Smoke is Smoke: The Impact of Secondhand Cannabis Smoke
By Fadya Abdullah | April 20, 2025
Since the mid-1980's, research has made it clear that exposure to secondhand tobacco smoke can be detrimental to everyone’s health, including non-users. As recreational cannabis use becomes more accessible, we are seeing a rise in questions about the impacts of secondhand cannabis smoke.
Secondhand smoke is the smoke released in the air from burning or exhaling a tobacco product. Secondhand cannabis smoke contains many of the same toxic and cancer-causing chemicals found in tobacco smoke, with some in higher amounts. It also contains tetrahydrocannabinol (THC), the chemical compound responsible for the psychoactive or the “high” effects of most cannabis products.
This blog highlights some of the potential health outcomes for adults, pregnant people, children, and pets, as well as cessation resources for people who may be interested in quitting cannabis use.
Health Effects of Secondhand Cannabis Smoke
There are many health risks associated with secondhand cannabis smoke. They include:
- Potential for cancer: chemicals in secondhand cannabis smoke are linked to lung cancer.
- Respiratory concerns: inhaled secondhand cannabis smoke can cause lung irritation, respiratory infections, asthma attacks, and increase risks for people with bronchitis or Chronic Obstructive Pulmonary Disease (COPD).
- Cardiovascular problems: exposure to secondhand cannabis smoke can impair blood vessel dilation, potentially causing blocked arteries, heart attacks, and strokes.
- Impairment: high levels of exposure to secondhand cannabis smoke can impair motor skills.
- Uncomfortable side effects: exposure can cause anxiety, paranoia, burning eyes, coughing, dry mouth, fatigue, headache, nausea, and restlessness.
Secondhand Cannabis Smoke and Pregnancy
Secondhand cannabis smoke around pregnant individuals not only affects the pregnant person, but their baby as well. Breathing in secondhand cannabis smoke passes the cancer-causing chemicals and THC to the infant. Cannabis chemicals entering body of a pregnant person can cause health problems in newborns, including lower birth weight and abnormal neurological development.
Secondhand Cannabis Smoke and Children
The THC in cannabis can be passed to infants and children through secondhand cannabis smoke, causing them to experience the psychoactive effects of cannabis. A study examining the effects of secondhand cannabis smoke on children showed that nearly half of the children in the study showed detectable levels of cannabis in their urine.
Children who inhale secondhand cannabis smoke can experience lung irritation and asthma attacks, as well as anxiety, blood-shot eyes, increased appetite, dry mouth, decreased coordination, and agitation. These health effects can last 24-36 hours in children. Research also shows that children who inhale secondhand cannabis smoke experience more viral respiratory infections.
Secondhand Cannabis Smoke and Pets
Cannabis, specifically the THC in cannabis, is poisonous to pets including cats, dogs, and horses. If an animal inhales THC through secondhand smoke, they may display signs of THC poisoning that are important to look out for. These signs include inactivity, incoordination, dilated pupils, increased sensitivity to motion, sound, or touch, hypersalivation, and urinary incontinence. These signs can last for less than an hour or for several days, depending on the amount of THC to which the animal was exposed.
Cannabis Cessation Resources
There can be many benefits to having a smokefree home, including the health of your loved ones. Below are a few helpful cannabis cessation resources:
- Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline: a free, confidential, 24/7, 365-day-a-year treatment referral and information service (in English and Spanish) for individuals and families facing mental and/or substance use disorders. Call 1-800-662-HELP (4357).
- SMART (Self Management and Recovery Training) Recovery: an evidenced-informed recovery method grounded in Rational Emotive Behavioral Therapy (REBT) and Cognitive Behavioral Therapy (CBT), that supports people with substance dependencies.
- National Poison Center: your resource for help in a poisoning emergency. If you think your child has eaten or inhaled cannabis, contact your local poison center. The national poison center hotline number is: 1-800-222-1222
Fadya Abdullah (she/her) is the Social Media & Digital Marketing Coordinator for the Tobacco Education Clearinghouse of California (TECC), a project of ETR.
