In November 2016, marijuana became legal for recreational use by adults 21 and older in California. While there is a lot of research underway about marijuana and potential health benefits and harms, one thing is very clear: marijuana secondhand smoke is harmful to people around it.
Marijuana secondhand smoke is dangerous, containing many of the same cancer-causing chemicals and toxic chemicals as cigarette secondhand smoke.
It has significantly higher amounts of toxic chemicals such as tar and ammonia, and more than twice the amount of hydrogen cyanide, an extremely poisonous chemical.3, 4 When you inhale the smoke, you are inhaling into your lungs some of the same hazardous fine particulates found in cigarette smoke.3
While they are different products, both marijuana and cigarettes produce harmful and toxic secondhand smoke associated with adverse cardiovascular effects like hardening and narrowing of the arteries which could lead to heart attack and stroke.5 And, unlike traditional tobacco products, research confirms that exposure to secondhand marijuana smoke produces a secondhand high.6
Studies have also shown that: Nonsmokers exposed to secondhand marijuana smoke report feeling the effects of a secondhand high, or “contact high,” 6 with detectable levels tetrahydrocannabinol (THC) – the psychoactive ingredient in marijuana– found in their blood and urine.7
Nonsmokers exposed to marijuana secondhand smoke in a room without ventilation tested positive for THC for up to three hours following exposure.8 Marijuana secondhand high effect is particularly troubling when considering the potential impact to children exposed to marijuana smoke.
Unfortunately, reports of marijuana secondhand smoke exposure are on the increase in California. A 2018 statewide survey found that adult exposure to marijuana secondhand smoke often occurs in public spaces, including sidewalks, parks, and shopping areas as well as private homes. In addition, 40% of adult Californians reported recent exposure to marijuana secondhand smoke in 2018, an 86% increase in just two years.9
The potential harm from marijuana secondhand smoke exposure highlights the importance of understanding marijuana use law in California:
- First, while it is legal to consume marijuana on private property, you cannot consume, smoke, or vape cannabis in public places or in any location where smoking tobacco is prohibited. This may also include apartments.10, 11
- Property owners and landlords have the right to prohibit smoking of marijuana on their properties.11, 12
- Even though it is legal under California law, you cannot consume or possess cannabis on federal lands such as national parks, even if the park is in California.13
- It is illegal to take marijuana across state lines, even if you are traveling to another state where it is legal.14, 15
Visit Let’s Talk Cannabis to understand the facts about marijuana use.
If you want to find out what your city is doing to protect you and your community from toxic secondhand smoke exposure, visit SecondhandDangers.org and enter your city’s name.