In March 2015, the International Agency for Research on Cancer (IARC) reported that glyphosate, the main herbicide in Roundup, was “probably carcinogenic to humans.” Later, on July 7, 2017, the California state Office of Environmental Health Hazard Assessment (OEHHA) named glyphosate as a chemical that can cause cancer and added it to the state’s list of dangerous substances. This requires Roundup manufacturer Monsanto to add new warnings to the product label for sales in the state of California, but they have taken the issue to court, claiming that the change is unwarranted.

Meanwhile, hundreds of people have filed Roundup lawsuits against Monsanto, claiming that after long-term exposure to the herbicide, they developed cancer and other serious injuries. Now, documents uncovered in discovery suggest that Monsanto may have manipulated evidence concerning glyphosate and its risks to human health.

Monsanto Hired Help to Rebut the IARC’s Conclusions

In October 2016, the U.S. Judicial Panel on Multidistrict Litigation (JPML) consolidated all federally filed Roundup lawsuits into one court in the U.S. District Court for the Northern District of California. Since then, the parties have been working on discovery and fact-finding, and the court has requested that Monsanto release a number of documents.

According to a report in Bloomberg, among those documents Monsanto produced in discovery, are internal company emails showing that the company hired a consulting firm to prepare a review of Roundup’s health effects that was published in September 2016 in the scientific journal Critical Reviews in Toxicology. Monsanto has argued that the publication was prepared by independent reviewers.

Bloomberg reports, however, that the review was in direct response to the IARC’s 2015 report that glyphosate was a probable human carcinogen, and presented a “critique of the evidence” used by the agency to reach their conclusion. The review also critiqued IARC’s position on the matter. The abstract reads, in part: “[t]he overall weight of evidence from the genetic toxicology data supports a conclusion that glyphosate does not pose a genotoxic hazard and therefore, should not be considered support for the classification of glyphosate as a genotoxic carcinogen.”

It also alleges that the data does not support a relationship between exposure to glyphosate and non-Hodgkin’s lymphoma (NHL)—a relationship that many plaintiffs claim in their Roundup lawsuits.

Monsanto Admits No Wrongdoing

Monsanto revealed that it worked with the consulting firm to develop the review, but admitted no other involvement. Internal emails show, however, that Monsanto scientists were involved in reviewing and editing drafts of the paper, and resisted requests from expert panelists to tone down the criticism of the IARC.

Monsanto maintains that their edits were only “cosmetic,” and that they did nothing to change the scientific conclusions reached by the panel of experts.

In response to the new information, the editor of the scientific journal said he was unaware of what happened internally at Monsanto, and that he had forwarded the information to the journal’s publisher, who has opened an investigation into the matter.