Since the Clean Air Act Amendments of 1990 (CAAA), atmospheric concentration of local pollutants has fallen drastically. A natural question is whether further reductions will yield additional health benefits. Investigators in this project further this research by addressing two related research questions: (1) what is the impact of automobile driving (and especially congestion) on ambient air pollution levels, and (2) what is the impact of modern air pollution levels on infant health? These questions directly impact children living in congested, impoverished neighborhoods.
The research setting is California (with a focus on the Central Valley and Southern California) in the years 2002-2007. Using an instrumental variables approach that exploits the relationship between traffic, ambient weather conditions, and various pollutants, findings suggest that ambient pollution levels, specifically particulate matter, still have large impacts on weekly infant mortality rates. These results also illustrate the importance of weather controls in measuring pollution’s impact on infant mortality.