WASHINGTON, Dec. 16, 2015 - A panel of experts assembled at Monsanto’s request is challenging a determination by a research arm of the World Health Organization that glyphosate probably causes cancer in humans.

The 16 experts convened by Intertek Scientific and Regulatory Consultancy Services, which was retained by Monsanto, said the International Agency for Research on Cancer’s reviews of the evidence were flawed. In an abstract presented at a recent Society for Risk Analysis conference, the panel said, “None of the results from a very large database, using different methodologies, provides evidence of, or a potential mechanism for, human carcinogenesis.”

In a press release, Monsanto said the panel also found that IARC animal bioassay and genotoxicity evaluations “suffered from significant weaknesses such as: selectivity in the choice of data reviewed, failure to use all relevant biologic information to evaluate relationship to treatment in animal bioassays, and failure to use weight-of-evidence evaluations using all available data and appropriate weighting.”

Twelve of the 16 panelists have some connection with Monsanto. A table posted on Intertek’s website indicates that five previously served as consultants to the company, and five have been consultants who, “as part of that consulting relationship, published peer-reviewed data regarding glyphosate.” Two of the panel members were Monsanto employees who published peer-reviewed data regarding glyphosate. Four have had no financial relationship with the company.

Ashley Roberts, senior vice president of Intertek’s Food and Nutrition Group, said different panel members headed up reviews of the primary evidence in the areas evaluated by IARC: animal bioassays, genotoxicity, exposure, and epidemiology. 

Glyphosate, contained in Monsanto’s Roundup and other herbicide formulations, has the highest global production volume of all herbicides, with the largest use in agriculture. It is used to control broadleaf weeds and grasses. In the U.S., its use increased from about 27 million pounds in 1996 to more than 250 million pounds in 2012, according to the U.S. Geological Survey.

Studies by regulatory agencies or scientific bodies have generally found it be safe for humans. EPA, for example, says on its website that glyphosate “has low toxicity for humans,” and in a June report, concluded that it does not disrupt the human endocrine system.

In March, IARC said it found “limited evidence in humans for the carcinogenicity of glyphosate” and that “a positive association has been observed for non-Hodgkins lymphoma.” In its monograph, IARC also said there is “sufficient evidence in experimental animals for the carcinogenicity of glyphosate.” This led the agency to place glyphosate in its Group 2A –  “probably carcinogenic to humans.”

Group 2A also includes the organophosphate insecticides diazinon and malathion. It is one rank higher than IARC's Group 2B (“possibly carcinogenic to humans”), which includes cell phones (some risk of brain cancer) and coffee (bladder cancer). Group 1 is the next highest category “carcinogenic to humans.” In October, IARC found that consumption of red meat was also probably carcinogenic.

The European Food Safety Authority concluded in November that glyphosate “is unlikely to pose a carcinogenic hazard to humans.

At the World Food Prize in Des Moines earlier this year, Robb Fraley, executive vice president and chief technology officer at Monsanto, said he was “extremely disappointed” in the IARC designation and expressed confidence that the “blue-ribbon panel” the company was putting together would give glyphosate a clean bill of health. 


For more news, go to: www.Agri-Pulse.com