Cannabis smokers beware: puff for puff, smoke from the plant contains significantly more chemicals and carcinogens than that from tobacco.
Cannabis smoke is well known to be more harmful to the lungs than tobacco, because smokers inhale cannabis one-third more deeply and hold it in their lungs for up to four times as long as cigarette smokers do. Yet while we have a list of more than 4000 chemicals and toxins present in tobacco smoke from dozens of studies, there is no comparable list for cannabis.
So David Moir of Health Canada and his colleagues set out to make a…
