EPA Roundup Safety Review Did Not Look At Occupational Exposure, Relied On Questionable Studies: Report

A new report raises questions about the process federal regulators used to previously conclude that the side effects of Roundup and other glyphosate-based weedkillers are not a threat to public health, indicating that officials have failed to look at independent studies and high-exposure scenarios. 

In a report published in the journal Environmental Sciences Europe (PDF) on January 14, researcher Charles Benbrook compares the methodologies used by the U.S. Environmental Protection Agency (EPA) against those used by the World Health Organization’s International Agency for Research on Cancer (IARC)

Although the EPA determined that glyphosate contained in Roundup is not a likely human carcinogen in a September 2016 safety review, IARC has classified the weedkiller as a probably human carcinogen, linking Roundup exposure to an increased risk of non-Hodgkins lymphoma and other cancers.

Benbrook is a former executive director of the National Academy of Sciences agricultural board, and concludes that the two agencies reached such different conclusions based on the data they used.

According to the evaluation, the IARC looked at 118 studies that were mostly peer-reviewed, meaning their techniques and modeling were vetted by independent scientists, of which about 70% found a link between glyphosate and cancer risks or genotoxicity. The IARC assessment relied on typical dietary, occupational and elevated exposure scenarios, determining that there is strong evidence that glyphosate is genotoxic and can cause cancer through two mechanisms: DNA damage and oxidative stress.

By comparison, the EPA relied 52 genotoxicity studies, most of which were never published for peer-review and were commissioned by Monsanto, the manufacturer of Roundup. Almost all of the manufacturer studies claimed there was no link between glyphosate and cancer. Benbrook also noted that the EPA’s evaluation was based solel on technical glyphosate, as opposed to the IARC studies, which looked at the actual formulations people used.

The EPA also focused more heavily on the risks of dietary intake, as opposed to occupational exposure, according to the findings. It also failed to look closely at high-exposure scenarios, Benbrook wrote.

“While unusually high-exposure scenarios generally arise from some combination of equipment malfunction, operator error or carelessness, or working in or near a recently treated field or area, the frequency of such episodes is a function of the diversity and number of applications made. In the case of glyphosate-based herbicides, the world’s most widely used pesticide ever, such relatively high-exposure episodes occur tens of thousands of times on a daily basis in the US and hundreds of thousands, if not millions of times globally,” Benbrook wrote. “IARC’s evaluation relied heavily on studies capable of shedding light on the distribution of real-world exposures and genotoxicity risk in exposed human populations, while EPA’s evaluation placed little or no weight on such evidence.”

Roundup Litigation

The findings come as Bayer’s Monsanto unit also faces nearly 10,000 Roundup lawsuits filed in courts throughout the United States, each involving similar claims by former users of the weedkiller who were diagnosed with non-Hodgkins lymphoma or other forms of cancer.

Plaintiffs allege that Monsanto has known for years about the risks associated occupational exposure to Roundup, yet withheld warnings and adequate safety instructions. According to evidence uncovered during the litigation, the manufacturer has engaged in a global campaign to influence the decisions of regulators, including ghostwriting studies and taking other unprecedented actions to suppress Roundup safety evaluations.

After considering the evidence last summer, a California jury determined that Monsanto should be forced to pay $289 million to a former school groundskeeper dying from non-Hodgkins lymphoma, including $250 million in punitive damages designed to punish the manufacturer. While the punitive damages were subsequently reduced, the judge who presided over the claim determined that the company should still pay $78 million in damages, and the decision has been widely regarded as a “bellwether” for how other juries and courts may respond to similar evidence and testimony that will be repeated throughout other claims.

Benbrook testified as an expert witness for the plaintiffs in that case.

Throughout 2019, a number of high-profile Roundup claims are scheduled to go before juries nationwide, including a multi-plaintiff trial involving more than 15 individuals that is set to begin in October if Roundup settlements are not reached to resolve the litigation.