Establishment of geochemical baseline and multiple assessment of vanadium pollution in sediment cores from the two cascade reservoirs, North China

Vanadium (V) is a potential toxic pollutant, and thus, V pollution in reservoir sediment should be scientifically evaluated because reservoirs are the main source of drinking water in China. However, the pollution assessment of V in reservoir sediment is often overestimated or underestimated due to the limitation for selecting local background values. In this study, the selection of the V background value in sediments was based on regional geochemical baseline (RGB) model. Multiple methods including geo-accumulation index (Igₑₒ), potential ecological risk index (EI), and health risk assessment were applied to evaluate V pollution in sediment cores collected from the Panjiakou–Daheiting Reservoirs (PDR). The results show that the mean value of V concentrations in the PDR sediment cores was 92.86 mg/kg (57.69–141.19 mg/kg), which is higher than the soil background in Hebei Province and stream sediment values in China. V concentrations in the Panjiakou Reservoir were higher than those in the Daheiting Reservoir. The RGB value of V was 96.33 mg/kg in the PDR sediments. A comparison of the V concentrations and RGB values in the sampling sites indicated that half of these sites are impacted by anthropogenic inputs. Among the sites influenced by human activity, the average anthropogenic contribution was 9.9%, suggesting that majority of V in the PDR sediments originated from natural source. The pollution assessments of V were evaluated using Igₑₒ and EI with RGB as the background value, and results indicated that the sediments in the PDR were not polluted with V. The environmental impact assessment model was also established for calculating V accumulation in fish due to sediment resuspension. Then, health risk assessment model was applied to further calculate the health risk to residents due to fish consumption. The evaluated target hazard quotient demonstrated that local fish consumption produced no adverse effect on human health during sediment disruption.