On Feb. 25, 2019, the first case in the federal multidistrict litigationIn re Roundup Products Liability Litigation (MDL) before Judge Vince Chhabria went to trial in San Francisco. Glyphosate is the active ingredient in most Roundup® brand herbicides and other weed-control products.
Glyphosate, given its effectiveness and wide adaptation, is one of the most studied herbicides in the world. An extensive body of research on it and glyphosate-based herbicides, including more than 800 studies over several decades, 40 years of real world experience and conclusions of regulators and international agencies around the world support the safety of these products when used as directed. The U.S. Environmental Protection Agency (EPA), European Food Safety Authorities (EFSA), European Chemicals Agency, German BfR, and Australian, Canadian, Korean, New Zealand and Japanese regulatory authorities, as well as the Joint FAO/WHO Meeting on Pesticide Residues have all concluded that glyphosate does not cause cancer in spite of the International Agency for Research on Cancer’s (IARC’s) 2015 risk assessment suggesting otherwise.
The largest and most recent epidemiological study – the National Cancer Institute-supported 2018 Agricultural Health Study that followed over 50,000 licensed pesticide applicators over more than 20 years – found no association between glyphosate-based herbicides and Non-Hodgkin’s lymphoma, the cancer identified in IARC’s opinion.
Independent regulatory authorities in more than 160 countries have approved glyphosate-based herbicides for use in their countries. Moreover, European and Canadian regulators have done recent reassessments to address issues raised by some critics, and both EFSA and Health Canada stood by their earlier conclusions that glyphosate can be used safely as directed and is not carcinogenic.
The EPA’s own risk assessment in 2017 examined more than 100 studies it considered relevant, concluding that glyphosate is “not likely to be carcinogenic to humans” – its most favorable rating. These included 23 epidemiological studies of real-world use of glyphosate-based formulations, plus long-term animal carcinogenicity and genetic toxicity regulatory-required studies and peer-reviewed publications – 90% of which were conducted by parties other than Monsanto, the maker of Roundup®.
Regarding pesticide residues, the EPA sets daily exposure limits for food crops, drinking water, and home products at levels 100 times lower than those shown to have no negative effect in safety studies. There is no reliable scientific evidence that glyphosate use results in levels of residue that pose health problems for consumers. In fact, at the highest level reported by a third party (1,300 parts per billion), an adult would have to eat 118 pounds of the same food item every day for the rest of his or her life in order to reach the limits set by the EPA. And again, that is still 100 times below the level at which no adverse effect is seen.
Given all of the counter-evidence above, IARC’s opinion on glyphosate is an outlier. Its classification system does not reflect real world human exposure, which is critical in assessing risks to human health. IARC puts common substances like red meat and hot beverages in the same category as glyphosate. Moreover, IARC does not do its own studies; it only reviews selective, existing science. The 2015 IARC assessment did not consider significant data available at the time, nor was updated after the Agricultural Health Study disassociated the herbicide from Non-Hodgkin’s lymphoma.
Crop protection products, including glyphosate-based herbicides, are an integral part of modern, sustainable farming. Weeds and other pests are among the toughest challenges farmers face every season. Farmers around the world count on glyphosate to help control their weeds safely and effectively. Glyphosate-based herbicides have also contributed to the widespread adoption of “no till” and “conservation tillage” practices, which reduce erosion and carbon emissions.