Supreme Court considers case over Roundup cancer claims

In the 1970s, Monsanto developed the pesticide Roundup, which became a popular weedkiller. However, there has been a growing number of claims that glyphosate, a key ingredient in Roundup, potentially causes cancer. Currently, roughly 200,000 claims have been made against Roundup, with over 125,000 since 2015.

Bayer, which acquired Monsanto in 2018, has disputed the cancer claims associated with Roundup, but the company has set aside $16 billion to settle cases related to the pesticide. Bayer has also removed glyphosate in Roundup sold in the U.S. residential lawn and garden market, but the ingredient is still included in Roundup sold to farmers and businesses.

Earlier this year, Bayer agreed to a proposed settlement of $7.25 billion to resolve thousands of lawsuits related to Roundup. Under the proposed settlement, Bayer would make annual payments into a special fund for up to 21 years for as much as $7.25 billion.

So far, the proposed settlement has been submitted to a Missouri circuit court judge for approval, but it is not guaranteed to go through. In 2020, a $10 billion settlement was thrown out after a judge objected to how future claims would be handled. 

The U.S. Supreme Court also recently heard arguments related to thousands of Roundup lawsuits. Specifically, the case focuses on warning labels about potential health risks associated with pesticides and whether states have the power to require companies to add them.

According to Bayer, the Environmental Protection Agency (EPA) approved a label without a cancer warning, so it should be required to follow federal standards instead of the state's laws or rulings that plaintiffs have sued under.

Sarah Harris, U.S. principal deputy solicitor general, backed Bayer in the case and argued EPA has authority over warning labels for pesticides rather than specific states.

Certain states may require "adding cancer warnings but federal law requires EPA to approve new warnings and tasks EPA with deciding what label changes would mitigate any health risks," Harris said. "State law must give way."

Although states determining warning labels for pesticides "does undermine the uniformity, … [i]f it turns out they were right, it might have been good if they had an opportunity to do something, to call this danger to the attention of people while the federal government was going through its process," Chief Justice John Roberts said.

Depending on how the justices rule, thousands of ongoing Roundup lawsuits could be blocked. A ruling on the case is expected by the end of June or early July. 

"This is the first time we have been able to link pesticide exposure, on a national scale, to biological changes suggesting an increased risk of cancer," said Stéphane Bertani, a researcher in molecular biology at the French National Research Institute for Sustainable Development.

A separate study presented at the annual meeting of the American Association for Cancer Research found that young people who had a diet rich in fruits and vegetables had a higher risk of lung cancer, which researchers suggested could be a result of pesticides sprayed on the foods.

According to Jorge Nieva, a medical oncologist and lung cancer specialist at USC Norris Comprehensive Cancer Center and lead author of the study, commercially produced, nonorganic fruits, vegetables, and whole grains are more likely to be associated with a higher pesticide residue than dairy, meat, and many processed foods. Nieva also noted that agricultural workers exposed to pesticides typically have higher rates of lung cancer.

In response, Marc Siegel, a clinical professor of medicine at NYU Langone Medical Center, said the study is "interesting" but added that it "raises far more questions than it answers."

"It is possible that the increased lung cancer risk could be due to pesticide exposure in whole farmed foods, but it is by no means certain," he said. "How much exposure is needed? How much of it gets into food and in which areas? This requires much further study."