Estimating the harms from smoking and second-hand smoke exposure in social housing: a modelling study

People living in social housing in Australia have higher prevalence of daily smoking and greater exposure to second-hand smoke (SHS), particularly in multi-unit housing where smoke can drift between dwellings. The health impact of this exposure has not been quantified for this population.

We developed a Monte-Carlo matrix model of household SHS exposure, including smoke drift between dwellings in multi-unit housing, and linked it to the SHINE Tobacco simulation platform. The model projected health outcomes for the population living in social housing in the state of Victoria, Australia, over 20 years as an open cohort, and over the lifetime of a closed cohort, comparing scenarios that eradicated SHS exposure and/or smoking with a business-as-usual (BAU) scenario of constant smoking rates. Outcomes were health-adjusted life years (HALYs) gained, and premature deaths averted across 31 smoking-attributable and eight SHS-attributable diseases.

Eradicating SHS exposure within the social housing population of Victoria in 2025 could result in 5350 HALYs (95% uncertainty interval [UI] 4670-6120) gained, and 600 premature deaths (95% UI 500-700) averted from 2025 to 2044 in the open cohort. In multi-unit housing, about half of the SHS-related health gain was attributable to eliminating smoke drift between units. Overall, SHS eradication accounted for approximately 27% of the total health gain achievable if tobacco smoking were fully eradicated in this setting.

Reducing SHS exposure in social housing would deliver substantial health benefits, with a large share resulting from preventing smoke drift in multi-unit housing. Better data on population dynamics and smoke infiltration would strengthen estimates and support policy design.