Millions report secondhand cannabis smoke exposure at home in the U.S. and Canada | Research

The takeaway

About one in five residents across the U.S. and Canada reported exposure to secondhand cannabis smoke at home, with about one in four multi-unit housing residents reporting cannabis smoke entering from other units.

Multi-unit housing residents, policymakers, and public health researchers.

~25% of multi-unit housing residents report cannabis smoke incursions

What the researchers found

Monthly secondhand cannabis smoke exposure at home was reported by 16.9% in Canada, 20.6% in U.S. legal states, and 15.5% in U.S. illegal states. Among multi-unit housing residents, 25.7% in Canada, 26.6% in U.S. legal states, and 20.1% in U.S. illegal states reported smoke incursions from other units or outdoors.

Why it matters

As cannabis legalization expands, involuntary exposure to secondhand cannabis smoke in shared housing is a growing public health concern that existing smoke-free policies may not adequately address.

The numbers in context

33,024 respondents for home exposure analysis. 15,634 multi-unit housing residents for incursion analysis. Exposure rates: 15.5-20.6% for home exposure, 20.1-26.6% for multi-unit housing incursions.

How the study worked

Cross-sectional survey from the 2019 International Cannabis Policy Study with 33,024 respondents for home exposure and 15,634 multi-unit housing residents for incursion analysis. Weighted logistic regression assessed associated factors.

What this study cannot tell us

Self-reported exposure without biomarker verification. Cross-sectional design captures one time point. Cannot distinguish between occasional and heavy exposure.

How to read the evidence

Large international survey with appropriate statistical methods, though reliant on self-report and cross-sectional design.

When this study was published

Published in 2022 using 2019 survey data.

The bigger picture

The similar incursion rates across legal and illegal jurisdictions suggest that secondhand cannabis smoke is a widespread issue regardless of legalization status, though rates were modestly higher in legal states.

Questions still open

Do cannabis-specific smoke-free policies reduce multi-unit housing exposure? Are there health effects from chronic, involuntary secondhand cannabis smoke exposure?

Common questions

Is secondhand cannabis smoke worse in states where it's legal?

Rates were modestly higher in U.S. legal states (20.6% at home, 26.6% in multi-unit housing) compared to illegal states (15.5% and 20.1%), but exposure was common everywhere.

Who was most affected?

Multi-unit housing residents reporting smoke incursions appeared to live in qualitatively different housing than those not reporting incursions, suggesting housing quality and type influence exposure risk.

Read the original research

Prevalence and factors associated with self-reported exposure to secondhand cannabis smoke in the United States and Canada in 2019.

Preventive medicine, 157, 107006

View on PubMed ↗Publisher’s paper ↗

Citation

Driezen, Pete; Kaufman, Pamela; Chaiton, Michael; Goodman, Samantha; Hammond, David. (2022). Prevalence and factors associated with self-reported exposure to secondhand cannabis smoke in the United States and Canada in 2019.. Preventive medicine, 157, 107006. https://doi.org/10.1016/j.ypmed.2022.107006