Cancer is the second most common cause of death in the United States, and it’s possible the most common weed killer used by farmers and home gardeners alike is contributing to this trend. In a 2015 report, the International Agency for Research on Cancer (IARC) determined that glyphosate, the main ingredient in global seed and chemical producer Monsanto’s weed killer Roundup, is “probably carcinogenic to humans.” In particular, glyphosate has been linked to various forms of non-Hodgkin’s lymphoma, follicular lymphoma, b-cell lymphoma, and other cancers.

As noted in the report, this claim is based on “limited evidence” drawn from studies on humans and experimental animals that suggest glyphosate causes significant chromosomal damage and may be linked to some cancers. Today, more than 1000 non-Hodgkin’s lymphoma patients across the U.S. have filed legal claims against Monsanto.

However, Monsanto claims the IARC failed to consider two studies that suggest glyphosate is safe. One Monsanto official stated that the IARC was corrupted with individuals who have an agenda and that this should warrant an external investigation into the agency’s leadership. It is important to note that one of these studies relied heavily on unpublished papers by the Glyphosate Task Force, and the other was written by researchers who were employed by either the Glyphosate Task Force or Monsanto.

Regarding potential flaws in Monsanto’s Research Practices

In March 2017 a federal court unsealed documents raising questions about the legitimacy of the research Monsanto has provided as evidence of glyphosate’s safety. These unsealed documents include internal emails within Monsanto, as well as, email exchanges between Monsanto and federal regulators. They suggest that Monsanto had ghostwritten research and later asked academics and scientists to endorse the work as their own.

Representatives from Monsanto say this is not true and point out that the research in question went through a rigorous peer review process before being published. One of the scientists mentioned in the emails backed this up by stating, “We had no interaction with Monsanto at all during the process of reviewing the data and writing the papers.”

However, declarations of interest concerning a Monsanto-financed paper on glyphosate stated that panel members were recruited by a consulting firm. Furthermore, email exchanges reveal that Monsanto officials debated which scientists should be considered for the paper and had a role in shaping the project.

Interference from the EPA

The unsealed Monsanto emails also revealed that a senior official at the EPA, Jess Rowland, tried to prevent a review of glyphosate by the United States Department of Health and Human Services. This review never occurred.

Though the EPA has most recently sided with Monsanto, court records suggest concerns within the EPA about how robust their own assessment of glyphosate has been. The assessment in question was carried out by the EPA’s Office of Pesticide Programs, where Jess Rowland was a senior official at the time.

Outcomes So Far

A California judge has ruled that glyphosate should be added to the state’s list of chemicals that cause cancer, potentially requiring a warning to be displayed on containers of Roundup within the state. Monsanto filed a lawsuit against the state of California’s Office of Environmental Health Hazard Assessment (OEHHA), stating that the listing of glyphosate as a carcinogen is unwarranted based on science and the law. Monsanto has been unsuccessful in preventing or appealing this decision.

At this point, Monsanto has not been required to add the cancer warning to their products. The OEHHA still needs to conduct further research to determine if the amount of glyphosate in Roundup products qualifies as posing a “significant risk” to humans according to the law. This assessment might not be ready until July 2018, and Monsanto would have a year after a decision has been made in order to add a warning label or opt for safer ingredients in its products.

Though we haven’t seen any definitive outcome from this controversy, the number of people and organizations filing claims against Monsanto continues to grow. In the past, Monsanto has been ordered to pay $93 million to a small town where they once produced the herbicide Agent Orange, and the company paid $46.5 million to three plaintiffs who were affected by different harmful chemicals known as PCBs that Monsanto continued to produce after they understood these chemicals weren’t safe.

If history is any indication of what might happen, there is a good chance Monsanto will have to pay for the harm its products have caused.