Environmental Science: Processes & Impacts最新文献

Correction for 'Wavelength-specific UV LED and far-UVC degradation of microplastics' by Thusitha Rathnayake et al., Environ. Sci.: Processes Impacts, 2026, https://doi.org/10.1039/d5em00818b.

Florfenicol (FF), a typical emerging contaminant, has potential environmental and health risks, arousing widespread concern. However, the role of δ-manganese dioxide (δ-MnO₂), a natural mineral, in the transformation of FF in mid-to-high latitude regions under low-temperature conditions remains unclear. In this study, reaction systems of δ-MnO₂ and FF were constructed to reveal the reaction kinetics, role of active substances, and FF transformation pathways under low-temperature conditions (5.0 °C). The results showed that the equilibrium oxidation amount and reaction rate of FF at 5.0 °C were 7.0 ± 0.2 µg mg^-1 and 0.02 ± 0.005 min^-1. After the reaction, the concentration of adsorbed Mn(II) reached 2.6 times that of free Mn(II), which was measured at 3.7 ± 0.3 µmoL L^-1. The adsorbed Mn(II) occupied the surface-active sites of δ-MnO₂, thereby terminating the transformation of FF. Mn(III) induced the formation of ⋅OH, O₂˙^-, and H₂O₂, which reacted with FF. The promoting order of these substances was Mn(III) > ⋅OH > O₂˙^- > H₂O₂. Under low-temperature conditions, the transformation pathways of FF mediated by δ-MnO₂ involved hydroxyl group oxidation, defluorination, dechlorination, and desulfonylation. Overall, the toxicity of most transformation products showed a decreasing trend. This study provides a theoretical basis for the natural transformation of antibiotics mediated by natural minerals in aquatic environments with low temperatures.

Marine animals consume microplastics; however, it remains unknown if plastic additives can be extracted from ingested microplastics. This research utilizes animal behavior experiments and analytical chemistry to determine if sea anemones consume plastic pre-production pellets and extract lead (Pb) and tin (Sn) additives from pellets. We compared the consumption of PVC pellets to shrimp-extract-flavored PVC pellets. The time from pellet ingestion to egestion (feeding retention time) averaged 7-10 hours and did not differ between untreated (83% of pellets consumed) and shrimp-flavored PVC pellets (100% of pellets consumed). Sequential feeding of the previously consumed pellets to new anemones rapidly decreased feeding retention time until pellets were no longer consumed. To determine if anemones could extract Pb and Sn additives, we ran additional feeding trials in which treatment anemones were offered one PVC pellet daily for 10 days and control anemones were not offered pellets. We quantified lead and tin in anemones, PVC pellets, seawater, and anemone food (Artemia spp.) fed to anemones using inductively coupled plasma mass spectrometry, and found that treatment anemones had significantly higher tin concentrations (0.80 ± 0.07 µg g^-1) and similar amounts of lead (0.13 ± 0.01 µg g^-1), compared to control anemones (0.53 ± 0.06 µg g^-1 of tin and 0.15 ± 0.02 µg g^-1 of lead). The increased tin concentrations in treatment anemones exceeded the amount quantified in PVC pellets, suggesting that the accumulation is attributable to other sources, at least in part. Loss of variability in tin concentrations in consumed pellets suggests that loosely associated tin may explain the observed increases in tin.

Plastic additives are widely used in plastic production, comprising up to 70% of the polymer mass. Due to inefficient waste management, the capacity of additives to leach from polymers under environmental conditions, and their chemical persistence, they are ubiquitous across the environment. However, the exposure pathways of biota to these chemicals remain poorly characterized and insufficiently known. Certain additive groups (e.g. flame retardants and ultraviolet stabilizers) have been detected in organisms inhabiting remote places, indicating their potential for long range transportation. A review of current research reveals a predominant analytical research focus on marine organisms, while the exposure of terrestrial species to plastic additives remains underexplored. This represents a critical knowledge gap, particularly considering that many of these additives exert adverse effects on biota. Moreover, only a limited number of studies have established a link between chemical exposure and the presence of plastics in the gastrointestinal tract, underscoring the need to consider other exposure pathways such as dermal contact and respiratory uptake as routes of exposure to plastics and plastic-associated chemicals. Understanding the exposure of terrestrial organisms, especially mammals, to plastic additives is essential as an initial step towards assessing their associated risks, including for humans.

Groundwater contamination in industrial parks, characterized by its concealment and time-lag effects, has emerged as a formidable challenge for regional environmental protection. To elucidate the mechanisms underlying contaminant enrichment and to predict pollutant migration trends, this study investigated a representative industrial park in southeastern China. By integrating hydrochemical analysis, multivariate statistical methods, and numerical modeling, the research systematically explored the mechanisms of groundwater contamination under complex hydrogeochemical conditions. The results indicate that the predominant hydrochemical type in the study area is HCO₃-Ca·Mg, with mixed water types such as HCO₃-Na formed under industrial influence. The hydrochemical evolution is primarily governed by water-rock interactions and cation exchange. Manganese (Mn), iron (Fe), fluoride (F), and ammonium-nitrogen (NH₄-N) were identified as the primary contaminants exceeding the permissible limits. The enrichment of Fe and Mn is associated with changes in ion activity, complexation reactions, and reducing conditions induced by the discharge of high-salinity wastewater. Fluoride enrichment is jointly influenced by water-rock interactions, cation exchange, and industrial discharge, while NH₄-N primarily originates from the mineralization of organic matter and cation exchange processes facilitated by high-salinity wastewater. Parameters such as TDS and HCO₃^- were found to play a significant role in the formation of these exceeding standard contaminants. An entropy-weighted water quality index assessment revealed poor water quality in downstream areas and along riverbanks, indicating favorable conditions for contaminant accumulation. Numerical simulation, using fluoride as a representative contaminant, demonstrated its migration along the groundwater flow direction (from northwest to southeast), with the contaminant plume continuously expanding over a 20 year period, posing a long-term potential threat to downstream groundwater environments. This study elucidates the multi-source composite mechanisms and migration patterns of groundwater contamination in industrial parks, providing a scientific basis for pollution control and sustainable groundwater management.

Black carbon (BC) is the organic residue produced from the incomplete combustion of biomass and fossil fuels. Dissolved black carbon (DBC) is operationally defined as the BC fraction that is water-soluble and able to pass through a filter of 0.1-0.70 µm. DBC acts as a crucial flux linking the two primary end-member BC pools-the soils and the ocean sediments, and is also an important component of dissolved organic carbon. Therefore, analysis of the molecular structures, concentrations, and sources of DBC in natural environments is essential for assessing the global carbon cycle. However, the chemical heterogeneity of DBC makes it challenging to discern and quantify in natural waters. Here, we reviewed the major analytical techniques for DBC and outlined promising methodological frameworks for future research. The contributions of nuclear magnetic resonance and Fourier Transform-Ion Cyclotron Resonance-Mass Spectrometry (FT-ICR-MS) in the structural characterization of DBC were evaluated. As the two primary methods for quantifying the condensed aromatic fraction of DBC, the chemo-thermal oxidation and the digestion-based benzenepolycarboxylic acids methods were comprehensively introduced. Intrinsic benzenepolycarboxylic acids in DBC have the potential to function as digestion-free markers for quantifying total DBC and assessing its cycling. Developing complementary techniques for FT-ICR-MS and identifying robust molecular markers for DBC in future research will be crucial for advancing DBC analysis and elucidating its global cycling.

Distinguishing anthropogenic perturbations from natural carbon cycling in mega-rivers remains a critical challenge. Carbon isotopes (δ¹³C_DIC) provide a powerful tracer to decode these complex interactions which are often masked in traditional hydrochemical assessments. This study investigated the hydrochemistry and multiple stable isotopes (δD, δ¹⁸O and δ¹³C_DIC) of the Yangtze River surface water (YRSW) during the dry season to quantify these contributions. δD values ranged from -117.8‰ to -44.6‰ and δ¹⁸O from -16.3‰ to -7.0‰, aligning with the Global Meteoric Water Line, which confirms atmospheric precipitation as the primary water source shaped by continental and altitude effects. DIC concentrations ranged from 1560 to 5724.29 µmol L^-1 (mean 2993.79 µmol L^-1), acting as a net CO₂ source with an average pCO₂ of 522.08 µatm. Stoichiometric and isotopic analyses reveal that carbonate weathering dominated by soil CO₂ is the primary DIC source. However, in the middle and lower reaches, anthropogenic sulfuric/nitric acid weathering and organic matter oxidation were identified as key drivers decoupling DIC from natural climatic controls. This study systematically reveals for the first time the spatial differentiation patterns of DIC and δ¹³C_DIC on the scale of the entire Yangtze River Basin and the main controlling factors, providing a new perspective for the study of carbon cycle in large river basins under high-intensity human activity interference.

Rubber derived compounds (RDCs) are a growing environmental concern. Several chemical classes of RDCs are known for their transformation potential, making the quantification of these compounds in samples difficult if not run directly after sampling. We performed a targeted stability study with 23 standards in a mixture of 31 rubber derived compounds placed under different solvent conditions at three temperature points in order to gauge the long-term stability of the compounds under various storage conditions. Methanol at -20 °C was found to be the best solvent for storage, while acidified DI water was the least stable. Our study indicates that the addition of glutathione at or below 12.3 µg mL^-1 does not prevent transformation of PPDs at relevant concentrations. Six compounds that showed loss during the targeted study were investigated using high resolution mass spectrometry to determine what transformations were occurring. Transformations for 2,2,4-trimethyl-2,4-hydroquinoline primarily formed 2,4-dimethylquinoline while 4-ADPA, 4sDPA, and HMMM involved a breakdown of the parent compound. Interestingly, MBT showed negligible loss indicating that the previous degradation was due to inter-compound interactions rather than the solvent they are stored in. Finally, the 31 standard mix was investigated using high resolution mass spectrometry with 91 unique features identified whose formations likely originate from reactions between RDCs. These results showcase the degradation and transformations that can occur for samples awaiting analysis under various storage conditions.

Emerging organic pollutants (EOPs) are increasingly detected in wastewater and pose potential vascular toxicity risks that remain inadequately assessed in current regulatory frameworks. This study developed an adverse outcome pathway (AOP)-informed machine learning approach to evaluate vascular toxicity for 312 EOPs. By integrating ToxCast high-throughput bioassay data with Morgan fingerprints, we trained fourteen multilayer perceptron (MLP) models targeting key events in AOP 509, including Nrf2 inhibition, oxidative stress, mitochondrial dysfunction, apoptosis, endothelial impairment, and angiogenesis disruption. Our optimized models achieved high predictive accuracy (70-95%), enabling activity classification for both tested and untested chemicals. The predicted activation profiles prioritized chemicals such as ketoconazole, sertraline, and miconazole, with literature evidence supporting their vascular toxicity potential. This AOP-guided modelling framework demonstrates how integrating mechanistic pathways with machine learning can inform chemical risk assessment and prioritization, supporting hazard evaluation and environmental decision-making for pollutants with limited toxicological data.

Rising levels of surface ozone (O₃) in the arable ecosystem have emerged as a serious threat to food security by reducing the yield of major food grains, yet long-term, stage-specific assessments of O₃ exposure and yield loss for wheat crop in India remain limited. Here, we present a comprehensive analysis of potential ozone-induced losses in yield and production of wheat across India for the past two decades (2005-2021) using a high-resolution surface O₃ data and the concentration-based accumulated ozone above a threshold of 40 (AOT40) method. Our analysis reveals a substantial increase in relative yield loss (RYL) of wheat from 2005 to 2021 (25.2-35.3%), resulting in an annual wheat production loss (WPL) of 21 ± 11.48 million tonnes (Mt) in 2005, rising to 48.6 ± 11.48 Mt by 2020. Critical reproductive stages of wheat, such as anthesis and grain filling, consistently experience AOT40 exposures exceeding the safe limit of 3000 parts per billion hour (ppb h) for crops, particularly across the Indo-Gangetic Plain (IGP). Prolonged and intense O₃ exposure during these sensitive phenological stages exacerbates yield loss and underscores the vulnerability of wheat in India relative to other major wheat producing regions. To safeguard national food security amid climate change, rising air pollution and growing population, future efforts must prioritise long-term air quality and crop monitoring, crop-specific ozone tolerance studies and integrated mitigation strategies linking agriculture and air quality policies.