沿海某省农村耕地土壤重金属含量调查

Investigation of Heavy Metals Pollution of Farmland Soil in a Coastal Province

目的调查沿海某省农耕土壤重金属含量并进行污染及生态风险评估。方法采用电感耦合等离子体—质谱法对沿海某省东部、北部、西部及中部地区380份农村耕地土壤样本中的Cd、Pb、Cr、Ni、Cu、Zn和As 7种重金属元素含量进行测定。以《土壤环境质量标准》(GB 15618-1995)为依据,采用单项污染指数法、内梅罗综合污染指数法对土壤重金属污染状况进行评价。采用Hakanson潜在生态风险指数法对土壤中重金属生态风险进行评估。结果该省农耕土壤中Cd的平均含量均较高。单项污染指数法评价结果显示:北部地区农耕土壤(PCd=2.862)Cd污染等级高于其它3个区,中部(PCd=1.896)、东部(PCd=1.634)及西部(PCd=1.056)达到轻度污染等级。其余6种重金属在4个区域的农耕土壤中均处在安全级别范围内。经内梅罗综合污染指数法评价:北部农耕土壤重金属污染较重,中部地区和东部地区重金属污染等级为轻度污染,西部地区农耕土壤重金属含量达到污染警戒级;全省农耕土壤重金属综合污染指数为1.31,总体受到轻度污染。Hakanson潜在生态风险指数评价结果显示:东部、西部和中部农耕土壤存在重金属生态风险危害,西部地区处于一般风险水平。结论该省农耕土壤总体受到轻度重金属污染,应当加强管理和防范工作。

Objectives To detect the heavy metal contents of farmland soil in a coastal province,evaluate the pollution hazard,and assess their ecological risk.Methods The contents of Cd,Pb,Cr,Ni,Cu,Zn and As in 380 farmland samples from 19 counties located in the east,north,west and middle area of the coastal province were determined by ICP-MS.According to ＂Environment Quality Standards for Soil＂（GB 15618-1995）,the evaluation was carried out by single pollution index and Nemerow index.And ecological risk was evaluated by Hakanson potential ecological risk index method.Results For the samples of farmland soil of the coastal province,the average contents of Cd were higher in reference to the criteria of GB 15618-1995 Safety Grade 2.Using single pollution index method,the pollution degree of Cd in north area was higher than the other 3 parts of area（P =2.862）.Middle（PCd=1.896）,east（PCd=1.634） and west（PCd=1.056） areas were at the light pollution level of Cd.The farmland soil of middle,north,east and west areas were within the range of safety grade in terms of other six heavy metals.Valued by Nemerow index,middle and east areas were at light polluted levels,north area was moderate and west area was at the alert level of heavy metal pollution.As estimated by Nemerow index,the overall comprehensive pollution index was 1.31,which indicated the farmland of the coastal province was slightly polluted by heavy metals.The heavy metals in the east,north and middle areas were at the corresponding risk level by Hakanson potential ecological risk index method.The farmland soil from west areas was at the moderate level of potential ecological risk.Conclusions The coastal province has been in light pollution by heavy metals,the administration should be strengthened to prevent the pollution.