In a room where cannabis was vaped, THC was detected on hard surfaces. This is a first step in understanding how vape deposits in an environment can lead to second and third-hand (tertiary) exposure for other users as well as bystanders. In this study, vapor was continually being removed from the study room using "an excellent ventilation system that is intended to reduce secondhand exposure to cannabis" and which is "not common" in "real-life environments." Due to the use of the ventilation system, results of the study may underestimate the amount of THC remaining on surfaces.
Article title: Surface Detection of THC Attributable to Vaporizer Use in the Indoor Environment / Dec. 9, 2019
Read Full Article published on Scientific Reports / Nature.com