Watershed seasonality regulating vanadium concentrations and ecological risks in the coastal aquatic habitats of the northwest Pacific.

Highlights

• Concentrations in water near vanadium-related industries are up to 54.45% higher.

• Seasonal variations in the vanadium concentrations linked with vanadium adsorption capacity.

• Vanadium concentrations in both study areas higher than those found across China.

• Medium and high ecological risks were estimated for both bays.

Abstract

Vanadium is a component of different natural and industrial products and a widely used metal, which, nonetheless, has only garnered attention in recent years owing to its potential risks. Six sampling trips were conducted over different seasons and years, collecting 108 samples from rivers and 232 from the bays and analyzed using high-precision inductively coupled plasma mass spectrometry. This study investigated the sources, spatiotemporal characteristics, and risks of vanadium in the aquatic ecosystems of two typical bays of the Northwest Pacific that have strong links with vanadium-related industries. Likewise, the health and ecological risks were assessed using probabilistic and deterministic approaches. Overall, vanadium concentrations were higher in Jiaozhou Bay (JZB: 0.41–52.7 μg L⁻¹) than in Laizhou Bay (LZB: 0.39–17.27 μg L⁻¹), with concentrations higher than the majority of the worldwide studies. Vanadium-realted industries significantly impacted (p < 0.05) the metal concentrations in the rivers with 54.22% (40.73–150%) and 54.45% (27.66%–68.87%) greater concentrations in JZB and LZB rivers. In addition, vanadium exhibited significant seasonal variation, and higher values were quantified during the monsoon period at LZB owing to the greater catchment area. Impacted by smaller freshwater inputs, the post-monsoon period had substantial impacts on JZB, and vanadium in the rivers and bays was significantly higher during the winter. Despite some concentrations being higher than that indicated in the drinking water guidelines established by China, vanadium presents low to null risks to the population as per both approaches. Last, species with limited resilience are likely to face medium to high risks, with an incidence of 65–93% using the probabilistic method and 52–97% using the deterministic assessment.

Introduction

Heavy metals are part of numerous products and minerals at variable concentrations, and even essential metals for humans, such as Cu, Mn, and Cr, yet are toxic in excessive amounts (Rubio Armendáriz et al., 2015). Vanadium is among the most versatile elements used in industry. It is found in natural products, coal, oil, minerals, and other manufactured materials, alloys, chemicals, and fuel (Huang et al., 2015). Several industries that manufacture and utilize these products are located around the globe, with a particular incidence in coastal areas (Bai et al., 2021). Coastal regions throughout the world experience high anthropogenic pressure due to agricultural, urban, and industrial development. At the same time, aquatic ecosystems encounter a highly polluted state driven by the exchange of organic and inorganic elements with the aquatic system (Hope, 2008; Jones and Voogt, 1999). Owing to their applications and benefits, vanadium and elements like lithium or titanium have exceeded the threshold of economic importance and supply risk indicators. They have been considered critical raw materials in the European Union since 2017 (Commission, 2020). Despite multiple natural and anthropogenic sources of vanadium, research often excludes vanadium from core analysis and investigation (Tulcan et al., 2021b); hence further analysis is required to understand its safety and proper regulation (White and Levy, 2021).

In marine environments, vanadium is the second most abundant trace element, with an average concentration ranging between 30 and 35 nM (1.528 $\mu g$) in the form of the ion pair $N{a}^{+}\left[H_{2}V{O}_4^{-}\right]$ (Rehder, 2013) and a residence time of ∼50,000–100,000 years (Schlesinger et al., 2017). Approximately 3 × 10⁹ t of vanadium are present in seawater (average $2\mu L^{-1}$), significantly higher than other critical elements like Galium or Cobalt (∼1.2 $ng·L^{-1}$). Studies in the North Atlantic revealed that dissolved vanadium is the dominant form (Riley and Taylor, 1972), showing a conservative distribution in open ocean seawater (Jeandel et al., 1987), with a mean concentration of 39.3 $nmol·k{g}^{-1}$ ranging between 35 and 45 $nmol·k{g}^{-1}$ (Emerson and Huested, 1991). Nonetheless, a non-conservative behavior of vanadium oxyanions also occurs in estuarine environments (Bauer et al., 2017; O'Connor et al., 2015) and coastal seas (Wang and Sañudo Wilhelmy, 2009). Ion exchange by scavenging terrigenous particles (Shiller and Mao, 1999), ferric oxyhydroxide particles (Frohne et al., 2015; Tsadilas and Shaheen, 2010) and manganese oxides (Shaheen et al., 2019) controls some of these behavioral changes. In freshwater environments, the average concentration was estimated at around 0.7 $\mu g·L^{-1}$ (Gaillardet et al., 2014), which is significantly higher than that of other elements. Rivers are valuable media due to their roles in multiple daily activities and as a direct source of trace metals and nutrients to coastal areas.

A significant agent of pressure-changing vanadium concentration is atmospheric deposition, constantly loading vanadium in water bodies, raising concerns regarding the integrity of aquatic environments (Blazina et al., 2017). Similar contamination media include soil erosion and runoff (Zhang et al., 2020), road dust (Mummullage et al., 2016), and wastewater (Leiviskä et al., 2015) that transport pollutants from freshwater to marine ecosystems. Therefore, metals and other pollutants enter the environment via multiple different pathways, which can disrupt the aquatic ecosystem and harm the population (Guo et al., 2022). The solution chemistry of vanadium is a function of the different environmental factors and local redox conditions. Colloidal or particulate Fe explained the vanadium concentrations in streams (Wällstedt et al., 2010), while weathering and source rocks have more substantial relationships with vanadium concentration in major rivers (Shiller and Boyle, 1987). Because vanadium species are, in general, anionic, low pH (pH < 8) maximizes sorption, which is then reduced with increasing pH (ARMCANZ, 2000). In seawater, the redox potential of the V(V)–V(IV) pair is higher than that of Fe(III)–Fe(II) (Bonatti et al., 1971).

Vanadium benefits for species are limited, yet concentrations around 0.2–29 $\mu g·L^{-1}$ have been suggested to be beneficial for cell growth (Veschetti et al., 2007). Nonetheless, it is species-specific, and risks to freshwater species could also exist at values around 0.01–2.8 $\mu g·L^{-1}$ (Smit, 2012). Sea urchin embryos experience alterations during the development and the mineralization process, principally by activating the cellular stress response (Chiarelli et al., 2021). Zebrafish (Danio rerio), a common model organism, highlighted the toxicity of some byproducts containing vanadium, such as water-soluble carbon black waste extract (Kim et al., 2019). Similarly, natural compounds (i.e., Dimethyl sulfoxide) have also been tested with vanadium, resulting in synergistic impacts on the development time of zebrafish embryos, likewise the occurrence of pericardial edema (Kim and Lee, 2021). In humans, independent of its exposure origin, most of the ingested vanadium is transformed to VO²⁺, while approximately 10% is absorbed in the gastrointestinal tract (Nriagu, 1998). Once in the bloodstream, vanadium, e.g., vanadate or vanadyl, bounds to serum proteins, principally transferrin (Gorzsás et al., 2006; Nechay, 1984) and redistributed to organs like the brain, heart, kidney, liver, and tissue (Rehder, 2018). Vanadate easily substitutes phosphate in enzymes like phosphatases, phosphomutases and -diesterases, ATPases, ribonucleases, and kinases, inhibiting the enzyme and Na, K-ATPase (Gorzsás et al., 2006). Similarly, vanadate induces tyrosine phosphorylation and activation of the respiratory burst in the presence of NADPH (Trudel et al., 1991).

In general, limited reports have addressed vanadium in marine environments compared to similar trace elements, e.g., arsenic or lead (Huang et al., 2015; Wällstedt et al., 2010). Previous articles studying vanadium have simultaneously investigated multiple trace elements (Avigliano et al., 2019; Chen et al., 2019; Haghshenas et al., 2020), with the majority briefly mentioning the average concentrations of vanadium and focusing on more traditional elements, e.g., lead, mercury, antimony, and cadmium. Thus this article provides detailed information on the accumulation, migration, and distribution of vanadium in two bays where substantial human populations and industrial development raise concern over ecosystem degradation by vanadium contamination. Such industrial development is highly linked with fossil fuels, and their presence around the coast of both the study areas bays could represent some risks to freshwater and marine species and convey higher concentrations than that in the inner area of the bays. This research work also integrates marine and freshwater samples to consider the difference and migration within and between locations. Therefore, the objectives of the present study were to investigate in detail the vanadium concentrations in water bodies, e.g., freshwater and seawater, in two typical bays of the northwest pacific with different morphological characteristics, yet similar vanadium-related industries throughout the bay to: i) quantify the impacts of vanadium-related industries over common anthropogenic sources, ii) explore vanadium migration and spatiotemporal variations to determine the impacts of the bay morphology in vanadium concentrations, and iii) conduct discrete and probabilistic ecological and health risk assessments to provide information about uncertainty and variability from the quantified vanadium concentrations.