Concentrations of Air Toxics in Motor Vehicle-Dominated Environments

This report describes research funded under HEI's Air Toxics Hot Spot program. Dr. Eric Fujita and colleagues characterized concentrations of mobile-source air toxics (MSATs) and other pollutants in potential Los Angeles County pollution hot spots, including on urban highways with a varying mix of gasoline- and diesel-powered traffic and sites at various distances from the highways and close to other roads. They conducted source apportionment using a chemical mass balance model to estimate the contributions of gasoline- and diesel-powered vehicles, and compared source contributions at the different sites.