Distribution and speciation of mercury in surface waters in mercury mining areas in Wanshan, Southwestern China

Abstract
Reactive, dissolved, particulate and total Hg concentrations were measured in surface waters originated from mercury mining areas to evaluate Hg contamination in fluvial systems in Wanshan district, Guizhou, China. Concentrations of total Hg in water samples varied from 17.3 ngl ^-1 to 585.8 ngrl ^-1 and were elevated comparing to total mercury concentrations in natural water. The total dissolved Hg concentrations usually ranged from 12.5 to 52.0 ngl ^-1, reactive Hg varied from 1.2 to 5.3 ngl ^-1, and particulate Hg changed between 3.5 and 533.8 ngl ^-1. The highest value of total Hg content occurred in a stream which is contaminated by leachate from the historic abandoned gangue piles was up to 585.75 ngl ^-1. It is suggested that the fluvial systems in Wanshan area were heavy contaminated due to long life of the mining operation and to Hg release from the waste even after the mining activity has been ceased.