Particulate Air Pollution from Secondhand Cannabis Smoke in Public Venues
XIAOCHEN TANG, Abel Huang, Morgan Murphy, Marion Russell, Suzaynn Schick, Hugo Destaillats, Lawrence Berkeley National Laboratory
Abstract Number: 689
Working Group: Indoor Aerosols
Abstract
Secondhand cannabis smoke poses a growing public health concern, partly associated with the rapidly changing legal status of cannabis in the US. Many states now permit cannabis consumption in designated stores and at certain events, on licensed buses and in hotels, restaurants, and other venues. This can create exposure risks for employees, event attendees, customers and the public. This study aims to measure the particulate air pollution caused by cannabis use in public places in the US, and to assess secondhand exposures of nonsmokers.
PM2.5 samples from secondhand cannabis emissions were collected in 1) a cannabis dispensary with a lounge where dabbing and vaporizing were allowed, but not smoking, 2) a cannabis dispensary with a lounge where smoking, dabbing and vaporizing were allowed, and 3) a cannabis festival in a large hall where smoking, dabbing and vaporizing were allowed. Background samples were collected at a nearby outdoor locations where cannabis was not being consumed.
Collected sample filters were cut to halves and weighed before solvent extraction and sonication. For PAH analysis, one half was extracted with a 50:50 acetone:hexane mixture with sonicated for 30 minutes, while for THC analysis using methanol as the solvent. The extracts were analyzed by gas chromatography/mass spectrometry (GC/MS, Agilent 5977). Spiking recovery tests suggested 60-100% extraction efficiency with this method.
Comparison of total PAH concentrations (µg m-3) corresponding to background and air samples collected at one cannabis festival and one cannabis dispensary lounge clearly show that cannabis consumption in these venues results in elevated PAH levels in indoor air. Most of the 22 PAHs were detected at levels above the limit of quantification of 3 pg per filter. The determination of THC concentration in the same samples will allow us to determine normalized compound-specific emission rates for individual PAHs.