JMIR Publications

ABSTRACT

Background:

An estimated 5–8 million U.S. children live with a parent who uses cannabis. A majority of cannabis users report smoking cannabis inside their home, which places children at risk for cannabis secondhand smoke (cSHS) exposure. Emerging evidence links caregiver cannabis use to children’s respiratory and behavioral problems. Indoor air quality (IAQ) monitoring, an approach that provides real-time feedback on airborne pollutants, has been successful in reducing in-home tobacco SHS exposure, and may similarly be an effective harm reduction strategy for cSHS.

Objective:

This pilot study evaluated the feasibility, acceptability, and preliminary effectiveness of using low-cost, off-the-shelf IAQ monitors to increase caregivers’ awareness of children’s cSHS exposure risk and change smoking behavior. Secondary aims were to assess participant engagement, perceived usefulness, and household communication around in-home cannabis smoking.

Methods:

Fourteen adults who smoked cannabis indoors and lived with at least one child under age 16 completed a 3-week trial. Participants received an Awair Element IAQ monitor, printed health education materials, and SMS prompts for brief surveys. The IAQ monitor continuously measured PM2.5, VOCs, CO₂, temperature, and humidity. Brief daily surveys captured self-reported PM2.5 readings and recent cannabis use, while baseline and end-of-study assessments evaluated IAQ perceptions, cSHS risk awareness, and in-home smoking behavior. Survey results were summarized via descriptive statistics, and linear mixed-effects models were used to characterize objective IAQ trends. Six additional adult household members provided parallel end-of-study data.

Results:

Engagement was high, with 84% of participants indicating that they reviewed the monitor at least daily. The average number of days in the previous week that a caregiver reported a child home while cannabis was smoked declined from 4.5 at the beginning of the trial to 2.8 at the end (41.6% of participants had a reduction, 8.3% increased). Sixty-two percent of participants reported that they either reduced (31%) or thought about changing (31%) their smoking habits during the study. Sixty-nine percent either agreed or strongly agreed that IAQ monitoring helped drive conversations about changing indoor smoking rules, while 100% reported no IAQ-driven disagreements among household residents regarding in-home smoking rules. A linear mixed-effects model did not indicate a consistent trend in PM2.5 levels across participants over time (β = –0.28, p = 0.81), but there was substantial heterogeneity in trends, and those with the largest reductions in PM2.5 over the trial had the largest reduction in reported children’s cSHS exposure.

Conclusions:

In-home IAQ monitoring was feasible, acceptable, and perceived as useful among caregivers who smoked cannabis indoors. Real-time IAQ feedback supported risk awareness, promoted family dialogue, and coincided with reductions in in-home smoking around children. These findings suggest IAQ feedback may represent a scalable tool for reducing children’s cSHS exposure and merit further testing in larger, controlled trials. Clinical Trial: No