Cannabis secondhand smoke exposure in apartments is as common as tobacco secondhand smoke

A population survey in Ontario found 7.5% of multi-unit housing residents reported involuntary exposure to cannabis smoke from neighbors, similar to the 6.6% reporting tobacco smoke exposure, with lower-income residents disproportionately affected.

Chu, Alanna K et al.·International journal of environmental research and public health·2019·Moderate EvidenceCross-Sectional
RTHC-01986Cross SectionalModerate Evidence2019RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Cross-Sectional
Evidence
Moderate Evidence
Sample
Not reported

What This Study Found

Among multi-unit housing residents in Ontario, 7.5% reported environmental cannabis smoke (ECS) exposure and 6.6% reported environmental tobacco smoke (ETS) exposure from neighboring units. ECS exposure was associated with being single, lower household income, and past-year cannabis use. Cannabis smoke exposure prevalence was comparable to tobacco smoke.

Key Numbers

Environmental cannabis smoke: 7.5% (95% CI 5.4-10.4%). Environmental tobacco smoke: 6.6% (95% CI 4.5-9.5%). Exposed individuals more likely to be single, have lower income, and have used cannabis.

How They Did This

Population random-digit-dial survey from the 2017 Centre for Addiction and Mental Health Monitor for Ontario, Canada. Self-reported cannabis and tobacco smoke entering the home from neighboring units at least once in the past 6 months.

Why This Research Matters

As cannabis legalization expands, involuntary exposure to cannabis smoke in multi-unit housing is an emerging public health concern. This is the first study to measure its prevalence alongside tobacco smoke exposure.

The Bigger Picture

Multi-unit housing residents are disproportionately lower-income and include vulnerable populations (children, elderly, people with respiratory conditions). Involuntary cannabis smoke exposure adds a new dimension to housing health policy that legalization frameworks have largely not addressed.

What This Study Doesn't Tell Us

Self-reported exposure with potential recall bias. Ontario-specific, pre-full Canadian legalization (October 2018). Cannot distinguish between smoke from the building interior versus exterior. No objective measurement of smoke levels.

Questions This Raises

  • ?Should multi-unit housing cannabis smoking bans mirror tobacco smoking bans?
  • ?Does secondhand cannabis smoke carry similar health risks to tobacco?
  • ?How should landlords and policymakers address this issue?

Trust & Context

Key Stat:
7.5% exposed to cannabis smoke
Evidence Grade:
Rated moderate because this is a population-representative RDD survey, though self-report and a single province limit the findings.
Study Age:
Published in 2019 using 2017 data, before full Canadian recreational legalization.
Original Title:
Prevalence of Involuntary Environmental Cannabis and Tobacco Smoke Exposure in Multi-Unit Housing.
Published In:
International journal of environmental research and public health, 16(18) (2019)
Database ID:
RTHC-01986

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study

A snapshot of a population at one point in time.

What do these levels mean? →

Frequently Asked Questions

Is secondhand cannabis smoke in apartments a real problem?

This study found it is about as common as secondhand tobacco smoke, affecting 7.5% of multi-unit housing residents in Ontario.

Who is most affected?

Lower-income residents are disproportionately exposed, as they are more likely to live in multi-unit housing with shared ventilation and less ability to choose their living conditions.

Read More on RethinkTHC

Cite This Study

RTHC-01986·https://rethinkthc.com/research/RTHC-01986

APA

Chu, Alanna K; Kaufman, Pamela; Chaiton, Michael. (2019). Prevalence of Involuntary Environmental Cannabis and Tobacco Smoke Exposure in Multi-Unit Housing.. International journal of environmental research and public health, 16(18). https://doi.org/10.3390/ijerph16183332

MLA

Chu, Alanna K, et al. "Prevalence of Involuntary Environmental Cannabis and Tobacco Smoke Exposure in Multi-Unit Housing.." International journal of environmental research and public health, 2019. https://doi.org/10.3390/ijerph16183332

RethinkTHC

RethinkTHC Research Database. "Prevalence of Involuntary Environmental Cannabis and Tobacco..." RTHC-01986. Retrieved from https://rethinkthc.com/research/chu-2019-prevalence-of-involuntary-environmental

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.