Lead Isotopic Tracing of Coal-Based Anthropogenic Pollution in Agricultural Soils in Jianghan Plain, China

Tuesday, 16 December 2014
Julia N Daniel1, Samantha Ying1, Ray Zhao1, Jianwei Bu2, Yiqun Gan2, Yanxin Wang2, Dominik J Weiss3 and Scott E Fendorf1, (1)Stanford University, Stanford, CA, United States, (2)China University of Geosciences Wuhan, Wuhan, China, (3)Imperial College London, London, United Kingdom
The Chinese demand for energy is one of the greatest in the world, and the vast majority of it is generated through coal combustion – a process by which diverse pollutants are released into the atmosphere. Due to the relative proximity of croplands to power plants in much of China, these pollutants can be deposited onto agricultural soils via atmospheric transport. Relative amounts of lead (Pb) isotopes in airborne anthropogenic coal-based contaminants (fly ash) are currently understood. However, contaminants’ effects on agricultural soil composition are less clear. We investigate the prevalence of anthropogenic contaminants in cropland soils using lead (Pb) isotope ratios as a tracer. Surface soil samples and deep core samples, taken from Chinese field sites in proximity to a coal combustion plant, undergo an acid extraction process and lead (Pb) isotope concentrations are measured. The results of this study illustrate the extent to which airborne contaminants have entered cropland soils and integrated themselves into the chemical processes at work. They further expand our understanding of the impacts of human coal combustion activities on the biogeochemistry of agricultural soils.