Generation and Characterization of Hardwood Smoke Inhalation Exposure Atmospheres

Abstract

An inhalation exposure system and operating protocol were developed that resulted in consistent achievement of targeted exposure concentrations of hardwood smoke without compromising the desire to include multiple phases of a burn cycle. A conventional, noncatalyzed stove was operated in a temperature-controlled room with a three-phase (kindling, high burn, and low burn) cycle. Equally sized wood of similar moisture content was loaded in a consistent fashion each day of the study. A stable and controllable dilution system was employed that involved simultaneous withdrawal of smoke from a primary dilution tunnel. Exposure operators utilized real-time measurements of particulate matter (PM), CO, and stove temperature, along with operational experience, to gauge when adjustments to dilution air or the firebox were necessary. Dilutions of smoke were controlled in four separate inhalation atmospheres with daily average particle mass concentrations of 30, 100, 300, and 1000 μg/m3. Each of these atmospheres was ...