Op-Ed: No, California, Roundup won’t give you cancer

A farmer holding Monsanto's Roundup Ready Soy Bean seeds in 2008.
A farmer holding Monsanto’s Roundup Ready Soy Bean seeds in 2008.
(Dan Gill / Associated Press)

The chemophobes who run California are at it again, siding with environmental activists and pseudoscience rather than evidence and common sense.

The state Office of Environmental Health Hazard Assessment announced last month that it was adding the weed-killer glyphosate to its list of chemicals that purportedly cause cancer. Glyphosate — sold as Roundup and under other brand names — is one of the world’s most widely used herbicides. It has been safely killing weeds on farms, in yards and in public areas for the last several decades. Right now, you can find it at your local home improvement store; but in California next year, in addition to its current 14-page label, those bottles will carry this warning: “Contains chemicals known to the state of California to cause cancer and birth defects and other reproductive harm” — even though there is no persuasive evidence for that claim. (The decision is being challenged in a California appellate court by Monsanto, the maker of Roundup.)

Glyphosate will join more than 800 chemicals on California’s Proposition 65 list, which is intended to alert the public about “substances identified as human or animal carcinogens by the International Agency for Research on Cancer.” But there’s the problem: That agency, which is part of the World Health Organization, is under fire for using a flawed approach — basing its decisions on hazard (the possibility of harm at any dose) instead of risk (the probability of harm, taking exposure into consideration).




Aug. 11, 2017: Physician and molecular biologist Henry Miller, a fellow at Stanford University’s Hoover Institution, co-wrote an opinion piece published April 27, 2017, that objected to the inclusion of the weed-killer glyphosate — sold as Roundup — on California’s list of potentially cancer-causing substances. The essay also attacked decision-making at the International Agency for Research on Cancer, which in 2015 classified glyphosate as a “probable human carcinogen.” Miller should have disclosed that in writing and researching a separate piece about the IARC decision for Forbes magazine in 2015, he asked for and made partial use of drafted material supplied to him by a contact at Monsanto. Monsanto manufactures Roundup.

IARC is also accused of cherry-picking data to reach politically motivated findings. The agency has reviewed nearly 1,000 substances and activities, and only one has been deemed noncarcinogenic. IARC looks for any shred of evidence to prove that something might cause cancer, even under extreme circumstances. It is confirmation bias at its worst: Reach a conclusion first, find the evidence later.

[Glyphosate] is in the same cancer-causing category as dental implants, consuming red meat, being a barber, and doing work that disrupts your biological clock.

In 2015, IARC classified glyphosate as a “probable human carcinogen.” It put the weed killer in the same cancer-causing category as dental implants, consuming red meat, being a barber, and doing shiftwork that disrupts your biological clock. Since then, government agencies from Japan to the EU, including the U.S. Environmental Protection Agency and another agency at WHO, have countered that glyphosate is not carcinogenic. (IARC is to date the only governmental organization to call glyphosate carcinogenic.)


But none of this stopped California officials from placing glyphosate on its danger list. The ubiquitous chemical has become a target of environmentalists, in part because it is used on genetically engineered crops and was created by Monsanto, a company much despised by green activists. Since IARC’s report was published, hundreds of lawsuits have been filed against Monsanto as lawyers in the “environmental justice” industry seek to profit from so-called glyphosate victims.

California’s anti-glyphosate mania has already prompted some local officials to ban its use on public property. School districts in Irvine, Burbank and Glendale will stop using glyphosate on school grounds because of parents’ fear of the chemical. When the city of Petaluma curtailed its use, it had to revert to a far more expensive weed-killing mix, and one that irritated workers’ eyes and lungs.

“It’s frustrating … using something labeled as organic, but you have to be out there in a bodysuit and a respirator,” Joe DeCarlo, head of maintenance for Petaluma’s public schools, told a local paper last year. No such protection was needed when Roundup was used.

Ultimately, glyphosate will be exonerated. It is not carcinogenic, and it is lower in overall toxicity than many other weed killers. (According to New York State’s Integrated Pest Management program, it has about the same Environmental Impact Quotient as vinegar.) A paper published April 10 in Nature Communications by Andrew Kniss, professor of weed biology and ecology at the University of Wyoming, examined herbicide use on several domestic crops and found that “even though glyphosate use has increased greatly over the last 25 years, my analysis suggests the relative contribution of glyphosate to the chronic toxicity hazard has remained relatively low. Glyphosate has a very low chronic toxicity compared to most other herbicides.”

Kniss, who makes his funding sources public (about a third comes from the seed and chemical industry), also warned that without glyphosate, weed control would become more complex, labor intensive and time consuming, and it would almost certainly be replaced by something more toxic and perhaps with unknown effects.

It’s often said that California is a bellwether, a place where nationwide trends begin. For the sake of farmers, particularly in the Midwest who rely on glyphosate to make their farms more productive and their jobs easier, we hope not.

Julie Kelly is a food writer and National Review Online contributor. Twitter: @julie_kelly2. Henry I. Miller is a physician and molecular biologist and a fellow at Stanford University’s Hoover Institution. He was the founding director of the FDA’s Office of Biotechnology. Twitter: @henryimiller.

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