Data for: Secondhand exposure from vaping marijuana: concentrations, emissions, and exposures determined using both research-grade and low-cost monitors
Description
Record of 124 experiments vaping marijuana in a dedicated room of an inhabited house. Three continuous monitoring instruments were used to measure PM2.5 concentrations. The Piezobalance is a research-grade instrument measuring mass accumulation directly on a quartz surface. The SidePak and the PurpleAir sensor are optical particle monitors providing number counts; with assumed density of the aerosol, the PM2.5 mass can be determined. The SidePak was calibrated against a gravimetric method and found to have a calibration factor (CF) of 0.35 for the exhaled aerosol mixture. An alternative method was developed for the PurpleAir monitor to avoid the "black box" nature of the two dataseries (CF1 and CF ATM) offered by the sensor manufacturers. This method, which is standard among researchers working with other instruments offering sub-2.5 um size categories, performed better by various measures than either the CF1 or CF ATM series. Source strengths (emission factors) were found to depend strongly on the heating time for the vape pen, Longer heating times (15 seconds vs. 6 seconds) were found to elevate the source strength fromabout 2.4 mg?puff to about 78 mg/puff. These can be compared to a typical tobacco cigarette of 1.4 mg/puff. Human exposures would depend mainly on the frequency of vaping, but under certain conditions, they could approach or exceed the outdoor annual standard of 12 ug/m3 or the outdoor 24-h standard of 35 ug/m3.