摘要
【目的】城市化是中国当前最显著的特征之一,在城市建设过程中,一些临时闲置土地常被用于农作物种植,然而土壤利用属性的变化可能导致这些作物种植地重金属含量增加,给农产品品质与安全带来风险。为此,对昆明呈贡新区零散分布的28块作物种植地进行了重金属污染调查与评估。【方法】对各种植地进行调查取样与重金属含量分析,以昆明市重金属含量背景值为参考,计算了各取样点Cu、Ni、Pb、Zn的单因子污染指数与内梅罗综合污染指数,利用Hankanson指数法计算了各样点的潜在生态风险指数,并基于Moran指数计算了各样点重金属含量的空间分布情况。【结果】各土样内梅罗综合污染指数范围为1.39~3.43,表现出不同程度的重金属污染;由于所调查的各金属元素毒性响应系数较低,反映出轻微潜在生态风险。土壤中Cu平均含量为背景值的2.77倍,是国家土壤环境质量二级标准的1.68倍,空间变异较大并体现出显著的空间自相关,说明人为因素(如城市建设过程中含重金属粉尘的沉降、汽车尾气、废水排放等)是导致土壤铜含量超标的重要原因。【结论】城市建设可能带来土壤重金属污染,为此有必要采取措施以减少由于城市建设所导致的“耕地”重金属污染问题,禁止重污染区域进行农业产生,以保障食品安全和民众健康。
【Objective】Urbanization is currently one of the most significant features in China.In the progress of urbanization,some lands in the newly-built city that not developed currently are left for planting crops,while the change of land use poses new threat for farming,especially the soil heavy metal(SHM)pollution.In the present paper,taking Chenggong New District,Kunming as an example,we investigated the status of SHM pollution across 28 farmlands in Chenggong.【Method】The contents of soil Cu,Ni,Pb,and Zn were analyzed.Single factor pollution index(Cu,Ni,Pb,Zn),Nemerow integrated pollution index and Hankanson potential ecological risk index for each farmland were calculated.Spatial autocorrelation for each heavy metal was investigated based on Moran’s I.【Result】Nemerow integrated pollution index ranged from 1.39-3.43,indicated the different extent of SHM pollution.The potential ecological risk index was small due to the low toxicological factors across the investigated heavy metals.The average Cu content was 2.8 times for the background value and 1.68 times for the national soil quality standard(Ⅱ),besides,strong spatial autocorrelation and variation across the samples indicated the possible human influence.【Conclusion】These types of farmlands should be regulated and some heavy polluted lands should be prohibited for agricultural production to ensure the quality and safety of agricultural products.
作者
徐武美
许俊
何翰宇
李思民
许庆豪
蜂建军
李静
王昆艳
官会林
XU Wu-mei;XU Jun;HE Han-yu;LI Si-min;XU Qing-hao;FENG Jian-jun;LI Jing;WANG Kun-yan;GUAN Hui-lin(School of Energy and Environment Science,Yunnan Normal University,Yunnan Kunming 650500,China)
出处
《西南农业学报》
CSCD
北大核心
2020年第10期2378-2383,共6页
Southwest China Journal of Agricultural Sciences
基金
国家自然科学基金项目(31901126,41661069)
云南省应用基础研究计划项目(2019FD112)
云南师范大学大学生科研训练基金项目(ky2017-139,ky2019-150)。
关键词
城市化
重金属
土壤质量
污染评价
Urbanization
Heavy metal
Soil quality
Pollution evaluation
