New questions have been raised about the safety of a herbicide that the World Health Organization says can cause cancer, but which American homeowners freely spread around to kill weeds.

The U.S. Environmental Protection Agency, the same agency President Donald Trump seems so dead set on marginalizing, should conduct a thorough and uncompromising review of the herbicide’s potential dangers.

Glyphosate, the active ingredient in Monsanto’s Roundup, is the world’s most widely used weed killer. For years, farmers have used it to drive up yields, which benefits everyone. Using industry-funded research, Monsanto has long claimed Roundup is safe — safer than table salt, in fact. But there’s a worry it causes cancer in humans. We are reminded once again — just as we were with tobacco — to be wary of industry-supported research.


The World Health Organization’s International Agency for Research on Cancer has warned that glyphosate can be a cause of cancer. But regulators in America have not been overly concerned, saying it has “low toxicity.” People have continued to spray it around their homes.

Earlier this week, however, a federal judge in San Francisco ruled that California can require Monsanto to label Roundup as a possible cause of cancer. The judge also released documents that cast new doubts on glyphosate and the research that attested to its safety.

The records were released as part of lawsuits filed by people who say they got non-Hodgkin’s lymphoma from glyphosate. The plaintiffs say part of two scientific reports on glyphosate by academic scientists were ghostwritten by Monsanto. The records also suggest a senior EPA official at the Environmental Protection Agency helped to block a review of glyphosate’s safety by the United States Department of Health and Human Services. And the records show the EPA’s Office of Research and Development was concerned about the thoroughness of a review by another EPA arm, the Office of Pesticide Programs.

None of that proves glyphosate is a serious health risk. Monsanto denies it, and says the plaintiffs are taking out of context a handful of the massive number of documents that are part of the case. The European Chemical Agency also says it is safe.

Glyphosate, which is designed to kill almost all plants except those that are genetically modified to resist it, is all around us. It’s sold in more than 160 countries, and farmers use it on at least 250 kinds of crops. Traces of it are showing up in food on grocery shelves and even in wine.

We need to know what the health risks are. The EPA — yes, the same agency the Trump administration is so skeptical about — needs to get to work.

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