Open Collections

Abstract

The rapid expansion of cannabis cultivation and processing facilities (CCFs/CPFs) following legalization has outpaced the understanding of their environmental and occupational impacts, particularly on air quality. This thesis addresses several stages of an air quality impact assessment, including method development, emission estimation, and consequences of emissions for occupational and ambient air. In Chapter 2, I present a comprehensive literature review on the air quality impacts of cannabis cultivation, identifying 16 key research gaps that informed the methodology of subsequent chapters. Chapter 3 examines the temporal variation of 22 terpenes across eight rooms in a CCF and six of a CPF using automated gas chromatography. Emissions increased with plant maturity, were affected by environmental conditions (e.g., lights-on periods raised terpene concentrations by 20–90%), and peaked during specific CPF activities. Omitting the chemical and temporal variability of emissions risks underestimating their impact, especially in odour modeling. In Chapter 4, I assess occupational concentrations of ultrafine particles (UFPs), an unregulated but health-relevant pollutant. Key findings include: (i) an artifact in the FMPS when terpene concentrations exceed 600 ppb, (ii) greater UFP concentrations in CPF rooms due to source-sink dynamics, and (iii) lung-deposited surface area (LDSA) concentrations in CPF environments comparable in magnitude to those in traffic and welding contexts. Chapter 5 evaluates downwind ambient air impacts of a > 440,000 m2 CCF using mobile monitoring and dispersion modeling. Results show: (i) a 3 ppb increase in ozone in urban downwind areas, (ii) a 150–200% decrease in UFPs downwind, and (iii) elevated sub-20 nm particles when urban NOx plumes intersected the facility under strong sunlight. Modeled terpene enhancements aligned with odour reports, defining a 3 km odour impact zone. Chapter 6 synthesizes findings and revisits the identified research gaps in light of five years of research and engagement with stakeholders across academia, industry, regulation, and the community.