常州市农田土壤重金属污染及其潜在生态风险

Contamination situation and ecological risks of heavy metals in farmland soils of Changzhou

目的了解常州市农田土壤铅、镉、铬污染状况及其潜在的生态风险。方法于2013—2015年,采集常州市160块农田土壤样本并检测重金属铅、镉、铬含量。运用地累积指数(Igeo)和潜在生态风险指数(RI)对土壤重金属污染状况和生态风险进行评价。结果在160件农田土壤样品中,铅、铬的含量均合格;镉含量的超标率为8.75%(14/160)。铅、铬的土壤污染程度为无污染或轻度污染,4件土壤镉污染程度为中度污染,1件土壤镉污染程度为强污染。仅1件土壤综合潜在生态危害为强,其余土壤综合潜在生态危害为轻微。结论常州市部分农田土壤存在镉污染及潜在生态风险,应予以关注。

Objective To understand the contamianation situation and potential ecological risk of the heavy metals in farmland soil of Changzhou.Methods A total of 160 soils samples were collected in the farmland soil of Changzhou from 2013 to 2015,and the contents of lead,chromium and cadmium were determined.The geo-accumulation index(Igeo)and Hakanson potential ecological index(RI)were used for assessing the heavy metals contamination situation and potential ecological risk.Results The contents of lead and chromium in all samples were under the limit of Environmental Quality Standards for Soils(GB15618-1995),while in 8.75%(14/160)of samples,the contents of cadmium exceeded the standard.Based on Igeo,contamination of cadmium was moderate in four samples,and heavy in one sample,and lead and chromium were no or slight contamination.Based on RI,the potential ecological risk was strong only in one farmland soil sample,while slight in the others.Conclusion The contamination of cadmium and potential ecological risk in some farmland soil of Changzhou should be paid more attention to.