​Study focus: The proportion of Californians reporting exposure to secondhand smoke (SHS) from tobacco and marijuana and electronic cigarette (e-cigarette) vapor has grown over time, despite an increasing number of smoke-free local laws in the last 10 years. Residents of market-rate, privately owned multi-unit housing (MUH) — e.g., apartments — are particularly at risk of drifting SHS.

Participants: Authors conducted a study of 4,800 tenants and 176 MUH owners in the city of Los Angeles in 2019.

Outcomes studied: Exposure to secondhand smoke in privately owned multi-unit housing, aggregating by race/ethnicity and by whether tenants have children or family members with chronic disease in the household; MUH tenant and owner attitudes toward smoke-free housing policies.

Findings: Forty-nine percent of tenants reported exposure to drifting SHS, including SHS from tobacco (39%), marijuana (36%), and e-cigarettes (9%). Tenants who lived with children and those who had lived or were living with someone who had a chronic health condition were significantly more likely to report exposure to drifting SHS. The vast majority of tenants and owners supported policies that restricted smoking in MUH, with most supporting tobacco and marijuana policies. Yet support for smoke-free policies was mixed with strong concerns about enforcement of such policies.

Findings reveal the high level of SHS in MUH, gaps in existing voluntary smoke-free policies, and the need for a consistent implementation and enforcement plan to prevent exposure to SHS for all Los Angeles residents.