摘要
以菜地、稻田、果园、旱地等4种典型土地利用为研究对象,通过413个土壤和对应作物样品的测试分析,探讨了研究区不同土地利用方式下土壤及其种植作物的As积累特征和对人体的健康风险。结果表明,稻田土壤As含量在5.69～148.5 mg kg-1,积累程度最高;果园土壤As含量在3.29～24.7 mg kg-1积累程度最低。研究区各土地利用类型下土壤As变异系数均在0.5以上,为中等变异性,各样点之间土壤As含量变化较大。研究区不同土地利用方式下,作物As含量差异较大,油料作物As平均含量最高达2.15 mg kg-1,旱地谷物和水果As含量均值最低,均为0.032 mg kg-1。根据研究区作物As的富集系数进行聚类分析,将研究区作物划分为4类,油料作物富集系数最高可划分为第1类,水稻划分为第2类,叶菜类蔬菜划分第3类,而富集系数较低的水果、瓜果类蔬菜、豆荚类蔬菜、根菜类蔬菜和谷物划分为第4类。依据JECFA推荐的ADI值和研究区居民膳食结构进行计算,结果表明研究区不同土地利用类型土壤As对人体健康的风险为稻田>菜地>旱地>果园,尤其是稻田土壤As对人体健康的风险较大,因水稻食用导致的居民As摄入量高达0.0043mg人-1d-1,已面临较大的健康风险,应采取积极措施对研究区作物的种植结构进行调整,并对土壤As污染的区域进行治理和修复。
A total of 413 soil samples and crops thereupon were collected from fields under four typical types of land use, i.e. vegetable field, paddy field, dry land and orchards, for analysis to explore characteristics of As accumulation in the soils and crops in the four different types of fields and its risk to human health. Results show that in the paddy soil arsenic concentration was in the range of 5.69 - 148.5 mg kg^ -1 , indicating the soil was the highest in As accumulation degree, whereas, in the orchards soil, it was in the range of 3.29 - 24.7 mg kg^-1 , indicating the soil was the lowest in As accumulation degree. However, soil As variation coefficients in all the soils were beyond 0. 5, being moderate in variabili- ty, regardless land use type Soil arsenic concentrations varied sharply between sampling sites. As concentrations in crops also varied greatly as affected by land use. On average, it reached as high as 2. 15 mg kg^-1in oil crops, and was the lowest, being 0. 032 mg kg^-1 in both dry land crops and fruits. Cluster analysis of the crop arsenic enrichment coefficients show that the crops in the study area could be divided into four groups. Oil crops were in Group I, the highest in crop arsenic enrichment coefficient, rice in Group Ⅱ, leaf vegetables in Group Ⅲand fruits, gourd, bean and root vegetables, and grain crops in Group Ⅳ, being the lowest in crop arsenic enrichment coefficient. Based on JECFA-recommended ADI value and dietary structure of the residents in the study area, hazard quotients of soil arsenic to human health were analyzed, showing an order of paddy 〉 vegetable field 〉 dry land 〉 orchard. Health risk posed by As in paddy soil was quite great, as the diet of rice led to ADI of As as high as to 0. 004 3 mg body ^-1day^-1and the people living in the study area were faced with high health risk. Active measures should be taken to readjust the cropping structure in the study area and to manage and remedy As-polluted soils.
出处
《土壤学报》
CAS
CSCD
北大核心
2011年第4期751-758,共8页
Acta Pedologica Sinica
基金
中央级公益性科研院所基本科研业务费专项资金(农业部环境保护科研监测所)项目和质检公益性研究专项(20091020)
