Estimating daily nitrogen dioxide level: Exploring traffic effects

Abstract

Data used to assess acute health effects from air pollution typically have good temporal but poor spatial resolution or the opposite. A modified longitudinal model was developed that sought to improve resolution in both domains by bringing together data from three sources to estimate daily levels of nitrogen dioxide (${\mathrm{NO}}_2$) at a geographic location. Monthly ${\mathrm{NO}}_2$ measurements at 316 sites were made available by the Study of Traffic, Air quality and Respiratory health (STAR). Four US Environmental Protection Agency monitoring stations have hourly measurements of ${\mathrm{NO}}_2$. Finally, the Connecticut Department of Transportation provides data on traffic density on major roadways, a primary contributor to ${\mathrm{NO}}_2$ pollution. Inclusion of a traffic variable improved performance of the model, and it provides a method for estimating exposure at points that do not have direct measurements of the outcome. This approach can be used to estimate daily variation in levels of ${\mathrm{NO}}_2$ over a region.

Published in at http://dx.doi.org/10.1214/13-AOAS642 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org)