Secondhand Smoke Transfer in Multiunit Housing

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 PM 2.5 , 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 PM 2.5 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 PM 2.5 levels were greatest between 4:00 PM and 11:59 PM but varied by location: 10.2 mg/m 3 in smoke-free units, 18.9 mg/m 3