As part of more than 300 lawsuits before his court, a federal judge held a week-long hearing in mid-March to examine the scientific evidence on whether a popular pesticide causes cancer.
Federal Judge for the Northern District Court of California Vince Chhabria spent a week reviewing published studies and questioning approximately a dozen experts offered by the plaintiffs and the defendant.
The plaintiffs—more than 700 farmers, landscapers, and gardeners—allege exposure through skin contact or inhalation of the weed-killer Roundup causes non-Hodgkin’s lymphoma (NHL).
Roundup is the trade name of the herbicide glyphosate, manufactured by Monsanto Corporation. Roundup is one of the most widely used herbicides in the world.
Chhabria convened the hearing to determine whether there is enough evidence of a link between NHL and glyphosate to allow the lawsuits to go to trial.
Chhabria’s comments in court indicate he is skeptical of the epidemiological evidence offered to suggest Roundup is causing NHL.
Chhabria said the hearings led him to conclude epidemiology is a “loosey-goosey … highly subjective field.”
“The evidence that glyphosate is currently causing NHL in human beings [is] pretty sparse,” Chhabria said during the hearings. Chhabria has not said when he will decide whether to allow the suit to proceed to trial.
WHO Came First
Citing epidemiological research, the International Agency for Research on Cancer (IARC), an arm of the World Health Organization, determined in 2015 glyphosate is a “probable human carcinogen.”
Monsanto immediately challenged IARC’s classification before the European Chemicals Agency and the European Food Safety Authority in 2015, pointing to hundreds of studies confirming the safety of Roundup. Monsanto also noted many regulatory agencies have approved Roundup for use. The U.S. Environmental Protection Agency says glyphosate is safe for humans when used in accordance with label directions, and a 2017 National Institutes of Health survey reached the same conclusion.
The IARC classification led the State of California to order Monsanto to put a warning label on Roundup identifying it as a “known carcinogen.” A federal judge in Sacramento stayed the requirement with a temporary injunction on February 26.
Angela Logomasini, a senior fellow with the Competitive Enterprise Institute, says IARC’s opinion has been roundly criticized by other scientific bodies.
“It’s positive the judge was able to recognize IARC’s determination is not compelling because so many other reputable scientific organizations have been critical
“A recent congressional hearing noted this flawed approach places plutonium and salty fish in same ‘known carcinogen’ category, which is ridiculous,” said Logomasini. “In the glyphosate case, there are also political conflicts of interest among IARC advisers that appear to have influenced the classification, raising even more questions concerning the validity of their determination.”
Joe Barnett ([email protected]) writes from Dallas, Texas.