AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Passive Exposure to Aerosols Emitted from Vaping Marijuana Liquid
LANCE WALLACE, Wayne Ott, Kai-Chung Cheng, Tongke Zhao, Lynn M. Hildemann, US EPA (retired)
Abstract Number: 356 Working Group: Indoor Aerosols
Abstract A popular method of inhaling marijuana is by heating marijuana oil (vaping). We study real-life PM1, PM2.5 and PM10 concentrations as well as ultrafine particle numbers in two inhabited homes and determine decay rates, source emissions, and volatile fraction of the aerosol. Each test was conducted in a closed-off room in the two homes. A Scanning Mobility Particle Sizer (SMPS) with water-based CPC (Model 3788, TSI) provided ultrafine particle counts between 3 and 100 nm. One or two pairs of optical PM monitors were employed: SidePaks (TSI) and PA-II (purpleair). The purpleair monitor provides data on five size categories between 0.3-10 μm. Monitors providing direct measurement of PM2.5 mass were also employed: the Piezobalance (Kanomax). The Piezobalance also has the property of losing volatiles from its crystal after some time, allowing an estimate of volatility of the aerosol. Aerosols were also collected on a filter and weighed. CO was measured by an electrochemical device (Langan Instruments) to provide estimates of the air exchange rate. A single puff of the heated marijuana oil was sufficient to elevate ultrafine numbers to >100000 cm-3, and PM2.5 concentrations to >100 μg/m3, remaining elevated for several hours. Decay rates were calculated for the ultrafine particles and for five size fractions and displayed a monotonic decrease with increasing diameter for the ultrafines and a monotonic increase with increasing diameter for the range from 0.3-10 μm. The estimates of source strength (mg/puff) from the direct measurements of mass (Piezobalance and gravimetric) were in the range of 1 to several mg/puff, similar to secondhand smoke from cigarettes. Air exchange rates in one room varied from 0.1 to 0.2 h-1. Initial estimates of the volatile constituents ranged up to 20%.