Contaminant fate models to support the sustainable use of chemicals in North America

This thesis describes an evaluation and analysis of multimedia mass balance models of contaminant fate in the environment. Two existing models are applied to describe the fate of contaminants on a regional geographic scale, and background chemical contamination is identified as an important contributor to environmental contamination levels. An analytical method for analysing sensitivity and propagation of variance in chemical fate models is described. Two novel regionally segmented models for the Canadian and the North American environment are developed and described. As an illustration, a dynamic mass budget for the persistent organochlorine pesticide toxaphene is presented accounting for all usage, transport and fate processes in North America between 1945 and 2000. The utility of mass balance models as a decision support framework to encourage co-operative chemical management on continental and global scales is discussed.