The environment around the Laurentian Great Lakes region has been adversely affected by agricultural runoff, urban waste, industrial discharge, landfill leachate, and atmospheric deposition. Although there have been some improvements over the last 20 years, persistent toxic organic pollutants are now a serious problem. This book brings together what is known about the major classes of these pollutants in the Great Lakes. Each chapter reviews our knowledge of the extent of contamination of the various parts of the Great Lakes ecosystem (air, water, sediment, fishes, birds, etc.), what is known about the trends over time of this contamination, and knowledge about the mechanisms by which these pollutants are mobilized in the lakes.