A leading Canadian public health official has commended New Brunswick’s review of a controversial herbicide used by the forestry industry and NB Power.

Dr. John McLaughlin, the chief science officer and senior scientist with Public Health Ontario, reviewed the report released by New Brunswick’s acting chief medical officer of health Dr. Jennifer Russell examining the use of glyphosate in the province.

That report concluded there is “no increased health risk to New Brunswickers exposed to glyphosate.”

“It’s a thorough and comprehensive summary of many reports that have been delivered by many other organizations,” McLaughlin told CBC News.

“Overall the risks associated to glyphosate are low and these are appropriately referred to in the New Brunswick report, while also recognizing that there is potential concern if it is not used wisely and sparingly and as approved by the regulatory agencies.”

Glyphosate is used in aerial spraying by the forestry industry to control undergrowth. NB Power sprays it along power lines for the same purpose. It is also an ingredient in household garden weed killers.

Safety concerns about glyphosate

But anti-spray activists have repeatedly raised concerns about the safety of the herbicide and are calling for an end to its industrial use in New Brunswick.

Opponents of spraying were galvanized last year when Dr. Eilish Cleary, then New Brunswick’s chief medical officer of health, was fired while working on the glyphosate study.

The province said her dismissal wasn’t related to any work her office was doing.

The study was finished under Russell, but Stop Spraying New Brunswick has dismissed the findings and called for the province to launch “human and wildlife health studies” on the herbicide’s impact.

While McLaughlin acknowledges Russell’s report doesn’t add new information about the health risks of glyphosate, McLaughlin says that information is documented in scientific reports from other jurisdictions “and those have been summarized in the New Brunswick report, quite appropriately and quite thoroughly.”

Good news for N.B. report

McLaughlin’s blessing is an important boost for the New Brunswick report and businesses that rely on glyphosate, not least because the herbicide has been found by the International Agency for Research on Cancer (IARC), part of the World Health Organization, to be “probably carcinogenic to humans.”

McLaughlin is a member of the IARC and was involved in that review.

“The only place where the International Agency for Research on Cancer detected any signal at all, any concern, was related to workplace or occupational exposures where workers were using pesticides including glyphosate.

“Again these are relatively high exposures that most people would not be receiving,” he added. “An agent like glyphosate is generally very safe, if used as directed.”

Risks measured against potential benefits

McLaughlin also cautions that nothing is completely without risk, but those risks must be measured against the potential benefits of using chemicals like glyphosate.

“If one looks at the use of a herbicide like glyphosate to reduce weeds in a garden for cosmetic reasons, one might say well, are the risks worth taking?  In contrast to generating food or timber, there might be some values.

“So it’s that risk benefit analysis that everyone should take, whether it’s at the level of an individual or a family, community or an industry.”

In July, David Miller, a New Brunswick-born biologist at Carleton University who sits on WHO panels, said last year’s FAO-WHO finding was based on the possibility glyphosate could be carcinogenic in mice “at very high doses.”

But those amounts were “many of millions of times lower exposure” than anything humans would consume, Miller said.