长江干流主要重金属污染状况及其来源解析

Pollution status and potential sources of main heavy metals in the main stream of the Yangtze River

沿长江干流从上游至下游采集84个点位样品,分析其表层水体重金属污染状况及可能来源。研究结果显示,长江干流重金属空间变化差异性明显:从上游至下游,长江干流Cu、Zn、Al浓度变化不明显,Mn和Ni浓度呈波动上升趋势,Cd和Pb浓度呈波动上升下降趋势。与已有研究相比,长江干流水体重金属污染呈不断增加趋势,人类活动对其影响明显。单因子污染评价显示,长江水体污染较轻,且对周边居民不存在致癌和非致癌健康风险。污染物来源解析显示,Cd、Pb、Ni可能主要来源于工业废气及废水;Al、Mn可能主要来源于自然过程及矿产开采;Cu可能主要来源于农业活动和矿产开采;Zn可能主要是农业和工业废水的混合来源。长江干流水体重金属污染不断加重的趋势需要引起关注。

In this study,we analyzed the pollution status and potential sources of heavy metals in the surface water of the main stream of Yangtze River.The results showed that the spatial distribution of metal concentrations from upstream to downstream of Yangtze River was significantly different,Cu,Zn and Al concentrations did not change significantly,Mn and Ni concentrations increased with fluctuation,while Cd and Pb concentrations increased and decreased with fluctuation.Heavy metal concentrations in the main stream of the Yangtze River increased compared with existing studies,which indicated the influence of human activities.However,the single-factor pollution evaluation showed that metals lightly polluted Yangtze River water and caused no carcinogenic and non-carcinogenic health risks to surrounding residents.The source analysis indicated that Cd,Pb and Ni may mainly be from industrial waste gas and wastewater,Al and Mn may be mainly derived from natural processes and mineral mining,Cu may be mainly derived from agricultural activities and mineral mining,Zn may mainly come from agriculture and industrial wastewater.Attention should be paid to the growing metal pollution of the main stream of Yangtze River because of anthropogenic activities.