Endogenous and exogenous lead in soils of Yangtze River Delta region, China: identified by lead isotopic compositions and multi-elemental approaches

Abstract

Thirty typical soil profiles were sampled in Yangtze River Delta (YRD) region and analyzed for stable lead (Pb) isotopes and total concentrations of Pb and scandium (Sc). Pb isotopic compositions of A-horizon and C-horizon and Pb/Sc ratio were combined to estimate the amounts of endogenous and exogenous Pb accumulated in topsoil and identify possible sources. The results indicated that Pb exhibits a trend of accumulation in topsoil at regional scale. The isotopic composition of endogenous Pb is characterized by a narrow range of isotope ratios, varying with parent material, while that of exogenous Pb is characterized by a comparatively wide range of isotope ratios, varying with anthropogenic source. Coal combustion is probably the most important anthropogenic source of exogenous Pb in the soils of YRD region, as identified by isotopic ratio cross-plot combined with multi-elemental approaches.

Pb Pollution Stress in Alnus cremastogyne Monitored by Antioxidant Enzymes

“…According to the actual situation of soil pollution in some areas of the Yangtze River Basin [20], the soil Pb stress treatments in this experiment were set at five levels of 0 (CK), 50 mg/kg (T1), 100 mg/kg (T2), 200 mg/kg (T3), and 400 mg/kg (T4), and Pb was applied as Pb(CH 3 COO) 2 solution. To simulate the form of Pb emission in reality, the prepared Pb(CH 3 COO) 2 solution was divided into 5 equal portions and applied to the soil 5 times, once every 15 d. A plastic disc was placed under the pot to collect the possible leakage of Pb solution and we poured it back into the basin, and CK was watered with an equal volume of deionized water.…”

Anthropogenic mercury sequestration in different soil types on the southeast coast of China

“…Endogenous Hg is derived mainly from mineral weathering during the process of soil development, and exogenous Hg is mainly from the inputs of various anthropogenic sources. Calculation of anthropogenic Hg concentration in the horizon soil samples is mainly based on the methods of and Zhang and Luo (2011). The anthropogenic Hg ([Hg] exo ) was estimated by…”