What are the health risks of exposing children to marijuana smoke?

Health Risks of Marijuana Smoke Exposure in Children

Children exposed to secondhand marijuana smoke face significant health risks including increased respiratory infections, and pediatricians must explicitly counsel parents that marijuana smoke contains harmful, toxic, and carcinogenic chemicals similar to tobacco smoke. 1

Documented Health Risks

Respiratory Effects

• Children with secondhand marijuana smoke exposure experience significantly more viral respiratory infections (1.31 episodes/year) compared to unexposed children (1.04 episodes/year). 2
• Marijuana smoke contains hundreds of harmful compounds and is associated with chronic bronchitis and chronic obstructive pulmonary disease in users, suggesting similar risks for exposed children. 3
• The link between cannabis smoking and respiratory disease exists, though data are often confounded by concomitant tobacco use. 3

Neurological and Developmental Concerns

• Cannabis smoke exposure is particularly dangerous for the developing adolescent brain, causing altered gray matter volume, changes in cortical thickness, and disrupted prefrontal cortex connectivity affecting decision-making and impulse control. 3
• Children exposed to marijuana smoke may experience learning and neurobehavioral problems, as documented with tobacco smoke exposure. 1
• Cannabis toxicity in children is especially concerning and can cause acute neurological symptoms including stupor, lethargy, seizures, and even coma. 4

Cardiovascular Risks

• Marijuana smoke causes cardiovascular effects including tachycardia, potential myocardial ischemia, and orthostatic hypotension. 3
• Cannabis affects heart rhythm through multiple mechanisms including sympathetic stimulation and promotion of a prothrombotic state. 3

Cancer Risk

• Marijuana smoke contains many harmful, toxic, and carcinogenic chemicals similar to tobacco smoke. 1
• Tobacco smoke exposure increases the risk of childhood cancers (good quality evidence), and marijuana smoke likely poses similar risks. 1

Prevalence of Exposure

• Approximately 10.5% of caregivers report smoking marijuana, representing a significant exposure risk for children. 2
• Detectable marijuana metabolites (COOH-THC) were found in 20.8% of young children (ages 0-3 years) tested in New York City. 5
• Children living in attached housing where smoking is allowed had 34.8% detection rates compared to 13.0% in smoke-free housing. 5
• Children with household tobacco smoke exposure are significantly more likely to also have marijuana smoke exposure (p < 0.01). 5

Clinical Recommendations for Pediatricians

Screening and Assessment (Strong Recommendations)

Pediatricians must inquire about marijuana smoke exposure as part of health supervision visits and visits for respiratory illnesses. 1

Essential screening questions to modify from tobacco guidelines:

• Does your child live with anyone who uses marijuana or cannabis?
• Does anyone ever smoke or vape marijuana in your home?
• Does anyone ever smoke or vape marijuana in your car?
• Do you smell marijuana smoke from neighbors?

Important caveat: Many families do not consider vaping or electronic delivery systems as "smoking," so explicitly ask about "vape," "vaping," "weed," "cannabis," and marijuana in all forms. 1

Counseling Parents and Caregivers

• Explicitly recommend that children not be exposed to marijuana smoke in the home, automobiles, or any other space where exposure can occur. 1
• Advise all caregivers not to use cannabis recreationally in any form around children. 1
• Emphasize that marijuana smoke contains harmful, toxic, and carcinogenic chemicals similar to tobacco. 1
• Counsel that there is no "safe or risk-free" level of smoke exposure for children. 6

Special Considerations

• Children with asthma have higher rates of secondhand smoke exposure and are at particular risk from marijuana smoke. 6
• Multi-housing units pose increased exposure risk due to smoke migration between units. 5
• Combined marijuana and tobacco use results in greater harm than either substance alone. 3

Critical Pitfalls to Avoid

• Do not assume marijuana smoke is less harmful than tobacco smoke—both contain toxic and carcinogenic compounds. 1
• Do not overlook marijuana exposure when screening for smoke exposure—10% of caregivers use marijuana regularly. 2
• Do not fail to ask about vaping and electronic delivery systems—many parents don't consider these as "smoking." 1
• Do not ignore housing situations—attached housing with permissive smoking policies dramatically increases exposure risk. 5