Wastewater-Based Epidemiology as an Input to National Statistics on Recreational Drug Use: A Canadian Pilot Study

Legalization of cannabis production, sale, and use in Canada in 2018 serves as the context for the formulation and implementation of the largest wastewater-based epidemiology (WBE) pilot test conducted to date in North America (8.4 million people) and the first by a national statistical agency. Matters of design, sampling, and chemical analysis are discussed. Key findings from the first six months of collection are presented, but more importantly, several counterintuitive findings are used to demonstrate priority areas requiring further research. The authors call for collaboration across several related disciplines in order to improve the utility of WBE for applications in public and environmental health.