Secondhand marijuana smoke reached concerning levels at golf courses and other outdoor locations

Across 24 visits to 10 golf courses, over 20% of visits encountered marijuana smoke, with peak PM2.5 exposures reaching 149 micrograms per cubic meter. Average outdoor exposures near public smoking/vaping were more than 3 times higher than those near enclosed sources. In-car secondhand smoke leakage produced higher outdoor exposure than building-based indoor emissions.

Pilot observational study measuring PM2.5 exposure from marijuana smoke at golf courses (24 visits to 10 courses over 6 months) and other outdoor locations (public parks, near parked cars, near residential garages). Total of 23 marijuana exposure events documented.

As cannabis legalization expands and outdoor use increases, understanding secondhand exposure levels in public spaces helps inform policies about where cannabis smoking should be permitted.

Most secondhand smoke regulations focus on tobacco and indoor spaces. This study highlights that outdoor marijuana smoke exposure in public settings can reach levels of concern, potentially necessitating cannabis-specific outdoor smoking policies.

Pilot study with small number of measurement events. PM2.5 levels alone do not identify specific harmful compounds in marijuana smoke. Golf courses may not be representative of all outdoor exposure scenarios. Cannot determine health effects from measured exposure levels.