The agency’s report claiming the chemical probably was carcinogenic contradicted studies by Health Canada and U.S. experts
The vicious fight over the safety of glyphosate has become even nastier.
In late October, 10 scientists who specialize in toxicology, pharmacology, genetics and related fields publicly slammed the World Health Organization and the International Agency for Research on Cancer (IARC).
The authors wrote in the Journal of the International Society for Regulatory Toxicology and Pharmacology that IARC’s method for evaluating the safety of chemicals is outdated, backward and causes unnecessary health scares.
“For example, inappropriately placing consuming red meat in the same category as exposure to mustard gas,” a press release said, announcing the publication of the journal article.
In March 2015, IARC proclaimed that glyphosate, the most popular herbicide in the world and the active ingredient in Roundup, was “probably carcinogenic to humans.”
The decision had an immediate and massive impact.
The European Union came close to banning glyphosate this spring. Several major nations, such as France and the Netherlands, refused to support an extension of glyphosate’s registration in Europe. After months of bickering, the European Commission granted an 18-month, temporary approval for the herbicide.
In North America, the IARC finding energized environmental groups and organic advocates, who lobbied the U.S. government to test food for glyphosate residues.
The U.S. Food and Drug Administration, which had not previously tested for glyphosate, relented in February and promised to monitor residues in corn, soybeans, milk, eggs and other food.
Several regulatory bodies, including Health Canada and the European Food Safety Authority, released their studies on glypho-sate after the IARC decision. They concluded the herbicide is not carcinogenic.
Experts have said the IARC conclusion is flawed because the agency uses an inappropriate method to evaluate chemical safety.
“They (IARC members) proudly proclaim that the only thing they do is what they call hazard assessments,” said James Bus, senior managing scientist with Exponent, a scientific consultancy near Washington, D.C.
“They introduce no concept of risk. Of course, dose and exposure are the critical elements of a risk assessment.”
Most regulatory agencies abandoned hazard based assessment three decades ago. They now use a risk-based assessment, which considers potential exposure to the chemical.
“I don’t believe there’s a regulatory agency around the world that views glyphosate as a carcinogen,” said Bus, a former president of the U.S. Society of Toxicology who worked for Dow Chemical for 23 years.
Keith Solomon, University of Guelph professor emeritus and globally recognized toxicologist, said agri-chemical companies must provide high-quality safety studies of pesticides to regulators. Agencies such as Health Canada evaluate those studies, but IARC does not.
“As a result, regulators might come to different conclusions about the substance,” Solomon said in an email.
“This often leads to contradictory opinions that are not easily understood by the public.”
However, in the case of glypho-sate, the scientific discussion has moved well beyond contradictory opinions. That’s because IARC’s decision on glyphosate was a direct attack on experts with Health Canada, the U.S. Environmental Protection Agency and other institutions, Bus said.
“Essentially, what IARC is saying publicly is that the regulatory agencies have it all wrong,” he said.
“It’s telling those individuals at the agencies … that they don’t know what they’re doing.”
That sort of attack was guaranteed to provoke a response, so it’s not surprising that many experts are describing IARC as a reckless institution.
“Health scares triggered by recently published IARC reports have resulted in governments and public agencies responding with costly supplemental reviews and, in some cases, restrictions or bans on products which had significant public benefits,” said Timothy Pastoor, a former industry scientist.
Scientists aren’t the only group taking shots at IARC.
This fall, U.S. politicians have threatened to cut off American government support for IARC.
In the letter, Jason Chaffetz, a congressman from Utah and chair of the House of Representatives’ committee on oversight and government reform, wanted to know why the National Health Institute continues to fund IARC.
“(Its) standards and determinations for classifying substances as carcinogenic, and therefore cancer-causing, appear inconsistent with other scientific research and have generated much controversy and alarm,” Chaffetz wrote, as reported by Reuters.
Canada’s meat industry asked the federal government to cut off funding to IARC this fall. In October 2015, IARC announced that red meat was probably carcinogenic to humans and processed meat was carcinogenic to humans.
Health Minister Jane Philpott said Canada would continue to fund IARC, iPolitics reported in early November.