Feds’ review of ‘dangerous’ pesticides is overdue, say experts

Canada's pesticide regulator is years behind on a cumulative assessment of health risks posed by a group of pesticides linked to autism, hyperactivity and reduced intelligence scores in children.

Organophosphates are insecticides that target the central nervous system and are related to the military-grade nerve gases sarin, VX and Novichok. They include the now-banned chemical chlorpyrifos, which Canada's National Observer revealed last year was the source of nearly two decades of internal warnings from concerned government scientists before the December 2023 ban.

Ten organophosphate-based chemicals are allowed for use in Canada. This includes the pesticide acephate, which has been banned in Europe since 2003. For decades, federal officials have been working on mandatory safety reviews for individual pesticides and releasing a trickle of decisions over several years, often approving their continued use.

In theory, these individual reviews are meant to assess how each pesticide contributes to Canadians' cumulative exposure to organophosphate chemicals and is vital information to protect people from harmful effects. But after promising in early 2022 that a cumulative assessment would be “initiated shortly," officials have pushed it off until each individual organophosphate pesticide evaluation is finished.

Almost nothing has happened since. Last week, the Pest Management Regulatory Agency — Canada's pesticide regulator — published a work plan that says the agency is aiming to finish planning how it will undertake a cumulative assessment of organophosphates this October. The agency is not required to meet its deadline and did not say when it will actually complete the cumulative assessment.

In a Tuesday statement, Health Canada said that its "cumulative health risk assessment for OP pesticides is currently underway," and referenced the recently-published work plan. That document gives an October 2024 deadline for the agency to plan how it will conduct a cumulative assessment, but not a deadline for the assessment itself.

"We've known that organophosphates have had to go for the last 20 years — they're just far too dangerous as a class of products," said Laura Bowman, a lawyer with Ecojustice who specializes in pesticides.

Researchers have found the chemicals' "widespread use … has resulted in ubiquitous human exposure." Moreover, they noted there is "compelling evidence" that low-level prenatal exposure puts children at risk of neurodevelopmental issues. These impacts can be caused by such small amounts of the pesticide that neither the mother nor infant appear to be poisoned, with symptoms appearing months or years later.

A 2018 paper noted the health indicators used by many pesticide regulators globally — including Canada — might not be accurate enough to capture these harmful impacts, meaning exposure to levels of the chemical "thought to be safe or inconsequential" can impact brain development.

Bowman said she is "sure" that even if farmers use legal quantities of the pesticides, several different types can combine in drinking water and push human exposure beyond safe levels.

Moreover, she noted that Canada does not even have a robust water monitoring system to track pesticides — including acephate — in drinking water. Consequently, it is hard to even know if new restrictions on the use of some organophosphate pesticides implemented by the PMRA during the review process are effective.

"We're just operating off of modelling without a robust monitoring program to validate it. It's all theoretical," she said. "The concern is: Do we really know?"

It is not the first time the PMRA has come under fire in recent years. Last year, Canada's National Observer found the agency had for years downplayed health and environmental concerns from its own scientists about the organophosphate pesticide chlorpyrifos. The same year, it downplayed the health risks of the pesticide dimethyl tetrachloroterephtalate (DCPA), which is not an organophosphate, in the wake of an emergency warning from the EPA about the chemical.

The agency's transparency and regulatory approach has also come into question, with prominent health researcher Bruce Lanphear resigning from a scientific advisory position with the PMRA last year due to transparency issues. During his departure, he lambasted the organization's "obsolete" approach to pesticide regulation.

The situation with acephate and other organophosphate pesticides is just the latest episode in this series of problems and flaws with the government's approach to reviewing the safety of pesticides and monitoring the threat they can pose, Bowman said.

"We're not looking for the pesticides. We're not understanding the extent of the problem," she said. "We don't know what the exposure of people in the environment is. We're just making wild guesses … and hoping that it isn't as bad as the models say."