Sediment Flux, Coastal Development, and Industrial Pressure Drive the Historical Vanadium Concentrations in the East China Sea and Two Bays of Shandong

Vanadium's historical changes in coastal areas arelimited. The vanadium concentrations and variations in bays are highlyimpacted by sediment flux and large-scale anthropogenic projects.Urbanized and industrial development have gradually polluted coastalsediments. Vanadiumis a versatile element gaining significant interestdueto its distribution, concentrations, accumulation, and risks. Itshistorical evolution in bays with substantial human populations andindustrial development that use vanadium-related products is essentialto evaluate environmental pollution events and the pressure on naturalecosystems. Vanadium concentrations in four sediment cores from JiaozhouBay (JZB), Laizhou Bay (LZB), and the East China Sea (ECS) were analyzedusing inductively coupled plasma optical emission spectrometry. Vanadiumwas higher in the open sea than in a semienclosed bay; the highestconcentrations were found in the ECS (98.01-131.70 & mu;gg(-1)), followed by LZB (66.35-104.33 & mu;gg(-1)) and JZB (34.95-75.58 & mu;g g(-1)). Vanadium concentrations in LZB and ECS showed drasticfluctuations and followed trends similar to those of sediment fluxescaused by anthropogenic activities and the natural courses of thetwo largest rivers in China, the Yangtze River and the Yellow River.Despite higher concentrations of vanadium in the ECS and LZB, thepollution indices indicated uncontaminated to low-contaminated habitats.Conversely, vanadium concentrations in the JZB illustrate the significantimpacts of industries and coastal development, principally after the1980s. Likewise, the high enrichment and pollution indices suggestthat vanadium emission, migration, and circulation of JZB occur atconcentrations beyond its natural threshold..