Indoor cannabis smoke was linked to worse child health outcomes in homes with smokers | Research

The takeaway

In homes where tobacco smoking already occurred, adding indoor cannabis smoking was associated with higher odds of adverse child health outcomes, though the association did not reach statistical significance.

Parents who smoke cannabis indoors, pediatricians, and public health researchers.

Homes with both cannabis and cigarette smoke had 3x the particle levels of non-smoking homes

What the researchers found

Homes with indoor cannabis smoking had higher air particle concentrations than those with cigarette smoking alone (3,131 vs. 3,095 particles/0.01ft3). Homes with both had the highest levels (6,006). Children in homes with indoor cannabis smoking had 1.83 times the odds of more adverse health outcomes compared to non-cannabis homes, though this was not statistically significant (95% CI 0.89-3.80, p=0.10).

Why it matters

Research on secondhand cannabis smoke exposure in children is scarce. While this study did not achieve statistical significance, the magnitude of the association suggests indoor cannabis smoking adds to the health burden on children already exposed to tobacco smoke.

The numbers in context

192 families analyzed. 29 (15.1%) reported indoor cannabis smoking. Air particles: no indoor smoking 1,968, cannabis only 3,131, cigarettes only 3,095, both 6,006 particles/0.01ft3. Child health OR: 1.83 (95% CI 0.89-3.80, p=0.10).

How the study worked

Cross-sectional study of 192 families in San Diego County with at least one cigarette smoker and one child under 14. Air particle monitors were placed in homes for 7 days. Child health outcomes (ED visits for respiratory issues, ear infections, bronchitis, asthma, eczema) were assessed.

What this study cannot tell us

Not statistically significant. Small number of cannabis-smoking households (n=29). All homes already had tobacco smokers, making it hard to isolate cannabis effects. Self-reported cannabis use.

How to read the evidence

Preliminary: small cross-sectional study with non-significant primary finding.

When this study was published

Published in 2019.

The bigger picture

As cannabis legalization spreads, more children may be exposed to indoor cannabis smoke. Even without reaching statistical significance, this study is among the first to quantify the potential health impact on children.

Questions still open

Would a larger study find a significant association? What are the effects of cannabis smoke alone (without concurrent tobacco) on children? Are there specific respiratory conditions most affected by secondhand cannabis smoke?

Common questions

Is secondhand cannabis smoke as harmful as secondhand tobacco smoke?

The research is limited. This study found that cannabis smoke added to air particle levels in homes, but the health effects were not statistically significant. More research is needed to compare the two.

Why wasn't the result statistically significant?

Likely due to the small number of cannabis-smoking households (29 out of 192). The effect size (OR 1.83) was meaningful but the study was underpowered to detect it with confidence.

Read the original research

Indoor cannabis smoke and children's health.

Preventive medicine reports, 14, 100853

View on PubMed ↗Publisher’s paper ↗

Citation

Posis, Alexander; Bellettiere, John; Liles, Sandy; Alcaraz, John; Nguyen, Benjamin; Berardi, Vincent; Klepeis, Neil E; Hughes, Suzanne C; Wu, Tianying; Hovell, Melbourne F. (2019). Indoor cannabis smoke and children's health.. Preventive medicine reports, 14, 100853. https://doi.org/10.1016/j.pmedr.2019.100853