Air pollutants and sources associated with health effects

This paper provides four complementary perspectives on the understanding of the risk posed to health by particular sources of air pollution. These perspectives are based on contributions to a plenary session Pollutants and Sources Associated with Health Effects at the American Association for Aerosol Research meeting. Research that advanced understanding of source impacts is critical to the prospects for more refined air quality management that moves from the pollutant-oriented approaches in place for the criteria pollutants to more targeted strategies. Such research will also be needed in support of multipollutant air quality management strategies. Here, after beginning with a discussion of mobile sources (Ayala), we provide brief historical summaries of relevant research and future research directions framed around the core scientific research disciplines: exposure sciences (Brauer), toxicology (Mauderly) and epidemiology (Samet). Overall, we find that the overarching most important need is to put the regulatory cart behind the research horse, in the sense that the focus of research, funding permitting, should not be limited to supporting existing air quality regulations. We suggest that more informative research can be carried out using increasingly sophisticated tools and drawing on advancing biological knowledge. However, these tools need to be used and managed in an appropriate framework.