Assessing Secondhand Cannabis Exposure at a Cannabis Consumption Lounge
Muchuan Niu, Yuan Yao, Haoxuan Chen, YIFANG ZHU, University of California, Los Angeles
Abstract Number: 164
Working Group: Indoor Aerosols
Abstract
The progressive legalization of recreational cannabis across the United States has fostered a variety of emerging cannabis businesses that include cannabis consumption lounges where customers are allowed to use cannabis in the indoor spaces. However, exposure levels in these unique public spaces have not been documented, and thus, raising concerns about high exposure risks for customers, staffs, and nearby businesses. This study measured secondhand cannabis exposure at a cannabis consumption lounge over a one-week period. The particle decay rate under various ventilation conditions in a cabin was tested to explore potential mitigation strategy. Our results showed that the peak PM2.5 (fine particles, diameter ≤ 2.5 µm) during weekdays exceeded 1,500 µg/m3 and registered levels over 5,000 µg/m3 during the weekends, suggesting extremely high particle exposure within the cabin. The mean cabin PM2.5 level (168 ± 237 µg/m3) during busy hours (12 pm - 11 pm) were significantly higher than those observed at the lounge backyard (26 ± 45 µg/m3) and the street control site (12 ± 4 µg/m3). Decay rates were obtained from five ventilating scenarios. After a series of puffs (n = 4), the highest decay rate (27 h-1) was found when the cabin door was opened; while the lowest decay rate (9 h-1) was detected when the air conditioning was turned on, but the door was closed. Nevertheless, particle exposure level after a 5-minute decay remained above the baseline level for all ventilating scenarios. Airborne THC (tetrahydrocannabinol) and nicotine were also collected as tracer chemicals and the results are to be reported.
These findings reveal the high exposure risks in cannabis consumption lounge and highlight the urgent need for regulatory measures to mitigate potential health risks associated with secondhand cannabis exposures in these public indoor settings.