新罗城区道路灰尘重金属Pb、Cd的污染研究

Contamination Assessment of Lead and Cadmium in Street Dust of Xinluo

对龙岩市新罗城区道路灰尘重金属铅(Pb)和镉(Cd)含量进行了研究分析,并采用Hakanson潜在生态危害指数评价重金属污染水平及其潜在的风险。结果表明,新罗区各功能区路段灰尘重金属Pb和Cd的平均含量分别为300 mg/kg和1.58 mg/kg,均显著高出国家土壤重金属环境背景值。其中新罗区街道灰尘重金属Pb含量随季节变化显著的有交通拥堵区和商业区,而Cd含量随季节变化显著的有工业区。Cd的平均污染系数Ci f高达16.3,潜在生态危害指数Ei r平均值达488,超出极强生态危害水平;Pb的Ci f为11.5,Ei r平均值为57.6,达到中等生态危害水平。综合潜在生态危害指数RI依次为:交通拥堵区(723.66)>工业区(658.80)>城市主干道(529.04)>商业区(489.54)>校园区(483.15)>城乡结合处(386.78),交通拥堵区和工业区达到很强生态危害水平,其他街道灰尘重金属污染达到中等生态危害水平。

The concentrations of heavy metals （Pb, Cd） in street dust were investigated in six different streets of Xinluo, Longyan City. The pollution levels and potential ecological risk of heavy metals were assessed by the methods of potential ecological risk index suggested by Hakanson. The results showed that heavy metal concentrations in street dust from different streets of Longyan City were all higher than soil background values in China, with average concentrations of Pb （300mg/kg） and Cd （1.58mg/kg）. The heavy metals Pb content changing with the seasons obviously in street dust of Longyan City were Jiuyi Road and Denggao Road, while the content of Cd changing with the seasons obviously was Gongye Road. The average pollution index （Cif） of Cd reached 16.3, and the average potential ecological risk index （Eir） reached 488 （extremely strong risk level） in all six streets. Cif of Pb was 11.5, Eir of Pb reached 57.6 respectively, belonging to moderate risk level. The calculated results of integrated potential ecological risk index （RI） revealed that the order of RI were Traffic congestion area （723.66）〉Industrial area （658.80）〉Major traffic arteries （529.04）〉Commercial district （489.54）〉School District （483.15）〉Joint of urban and rural areas （386.78）. The traffic congestion area and industrial area have reached a very strong risk level, and the other areas have reached amoderate risk level.