Innocent until proven guilty works for people — not chemicals.

Toxic threats

An old postcard of workers in an apple orchard with the words
Adrian Pforzheimer
Adrian Pforzheimer

Policy Analyst

Last month, the EPA announced a ban on the food-related use of chlorpyrifos, a pesticide that has been linked to lower birth weights and reduced IQs in children. Though the ban was long overdue, it was significant simply for happening. The EPA is all too efficient at allowing new chemicals to join the 86,600 chemicals registered for use in the U.S., but its process for restricting dangerous, existing chemicals remains stuck in the past.

One of my more offbeat hobbies is collecting postcards. For a dollar, you can own a hundred-year-old photograph, a snapshot of life in another era. I recently came across a postcard that certainly felt like it belonged to a different time. People in fancy dresses are picking apples from an overloaded tree full of ripe red fruit. The caption: “The kind of results you get from spraying with Hemingway’s Pure Lead Arsenate.”

“Lead arsenate” is exactly what it sounds like: an insecticide made up of arsenic and lead, both of which are highly toxic to humans. Unsurprisingly, the compound is also poisonous; it’s immediately toxic in large quantities and linked to tumor growth and birth defects.

But little of that was known back when lead arsenate was first used in 1892. It was cheap, effective, and replaced the wildly toxic copper arsenate. It was used everywhere. By 1905, almost every commercial apple orchard was using it. But over time, as pests built up a tolerance, applications rose from one to three times a season to five or six.

As far back as 1919, growers recognized they were using so much that arsenic residue was being left on apples even after they were washed. But they didn’t cut back — they kept upping the application amount, and used different chemicals to help wash off the arsenic residue. The only reason lead arsenate eventually fell out of favor was its replacement by a new chemical — DDT.

And so the cycle went — one poison replaced by another, “safer” one, neither of which were truly safe but neither of which were evaluated by that standard in the first place. Once a chemical is allowed to be sold, it’s assumed to be safe until an unignorable mountain of evidence proves otherwise. Lead arsenate was still being used to extend the growing season for Florida grapefruit up until 1988, the year it was banned by the EPA.

More than a century after my postcard extolling Hemingway’s Pure Lead Arsenate was mailed, there’s been little fundamental change in how we treat chemical safety and regulation. New industrial chemicals don’t have to prove they’re safe, because the burden of proof falls on the EPA to prove that they’re not. The EPA considers this program a “gatekeeper” — but in practice, it’s more of a greeter than a bouncer. A 2016 law requiring a basic safety finding for new chemicals was a step in the right direction, but too weak to make much difference.

The trouble with delaying action on toxic chemicals is that by the time overwhelming harm is proven, it’s already been caused. Leaded gasoline wasn’t eradicated in the U.S. until 1996 and globally until the summer of 2021. A fatally flawed, manufacturer-funded study from the 1970s set mistaken safety standards for chlorpyrifos for over 15 years. In the state of Washington, where the photo on my postcard was taken, up to 188,000 acres of historic orchards may be contaminated with lead arsenate, which is doing what it was designed to do — persist.

The EPA should move much more strongly than it currently does to review and restrict chemicals known to cause harm, even if they’ve been grandfathered in as “safe.” It should fully ban chlorpyrifos, which is still allowed for use on golf courses and lawns. It should also ban neonicotinoids, a class of pesticides so toxic that just one variety can adversely affect nearly 80% of endangered species, and many of their critical habitats.

But more is needed to finally move beyond the exhausting whack-a-mole of fighting chemical-by-chemical to ensure individual and public health. The EPA needs to shift to the precautionary principle, where the burden of proof is on chemical manufacturers to demonstrate their products are safe before they’re put into widespread use, as opposed to the current system where victims and advocates fight an uphill battle after the harm has been done.

Until we prioritize the health of people and the environment in chemical regulation, we’re still putting poison on our crops and hoping for the best — we’re just not making postcards advertising the fact.

Photo credit Adrian Pforzheimer


Adrian Pforzheimer

Policy Analyst