Pro-inflammatory potential of particles from residential wood smoke and traffic : importance of physicochemical characteristics

Abstract

Exposure to particulate matter (PM) has been associated with increased cardiopulmonary morbidity and mortality, and inflammation has been suggested as a mechanistic link between PM exposure and adverse health effects. Physicochemical properties such as size surface area and chemistry are thought to influence the negative effects of particles.<br> In this study, the physicochemical properties of particles from residential wood smoke and traffic were analysed by transmission electron microscopy techniques and bulk chemical analyses. In addition, the pro-inflammatory potential of particles from these two sources was compared in in vitro model systems, and the influence of physicochemical particle properties on the pro-inflammatory response was investigated.<br> In the in vitro experiments, particles from traffic induced a higher release of pro-inflammatory mediators, while wood smoke particles induced a greater reduction in proliferation. Thus, particles from these two sources may induce different biological effects, but be equally harmful. The organic fraction was the particle fraction that was found to exert the strongest influence on the biological responses. Reduction of the organic fraction of PM emissions could, therefore, be a useful approach for environmental strategies to reduce emissions of hazardous PM components.