Assessing Smoke Exposure in Space and Time

Numerous toxic air pollutants compose smoke from biomass burning, including fine particulate matter (PM 2.5 ), nitrogen oxide (NO x ) and volatile organic carbon (VOC) emissions that contribute to ozone formation, carbon monoxide (CO), polycyclic aromatic hydrocarbons (PAH), formaldehyde, and metals. This chapter provides a conceptual framework and vocabulary related to characterizing human exposures to smoke, focusing on inhalation exposure at individual and population levels. We briefly describe fundamental concepts of exposure assessment relevant to air pollution from biomass burning. Studying exposure requires knowledge of both the receptors (e.g., how the stressor acts on the human body, relevant periods of susceptibility) and the ways in which the stressor presents at this interface (e.g., fate and transport of chemical agents, social patterns that affect exposures and access to mitigation, time and activity patterns). We present considerations for quantifying exposure to air pollution, specifically for developing geospatial assessments of exposure, the types of exposure metrics, and associated reporting error and uncertainty. An area of active research is to what extent PM 2.5 exposure from smoke is associated with various types of health outcomes as compared with fossil fuel combustion emissions and all other sources and if similar populations are susceptible. Finally, we discuss research needs for quantifying exposure to fire pollution.