Abstracts: ISEE 22nd Annual Conference, Seoul, Korea, 28 August–1 September 2010: Outdoor Air Pollution From Residential Wood Combustion and Associated Health Effects
Changes in Respiratory Symptoms and Infections Following a Reduction in Wood Smoke PM
A wood stove changeout program was implemented in a community heavily impacted by wood smoke-derived particulate matter (PM). Approximately 1180 old wood stoves were replaced with new EPA-certified wood stoves or other heating sources.
Ambient and indoor PM concentrations were measured during the changeout program. Parental reporting of children's respiratory symptoms and infections were captured during 4 winter periods. Generalized estimating equations were used to evaluate the change in prevalence of symptoms and infections per 5 μg/m3 reduction in ambient PM2.5. Risk estimates were adjusted for age, presence of wood stove in home, and annual flu incidence in the community.
By the end of the changeout program, winter period ambient PM2.5 was approximately 20% lower than prechanegout levels. Reporting of wheeze and other asthma-related symptoms were lower in the postchangeout winter compared to the first winter period. Preliminary analysis across the 4 winter seasons found the odds ratio (and 95% confidence interval) for 5 μg/m3 reduction in PM2.5 and reporting of wheeze was 0.75 (0.56–1.00). Associations were also observed for reporting of cold (0.75 [0.60–0.94]) and bronchitis (0.46 [0.27–0.79]). Elevated risk estimates were also observed for some nonrespiratory symptoms for which there were no a priori associations anticipated.
Winter period ambient PM2.5 concentrations were substantially reduced following the community-wide wood stove changeout program. Preliminary analyses found associations between change in winter PM2.5 concentrations and reporting of some respiratory symptoms and infections. Findings of reductions in additional nonrespiratory symptoms suggest caution in interpreting these results.
This study was funded by the Health Effects Institute.© 2011 Lippincott Williams & Wilkins, Inc.