Elevated selenium and other mineral element concentrations in soil and plant tissue in bone coal sites in Haoping area, Ziyang County, China

The Shuang'an site is the most serious selenosis site in Ziyang County, Shaanxi Province, which was the second selenosis site in China. In order to investigate the relationships between Se and other mineral elements and selenosis, bone coals, V-Mo ores, rocks, soils and plants were sampled from each site. The higher mean concentrations of Se, Mo, V and F in bone coals and ores may be the main environmental geochemical sources for soils and plants in this local ecosystem. Inappropriate revegetation in the Shuang'an mining site have posed the greatest risk of pollution, resulting in elevated mean concentrations of Se (16.9 μg/g), Mo (99 μg/g), V (1134 μg/g), F (1041 μg/g) and As (111 μg/g) in the soil directly derived from bone coal and V-Mo ore dumps. Most plants, which grow in the revegetated soil, contain elevated Se, Mo, V and F concentrations. The revegetated soil derived from bone coal and V-Mo ore dumps with excess Se, Mo, V and F concentrations in this ecosystem might have been essentially responsible for selenosis incidence of Shuang'an site in Ziyang County, Shaanxi Province. It is proposed that this selenosis area coincides with Mo, F and V toxicity based on their higher concentrations in rocks, soils and plants.