基于土地利用类型的土壤重金属区域生态风险评价:以珠江三角洲经济区为例  

Regional Ecological Risk Assessment of Soil Heavy Metals in Pearl River Delta Economic Zone Based on Different Land Uses

作　　者：宗庆霞 窦磊 侯青叶[1] 杨忠芳[1] 游远航 唐志敏 

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]广东省地质调查院,广东广州510080 [3]广东省地质局第三地质大队,广东韶关512023 [4]中国地质调查局南京地质调查中心,江苏南京210016

出　　处：《地球科学进展》2017年第8期875-884,共10页Advances in Earth Science

基　　金：中国地质调查局地质大调查项目"珠江三角洲土壤重金属地球化学成因与风险评价"(编号:12120115050401)和"珠江三角洲土壤重金属成因与生态风险评价"(编号:121201108000150012-10)资助~~

摘　　要：引用国外较成熟的2种风险评价模型,基于珠江三角洲经济区生态地球化学调查结果,结合研究区土地利用现状对珠江三角洲表层土壤(0~20 cm)8种重金属的生态风险进行评价,并采用GIS技术表征重金属在区域空间上的风险分布特征。结果表明:珠江三角洲的土壤重金属风险主要来自于As,Cd,Cu,Hg元素,Cr和Zn几乎不存在风险。23.89%的土壤慢性风险指数大于1,表明有引发慢性病的可能,风险高值区主要分布在第四系平原区。37.22%的土壤几乎不存在慢性风险,其空间分布与珠江三角洲花岗岩分布较为一致。致癌风险空间分布与慢性风险相似,25.68%的土壤致癌风险指数超过了美国环保署推荐的1×10-4。基于行政单元的人体健康风险区划表明番禺区和南沙区均存在较高的风险,应当引起足够重视。Based on the results of regional eco-geochemical survey in Pearl River Delta Economic Zone and the local land use patterns, two conventional risk assessment models are introduced to evaluate the ecological risk of eight heavy metals in the topsoil （0-20 cm） of Pearl River Delta. The spatial distribution characteristics of risk caused by metals in the region were characterized by GIS. Results show that As、Cd、Cu and Hg in the topsoil are the primary heavy metals posing risk to the Pearl River Delta while Cr and Zn are negligible. Meanwhile, 23.89% of soil samples have a hazard index of more than 1 which suggests that it is likely to cause chronic diseases in the region. The soils with high hazard index are mainly distributed in the Quaternary area. 37.22% of soil samples have a negligible chronic risk level, of which the spatial distribution is consistent with granite area. Moreover, the spatial distribution of carcinogenic risk is similar to chronic risk, where 25.68% of samples exceed the cancer risk index （1×10^-4） recommended by USEPA. Furthermore, the evaluation results presented at administrative units indicate that there are both higher chronic and cancer risk in Panyu and Nansha district where more attentions should be paid to.

关 键 词：土壤重金属 生态风险评价 珠江三角洲 土地利用类型 

分 类 号：P934[天文地球—自然地理学] X53[环境科学与工程—环境工程]