In both Europe and the United States, the current political climate has placed an unprecedented amount of scrutiny on how regulatory policies are crafted and how science influences the debate. The ongoing debates over the future of glyphosate, an herbicide used in Monsanto’s “Roundup” weed killer, offer an example of a disconcerting trend in which politics and activism drown out the voices of scientific authorities.

Just last week, the European Chemical Agency (ECHA) cleared the chemical for public use, after the agency was asked by European Union authorities to assess its carcinogenic potential amidst a debate over glyphosate’s market reauthorization. On Wednesday, the agency’s Committee for Risk Assessment (RAC) said “the available scientific evidence did not meet the criteria to classify glyphosate as a carcinogen, as a mutagen or as toxic for reproduction.” The finding was issued by a panel of 52 experts and follows a positive recommendation issued last year by the European Food Safety Authority (EFSA), which provides independent scientific advice on the risks associated with the food chain.

According to experts, ECHA’s finding is consistent with 90,000 pages of evidence and 3,300 peer-reviewed studies as well as the findings of other organizations, including the German Federal Institute for Risk Assessment. Shortly after the CAR panel concluded that glyphosate is not a carcinogen, the Scientific Advisory Panel of the US Environmental Protection Agency (EPA) issued its own report on glyphosate. The SAP concluded that, “there is no reliable evidence of an association between glyphosate exposure and any solid tumor, or between glyphosate exposure and leukemia or Hodgkin’s lymphoma.”

The plot thickens

Both reports debunked the notion that glyphosate is a carcinogen, leaving the World Health Organization’s International Agency for Research on Cancer (IARC) as the only dissenting opinion among health bodies. In its March 2015 Monograph, IARC classified glyphosate as “probably carcinogenic.” Activists groups such as Greenpeace, US Right To Know, Moms Across America quickly embraced the finding, using it to apply pressure on decision makers to take a stronger line against the weed killer. However, even IARC’s Monograph takes a very soft stance towards glyphosate, saying that only “limited evidence of carcinogenicity” was ever found in humans for non-Hodgkin lymphoma and that the panel’s conclusions were based on studies of agricultural exposures – and not, as some maintained, on the idea that corn sprayed with the substance could lead to cancer.

A series of allegations arguing that an EPA employee helped industry players “kill” the agency’s study further added to public suspicion of the scientific community. According to court records, Jess Rowland, a former deputy director at the EPA, is alleged to have been part of an alleged cover-up meant to hide any link between glyphosate and cancer. The accusations sound sinister, but the implications behind them don’t stand up to scrutiny. They assume a single official, in the Obama EPA at that, would have been able to convince the other 12 scientists involved in the drafting of the report to sign off on the agency’s findings. Even more importantly, arguing that Jess Rowland singlehandedly upended the EPA fails to explain why so many other regulatory agencies have cleared glyphosate as safe for public use. Former colleagues rallied to Rowland’s support, pointing out that he was a dedicated employee, a “straight shooter” with a sarcastic sense of humor not known for having industry ties.

Hazard versus risk

Considering the consensus among other researchers, why do IARC’s findings stand so far outside the mainstream? To begin with, there is a major difference in the methodology used by different bodies. As the World Health Organization itself said last year, the reason why IARC and agencies such as the EPA and EFSA are at odds comes from the fact that these findings are “different, yet complementary.” A joint meeting of the Food and Agriculture Organization and the WHO explained that IARC focuses on identifying potential cancer “hazards,” rather than to estimate the actual degree of risk to the population from exposure to those hazards. They described “hazard identification” as simply the first step towards actual “risk assessment.” Notably, the FAO also found glyphosate to be non-carcinogenic.

As with IARC’s scaremongering conclusions regarding the cancer-causing potential of red meat, coffee and other common substances, the panel’s analysis was deeply hypothetical in nature, untethered from real-world exposure to the substance. As the University of Michigan’s Andrew Maynard said in his explanatory video about the IARC classification:

It is the equivalent of saying a rock could kill you but not pointing out that it probably needs to be dropped on your head from a great height first.

 Indeed, IARC assesses whether a substance could somehow be related to cancer, and notes whether a chemical “is,” “is probably,” “is possibly,” or “is not” related to cancer, based on a selected body of research. In other words, it says what would happen, but without saying how likely that is in the real world.

Whether real world exposure is likely to lead to cancer is left to risk assessment, which is completely different from IARC’s hazard assessments. This distinction is key to understanding why IARC, a WHO subsidiary, can issue a report calling glyphosate “probably carcinogenic” at the same time a separate WHO panel rejects the need for further regulation of glyphosate. With that in mind, the significance of ECHA’s decision is laid bare. Not only did ECHA conduct a hazard assessment using IARC’s own methodology, it studied a far greater number of studies before arriving at its assessment that the weed killer poses no carcinogenic risk to humans.

So what explains then this unwarranted outrage over glyphosate? The head of EFSA Bernard Url probably explained it best last year before t the European Parliament:

This is the first sign of the Facebook age of science. You have a scientific assessment, you put it in Facebook and you count how many people like it. For us, this is no way forward. We produce a scientific opinion, we stand for it but we cannot take into account whether it will be liked or not.

Unfortunately, the scientific consensus over glyphosate seems to have fallen victim to the fake news phenomenon that has wrecked havoc in many other political and social debates. As the EFSA head went on to say: “Given the uncensored nature of social media as an information source, it is more important than ever that the public understands and respects the nuances of the scientific process before jumping to conclusions.”

Leave a Reply

Your email address will not be published.