Environ. Sci. Technol. 2004, 38, 4285-4292
Mercury Speciation and Microbial Transformations in Mine Wastes, Stream Sediments, and Surface Waters at the Almade´ n Mining District, Spain J O H N E . G R A Y , * ,† M A R K E . H I N E S , ‡ PABLO L. HIGUERAS,§ ISAAC ADATTO,‡ AND BRENDA K. LASORSA| U.S. Geological Survey, P.O. Box 25046, MS 973, Denver, Colorado 80225, University of Massachusetts Lowell, Department of Biological Sciences, Lowell, Massachusetts 01854, Universidad de CastillaLa Mancha, Plaza M. Meca 1, 13400 Almade´n, Spain, and Battelle Marine Sciences Laboratory, 1529 West Sequim Bay Road, Sequim, Washington 98382
Speciation of Hg and conversion to methyl-Hg were evaluated in mine wastes, sediments, and water collected from the Almade´ n District, Spain, the world’s largest Hg producing region. Our data for methyl-Hg, a neurotoxin hazardous to humans, are the first reported for sediment and water from the Almade´ n area. Concentrations of Hg and methyl-Hg in mine waste, sediment, and water from Almade´ n are among the highest found at Hg mines worldwide. Mine wastes from Almade´ n contain highly elevated Hg concentrations, ranging from 160 to 34 000 µg/g, and methylHg varies from
