Why It Matters

For decades, we have understood the serious health risks posed by secondhand tobacco smoke. Today, research is showing that marijuana smoke and aerosols from electronic smoking devices contain many of the same cancer-causing chemicals as tobacco smoke.

The Facts

The serious health risks posed by secondhand tobacco smoke have been well-established. (1) There is no safe level of exposure to secondhand smoke; (2) exposure causes disease and nearly 50,000 annual deaths; and (3) even a small amount of exposure can have immediate adverse effects on the heart. Now, science indicates that marijuana smoke and aerosols from electronic smoking devices contain many of the same cancer-causing chemicals as tobacco smoke.

Scientists have found that marijuana smoke contains three times the amount of ammonia as tobacco smoke, as well as mercury, cadmium, nickel, lead, chromium, hydrogen cyanide, benzene, isoprene and toluene.  At least 33 chemicals known to cause cancer are present in both marijuana smoke and tobacco smoke.

A 2021 study found that marijuana joints produce 3.5 times the average fine-particle emission rate of Marlboro tobacco cigarettes, the most popular US cigarette brand. The average emission rate of the cannabis bong was 67% that of the joint; the glass pipe was 54% that of the joint, and the vaping pen was 44% that of the joint.  Fine-particle matter of 2.5 or greater pose the greatest risk to people’s health and can get deep into lungs, may even get into the bloodstream, and can affect a person’s lungs and heart. 

Particle emissions from dabbing and vaping marijuana can create levels of indoor air pollution similar to extreme air pollution events like wildfires. Exposure to air pollution at this level of concentration can cause cardiovascular and respiratory disease.

To learn more about secondhand marijuana smoke
visit Smokeissmoke.com and no-smoke.org