Introduction to Mercury Special Issue

This special issue contains 11 papers derived from a topical session titled ‘‘The Impact of Mercury on the Global Environment’’, held in Reno, Nevada, at the 2000 Annual Meeting of the Geological Society of America (GSA). Mercury is of particular concern because of its toxicity, persistence in ecosystems, capacity to bio-accumulate, and global dispersion pattern. The GSA session brought together researchers addressing aspects of this global environmental problem. Topics discussed included natural and anthropogenic sources of mercury, its transport and cycling, the production of methylmercury, and its potential and actual uptake by organisms in mercury-impacted ecosystems. Interest in mercury in the US has been heightened by fish consumption advisories in many states. The 1990 amendments to the US Clean Air Act (CAA) identify mercury as one of several, potentially hazardous air pollutants. Subsequent reports by the National Academy of Sciences and the USA Environmental Protection Agency (EPA) single out mercury as having the greatest potential to impact human health of any of the pollutants identified in the CAA. In December 2000, the EPA announced it would seek to limit mercury emissions from US coalburning power plants, the only major anthropogenic point source not currently regulated. This determination was made after EPA analysis of weekly data on mercury contents in feed coals, and on the quantity and speciation of mercury in stack emissions, collected for US power plants during the1999 calendar year. This special issue includes an analysis by Quick et al. (DOI 10.1007/s00254-002-0622z) of the mercury content of US coals delivered to power plants, based on the EPA results. The behavior of mercury in wetlands and aquatic ecosystems is another important topic addressed in the GSA session and in this special issue. The paper by Marvin-DiPasquale et al. (DOI 10.1007/s00254-002-0623-y) determines rates of methylation and microbial cycling of mercury in San Francisco Bay sediments impacted by Gold Rush-era hydraulic mining debris. In the paper by Varekamp et al. (DOI 10.1007/s00254-002-0624-x), the authors show the chronology of mercury deposition in Connecticut wetlands and Long Island Sound sediments locally impacted by anthropogenic mercury sources. The study by Loukola-Ruskeeniemi et al. (DOI 10.1007/s00254002-0625-9) goes a step further, considering potential uptake of mercury from black shales by lakes and lake sediments, crayfish, fish and, ultimately, human residents of an area in eastern Finland. Several papers in this issue discuss the impact of mercury derived from past and present mining activities. Gray et al. (DOI 10.1007/s00254-002-0626-8) studied dispersion of mercury and methylmercury from an abandoned mercury mine in the Philippines, in close proximity to coastal settlements where residents consume a high proportion of fish and other seafood. Drude de Lacerda (DOI 10.1007/ s00254-002-0627-7) estimates the amount of mercury used worldwide in small-scale gold-refining operations. Papers by Rytuba (DOI 10.1007/s00254-002-0629-5), Miller and Lechler (DOI 10.1007/s00254-002-0628-6), and Gustin et al. (DOI 10.1007/s00254-002-0630-z) consider potential mercury sources, transport and cycling of mercury, and its atmospheric dispersal, respectively, as a result of historic gold mining or mercury mineralization. The papers by Abbott et al. (DOI 10.1007/s00254-0020631-y) and Susong et al. (DOI 10.1007/s00254-002-0632x) are important case studies of point-source mercury emission by a fluidized bed thermal-treatment calciner at Idaho National Engineering and Environmental Laboratory. These studies consider mercury deposition in soils and its potential re-emission from soils to the atmosphere, resulting from an atmospheric source whose mercury emission rate and operational parameters are known. The papers included in this special issue are illustrative of the complex nature of mercury dissemination in the environment. Understanding mercury dispersion and Received: 27 November 2001 / Accepted: 11 January 2002 Published online: 26 June 2002 a Springer-Verlag 2002