A Critical Review of Cannabinoid Metabolites: From Biotransformation to the Urban Water Cycle and Reported Monitoring

As cannabis usage persists within communities across regions globally, the aftermath of consumption raises concerns for environmental and public health. The exploration of novel metabolites has expanded knowledge on cannabis metabolism, but the impact of these metabolites when released through bodily excretions into the wastewater system remain limited. Illicit drug consumption can induce adverse effects within the human body in addition to any preexisting health risks and complications; monitoring the release of cannabinoid compounds into the urban water cycle can provide insight into usage patterns and contamination concerns. As legal status of cannabis expands regionally to permit medicinal and recreational uses due to its prospective benefits and psychoactive properties, the rate of consumption and release is expected to increase. Cannabis metabolites within the water system are detected using liquid chromatography paired with tandem mass spectrometry (LC-MS/MS) due to its reliability and specificity. Cannabinoid analysis using LC-MS/MS is cost effective and reduces risk of heat degradation from alternatives like gas chromatography-mass spectrometry (GC-MS). The detection of cannabinoids and their metabolites utilizing primarily LC-MS/MS methodology within past literature is essential for understanding consumption trends and health impacts for residues of tetrahydrocannabinol (THC), cannabinol (CBN), cannabidiol (CBD), cannabigerol (CBG), and cannabichromene (CBC).