Believing Secondhand Cannabis Smoke Is Harmful Was Strongly Linked to Home Smoking Bans

Those who perceived secondhand cannabis smoke as "extremely harmful" had 6x higher odds of a complete home smoking ban (OR=6.0) compared to those rating it "totally safe." Even moderate harm perception ("somewhat harmful") was associated with 2.6x higher odds of a ban. Despite this, nearly 29% of Americans rated secondhand cannabis smoke as at least "mostly safe."

Cross-sectional survey of 21,381 US adults from the Marijuana Use and Environmental Survey (Dec 2019-Feb 2020). Logistic regression estimated associations between perceived harm levels and complete home smoking bans, with stratification by smoking status, state legalization, and presence of young children.

With 72% of respondents reporting a complete home ban, indoor cannabis smoking norms are already shifting. But nearly 29% thinking it is at least "mostly safe" represents a large population that could be reached with public health messaging to reduce residential secondhand exposure.

The dose-response relationship between harm perception and home bans parallels what happened with tobacco. As public awareness of secondhand tobacco smoke harms grew, indoor smoking bans followed. This study suggests the same trajectory is possible for cannabis.

Cross-sectional design cannot prove perception causes ban adoption. Self-reported home bans may not reflect actual behavior. Survey conducted before COVID-19 may not reflect current patterns. Convenience of the survey platform may introduce selection bias.