厦门市大气降尘中重金属生态风险评价与源解析

用电感耦合等离子体发射光谱(ICP-OES)对厦门市不同功能区大气降尘中12种重金属含量进行了分析,评价了重金属生态风险,并进行了源解析。结果表明,厦门市大气降尘中重金属Fe、Zn、Ti、Mn、Ba、Cu、Sr、Cr、Pb、Ni、V、Co的平均含量分别为47 843、4 515、2 797、800、780、448、199、179、151、41.39、27.85、11.22mg/kg。与土壤背景值相比,除Ti和V,其他元素存在不同程度的积累。富集因子结果显示,Cu和Zn在5个功能区都存在不同程度富集,其他元素为非富集状态。潜在生态风险评价结果显示,Cu的潜在生态危害程度很高,Zn较高,其他元素较低。所有功能区的重金属综合潜在生态风险程度都为极高:工业区最大、居住区最小。多元统计分析(因子分析和聚类分析)结果表明,厦门市大气降尘中重金属主要来源于工业污染和交通污染、土壤扬尘、燃烧活动,贡献率分别为42.5%、17.9%、14.2%。

Ecological Risk Assessment and Source Analysis of Heavy Metals in Dustfall of Xiamen City, China

Concentrations of 12 heavy metals in dustfall from different functional areas in Xiamen City, China, were determined by inductively coupled plasma optical emission spectrometry (ICP-OES) for potential ecological risk evaluation and sources analysis of heavy metals. The average concentrations of Fe, Zn, Ti, Mn, Ba, Cu, Sr, Cr, Pb, Ni, V and Co are 47 843, 4 515, 2 797, 800, 780, 448, 199, 179, 151, 41.39, 27.85 and 11.22 mg/kg, respectively. Except Ti and V, other elements present different accumulation degree compared with the background values of local soil. Results of enrichment factor indicate that Cu and Zn show different enrichment degrees in all 5 functional areas, while the other elements present no enrichment. Results of potential ecological risk assessment show that the potential ecological risk of Cu is high, followed by Zn. Other elements present low potential ecological risk. The comprehensive potential ecological risk of heavy metals in all functional areas is very high with the highest for industrial area and the lowest for residential area. Results of multivariate statistical analysis (factor analysis and cluster analysis) show that the heavy metals in the dustfall of Xiamen City mainly come from industrial and traffic pollution, soil dust and combustion activities with the contribution rates of 42.5%, 17.9% and 14.2%, respectively.