National and state estimates of secondhand smoke infiltration among U.S. multiunit housing residents.

INTRODUCTION: Multiunit housing (MUH) residents are susceptible to secondhand smoke (SHS), which can infiltrate smoke-free living units from nearby units and shared areas where smoking is permitted. This study assessed the prevalence and characteristics of MUH residency in the United States, and the extent of SHS infiltration in this environment at both the national and state levels.
METHODS: National and state estimates of MUH residency were obtained from the 2009 American Community Survey. Assessed MUH residency characteristics included sex, age, race/ethnicity, and poverty status. Estimates of smoke-free home rule prevalence were obtained from the 2006-2007 Tobacco Use Supplement to the Current Population Survey. The number of MUH residents who have experienced SHS infiltration was determined by multiplying the estimated number of MUH residents with smoke-free homes by the range of self-reported SHS infiltration (44%-46.2%) from peer-reviewed studies of MUH residents.
RESULTS: One-quarter of U.S. residents (25.8%, 79.2 million) live in MUH (state range: 10.1% in West Virginia to 51.7% in New York). Nationally, 47.6% of MUH residents are male, 53.3% are aged 25-64 years, 48.0% are non-Hispanic White, and 24.4% live below the poverty level. Among MUH residents with smoke-free home rules (62.7 million), an estimated 27.6-28.9 million have experienced SHS infiltration (state range: 26,000-27,000 in Wyoming to 4.6-4.9 million in California).
CONCLUSIONS: A considerable number of Americans reside in MUH and many of these individuals experience SHS infiltration in their homes. Prohibiting smoking in MUH would help protect MUH residents from involuntary SHS exposure.