How safe is our cannabis? Nearly five years after legalization, we still don’t know

Nearly five years after Canada legalized recreational cannabis, Anne McLellan is still waiting for what she thought would happen after ending prohibition: testing the smoke.

A former federal health minister and deputy prime minister who later chaired the task force that laid the framework for legalization, Ms. McLellan had expected a flurry of analyses on the potential health effects of frequent cannabis consumption, as governments had promised to fund further study. But none of that research has happened, and so Canadians have no greater knowledge about what cannabis does to their bodies.

“The big disappointment coming out of the legalization project is that governments and researchers have not stepped up in the way that we had hoped after legalization to do a lot of that research,” Ms. McLellan said in an interview. “There is a lot that we do not know that we are going to need to know.”

Testing cannabis emissions (the chemicals released when dried cannabis flower is burned) as well as toxicity (the impact those chemicals have on the body) are not mandated by any federal regulations. Ms. McLellan said her hope – and the source of her subsequent disappointment – was that Ottawa would “incentivize” the private sector to conduct those tests voluntarily.

But the incentives were never offered, and the tests were never done. And now, as newer and stronger cannabis products come on the market – including concentrates such as hash and an increasing variety of vapes – experts are warning the government could face legal liability akin to the claims against Big Tobacco in the 1990s if action is not taken soon.

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The limited research on cannabis smoke to date has raised red flags suggesting the risks of developing severe illnesses – such as lung cancer – could actually be much greater than tobacco. At the same time, polls show that the public considers cannabis smoking to be less harmful than tobacco smoking.

Among the country’s cannabis consumers, virtually all of them – 95 per cent – perceive tobacco smoking as carrying at least a moderate risk, according to data from Health Canada’s 2021 Canadian Cannabis Survey. The same study found only half attributed the same level of risk to smoking cannabis.

The legal cannabis industry has no incentive to challenge that perception, as the sector faces financial struggles that have restricted privately funded research. Smokable forms of cannabis – such as dried flower and prerolled joints – also happen to be the industry’s most popular and profitable products.

Despite a years-long effort by a group of concerned scientists, physicians and industry executives for the federal government to ensure cannabis emissions are at least subject to the same testing standards as the law requires for tobacco, Ottawa has instead largely focused on the mental-health risks. Currently, only one of the eight packaging warning options the government requires producers to choose from mentions the health risks specifically related to smoking cannabis.

“The smoke from cannabis is harmful,” the warning reads. “Toxic and carcinogenic chemicals found in tobacco smoke such as polyaromatic hydrocarbons, aromatic amines, and N-heterocyclics are also found in cannabis smoke.”

Producers are under no specific obligation to use this warning on packaging, as long as they include one of the other seven options the government makes available, which are about mental health and impairment and make no reference to smoke.

Health Canada does acknowledge cannabis contains “the same harmful chemicals found in tobacco smoke” and encourages consumers to lower the risk by avoiding smoking it.

“We just want to have a conversation about what exactly we are consuming, and for whatever reason that has just not been able to happen,” said Ken Weisbrod, a licensed pharmacist who previously created the medical cannabis program for Shoppers Drug Mart and now leads the medical advisory board calling for more testing.

“In multiple conversations with government officials, bureaucrats and politicians, everybody just nods their head and then nothing happens. We are getting radio silence.”

Mr. Weisbrod formed the advisory board in late 2021. Its members are not prohibitionists – to the contrary, they are among the earliest and most ardent supporters of legalization. Four of the six members are licensed physicians and medical experts who pioneered the field of medicinal cannabis.

The first person Mr. Weisbrod asked to join the group was Ivan Ross Vrana, a consultant who had previously spent 18 years as a policy analyst for Health Canada, most recently on the cannabis file.

“This baffles me as a policy guy,” Mr. Vrana said in an interview. “I understand how governments work and that things take time, but I was surprised that no matter who we spoke with, there was never a, ‘Hey, let’s follow up and start to get the process moving.’ ”

Another member of Mr. Weisbrod’s advisory board, physician and former Alberta cabinet minister Lyle Oberg, said the group held several meetings between June, 2022, and March, 2023, with various officials in Ontario, Alberta and at Health Canada in order to make the case for more testing to be done.

Among those who met with Mr. Weisbrod or one of his associates during that period were Ontario Cannabis Store (OCS) chief executive officer David Lobo, Health Canada cannabis director general John Clare and Carolyn Bennett, former federal minister of mental health and addictions and associate minister of health.

Those officials “were shocked” when they learned no recent testing had been done, “but they did nothing about it,” Dr. Oberg said in an interview. “We got the real runaround, nobody wants to make a decision, which puzzles me because we are not talking about de-legalizing cannabis.”

He said the advisory board’s basic demand is a “buyer-beware strategy to find out what it is exactly that people are putting in their lungs and potentially eliminate a health risk down the road.”

Most of the research done on cannabis health risks to date has focused on the psychogenic effects or “high” produced by consumption. Yet the majority of cannabis consumption still occurs through combustion – smoking dried cannabis flower – so the physical health concern, Dr. Oberg said, “is this toxicity and emissions issue. You’re going to have a longer-term problem.”

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Hance Clarke, medical director of the pain research unit at Toronto General Hospital and another member of the group pushing for cannabis emissions testing, said “public opinion right now is that cannabis is safer than tobacco.”

He noted that “whether you’re smoking tobacco or cannabis, you’re inhaling something into your lungs and you are going to have issues with COPD [chronic obstructive pulmonary disease] and obstructive lung disease over the long term, and you don’t have to be a scientist to understand that.”

Health Canada appears to be “hanging their hat” on the idea that the risks of smoking anything should be obvious to anyone, Dr. Clarke said – and that testing is therefore unnecessary.

“But I do think you owe it to the public to give them accurate knowledge,” he said. “Because then they can’t come back to you and say, ‘You knew this and you didn’t tell us.’ ”

Dr. Clarke warned of the legal consequences for cannabis smokers who contract diseases but say they weren’t aware of the possibility: “I do think there is going to be a class-action lawsuit over this.”

Ms. McLellan, who was a professor of law at the University of Alberta prior to entering politics, said there is “potentially” a class-action lawsuit risk facing the government – though she stressed that possibility is still 10 to 15 years down the line, leaving plenty of time for research to be done.

Guillaume Bertrand, a spokesperson for federal Health Minister Mark Holland, referred The Globe and Mail’s questions on cannabis testing to Health Canada.

The most recent Health Canada-commissioned study of cannabis emissions was published in 2013, five years before legalization in 2018. That work was based on testing conducted in 2005 by Labstat International Inc., based in Kitchener, Ont. Records show the cannabis that Labstat tested at that time came from Saskatoon-based Prairie Plant Systems Inc., subsequently acquired by CanniMed Therapeutics Inc. – specifically from a single harvest in May, 2004.

In other words, virtually none of the cannabis harvested in Canada over the past two decades has been subjected to emissions and toxicity testing.

Globally, data on the effects of cannabis smoke are scarce. Canada and Uruguay remain the only two countries in the world where cannabis is legal at the national level. Elsewhere, such as in the United States, where many but not all states have legalized cannabis, obtaining it even for research and testing purposes is prohibitively difficult.

Labstat was commissioned for a new round of tests in 2022, Health Canada spokesperson Tammy Jarbeau said in an e-mail. That research, however, was “an extremely small pilot project with a single product,” said Peter Joza, Labstat’s chief technical officer for chemistry, with a budget allowing for only a limited number of emissions tests.

The results from the 2005 tests, meanwhile, contrast sharply with the public perception of cannabis being less harmful than tobacco. Compared with tobacco smoke, those tests found cannabis smoke contained twice as much tar, between three and five times as much hydrogen cyanide, and 20 times as much ammonia.

And that was from cannabis produced more than 19 years ago, long before a multibillion-dollar industry would focus much of its resources on producing the strongest products they possibly could. In fact, even the limited testing Labstat was able to conduct in 2022 found levels of aromatic amides – derivatives of ammonia – above those found in 2005.

“These infused products available today, taking chunks of hash and other cannabinoid concentrates and shoving them into joints, we have no idea what the toxicity is for those products,” Mr. Weisbrod said.

It only took Dr. Oberg a few keystrokes to pull up a legally available “fortified joint with 57 to 70-per-cent THC” from a popular cannabis retailer’s website.

“From a medical point of view, all of a sudden people are inhaling these products that we know basically nothing about,” he said.

Last September, the federal government launched a legally mandated review of the Cannabis Act, appointing former deputy health minister Morris Rosenberg to lead the effort. He said in an e-mail that cannabis emissions-related testing “is not an issue that I have yet focused on.”

Then there is the issue of cannabis vaping products. Very little is known about their effects on the lungs, as emissions testing is only required for tobacco vaping oils.

“I think you have to test the cannabis oil vapes as well,” Dr. Clarke said. Vaping cannabis is seen as healthier than smoking it to some people, he added, “but look what happened with those oil vapes that were killing people.”

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In 2019, hundreds of people across the U.S. and Canada contracted a life-threatening lung disease after using cannabis vape products that included vitamin E acetate. Several people died as a result, and at least one death was linked to an untested cannabis vape product purchased legally.

Many jurisdictions, including Canada, banned the use of vitamin E acetate in both cannabis and nicotine vape products once it was confirmed to be the source of the illness, though any additive not included in the list of nine prohibited ingredients are still allowed. The only requirement for other ingredients is that they be of pharmaceutical quality, according to federal regulations.

Labstat generates about 10 per cent of its revenues from cannabis testing, mostly from licensed producers, but that work is focused more on finding potential contaminants in the product itself than on analyzing the smoke generated by consumption.

“A lot of the measures that have been put in place for regulated cannabis now is more of a standard for processing large batches, which is why we look for things like metals content and the microbiology,” Mr. Joza of Labstat said. “The regulations have focused on the production process at this point versus focusing ultimately on what is being delivered to the consumer.”

Tobacco smoke contains anywhere from 4,500 to 7,600 different compounds, Mr. Joza said, “and you can expect the exact same thing in cannabis” – but only proper testing would verify that assumption.

Applying the same testing standards required by law for tobacco products to cannabis products would be a good start, he added. There are also global bodies looking at the issue: The American Society for Testing and Materials International, for example, has a committee tasked with developing cannabis testing standards, though it has not established a specific set of standards for measuring emissions and toxicity.

Even without new rounds of testing, MediPharm Labs Corp. co-founder Keith Strachan said there are still “a number of initiatives that could be done to promote non-combustible cannabis options” that are simply not being explored.

His company, based in Barrie, Ont., produces various cannabis products meant to be consumed without smoking such as oils, capsules and edibles. Yet because of the way provincial wholesalers distribute different types of cannabis products, Mr. Strachan said it is more difficult to keep them on store shelves.

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The government-owned OCS is a case in point. It categorizes products as either “A,” “B” or “C” based on average units sold, holding eight weeks of the top-selling A-class inventory, four weeks of B-class inventory and two weeks of C-class inventory.

“As a retailer, that means there is an abundance of dried flower and prerolls to order from, but because things like capsules are smaller categories, they might only be keeping one or two weeks on hand,” Mr. Strachan said.

According to the latest OCS quarterly insights report (Jan. 1 to March 31, 2022), sales of both dried flower, prerolled joints and concentrates such as hash accounted for a combined 73 per cent of all sales – an increase in proportion compared with the previous three-month period.

Five years since legalization might feel like a long time, but Ms. McLellan says it is still early days for this new era. She remains optimistic that consumers will gain access to the information they need to make more informed cannabis-related decisions sooner rather than later, despite feeling disappointed that the research has not happened yet.

“This is just the beginning of something, and I would have hoped it was the beginning of research, but that does not seem to be happening,” she said. “Not doing the research is problematic.”