Vanadium's journey from essential trace metal to emerging environmental pollutant in the Anthropocene era

Vanadium, previously considered a minor trace element, is gaining global environmental attention due to its expanding applications in metallurgy, energy storage, catalysis, and agriculture. With this rise in its industrial and technological uses, however, anthropogenic emissions of vanadium into the atmosphere, soils, and water bodies have also escalated. Unlike many heavy metals, vanadium exhibits complex redox behavior, primarily existing as V(IV) and V(V) species, which significantly impacts its environmental mobility, bioavailability, and toxicity. Vanadium exhibits complex behavior that necessitates an integrated research approach to better understand its various roles in scientific fields. This review summarizes the current knowledge on vanadium's environmental presence, transport, chemical forms, and ecological impacts, investigating primary sources like fossil fuel combustion and mining, as well as innovative technologies such as vanadium redox flow batteries. The study highlights vanadium's toxic effects on aquatic life, plants, and soil microbes, addressing risks linked to different chemical forms and chronic exposure gaps. It also discusses human exposure and regulatory disparities alongside challenges in analytical methods for measuring trace vanadium fluxes. In this review, "vanadium speciation" denotes the occurrence of vanadium across different oxidation states, coordination environments, and environmental phases. The study concludes by highlighting important research gaps in the areas of long-term ecological effects, microbiological interactions with vanadium, and the environmental consequences of recovering and recycling vanadium within the context of a circular economy. This places vanadium in the Anthropocene era as a trace metal that is evolving from an industrial element to an emergent environmental pollutant.