贵州万山汞矿区稻田土壤汞的分布及污染特征

受历史汞矿开采活动影响,万山汞矿区稻田遭受了严重的汞污染.为了查明万山汞矿区稻田土壤的汞污染现状以及评估其环境质量改善情况,系统采集了受汞矿区影响的五条主干河流沿岸稻田土壤进行汞含量分析,评价总汞和甲基汞污染程度及其生态风险,并与2008 年以来该区域稻田土壤汞数据进行对比.结果表明,研究区稻田土壤的总汞含量为0.21...

Temporal and Spatial Distribution and Pollution Characteristics of Mercury in Paddy Soils of the Wanshan Mercury Mining Area,Guizhou Province

Due to influences of historical mercury mining and other activities,paddy fields in the Wanshan mercury mining area had been seriously polluted by mercury.To understand the present mercury pollution situation of paddy fields and to evaluate the environmental quality improvement of paddy soils in the Wanshan mercury mining area,we systematically collected paddy soil samples along five main rivers of the area,analyzed their pollution degrees of total mercury and methylmercury,evaluated their ecological risks,and then compared with corresponding data of 2008.The results showed that the total mercury contents of paddy soils in the area ranged from 0.21 to 207 mg/kg,with a geometric mean of(4.26±4.83)mg/kg and the methylmercury contents ranged from 0.42 to 13μg/kg,with a geometric mean of(1.81±1.93)μg/kg,and that 59%of paddy soil samples were heavily polluted by mercury and 75%of paddy soil samples had the strong potential ecological risk of mercury.Compared with previous data,it was found that mercury contents in paddy soils showed a downward trend after 2012,reflecting the implementation effect of the local mercury source control.To avoid safety and health risks of the mercury pollution in paddy soils,besides the pollution source control,the remediation and risk control of paddy soils should be taken in the future.