Lead isotopic fingerprinting as a tracer to identify the pollution sources of heavy metals in the southeastern zone of Baiyin, China

Bihong He; Xiaolan Zhao; Ping Li; Jianjun Liang; Qiaohui Fan; Xiangxian Ma; Guodong Zheng; Junli Qiu

doi:10.1016/j.scitotenv.2018.11.339

Lead isotopic fingerprinting as a tracer to identify the pollution sources of heavy metals in the southeastern zone of Baiyin, China

Sci Total Environ. 2019 Apr 10:660:348-357. doi: 10.1016/j.scitotenv.2018.11.339. Epub 2019 Jan 3.

Authors

Bihong He¹, Xiaolan Zhao¹, Ping Li², Jianjun Liang², Qiaohui Fan³, Xiangxian Ma², Guodong Zheng², Junli Qiu⁴

Affiliations

¹ Key Laboratory of Petroleum Resources, Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² Key Laboratory of Petroleum Resources, Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China.
³ Key Laboratory of Petroleum Resources, Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China. Electronic address: fanqh@lzb.ac.cn.
⁴ Key Laboratory of Petroleum Resources, Gansu Province, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China. Electronic address: jlqiu@lzb.ac.cn.

PMID: 30640103
DOI: 10.1016/j.scitotenv.2018.11.339

Abstract

Baiyin (Gansu Province, China) is a heavily industrialized city with non-ferrous metal mining, ore dressing, and chemical production. The surrounding district has suffered from serious heavy metals (HMs) contamination over half a century. In this study, a Pb isotopic approach was adopted to trace the sources of HMs and explore the environmental behaviors of HMs in the area surrounding Baiyin. HMs concentrations in topsoil showed a clear decrease as the distance from the ore district increased, which suggested that atmospheric transportation is one of the main pathways of HMs dispersal. The Dongdagou irrigation area was an exception where contaminated water from Dongdagou had been used for a long time. The plots of ²⁰⁶Pb/²⁰⁷Pb vs. ²⁰⁸Pb/²⁰⁶Pb and 1/Pb vs. ²⁰⁶Pb/²⁰⁷Pb from the topsoil samples could be described in terms of a binary mixing model with the two average ²⁰⁶Pb/²⁰⁷Pb end-members being (1) the mining and smelting activities (1.1494) and (2) the soil background (1.1992). The relative anthropogenic contribution quickly decreased from 88.3% in the ore district to 30.6% in the Yellow River irrigation area. These results suggested that HMs in the Baiyin District were mainly contributed by anthropogenic mining and smelting activities. The isotope ratios of ²⁰⁶Pb/²⁰⁷Pb in the sediments maintained a consistent low level from the ore district to the Yellow River irrigation area, thereby suggesting that HMs from anthropogenic sources could also be transported over a long distance in the river systems. Moreover, the positive correlation between S content and HMs concentrations in topsoil and sediment confirmed that the HMs mainly originated from the sulfide deposits and smelters.

Keywords: Anthropogenic activities; Ore district; Sewage irrigation; Smelter; Source identification.