Introduction: Cannabis is a widely used drug like tobacco and alcohol. In the meantime, it is also prescribed for medical treatment in some countries. Tobacco smoke contains chemical carcinogens and particulate matter (PM) that are both harmful to health. Method: In this study, we investigated PM levels in second-hand smoke (SHS) of hand-tamped cannabis cigarettes compared to cigarettes with tubing tobacco and the 3R4F reference cigarette. Results: It could be demonstrated that the largest proportion of the particle mass is attributable to particles with a diameter of less than 1μm and that every tested cigarette emitted more PM than the 3R4F reference cigarette. In addition, our data clearly revealed that cannabis smoke contains higher PM levels in SHS than tobacco cigarettes. Compared to the reference cigarette, the PM1 emissions of cannabis were 105% higher. Also, the cannabis mixed cigarettes had higher PM levels than the 3R4F cigarettes. For instance, the PM10 emissions were 93% higher. Also, the Gauloises Mélange tubing tobacco also reached higher PM concentrations than the 3R4F cigarette. Discussion: Regardless of negative health effects, cannabis is seen as a harmless drug in the public eye. We found strong indications for potential health risks by PM from cannabis products and, therefore, the public should be educated about a potential harm.
Keywords: health policy; marijuana; medical cannabis; passive smoke; second-hand smoke; tubing tobacco.