Pollution characteristics and their comparative study of heavy metals in the gold and iron mine soil of the upstream area of Miyun Reservoir, Beijing
北京市密云水库上游金铁矿区土壤重金属污染特征及对比研究

The distribution and cumulative characteristics of heavy metals in different mines and surrounding soil caused by ore dressing and smelting activities were different. In order to investigate the geochemical characteristics and pollution status of heavy metals in the upstream areas of Miyun Reservoir, the soil samples from typical gold and iron mines were analyzed by the geochemical method and the Geoaccumulation Index was used to evaluate the pollution status of heavy metals. The results showed that, the metal concentrations in the Gold and Iron mine soil samples exceeded the background levels in Beijing except for As, and the content of heavy metal in gold mine soil was higher than that of iron mine soil. Moreover, correlation analysis indicated that significant correlations existed among Pb, Zn (p<0.01), Cr, OM (p<0.05) and Cu, while significant negative correlations existed among Pb (p<0.01), Hg (p<0.05) and pH in gold mine soil. There were no significant correlations among metals in iron mine soil. In addition, heavy metals in gold mine tailings were significantly higher than those in iron ore tailings, which was consistent with the soil pollution status in mines. The Geoaccumulation Index suggested that heavy metals in both soil samples were very serious and the pollution degree of gold mine was higher than that of iron mine. The pollution degrees of gold mine soil samples was ordered as Pb>Hg>Cd>Cr>Cu>Zn>Co>As, while Pb>Cd>Cr>Co>Cu>Zn>Hg>As for iron mine soil samples. The results can provide scientific basis for the effective monitoring and management of heavy metal pollution in different metal mines within this region.