Stream-sediment samples collected within 1 km of the mercury mines studied contain mercury concentrations as high as 170 ?g/g, but sediments collected from the Humboldt River and regional baseline sites have much lower mercury contents, less than 0.44 ?g/g. Mine-waste calcine contains mercury concentrations as high as 14,000 ?g/g. The climate in the study area is arid, and due to the lack of mine-water runoff, water-leaching laboratory experiments were used to evaluate the potential of mine wastes to release mercury. Mercury and methylmercury concentrations were measured in mine wastes, stream sediments, and stream waters collected both proximal and distal from abandoned mercury mines to evaluate mercury contamination and mercury methylation in the Humboldt River system. Leaching, transport, and methylation of mercury in and around abandoned mercury mines in the Humboldt River basin and surrounding areas, Nevada.

Data suggest that past Hg mining activities have big influences on the increased Hg concentrations around abandoned sites and that atmospheric transfer is a major pathway for Hg cycling in these environments. It was found that average atmospheric Hg concentrations are higher than the background level in the area (0.1 microg Nm(-3)), reaching up to 203.7 microg Nm(-3) at 0.2 m above the ground level, close to the old smelting chimney at El Terronal mine site. This paper presents the synthesis of current knowledge about atmospheric Hg contents in the area of the abandoned Hg mining and smelting works at 'La PeÃ±a-El Terronal' and La SoterraÃ±a, located in Mieres and Pola de Lena districts, respectively, both within the Caudal River basin. Total Hg concentrations in the ambient air of these abandoned mine sites have been investigated to evaluate the impact of the Hg emissions. In Asturias, northern Spain, past mining operations have left a legacy of ruins and Hg-rich wastes, soils and sediments in abandoned sites.

Mercury concentrations are usually significant in historic Hg mining districts all over the world, so the atmospheric environment is potentially affected. Loredo, Jorge Soto, Jorge Alvarez, Rodrigo OrdÃ³Ã±ez, Almudena Atmospheric monitoring at abandoned mercury mine sites in Asturias (NW Spain).

Abandoned mine shelter fallout 76