Introduction Cannabis (Cannabis sativa, marijuana) is the most valuable crop in California. Approximately 10% of cannabis is grown and sold on the legal market, with combined legal and illegal revenues exceeding $10 billion per year. There are approximately 58,000 legal cannabis jobs in the state, but the total size of the workforce is unknown. There has been little research on the health and safety of cannabis workers; none includes seasonal immigrant workers.

Material and Methods We performed a qualitative study of Northern California cannabis cultivation and processing workers’ experiences and perception of workplace hazards based on four focus group discussions including 32 cannabis workers and nine key informant interviews. Transcripts were analyzed to identify major themes of exposures and health effects. We briefly report results of a pilot study of respiratory and dermal symptoms among 29 workers at two legal cannabis farms in the Sacramento, California area.

Results Most (56%) focus group participants were Latino, and 50% were women. They were exposed to physiological hazards including respiratory and dermal exposures, 10–12 hour work shifts of repetitive tasks at uncomfortable workstations, and substandard worker housing. Immigrant workers reported experiences of discrimination and violence due to immigration documentation status, race, and gender. Psychosocial stress due to production pressure and geographic and social isolation was common. Pilot study participants were mostly white (58%) men age ≤ 30 years. Work-related symptoms of any type were reported by 38% of participants, and 38% reported symptoms suggestive of asthma.

Conclusions This is the first study of seasonal cannabis worker health. Some physiological exposures were consistent with previous studies of cannabis worker health, but other concerns were identified that have not previously been characterized including structural and interpersonal violence and stress. The high proportion of pilot study with work-related symptoms including those suggestive of asthma raises concern.