Polycyclic aromatic hydrocarbons and cannabinoids in secondhand cannabis smoke

Journal Article · Sun Feb 01 00:00:00 EST 2026 · Environment International

DOI:https://doi.org/10.1016/j.envint.2026.110175· OSTI ID:3030167

Tang, Xiaochen; Huang, Abel S; Russell, Marion L; St. Helen, Gideon; Jacob, Peyton; Destaillats, Hugo; Schick, Suzaynn F

The legalization of cannabis is exposing more people to secondhand smoke (SHS) generated during cannabis use. Given the serious health effects caused by tobacco SHS, there is a need to assess the potential health effects of exposure to cannabis SHS. As a step toward this, we measured the concentrations of cannabinoids, nicotine and polycyclic aromatic hydrocarbons (PAHs) in air samples collected in public places where cannabis was being consumed. These were compared with concentrations in exhaled aerosols from cannabis smoking and vaping, and in tobacco SHS. Tetrahydrocannabinol concentrations were 22 to 255 µg/m3 in field samples, below the threshold for psychoactive effects. Nicotine concentrations in field samples did not exceed 1 µg/m3. The total PAH concentrations in field samples were from 3.2 to 80.5 ng/m3, depending on location type. By contrast, PAH levels averaged 72 ng/m3 in tobacco SHS and 220 ng/m3 in the more concentrated, exhaled cannabis aerosols. A total of 22 different PAHs were identified in field samples of cannabis aerosols, from which benz[a]anthracene (B[a]A) was present in the highest concentrations. The PAH profile of cannabis aerosols was different from that of tobacco SHS. A preliminary cancer risk evaluation showed that the dose associated with inhalation of cannabis SHS during an 8-h work shift exceeded the California No Significant Risk Level for B[a]A at all venues where cannabis was consumed primarily via smoking. In , the consumption of cannabis, by smoking and by vaporizing, can create aerosols that contain carcinogenic PAHs. Thus breathing secondhand cannabis aerosols increases exposure to carcinogens.

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: US Department of Energy; USDOE Office of Science (SC)
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 3030167
• Journal Information: Environment International, Journal Name: Environment International Vol. 209
• Country of Publication: United States
• Language: English