Indoor Air Quality in Rural, Wood Stove Heated Homes

Abstract

Indoor Air Quality in Rural, Wood Stove Heated HomesAbstract Number:2705 Erin Semmens*, Tony Ward, Emily Weiler, Curtis Noonan Erin Semmens* University of Montana, United States, E-mail Address: [email protected] Search for more papers by this author , Tony Ward University of Montana, United States, E-mail Address: [email protected] Search for more papers by this author , Emily Weiler University of Montana, United States, E-mail Address: [email protected] Search for more papers by this author , and Curtis Noonan University of Montana, United States, E-mail Address: [email protected] Search for more papers by this author AbstractBackground: Biomass combustion generated from cooking and home heating is a major source of particulate matter (PM) in the developing world and rural areas of the United States (US), but research evaluating indoor PM concentrations in rural homes using wood as fuel for heating is limited. Our objective was to characterize indoor PM mass and particle number concentrations (PNCs) and investigate potential predictors of these indoor air quality measures.Methods: During four 24-hour sampling periods in 96 wood stove homes in the northwestern US and Alaska, we assessed PM mass (< 2.5 µm) and PNCs (particles/cm3) of five size fractions (0.3 – 0.49, 0.50 – 0.99 and 1.0 – 2.49 µm and fine and coarse fraction PNCs). Residents reported household characteristics and wood stove usage, and we utilized a repeated measures approach to assess relationships between these factors and various indoor air quality measures.Results: Mean (SD) PM2.5 concentrations ranged from 27.8 (29.9) µg/m3 to 31.2 (35.5) µg/m3 over the four sampling periods. PNCs decreased with increasing size fraction. Reported household income of greater than $50,000/year was associated with a 55% (95% CI: 39%, 67%) reduction in geometric mean PM2.5 with comparable results observed for smaller size fraction PNCs. A similar pattern was observed with caregiver’s education. Finally, the length of time wood was seasoned before burning was linked to lower PM2.5 (2+ years relative to < 1 year: 33% reduction; 95% CI: 7%, 52%) and PNCs of all size fractions.Conclusions: Findings demonstrate that indoor PM concentrations in rural homes with wood stoves approach or exceed ambient health-based standards and that socioeconomic factors contribute to substantial exposure disparities. The lower PM concentrations associated with well-aged compared to newer ‘wet’ wood indicate the potential benefits of behavioral- or education-based interventions on best-burn practices to improve both indoor air quality and health.