Abstract:
Cannabis sativa L (cannabis) is a plant material that has been used for centuries by many cultures around the world for therapeutic and recreational purposes. The psychoactive constituent of cannabis, delta-9-tetrahydrocannabinol, is responsible for the pharmaceutical properties of cannabis. The most common method of administration for cannabis is by smoke inhalation. However, there is good reason to believe that cannabis smoke is detrimental to human health in similar ways to tobacco smoke. Studies suggest that cannabis has a greater toxic potential to human health than tobacco because of the way it is smoked e.g. with no cigarette filter, deeper inhalations, longer puffs and shorter puff intervals. Studies have compared the chemical properties of tobacco smoke with cannabis smoke, with objectives to identify the chemical attributes explaining the toxicity. Most comparative studies have used small sample sizes and produced contradicting results. The aim of this study is to assess the major chemical variations of cannabis across a broad range of cannabis of different potencies and origins, sourced from the illegal market in New Zealand. Along with cannabis, the popular modern legal cannabis derivatives known as “synthetic cannabinoids” were also investigated. A smoking machine was developed, validated and used to smoke ‘joints’ (cannabis cigarettes) and the chemical properties of the smoke assessed. The chemical constituents of cannabis smoke were assessed by extracting the smoke condensates produced using the smoking machine and analysis using gas chromatography-mass spectroscopy. A range of different chemical constituents were identified and semi quantified. In particular, terpenoids were identified as the major variable in cannabis smoke and the terpenoids may have both positive and negative consequences to human health. Synthetic cannabis products were found to produce a different smoke chemical composition and observations were made regarding the efficiencies of synthetic cannabinoids liberated in the smoking process. Analysis of the total particulate matter showed that significantly different levels of particulate matter are produced per gram smoked between different cannabis samples and synthetic cannabis products. The results indicate the need for further research in greater varieties of the cannabis and synthetic products used in society.