Engineering researchers at the University of Alberta have identified more than 100 toxic chemicals in cannabis smoke.
The researchers have characterized the potentially hazardous particles in cannabis smoke and have raised awareness about their potential health effects.
“It’s not out of line to say there’s potential health risk in marijuana smoke, and there’s not nearly enough research,” said Robert Nishida, a co-lead on the study.
Out of the billions of particles found in a single puff of cannabis smoke, Nishida’s team observed 2,575 chemical compounds and was able to identify 536. Of those, 110 are known to be toxic, whether they be carcinogenic, mutagenic or teratogenic.
Nishida’s team found the particles in cannabis smoke were about 29 percent larger than those toxic chemicals found in tobacco, however they still found more in tobacco. The researchers found 3.4 times more mass from the total particulate matter in a typical cannabis joint than a cigarette.
“And with some caveats, that mass is what you consider tar,” said Nishida.
Nishida’s team employed a “smoking machine,” which acts like a lung to draw the desired volume of smoke from samples of both a standard tobacco and a cannabis cigarette.
“We compared all of our measurements against a standard reference cigarette. We picked what we think is the most standard or typical type of marijuana joint.”
Nishida explained the size of particles determines where in the lungs they, and the chemicals they’re composed of, get deposited.
“Whether it’s in the throat, or the upper airways, or if it gets transported all the way down into the alveoli, that depends on the size of the particles and their other physical characteristics,” he said.
“It’s not out of line to say there’s potential health effects of marijuana smoke,” he said. “Tobacco cigarettes have been studied for decades, and even with tobacco I don’t think the picture is fully there. The body of research for marijuana smoke is not even remotely comparable.”
The study, “Comprehensive Characterization of Mainstream Marijuana and Tobacco Smoke,” was published in Scientific Reports.