Anthropogenic Pb contribution in soils of Southeast China estimated by Pb isotopic ratios.

Isotopic ratios were used to identify the source of Lead (Pb) contamination in rural soils from Southeast China. Enrichment of Pb in surface soils was detected from three sampling locations, with the 206Pb/207Pb ratio indicating recent anthropogenic input. The 206Pb/207Pb ratio from deeper soil profiles reflected the ratio from parent basalt. Mass fractions of anthropogenic-derived Pb for soil samples in the upper profiles was as high as 50%, implying that surface soils in the current study were impacted by anthropogenic activity. The 206Pb/207Pb and 208Pb/206Pb ratios were similar to anthropogenic sources including the combustion of coal, which has been common practice in the region for 2500 years. Considering the relatively short history of petroleum use in this area and the rural location of soils, anthropogenic Pb source from coal burning was considered to be the main cause of lead pollution.