In 2000, a landmark study claimed to set the record straight on glyphosate, a contentious weedkiller used on hundreds of millions of acres of farmland. The paper found that the chemical, the active ingredient in Roundup, wasn’t a human health risk despite evidence of a cancer link.
Last month, the study was retracted by the scientific journal that published it a quarter century ago, setting off a crisis of confidence in the science behind a weedkiller that has become the backbone of American food production. It is used on soybeans, corn and wheat, on specialty crops like almonds, and on cotton and in home gardens.
The Environmental Protection Agency still considers the herbicide to be safe. But the federal government faces a deadline in 2026 to re-examine glyphosate’s safety after legal action brought by environmental, food-safety and farmworker advocacy groups.
The E.P.A. has also faced pressure to act on glyphosate from the Make America Healthy Again movement, led by supporters of the health secretary, Robert F. Kennedy Jr., who once served as co-counsel in a lawsuit against Monsanto over exposure to Roundup.
