TRACKING MULTIPLE PATHWAYS OF HUMAN EXPOSURE TO PERSISTENT MULTIMEDIA POLLUTANTS: Regional, Continental, and Global-Scale Models

Widespread observations of organic pollutant compounds in vegetation, soil, animals, and human tissue have motivated research on more accurate characterizations of chemical transport over regional, continental, and global scales. Efforts to assess human and ecosystem exposure to contaminants from multiple environmental media have been evolving over the last several decades. In this review, we summarize the development and evolution of the multimedia mass-balance approach to pollutant fate and exposure evaluation and illustrate some of the calculations used in multimedia assessments. The concepts that form the foundation of Mackay-type mass-balance compartment models are described, and the ongoing efforts to use multimedia models to quantify human exposures are discussed. A series of case studies of varying complexity are used to illustrate capabilities and limitations of selected multimedia approaches. We look to the future and consider current challenges and opportunities in the field of multimedia contaminant fate and exposure modeling.