Deng Wenbo, Li Xuxiang, An Zhisheng, Yang Liu
School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, 710049, China.
Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, 710061, China.
Arch Environ Contam Toxicol. 2016 Nov;71(4):500-508. doi: 10.1007/s00244-016-0317-1. Epub 2016 Sep 23.
Economic reforms in China since 1978 have promoted nationwide socioeconomic advancement but led to a considerable amount of environmental pollution. The distribution and sources of Pb in a typical peri-urban industrial part of Baoji, China, were assessed by determining the Pb contents and isotopic compositions in 52 topsoil samples from the study area. The topsoil samples were polluted averagely with 40.88 mg Pb kg, was 1.86 times higher than the Pb content of local background soil (22.04 mg kg). Pb isotopic compositions were determined by analyzing samples prepared using total digestion and acid extraction methods. Radiogenic isotopes contributed more to the Pb concentrations in the acid extracts than in the total digests. This was shown by the Pb and Pb ratios, which were 0.845-0.88 and 2.088-2.128, respectively, in the acid extracts and 0.841-0.875 and 2.086-2.125, respectively, in the total digests. This indicates that anthropogenic sources of Pb could be identified more sensitively in acid extracts than in total digests. The Pb isotope ratios showed that burning coal and smelting ore are the predominant anthropogenic sources of Pb in the study area, i.e., a lead-zinc smelter and a coking plant are major sources of Pb in the study area.
自1978年以来，中国的经济改革推动了全国社会经济的发展，但也导致了大量的环境污染。通过测定研究区域内52个表层土壤样品中的铅含量和同位素组成，对中国宝鸡一个典型的城郊工业区域的铅分布和来源进行了评估。表层土壤样品平均受到40.88毫克/千克铅的污染，是当地背景土壤铅含量（22.04毫克/千克）的1.86倍。通过分析采用全消解和酸提取方法制备的样品来测定铅同位素组成。与全消解物相比，放射性同位素对酸提取物中铅浓度的贡献更大。酸提取物中的²⁰⁶Pb/²⁰⁴Pb和²⁰⁷Pb/²⁰⁴Pb比值分别为0.845 - 0.88和2.088 - 2.128，全消解物中的这两个比值分别为0.841 - 0.875和2.086 - 2.125，这表明在酸提取物中比在全消解物中能更灵敏地识别铅的人为来源。铅同位素比值表明，燃煤和矿石冶炼是研究区域内铅的主要人为来源，即一个铅锌冶炼厂和一个焦化厂是研究区域内铅的主要来源。
