from chemical warfare, in addition to misrepresenting the real issue at hand.

The chemical in question is not some dangerous warfare agent, it’s a common pesticide known as chlorpyrifos. Farmers have safely used it for decades without any measurable adverse public health impacts. And sure, it’s like sarin gas—but only for bugs.

Before tackling these outlandish claims, consider the impact of such rhetoric. Some lawmakers have embraced this absurdity hook, line, and sinker. Senator Ben Cardin (D-MD) and six other Democratic Senators recently proposed the “Protect Children, Farmers and Farmworkers from Nerve Agent Pesticides Act of 2017” (S. 1624), legislation that would ban chlorpyrifos.

These legislators are trying to tack this bill onto the reauthorization of the Pesticide Registration Improvement Act (PRIA), which sets application fees and decision deadlines for Environmental Protection Agency pesticide registrations. Holding up PRIA might muck up the pesticide regulatory process, slow pesticide registrations, and impede collecting of registration fees from industry.

But far worse, if Congress passed this ban, it would be more difficult for farmers to produce food, which means higher prices for consumers. For details see this Huffington Post article or my paper on the topic.

While the benefits of judicious use of pesticides are quite clear and documented, the claims about chlorpyrifos being risky lack substance. In fact, there’s no hard evidence that anyone has ever suffered ill effects from legal use of, and trace exposures to, chlorpyrifos.

Essentially, the New York Times piece, authored by Nicolas Kristof, indicts chlorpyrifos largely because it’s classified as a neurotoxin. Chlorpyrifos is an organophosphate pesticide, which means it works by inhibiting the effectiveness of an enzyme called cholinesterase, which is necessary for the proper functioning of the nervous system.

In very low, dilute doses, the impact of chlorpyrifos on insects’ nervous systems is enough to kill them. In humans, exposure must reach relatively high and concentrated levels for a period of time before significant health effects can occur. Federal pesticide regulation keeps human exposures low enough to avoid health effects on people, while still high enough to kill crop-destroying insects.

To put the issue in more perspective, if we applied Kristof’s logic to chemicals naturally formed in foods, we would need to ban many fruits and vegetables. Many foods naturally contain chemicals that are safe at low doses, but could be harmful at concentrated, relatively high levels.

Consider potatoes. They naturally contain a “neurotoxin” called solanine, which that also inhibits cholinesterase. It forms as part of the skins and protects the potato from insects. If you store a potato long enough, the solanine levels also become more concentrated, which can make you sick. You can tell if a potato is building up solanine concentrations because it also builds up chlorophyll, which is harmless, but also gives the aged potatoes a green hue. 

There are cases when improper storage has produced very toxic potatoes that have make people sick and even put them in comas. But you don’t have to stop eating potatoes or their skins because they don’t contain enough solanine to cause effects—unless you store them improperly or for too long. So if your potatoes go green and sprout shoots, toss them in the trash.  

Solanine is also naturally formed in many healthy foods including vegetables like tomatoes, eggplants, and peppers, as well as in some fruits including blueberries, apples, and cherries. But because levels are low, you can enjoy the health benefits of these foods without much concern about this naturally forming neurotoxin.

Unlike plants that produce solanine, plants grown with the aid of chlorpyrifos or other pesticides, do not continue to build up the concentration of these synthetic pesticides—quite the opposite. In fact, most foods have no detectible residues of synthetic pesticides and anything remaining can be washed off.

So you can see that what Kristof and the Washington Post writers neglect to mention is that it’s the dose that makes the poison. As this health advisory shows, chlorpyrifos has not been shown to cause cancer even where there is relatively high exposures, and the only other observed health effects (such as dizziness and/or vomiting) occur in high/over exposure scenarios. Accordingly, the trace exposures of chlorpyrifos from food and the environment have not been shown to pose any substantial risk to humans.

Kristof also implies that this chemical is dangerous by pointing out that most home uses for chlorpyrifos were canceled in 2000. Yet it was the companies that make chlorpyrifos that chose to discontinue registrations for in-home uses because heavy regulations make those uses unprofitable—not because there were any significant risks.

Nonetheless, environmental activists petitioned EPA to ban agricultural uses of chlorpyrifos as well in 2007, but the Trump EPA rejected that petition for good reasons. The EPA staff wanted to ban the chemical based on one faulty study that EPA’s Science Advisory Panel found to be “possibly inappropriate” for use in a regulatory decision. Panel members also noted that the data was highly flawed, the effects alleged lacked biological plausibility, and its methodologies were questionable. The EPA has continued its scheduled scientific safety review, after rejecting this activist call to ban it based on junk science."