Mercury-Contaminated Industrial and Mining Sites in North America: an Overview with Selected Case Studies

Mercury (Hg) has been used in highly diverse industrial and mining applications in North America, often with both intentional and unintentional releases to environmental media. While industries producing chlorine and caustic soda using the Hg-cell process, and the earlier extensive use of mercury in the mining of noble elements, have historically been among the most significant sources of such releases, other industries, including the US government, have also contributed substantially. Significant curtailment of intentional releases to aquatic systems in North America began about 1970, but it has only been recently that the legacies of past, and in some cases unrecognized continuing releases have begun to be addressed at many sites. This chapter briefly summarizes typical contamination scenarios at a variety of industrial sites and provides more detailed reviews of selected case studies which illustrate some remarkable consistencies among such sites.