Book excerpt: During this century we have experienced a shift in the leading causes of death from infectious diseases, such as pneumonia and influenza, to chronic diseases, such as heart disease and cancer. Whereas infectious diseases are often related to a single infectious agent, chronic diseases are often related to a combination of environmental (including occupational) chemical exposures and genetic factors. This valuable reference helps the reader to identify these chemical pollutants in environmental matrices such as air, water, food, and soil. It provides improved analytical methods to measure the pollutant, its metabolites, and its various possible adducts in humans. This book presents the latest work designed to assess potential exposure (environmental concentration and activity of pollutants), dose to humans, and a molecular basis for some of the affected biological mechanisms.