Air Pollution Mixtures

Most air pollution health research focuses on a single pollutant or treats other pollutants as confounders, although in reality we breathe a complex mixture. We explore methods to investigate multi-pollutant systems and estimate health response to simultaneous exposure of multiple pollutants. Although airborne particulate matter constitutes a complex mixture, particles are regulated and largely studied according to total mass, without regard to chemical structure. Policy-makers would benefit from information on which components or sources are most toxic. We identified regional and seasonal variation in health effects for particle mass. We hypothesize that some particles are more toxic than others due to their chemical composition, which exhibits similar spatial and temporal patterns as particulates’ health effects. Our current projects investigate which particle characteristics are most harmful, with respect to size, chemical structure, and source. As an example, we found that particles from vehicles are associated with low birth weight.