Scientists who have advised Ottawa’s pesticide regulator say it could be exposing Canadians to chemicals at unsafe levels, and one has resigned from the agency, citing concerns about transparency.
Both researchers told Breaking: that they are calling for changes to Health Canada’s Pest Management Regulatory Agency (PMRA). They say the agency is relying on an “outdated” system that could be allowing pesticides to continue to be used with worrisome impacts on nature and human health.
“I’m not 100 percent sure that all pesticides (that have been approved) are safe,” said Valerie Langlois, a researcher and professor at the National Institute for Scientific Research at the University of Quebec.
Langlois studies the impacts of pesticides and plastics on the health of fish, frogs, and birds. He also co-chairs the PMRA scientific advisory committee.
The federal government established the committee in 2022 in response to pressure to reform the PMRA. Environmental groups had argued that the agency was based on outdated science and was being improperly influenced by the pesticide industry and food producers.
Health Canada defended the reputation of its pesticide regulator.
“(The) PMRA has a strong pesticide regulatory system, which is recognized worldwide. It takes its role as regulator very seriously, and the pesticide review process used by PMRA remains fully rooted in science,” spokesman Mark Johnson said.
Scientific adviser to the regulator resigns
Bruce Lanphear shares Langlois’s views. Until June, Lanphear and Langlois co-chaired the PMRA’s scientific advisory body.
Lanphear, a public health physician who studies fetal and early childhood exposure to environmental toxins at Simon Fraser University, said he was frustrated by the way the regulator withheld information from committee scientists. He resigned from the advisory panel in June, and his resignation letter was widely shared by the nonprofit Center for Health Sciences and Law.
“I have little to no confidence that the scientific advisory committee can help PMRA be more transparent or ensure that Canadians are protected from toxic pesticides,” Lanpher wrote in that letter.
Speaking to Breaking:, Lanphear said the regulator’s methodology for evaluating pesticides is “outdated” because it is based on old assumptions that are no longer valid.
Among other things, he said, it assumes that there are safe levels or thresholds for chemicals that increase cancer risk.
“What we now know for some of the most widely studied and publicized chemicals, like lead… like asbestos, is that there are no safe levels,” Lanphear said. “And yet we continue to regulate chemicals as if there were any.”
“I am not confident because PMRA is based on outdated methods. They are not being transparent about how they regulate chemicals.
“Things that should have been banned ten years ago and were only slated for outright ban this year indicate that we’re not up to date with the science.”
Many Canadian forests are managed through the use of the herbicide glyphosate, which has now been linked to forest fires. The herbicide shapes the way forests grow, which can maximize profits, but not without unforeseen costs.
Lanphear said studies show that chronic low-level exposure to harmful chemicals increases the risk of children being born prematurely and developing leukemia, and of behaviors related to autism and ADHD.
“What’s at stake here is increased risk for a number of chronic conditions,” he said.
Langlois says he remains on the committee and is working with the regulator to help it reform.
Is the industry controlling the regulator?
Lanphear and others fear that the pesticide industry is exerting undue influence over Canada’s pesticide regulator.
A group representing Canada’s food producers, pesticide manufacturers and plant biotech companies disputes that suggestion.
“It is disappointing to see the former co-chair of the Pest Control Regulatory Agency’s Scientific Advisory Committee making unsubstantiated allegations about industry influence on pesticide regulation in Canada,” Crop Life CEO Pierre Petelle said in a statement sent to Breaking:.
“As an industry, we hold ourselves to the highest standards when it comes to the integrity of the scientific data we provide to regulators around the world.”

Radio Canada reported in 2021 that Health Canada proposed increasing the allowable amount of glyphosate that can be detected in food after requests from manufacturers Bayer and Syngenta. The ensuing protest led the government to bring in independent scientists to the agency.
“What we’re up against right now is a regulator that is heavily dominated by industry players, especially chemical companies and pesticide user groups,” said Laura Bowman, an attorney with environmental law group Ecojustice.
On Wednesday, Health Canada announced that it had appointed a new co-chair of its scientific advisory committee to replace Lanphear.
Eric Liberda, a professor at the Toronto Metropolitan University School of Public and Occupational Health, will join Langlois to lead the independent advisory committee.
Despite agreeing with Lanphear’s position, Langlois said he will not leave the committee because he believes a change in the regulator is still possible.
“I would say that PMRA is changing for the better and we as committee members will make sure of that,” Langlois said. “And if I also resign, it is because no action is being taken.”
She said she expects to see changes to the regulator within the year.