Monday March 9th, 4pm, Mann Hall 323
Abstract: Exposure assessment is an important component in the risk assessment process because it describes the degree of contact between a stressor (pollutant) and a receptor (human). For exposure to occur, the stressor and receptor must intersect in both space and time. Inhalation exposures may vary considerably from person to person because the concentrations of air pollutants often vary in both space and time, and people move through the environment. Credible exposure assessments, therefore, require knowledge of the temporal and spatial variations in pollutant concentrations and the time-activity patterns of individuals. Motor vehicles are a common way that people move through the environment, especially in the U.S. and in much of the developed world. For many years mobile sources emissions have been recognized as important contributors to poor air quality and several regulatory efforts have reduced emissions and the hazards posed by such emissions. As the population increases and metropolitan areas grow larger, though, so does the amount of time people spend driving on the expanding network of roadways that often reach into areas where we live, work and go to school. There has been continued interest in the hazards associated with exposures to mobile source emissions because studies find associations between mobile source exposures and various human health effects. This seminar will focus on the fundamental principles of exposure assessment to air pollutants with example applications for characterizing on-road and near-road human exposures to mobile source air pollutants. Results will be presented from recent studies performed by the U.S. Environmental Protection Agency and relevant studies from the scientific literature.