On Monday, a federal court hearing in San Francisco will turn a public spotlight on to the science surrounding the safety of one of the world’s most widely used pesticides, a weedkilling chemical called glyphosate that has been linked to cancer and is commonly found in our food and water, even in our own bodily fluids. Given the broad health and environmental implications tied to the use of this pesticide, we would be well served to pay attention.

As the active ingredient in Monsanto’s branded Roundup and hundreds of other herbicides, glyphosate represents billions of dollars in annual revenues for Monsanto and other companies, and is prominently used by farmers as an aid in food production. It’s also favored by cities for keeping public parks and playgrounds weed free, and by homeowners who want a tidy lawn. But the chemical was deemed a probable human carcinogen by the World Health Organization’s cancer experts in 2015 in a finding that has since triggered waves of liability lawsuits against Monsanto.

Heated debates over the safety – or lack thereof – of this popular pesticide have spanned the globe and sparked propaganda warfare with each side claiming the other has misrepresented the scientific record. Cancer victims allege Monsanto has “ghost” written research reviews, unduly influenced regulators and created front groups to falsely claim glyphosate safety. Monsanto, meanwhile, asserts multiple studies by international scientists are flawed and politically motivated, and says industry studies demonstrate the product is safe when used as intended.

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This week’s events will mark the first time that the body of research, some that has been gathering dust in stuffy scientific journals or confidential corporate files, will be analyzed under oath for all to see.

It is no idle exercise. Real lives are at stake in this and broader debates about pesticide risks to our health. One in every two men and one in every three women are now expected to develop cancer in their lifetimes and childhood cancers are on the rise.

In children, pesticide exposure is linked not just to pediatric cancers, but also to decreased cognitive function, and behavioral problems. In adults, pesticides are linked to non-Hodgkin’s lymphoma, leukemia, brain, prostate and other cancers. More than 3,000 plaintiffs suing Monsanto allege exposure to the company’s glyphosate-based Roundup caused them or their family members to develop non-Hodgkin’s lymphoma.

Monsanto has tried to persuade US judge Vince Chhabria to throw out the litigation, and sought to keep secret the many internal documents it has been forced to turn over in discovery. But Chhabria has ordered that the hearing be video-recorded and shared publicly over the internet. And he has granted permission for plaintiffs to explore in open court such things as the ghostwriting of science as well as a controversial 1983 study that EPA scientists at the time said showed evidence of glyphosate’s cancer-causing potential.

The court has dubbed the 5-9 March events as “science week” because the only evidence to be presented will come from experts in cancer science, including epidemiologists, toxicologists and others called to analyze relevant research. There will be no crying cancer victims to tug on heart strings; just opposing sides presenting science to a judge who will decide if the lawsuits can move forward.

To bolster its defense, the company and chemical industry allies have been working to discredit cancer scientists and others who have been warning of danger. That effort was highlighted when members of the House committee on science, space and technology held a hearing in Washington on 6 February to air Monsanto’s complaints about the International Agency for Research on Cancer’s (IARC) classification of glyphosate as a probable carcinogen, and to threaten to strip funding from the scientific body.

The committee effort – effectively turning a war on cancer into a war on cancer science – was applauded by the chemical industry. Monsanto, along with lobbyist CropLife America and other agricultural organizations, has also sued California to stop environmental regulators from requiring cancer warnings on glyphosate products, and on 26 February they won an injunction blocking such a warning.



The debate over glyphosate is but the latest example of how industry efforts often focus not on scrutinizing scientific evidence of harm, but on discrediting the offending science. Last year, for instance, Dow Chemical successfully lobbied the Environmental Protection Agency leadership to ignore warnings from its own scientists (and others) about extensive research tying a profitable Dow pesticide called chlorpyrifos to brain development problems in children.

The public offering of expert testimony in San Francisco about Monsanto’s pervasive pesticide presents an important opportunity to separate the science from the spin. We all should be watching.