东江流域农村土壤中多环芳烃的分布特征及其健康风险评估  

Polycyclic aromatic hydrocarbons in the rural soils of Dongjiang River Basin:distribution and human health risks

作　　者：郑太辉[1,2] 冉勇[1] 陈来国[3] 

机构地区：[1]中国科学院广州地球化学研究所,广东广州510640 [2]中国科学院大学,北京100049 [3]环境保护部华南环境科学研究所,广东广州510655

出　　处：《生态环境学报》2014年第4期657-661,共5页Ecology and Environmental Sciences

基　　金：国家自然科学基金-广东省联合基金项目(U1201235);面上项目(41073082)

摘　　要：为了解东江流域农村土壤多环芳烃的分布特征与人类健康风险，采集了30个不同土地利用类型农村表层土壤样品，进行采用索氏抽提法，硅胶/氧化铝（2：1）层析柱分离纯化，最后加内标经气相色谱-质谱仪定量解析的方法测定16种多环芳烃的含量。同时，测定了土壤中不同形态有机质包括总有机碳（TOC）、非水解性有机碳（NHC）、黑碳（BC）以及无定形有机碳（AOC）的含量。结果表明，土壤多环芳烃质量分数在24-238μg·kg-1之间，平均质量分数为107±60μg·kg-1。在16种多环芳烃中，萘、菲、荧蒽和苯并（b）荧蒽的含量最高，占总多环芳烃含量的比重依次为16%、20%、10%和10%。土壤中多环芳烃含量与TOC、NHC以及BC均具有极显著的线性关系（p〈0.01），三者斜率的大小顺序为BC〉NHC〉TOC（p〈0.01），表明土壤有机碳中的非水解性有机碳和黑碳在控制土壤中多环芳烃的分布、积累中发挥着重要的作用。土壤中多环芳烃含量与AOC的相关性不显著（p=0.29）。另外，健康风险评价表明儿童暴露的增量终身致癌风险（ILCRs）在可接受的安全范围内（ILCRs 〈10-6），而成人暴露的增量终身致癌风险则相对较高（10-6皮肤接触〉呼吸；而成人则为：皮肤接触〉误食土壤〉呼吸。In order to investigate the distribution and human health risks of the polycyclic aromatic hydrocarbons （PAHs） in the Dongjiang River Basin （DRB）, thirty rural surface soil samples with different land use types were collected. 16 USEPA priority PAHs were measured. PAHs were Soxhlet extracted, purified by silica/alumina （2：1） column, and finally determined by GC-MS with the addition of the internal standards. In addition, different organic matter including total organinc carbon （TOC）, nonhydrolyzable organic carbon （NHC）, black carbon （BC） and amorphous organic carbon （AOC） in the soils were also quantified. Total PAH concentrations ranged from 24μg·kg-1 to 238μg·kg-1 with an average value of 107±60μg·kg-1. Naphthalene, phenanthrene, fluoranthene and benzo[b]fluoracene were dominated, accounting for 16%, 20%, 10% and 10%, respectively. PAHs were highly significantly correlated with TOC, NHC, and BC （p〈0.01）, but not significantly correlated with AOC （p=0.29）. Moreover, their slopes differed significantly （p〈0.01） with an order： TOC （9.56） 〈 NHC （14.34） 〈 BC （249.7）. Therefore, it was indicated that the NHC fractions and the BC fractions played a more important role to the distribution of the PAHs in the soils. In addition, the human health risk assessment suggested that the cancer risk of child for exposure to PAHs in the soils were much lower than the baseline value of acceptable risk. But the cancer risks of adult were close to or slightly higher than the baseline value of acceptable risk （10-6dermal contact〉inhalation, but for adult： dermal contact〉ingestion〉inhalation.

关 键 词：东江流域 土壤 多环芳烃 分布 健康风险评价 

分 类 号：X131.3[环境科学与工程—环境科学] X822.1