Ask experts whether the active ingredient in the world's most widely used weed killer causes cancer, and you're not likely to receive a definitive answer.
"Maybe," "probably" or "perhaps - in very high doses" seem to be the most popular answers when experts are asked whether glyphosate, the active ingredient in RoundUp, is a carcinogen. Until now.A recent study, published in the November issue of Journal of the National Cancer Institute concluded there was no relationship between glyphosate and cancers including "any solid tumors or lymphoid malignancies overall, including non-Hodgkin Lymphoma and its subtypes."
The study also concluded there is "some evidence of increased risk of acute myeloid leukemia among the highest exposed group", but that the association was "not statistically significant".
The research is part of the Agricultural Health Study that has been tracking the health of farmers, farm workers and their families in Iowa and North Carolina.
In a summary of the results, the researchers, led by Laura Beane Freeman, principal investigator of the Agricultural Health Study at the U.S. National Cancer Institute, said that among 54,251 pesticide applicators studied, 44,932, or 82.9 percent, used glyphosate.
"Glyphosate was not statistically significantly associated with cancer at any site," researchers wrote in the summary.
The results of the study are almost certain to impact a host of pending legal proceedings against Monsanto. Currently, nearly 200 plaintiffs have claimed that exposure to glyphosate is responsible for them getting cancer, according to published reports.
Concerns about the safety of handling and working with products containing glyphosate have circulated for years in 2015 when the World Health Organization's International Agency for Research on Cancer concluded that the active ingredient in RoundUp was "probably carcinogenic."
As a result of that report, California's Office of Environmental Health Hazard Assessment, in July, added glyphosate to its list of cancer-causing agents and the state will require all products containing the chemical to carry a cancer warning on their label by next year.
Since the results of the Agricultural Health Study research have been published, Monsanto, as well as advocacy groups from the agricultural industry, have filed suit against the California agency to stop the amended warning labels.