A trial is getting underway in California today in which a consumer who used Monsanto's weedkiller Roundup claims the product caused his cancer.
Forty-six year-old Dewayne Johnson is the first of hundreds of plaintiffs against the chemical giant to have his case heard in court. Johnson worked as a school groundskeeper and, during the course of his job, says he regularly used Roundup to keep grass and weeds under control.
Johnson's case was bumped to the top of the heap after his attorney informed the court that his client was near death. Under California law, dying patients have the right to an expedited court hearing.
The issue in the case is whether Roundup causes cancer, and if so, whether Monsanto adequately warned consumers. Monsanto has vigorously argued that its product does not cause cancer.
World Health Organization has doubts
The World Health Organization (WHO) isn't so sure. Three years ago it found that the main ingredient in Roundup, an herbicide called glyphosate, is "probably carcinogenic to humans."
A year ago the state of California officially classified glyphosate as a chemical known to cause cancer under the state's Proposition 65. That law requires Roundup sold in California to carrying a warning label to that effect.
Monsanto sought to block the move, calling it "unwarranted on the basis of science and the law," but a court dismissed the company's challenge.
Environmentalists have put Roundup under the microscope since the WHO finding in 2015. The Environmental Working Group (EWG) argued the state of California should have set much lower exposure limits than those that were finally adopted.
Earlier this year, a peer-reviewed study found that women in agriculture-intensive areas of Indiana tended to have shorter pregnancies if they had been regularly exposed to glyphosate, which is used in agriculture as well as to control weeds in suburban lawns.
“Glyphosate is the most heavily used herbicide worldwide but the extent of exposure in human pregnancy remains unknown,” researchers from Indiana University wrote in the journal Environmental Health.
For its part, Monsanto argues that its product has undergone rigorous testing and is the subject of more than 800 studies that have established its safety.
"We have empathy for anyone suffering from cancer, but the scientific evidence clearly shows that glyphosate was not the cause," said Scott Partridge, Monsanto's vice president of strategy, in a statement to the media. "We look forward to presenting this evidence to the court."