大宝山矿区周边大气重金属来源与风险评估

Sources and risk assessment of atmospheric heavy metals in the vicinity of Dabao Mountain mining area

为认识大宝山多金属矿区周边大气PM_(2.5)中重金属的污染特征及潜在生态风险和健康风险,于2022年8月20日~9月10日和10月18日~11月8日,在翁源县铁龙镇铁龙中学采集和分析了大气PM_(2.5)中的Al、Ti、Cr、Mn、Ni、Cu、Zn、As、Mo、Ag、Cd、Sn、Sb、Tl和Pb等15种重金属.利用正定因子矩阵(PMF)模型结合相关性分析进行相关重金属的来源解析,并运用潜在生态风险模型、健康风险模型进行风险评价.分析结果显示,大气PM_(2.5)中Al、Zn、Pb和Mn四种金属含量居前4位,占已测金属总浓度的87.8%,平均浓度分别为:112.70,68.53,26.82和11.96ng/m^(3),其余重金属的平均浓度范围为0.12~7.99ng/m^(3).不同金属元素季节分布差异与不同风向背景下不同污染源的排放影响有关.大气PM_(2.5)中重金属主要有6个来源,分别为水泥生产(13.8%)、金属冶炼(24.6%)、扬尘源(13.7%)、污泥处置(19.4%)、交通源(9.4%)和自然源与农业源的复合源(19.1%).生态风险和健康分析评价结果显示,研究区重金属综合生态风险等级为强烈,Cd属于极强生态风险,Sb属于强烈生态风险,其余重金属属于轻微生态风险.重金属的总体非致癌风险较低;Cr致癌风险显著,As和Cd具有一定致癌风险.

To understand the pollution characteristics and potential ecological and health risks of heavy metals in atmospheric PM_(2.5) around Dabaoshan polymetallic mining area,PM_(2.5) samples were collected and analyzed for 15 heavy metals including Al,Ti,Cr,Mn,Ni,Cu,Zn,As,Mo,Ag,Cd,Sn,Sb,Tl and Pb from August 20 to September 10,2022 and October 18 to November 8,2022,at Tielong Middle School,Tielong Town,Wengyuan County.The positive matrix factorization(PMF)model was utilized in conjunction with correlation analysis was to identify the source of relevant heavy metals.Additionally,risk assessments were conducted employing both the potential ecological risk model and health risk model.The findings revealed that out of the fifteen metals analyzed in atmospheric PM_(2.5),Al,Zn,Pb,and Mn exhibited the highest concentrations,collectively accounting for 87.8%of the total measured metal concentration.Their average concentrations were determined as follows:Al(112.70ng/m^(3)),Zn(11.96ng/m^(3)),Pb(68.53ng/m^(3))and Mn(26.82ng/m^(3)).The remaining heavy metals displayed average concentrations ranging from 0.12ng/m^(3) to 7.99ng/m^(3).Variations in seasonal distribution of different metal elements were influenced by the emission from different pollution sources under varying wind directions.Atmospheric PM_(2.5) primarily contains heavy metals originating from six main sources:cement production(13.8%),metal smelting(24.6%),dust sources(13.7%),sludge disposal(19.4%),traffic sources(9.4%),and a composite source of natural sources and agricultural sources(19.1%).The results of the ecological risk and health analysis evaluation showed that the comprehensive ecological risk level of heavy metals in the study area was classified as“strong”.Specifically,Cd posed an“extremely high”ecological risk,Sb exhibited a“strong”ecological risk,while the remaining heavy metals posed a“slight”ecological risk.The overall non-carcinogenic risk from heavy metals was relatively low.However,Cr presented a significant carcinogenic risk,and both As and Cd carried certain carcinogenic risks.