A U.S. court blamed Roundup for causing cancer. Then Canada defended the herbicide, emails show

Agriculture Ministry officials worried the government's position on the health risks of Canada's most widely used herbicide were "contradictory" following a landmark California court ruling blaming glyphosate for causing cancer, internal emails show.

Agriculture Canada says herbicide is crucial for modern farming, despite 'stakeholder concerns' over safety

Containers of Roundup are displayed on a store shelf in San Francisco in 2019. Emails from Agriculture Canada obtained under access to information legislation show how officials grappled with concerns the herbicide causes cancer in light of court rulings in California. (Haven Daley/The Associated Press)

Agriculture Ministry officials worried the government's position on the health risks of Canada's most widely used herbicide were "contradictory" following a landmark court ruling blaming glyphosate for causing cancer, internal emails show.

In 2018, a groundskeeper in California won a multimillion-dollar judgment in San Francisco State Court after arguing the weed killer, frequently sold under the brand Roundup, caused his cancer.

That case inspired a slew of ongoing lawsuits in the U.S. and Canada. Plaintiffs accuse Monsanto, the corporation behind the chemical, of poisoning them. A spokesperson for Bayer, Monsanto's parent company, said the herbicide is safe when used as directed, citing more than 100 scientific studies backing that position. 

U.S. litigation also triggered a series of emails among Agriculture Canada officials who outlined plans to defend the chemical, according to government records released under access to information laws.

"Recent media coverage of the U.S. court rulings linking glyphosate to cancer cases may increase stakeholder concerns with the safety of glyphosate," said one internal email in 2019.

In a message with the subject, "OVERVIEW OF THE CHEMICAL ROUNDUP, AND HOW TO COUNTER CLAIMS THAT IT CAUSES CANCER," an Agriculture Canada official worried the government's position on its health risks "may appear contradictory."

"Can we qualify … a bit to say that 'exposure to glyphosate through regular use is not a carcinogenic risk,'" one official wrote. "Or something like that."

The internal records underscore a delicate balancing act for governments trying to regulate what Agriculture Canada says is the most widely used herbicide in Canada, and crucial for food production, despite some evidence it causes cancer. 

"I can see why they would think their position is contradictory," Elaine MacDonald from the environmental group Eco-Justice said in an interview after reviewing the files. "The way they have nuanced their writing, they're not saying it's not a risk.

"They are being careful in their wording — they know the science is out there on the risk of non-Hodgkin's lymphoma."

'Sustainable farming practices'

A spokesperson for Agriculture Canada said the government's position is clear: "Glyphosate has been found unlikely to pose a carcinogenic risk to humans."

"Glyphosate is used globally and in Canada for the control of weeds. It plays an important role in managing weeds under sustainable farming practices," he said in response to written questions. 

Dewayne Johnson reacts after hearing the verdict in his case against Monsanto at the Superior Court of California in San Francisco in 2018. The groundskeeper said he will accept a judge's reduced verdict of $78 million US against Monsanto after a jury found the company's weed killer caused his cancer. (Josh Edelson/Pool Photo via The Associated Press)

First sold for agricultural use in the U.S. in 1974 under the brand Roundup, glyphosate is now a staple of modern agriculture.

The chemical helps to promote healthy soils and allows farmers to produce affordable food for Canadians because of increased yields, according to CropLife Canada, an Ottawa-based association representing herbicide producers. 

The vast majority of international regulators, including Health Canada, the U.S. Environmental Protection Agency, the European Food Safety Authority and regulators in Japan, South Korea, New Zealand and Australia have affirmed that glyphosate-based products are safe, said a spokesperson for Bayer, which produces the herbicide. 

"Farmers and growers have been using glyphosate safely and effectively for more than 40 years," Bayer's spokesperson said in response to emailed questions, calling the chemical "foundational to agriculture around the world" and "an essential tool for farmers to deliver crops to markets effectively and sustainably."

The Bayer logo is pictured at the main chemical plant of German Bayer AG in 2019 in Leverkusen, Germany. The company faces more than 18,000 lawsuits against its subsidiary Monsanto over its glyphosate-based weedkiller Roundup in the United States. Bayer acquired Monsanto for $63 billion US in 2018. (Martin Meissner/The Associated Press)

However, in 2015 the World Health Organization's International Agency for Research on Cancer (IARC) concluded that glyphosate was probably carcinogenic to humans

Bayer said the UN agency's position is "inconsistent with 40 years of scientific research and the conclusions of leading health regulators worldwide." 

Randall McQuaker from the Toronto-based advocacy group Canadian Association of Physicians for the Environment disputes Bayer's contention. IARC, he said, came to a reasonable conclusion.   

Compared to studies from the U.S. EPA and other government agencies, IARC's findings relied mostly on public, peer reviewed studies, McQuaker said in an interview. 

The conclusion that Roundup is probably carcinogenic was "based more on the real world, the way people actually encounter glyphosate," he said, "while the EPA looked more at laboratory conditions."

Ghostwriting the science

During recent California litigation, lawyers unearthed a series of memos showing scientists at Monsanto, the company then producing the herbicide, had ghostwritten academic studies indicating that glyphosate was safe.

These Monsanto memos did not lead to a review of glyphosate by Ottawa because they didn't introduce new scientific information, according to Agriculture Canada emails. 

French activists stand in front of the Paris headquarters of Bayer AG to protest its production of pesticides in March 2019. (Francois Mori/The Associated Press)

Bayer's spokesperson said the ghostwriting issue only applied to a secondary studies. "These allegations relate to secondary literature review articles sponsored by Monsanto, not original studies or science, and the company's sponsorship is appropriately disclosed in each article," she said. 

"These allegations do not change the extensive body of science that confirms glyphosate-based herbicides can be used safely." 

McQuaker and other environmentalists said Monsanto's role in financing health research into the safety of glyphosate underscores the need for more independent scientific inquiry into the chemical's effects. 

Diamond & Diamond, a Toronto-based personal injury law firm behind a class action suit against Bayer on behalf of Canadians who say glyphosate made them sick, declined to comment as the litigation is currently before the courts.

'Trade implications'

The internal government emails also note how widespread use of the chemical has harmed some Canadian farm exports. 

"Consumer concerns with the safety of glyphosate may have trade implications," according to a government memo from March 2019. "For example, widespread media campaigns in Italy over the safety of Canadian wheat, because of glyphosate residue on shipments … have negatively affected the reputation of Canadian durum in the Italian market.

"In the last year, Italian imports of Canadian durum wheat have dropped approximately 80 per cent."

Winter wheat is harvested in a field near McCracken, Kan., in 2018. Canada's wheat exports to Italy have dropped sharply due to concerns over herbicide residue. (Charlie Riedel/The Associated Press)

Agriculture Canada's spokesperson said those concerns were unique to Italy, and restrictions on Canadian food exports over glyphosate concerns have not impacted any other markets or commodities. 

Canada is closely monitoring the situation with Italy and is working with its European counterparts to "determine a constructive way forward," the spokesperson said, adding that "Italian consumers have enjoyed delicious pasta products made from high-quality Canadian durum wheat" for more than a century. 

Eco-Justice's MacDonald said glyphosate is often used as a drying agent and applied to wheat just before harvest, potentially leading to higher residue levels of the chemical on the crop.

"If people don't like the thought of glyphosate on their wheat, that's a fair thing," she said of Italy's lost appetite for Canadian grain.


Chris Arsenault

Senior Writer

Chris Arsenault joined CBC News in Toronto after a decade as a foreign correspondent with Al Jazeera and the Thomson Reuters Foundation in South America, Europe and the Middle East. He has been awarded best national feature from Canada's Radio Television Digital News Association and the United Nations Correspondents' Prize, among others, and can be reached at