Public perceptions and discussions of synthetic nicotine on Twitter.

Background: As alternative replacement products for tobacco-derived nicotine, synthetic nicotine products have recently emerged and gained increasing popularity. This study analyzes public perception and discussion of synthetic nicotine products on Twitter (now "X"). Methods: Through Twitter streaming API (Application Programming Interface), we have collected 2,764 Twitter posts related to synthetic nicotine from December 12, 2021, to October 17, 2022, using keywords related to synthetic nicotine. By applying an inductive approach, two research assistants manually determined the relevance of tweets to synthetic nicotine products and assessed the attitude of tweets as positive, negative, and neutral of tweets toward synthetic nicotine, and the main topics. Results: Among 1,007 tweets related to synthetic nicotine products, the proportion of negative tweets (383/1007, 38.03%) toward synthetic nicotine products was significantly higher than that of positive tweets (218/1007, 21.65%) with a p-value <0.05. Among negative tweets, major topics include the concern about addiction and health risks of synthetic nicotine products (44.91%) and synthetic nicotine as a policy loophole (31.85%). Among positive tweets, top topics include alternative replacement for nicotine (39.91%) and reduced health risks (31.19%). Conclusion: There are mixed attitudes toward synthetic nicotine products on Twitter, resulting from different perspectives. Future research could incorporate demographic information to understand the attitudes of various population groups.

Distinguishing contributions of diverse sediment components to vanadium transport, immobilization and transformation in aquifer.

Vanadium (V) occurs in environment naturally and anthropogenically, but little has been understood about its environmental behavior in groundwater aquifer with sediments. This study investigated the pentavalent V [V(V)] transport and transformation under the influence of different sediment components (minerals, organic matter, and microorganisms) through column experiments. All these components played pivotal roles in V immobilization. The synergistic effects of sediment components enhanced V retention compared to individual component. Mineral components, particularly those containing carbonates and metal oxides, predominantly influenced V(V) transport as indicated by XRD analysis. Organic matter, especially under low pH conditions, induced particle aggregation, thereby inhibiting the transport of V(V). The V K-edge X-ray absorption near-edge structure spectroscopy revealed the formation of tetravalent V[V(IV)] in treatments involving organic matter and microorganisms. Notably, organic matter exhibited the capability to directly reduce V(V). The introduction of microorganisms restricted V(V) transfer. V(V) reducing genera (e.g., Brevundimonas, Arenimonas, Xanthobacter) were detected, achieving V(V) reduction to insoluble V(IV). V(V) bioreduction was improved by minerals that promote microbial metabolism with enhanced electron transfer, or by organic matter that increases levels of intracellular nicotinamide adenine dinucleotide and extracellular polymeric substances. This study specifies the contributions of different sediment components to the transportation and transformation of V, deepening our understanding of V biogeochemistry in groundwater aquifer.

Deciphering Vanadium Speciation in Smelting Ash and Adaptive Responses of Soil Microorganisms.

Abundant smelting ash is discharged during pyrometallurgical vanadium (V) production. However, its associated V speciation and resultant ecological impact have remained elusive. In this study, V speciation in smelting ash and its influence on the metabolism of soil microorganisms were investigated. Smelting ashes from V smelters contained abundant V (19.6-115.9 mg/g). V(V) was the dominant species for soluble V, while solid V primarily existed in bioavailable forms. Previously unrevealed V nanoparticles (V-NPs) were prevalently detected, with a peak concentration of 1.3 × 1013 particles/g, a minimal size of 136.0 ± 0.6 nm, and primary constituents comprising FeVO4, VO2, and V2O5. Incubation experiments implied that smelting ash reshaped the soil microbial community. Metagenomic binning, gene transcription, and component quantification revealed that Microbacterium sp. and Tabrizicola sp. secreted extracellular polymeric substances through epsB and yhxB gene regulation for V-NPs aggregation to alleviate toxicity under aerobic operations. The V K-edge X-ray absorption near-edge structure (XANES) spectra suggested that VO2 NPs were oxidized to V2O5 NPs. In the anaerobic case, Comamonas sp. and Achromobacter sp. reduced V(V) to V(IV) for detoxification regulated by the napA gene. This study provides a deep understanding of the V speciation in smelting ash and microbial responses, inspiring promising bioremediation strategies to reduce its negative environmental impacts.