Secondhand Exposure to Simulated Cannabis Vaping Aerosols

Area of Science:

• Environmental Health
• Aerosol Science
• Toxicology

Background:

• Cannabis vaping poses risks to indoor air quality and exposes non-users to secondhand pollutants.
• The composition of vaping mixtures is a key factor influencing aerosol characteristics and potential health impacts.

Purpose of the Study:

• To investigate how different cannabis vaping mixture compositions affect indoor aerosol properties.
• To assess the impact of these aerosols on non-user exposure and respiratory deposition.

Main Methods:

• Simulated cannabis vaping aerosols were generated in a controlled chamber.
• Aerosol particle number and mass concentrations were measured over time and by size.
• A dosimetry model was used to estimate particle deposition in the respiratory tract.

Main Results:

• Peak particle number concentrations ranged from 0.7 to 13 × 10^6 cm^-3, and peak PM1.0 from 65 to 1191 μg m^-3.
• Mixtures with high cannabidiol (CBD) or vitamin E acetate (VEA) showed significantly higher PM1.0 yields (>1).
• Aerosols <100 nm were primarily deposited in the pulmonary, tracheobronchial, and head regions, with deposition increasing in the presence of THC, CBD, or VEA.

Conclusions:

• Cannabis vaping aerosol composition critically influences indoor air quality and exposure levels.
• Vitamin E acetate and high CBD concentrations dramatically increase aerosol yield and potential respiratory deposition.
• Understanding these relationships is crucial for mitigating health risks associated with secondhand cannabis smoke exposure.