Introduction: The home can represent a significant source of secondhand smoke (SHS), especially for individuals who live in close proximity to one another in multiunit housing (MUH). The objective of this study was to quantify real-time SHS transfer between smoke-permitted and smoke-free living units within the same MUH structure.
Methods: Air monitors were used to assess PM₂.₅, an environmental marker for SHS, in 14 smoke-free living units and 16 smoke-permitted units within 11 MUH buildings in the Buffalo, New York, area between July 2008 and August 2009. Air monitors were operated concurrently in both smoke-permitted and smoke-free units within each building. When feasible, additional monitors were stationed in shared hallways and on outdoor patios. Participants completed logs to document activities that could affect air quality.
Results: Evidence of SHS transfer from smoke-permitted units was detected in 2 of the 14 smoke-free units and 6 of the 8 hallways. Real-time PM₂.₅ plots and participant logs suggest that SHS transfer is a function of many determinants, including ventilation and proximity between units. Following stratification by time of day, median PM₂.₅ levels were greatest between 4:00 PM and 11:59 PM but varied by location: 10.2 μg/m³ in smoke-free units, 18.9 μg/m³ in hallways, and 29.4 μg/m³ in smoke-permitted units.
Conclusions: This study documents SHS incursions from smoke-permitted units into smoke-free units and adjacent hallways within the same building. Since many factors appear to impact the amount of SHS transfer between these areas, the implementation of a smoke-free building policy represents the most effective way to ensure that residents of MUH units are not exposed to SHS.