Study: Monsanto’s Roundup Herbicide Probably Causes Cancer [UPDATED]

<a href="http://www.shutterstock.com/cat.mhtml?lang=en&language=en&ref_site=photo&search_source=search_form&version=llv1&anyorall=all&safesearch=1&use_local_boost=1&searchterm=herbicides&show_color_wheel=1&orient=&commercial_ok=&media_type=images&search_cat=&searchtermx=&photographer_name=&people_gender=&people_age=&people_ethnicity=&people_number=&color=&page=1&inline=258516386">keantian</a>/Shutterstock

Fight disinformation: Sign up for the free Mother Jones Daily newsletter and follow the news that matters.


UPDATE: Monsanto is trying furiously to discredit the World Health Organization’s assessment that glyphosate is a probable carcinogen. The company is pushing the WHO to retract the assessment, Reuters reports. And in an email, a Monsanto public relations person wrote that “[W]e are reaching out to the World Health Organization (WHO) to understand how, despite the wealth of existing science on glyphosate, the IARC [International Agency for Research on Cancer] panel could make a classification that disagrees with scientific and regulatory reviews.”

Monsanto has assured the public over and over that its flagship Roundup herbicide doesn’t cause cancer. In a stunning assessment (free registration required) published in The Lancet, a working group of scientists convened by the World Health Organization reviewed the recent research on glyphosate, the key ingredient in Roundup and the globe’s most widely used weed-killing chemical, and found it “probably carcinogenic to humans.”

One scientist called the report’s finding “the most surprising thing I’ve heard in 30 years” of studying agriculture.

The authors cited three studies that suggest occupational glyphosate exposure (e.g., for farm workers) causes “increased risks for non-Hodgkin lymphoma that persisted after adjustment for other pesticides.” They also point to both animal and human studies suggesting that the chemical, both in isolation and in the mix used in the fields by farmers, “induced DNA and chromosomal damage in mammals, and in human and animal cells in vitro”; and another one finding “increases in blood markers of chromosomal damage” in residents of several farm communities after spraying of glyphosate formulations.

Monsanto first rolled out glyphosate herbicides in 1974, and by the mid-1990s began rolling out corn, soy, and cotton seeds genetically altered to resist it. Last year, herbicide-tolerant crops accounted for 94 percent of soybeans and 89 percent of corn, two crops that cover more than half of US farmland. The rise of so-called Roundup Ready crops has led to a spike in glyphosate use, a 2012 paper by Washington State University researcher Charles Benbrook showed.

Benbrook told me the WHO’s assessment is “the most surprising thing I’ve heard in 30 years” of studying agriculture. Though a critic of the agrichemical industry, Benbrook has long seen glyphosate as a “relatively benign” herbicide. The WHO report challenges that widely held view, he said. “I had thought WHO might find it to be a ‘possible’ carcinogen,” Benbrook said. “‘Probable,’ I did not expect.”

He added that the report delivered no specific conclusions about the dosage glyphosate requires to trigger cancer. But given that US Geological Survey researchers have found it in detectable levels in air, rain, and streams in heavy-usage regions, that it’s widely used in parks, that it has also been found in food residues (though the US Department of Agriculture does not regularly test for it), the Environmental Protection Agency will likely come under heavy pressure to demand new research on it. Most US research on glyphosate, Benbrook added, has focused on the chemical in isolation. But in the real world, glyphosate is mixed with other chemicals, called surfactants and adjuvants, that enhance their weed-slaying power. Importantly, some of the research used in the WHO assessment came from outside the US and looked at real-world herbicide formulations.

Monsanto shares closed nearly 2 percent lower Monday as investors digested the news. It’s not heard to see why they’re squeamish. The agribusiness giant is most known for its high-tech seeds, but its old-line herbicide business remains quite the cash cow, as its 2014 annual report shows. That year, the division reaped about a third of the company’s $15.8 billion in total sales. Indeed, Monsanto’s herbicide sales grew at a robust 13 percent in 2014 clip, vs. an anemic 4 percent for its other division, seeds and genomics.

AN IMPORTANT UPDATE

We’re falling behind our online fundraising goals and we can’t sustain coming up short on donations month after month. Perhaps you’ve heard? It is impossibly hard in the news business right now, with layoffs intensifying and fancy new startups and funding going kaput.

The crisis facing journalism and democracy isn’t going away anytime soon. And neither is Mother Jones, our readers, or our unique way of doing in-depth reporting that exists to bring about change.

Which is exactly why, despite the challenges we face, we just took a big gulp and joined forces with The Center for Investigative Reporting, a team of ace journalists who create the amazing podcast and public radio show Reveal.

If you can part with even just a few bucks, please help us pick up the pace of donations. We simply can’t afford to keep falling behind on our fundraising targets month after month.

Editor-in-Chief Clara Jeffery said it well to our team recently, and that team 100 percent includes readers like you who make it all possible: “This is a year to prove that we can pull off this merger, grow our audiences and impact, attract more funding and keep growing. More broadly, it’s a year when the very future of both journalism and democracy is on the line. We have to go for every important story, every reader/listener/viewer, and leave it all on the field. I’m very proud of all the hard work that’s gotten us to this moment, and confident that we can meet it.”

Let’s do this. If you can right now, please support Mother Jones and investigative journalism with an urgently needed donation today.

payment methods

AN IMPORTANT UPDATE

We’re falling behind our online fundraising goals and we can’t sustain coming up short on donations month after month. Perhaps you’ve heard? It is impossibly hard in the news business right now, with layoffs intensifying and fancy new startups and funding going kaput.

The crisis facing journalism and democracy isn’t going away anytime soon. And neither is Mother Jones, our readers, or our unique way of doing in-depth reporting that exists to bring about change.

Which is exactly why, despite the challenges we face, we just took a big gulp and joined forces with The Center for Investigative Reporting, a team of ace journalists who create the amazing podcast and public radio show Reveal.

If you can part with even just a few bucks, please help us pick up the pace of donations. We simply can’t afford to keep falling behind on our fundraising targets month after month.

Editor-in-Chief Clara Jeffery said it well to our team recently, and that team 100 percent includes readers like you who make it all possible: “This is a year to prove that we can pull off this merger, grow our audiences and impact, attract more funding and keep growing. More broadly, it’s a year when the very future of both journalism and democracy is on the line. We have to go for every important story, every reader/listener/viewer, and leave it all on the field. I’m very proud of all the hard work that’s gotten us to this moment, and confident that we can meet it.”

Let’s do this. If you can right now, please support Mother Jones and investigative journalism with an urgently needed donation today.

payment methods

We Recommend

Latest

Sign up for our free newsletter

Subscribe to the Mother Jones Daily to have our top stories delivered directly to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.

Subscribe

Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.

Donate