兰州市土壤-蔬菜系统典型重金属空间评价及健康风险分析  

Spatial analysis and the health risk assessment of typical heavy metal of soil-vegetable system in Lanzhou City

作　　者：齐鹏[1] 张仁陟[1] 张伯尧 王晓娇[1] 

机构地区：[1]甘肃农业大学资源与环境学院,甘肃兰州730070 [2]兰州市农产品质量监测中心,甘肃兰州730000

出　　处：《干旱区地理》2012年第1期162-170,共9页Arid Land Geography

基　　金：甘肃省环保世纪行基金项目;国家支撑计划(2007BAD88B07)共同资助

摘　　要：通过田间试验和室内分析相结合,对兰州市蔬菜和土壤中重金属Cd、Hg、Pb、As和Cr的含量进行测定并评估经食入途径对人体的健康风险,同时运用改进的物元模型综合评价兰州市三县四区土壤重金属污染并进行分区。结果表明:(1)兰州市菜地土壤中Cd、Hg、Pb、As和Cr的平均含量都高于背景值,存在明显的积累,但均低于《土壤环境质量标准》二级标准,适宜蔬菜种植。(2)单一重金属在不同调查区域内评价结果以"尚清洁"或"清洁"为主,只有Pb在七里河区为"轻污染",兰州市及各县区综合评价结果均为"尚清洁"。(3)与食品中污染物限量值(GB2762-2005)相比较,叶菜类蔬菜中Cd和Pb超标,瓜果类和根茎类Pb超标,葱蒜类Cr和Pb超标,茄果类和豆类都未超标。(4)健康风险评价表明兰州市居民经蔬菜途径摄入重金属量均未超出相应标准,儿童食用蔬菜的THQ要远远高于成人,存在较高的重金属健康风险,成人具有潜在风险。For the sake of investigating the heavy metal contamination of vegetable and exploring effects of soil properties on soil heavy metal accumulation in Lanzhou City, Gansu Province, the study was conducted in Yuzhong County, Gaolan County, Yongdeng County, Qilihe District, Anning District, Xigu District and Honggu District. On the basis of the field and laboratory experiments, the soil heavy metal pollution of Cr, Cd, Hg, Pb and As to the vegetable soil were quantitative analysis by employing mathematical model, and evaluation of soil heavy metal contamination and their distribution were analyzed by combining improved Matter Element Analysis Model and toxic response factor. At the same time, the heavy content in 118 samples involved 36 kinds of vegetable with 6 catego- ries, such as leaf vegetables, solanaceous fruits, gourd vegetables, rhizome vegetables, bean vegetables and allinm vegetables, were tested to conduct the health risk assessment of heavy metals and discuss the dominant or recessive risk to human health by Target hazard quotients （THQ）. The key results from the study were summarized as follows： The average content of Cd, Hg, Pb, As and Cr of vegetable soils in Lanzhou City were 0.22 mg · kg- 1,0.07 mg · kg-1, 26.40 mg · kg- 1, 11.23 mg · kg -1 and 65.47 mg ·kg-1, respectively. The contents of Cd and Hg were 1.57 and 2.69 times higher than the background values, indicating that Cd and Hg were the main pollution ele- ments and significant accumulated in soil. However, The contents of Cr, Cd, Hg, Pb and As lower than secondary standard of Soil Environmental Quality Standard, indicating that the fields were apt for vegetables. According to the improved Matter Element Analysis Model, the single assessment results of heavy metals in different surveyed dis- tricts were mainly ＂still clean＂ or ＂clean＂, except the concentration of Pb in Qilihe districts, being slightly pollu- ted. The integrated assessment results in surveyed districts and Lanzhou city were ＂still clean＂. This study fur

关 键 词：重金属 空间评价 物元模型 健康风险评价 兰州市 

分 类 号：X820.4[环境科学与工程—环境工程]