Assessing dynamic exposure to air pollution

Accurate assessment of human exposures to air pollution (e.g., nitrogen dioxide and fine particulate matter) is critical to a wide range of geographic an health studies, such as modeling the association between air pollution exposure and health outcomes (e.g. asthma, premature mortality, and cancer), evaluating health impacts or disease burdens in different population groups, and determining environmental injustice that may be occurring with respect to exposures (Brunekreef and Holgate 2002). Methodologies of exposure assessment thus have significant implications for enhancing our understanding of and shedding light on how certain social issues can be addressed (e.g., how air pollution differentially affect different social groups). Health studies in the past typically assess air pollution exposure by assigning temporally averaged (e.g. annual mean) pollution concentration at people’s residential locations (Jerrett et al. 2005). However, air pollution exposure is much more complicated as the exposure process is determined by the interaction of two complex geographic processes: air pollution concentrations and people’s activity-travel patterns, both vary in space and time in highly complex ways.