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Last month, the study was retracted by the scientific journal that published it a quarter century ago, setting off a crisis of confidence in the science behind a weedkiller that has become the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.

…The 2000 paper, a scientific review conducted by three independent scientists, was for decades cited by other researchers as evidence of Roundup’s safety. It became the cornerstone of regulations that deemed the weedkiller safe.

But since then, emails uncovered as part of lawsuits against the weedkiller’s manufacturer, Monsanto, have shown that the company’s scientists played a significant role in conceiving and writing the study.

…“This is a seismic, long-awaited correction of the scientific record,” said Dr. Philip J. Landrigan, who is a pediatrician and epidemiologist and the director of the Program in Global Public Health at Boston College.

Dr. Landrigan recently chaired an advisory committee for a global glyphosate study that found that even low doses of glyphosate-based herbicides caused leukemia in rats.

“It pulls the veil off decades of industry efforts to create a false narrative that glyphosate is safe” he said. “People have developed cancers, and people have died because of this scientific fraud.”

…The retraction points to a wider problem of research secretly funded by industries like tobacco and lead, said David Rosner, co-director of the Center for the History and Ethics of Public Health at Columbia University. “Shading the science to favor the corporate interest,” he said, was likely “the rule rather than the exception.” Journals needed to “press scientists more forcefully to identify conflicts of interest,” he said. “Huge financial interests are at stake.”