2nd- & 3rd-hand marijuana smoke is harmful to non-users
Third-hand smoke includes “residue from smoke that remains on walls, carpets, furniture, and other surfaces long after the smoke has left the room”. These items continue to off gas and “expose non-users to potentially harmful toxicants”.
Ventilation and air filtration devices do not eliminate the health risks caused by second-hand marijuana.
Non-users exposed second-hand to marijuana smoke in confined, unventilated spaces can test positive for THC drug tests.
Studies on rats indicate that exposure to secondhand marijuana smoke resulted in slower recovery rate (for arteries) that exposure to secondhand tobacco smoke.
Marijuana smoke is carcinogenic and contains “at least 33 individual constituents…that have been classified as carcinogenic”, according to the California Office of Environmental Health Hazard Assessment.