Environmental Research最新文献

Since the discovery of antibiotics, the dispersion of resistance genes has increased exponentially, leading to the current state in which it has become increasingly difficult to achieve an effective treatment for infectious diseases. The enormous capacity for genetic exchange between microorganisms is causing resistance genes to be able to reach all environments, even those where there is no anthropogenic impact or exposure to these drugs. In this work, a phenotypic study of the resistome has been conducted in a peri-urban ecosystem (Granada, Spain), wherein the resistance to 32 antibiotics of 710 bacterial strains isolated from 70 samples from different ecological niches with varying levels of exposure to antibiotics and anthropic action has been determined. The study of resistances using phenotypic procedures constitutes a very useful and complementary alternative to genomic methods. The obtained results show a high percentage of resistance in all the subsystems analysed, stating high multi-resistance profiles. Vancomycin and erythromycin were the antibiotics to which the highest levels of resistance were observed, whereas the lowest levels were obtained in chloramphenicol. Regarding the environments studied, the highest percentages of resistance were found in wastewater, farms and food. It should be noted that in natural soil samples (not exposed to antibiotics or anthropogenic activities), worrying levels of resistance to practically all the groups of antibiotics analysed were detected. These results support the generally accepted conclusion that an appropriate control and management of wastewater and solid waste that may contain antibiotics or resistant bacteria is really important to prevent the wide propagation of the resistome in the environment.

Linear substituents, despite their simpler structures compared to heterocyclic ones, exhibit distinct chemical behaviors. Using sulfacetamide (SAM) and sulfaguanidine (SGD) as model compounds, we assessed the impact of these substituents on degradation efficiency, active species identification, reaction pathways, and intermediate toxicity during electrooxidation in water. Through density functional theory, we elucidated the mechanisms, focusing on electronic structural changes and interactions with active species. Notably, the acetyl group in SAM (0.1016) acquired more electrons than the guanidyl group in SGD (0.0281), resulting in SAM having a higher free energy change (ΔG=15.06kcal/mol) compared to SGD (ΔG=9.59kcal/mol). This difference makes SAM less likely to undergo direct electron transfer and less reactive towards hydroxyl radical addition, leading to slower degradation rates. The applied potential notably increased SAM's sensitivity to hydroxyl radicals. Both the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were contributed by the parent fragment, facilitating electrophilic reactions mainly on the aniline part. Seventeen intermediate products and three major transformation pathways were identified, emphasizing aniline group destruction before discharge. This research enhances understanding of the degradation and environmental fate of sulfonamides, providing valuable insights for optimizing pollutant degradation and discharge reduction.

The relationship between structure and function in microbial communities is intriguing and complex. In this study, we used single-carbon source domestication to derive consortium YL from the straw-degrading consortium Y. Y and YL exhibited similar straw degradation capabilities, yet YL harbored only half the species diversity of Y, with distinct dominant species. The most enriched microorganisms in Y were Ureibacillus, Acetanaerobacterium, and Hungateiclostridiaceae, whereas Bacillaceae, Bacillus, and Peptostreptococcales-Tissierellales were most enriched in YL. In-depth analysis revealed that Y and YL had comparable abundances of core lignocellulose-degrading genes, as validated by lignocellulolytic enzyme activity assays. However, the number of species harboring these key lignocellulose-degrading genes (K01179, K01181, K00432) in YL was reduced by over 50%, suggesting that functional redundancy enabled YL to maintain similar degradation capabilities to Y despite reduced diversity. Further analyses of key degradative species and co-occurrence networks highlighted the critical functional roles of dominant degradative species within these communities. An analysis of the overall functional pathways in the two microbial consortia revealed distinct metabolic characteristics between them. Pathways such as polycyclic aromatic hydrocarbon degradation and fluorobenzoate degradation were down-regulated in YL compared to Y, a finding corroborated by the metabolomic data. These results suggest a coupling between community structure and functional capacities within these microbial consortia. Overall, our findings deepen our understanding of the structure-function relationship in microbial communities and provide valuable insights for the design of lignocellulose-degrading consortia.

Despite being a model in waterborne risk assessment, rotavirus attenuation and transport in sand filtration water treatment remains poorly understood due to a lack of representative surrogates. We investigated the suitability of DNA-labeled chitosan nanoparticles (DCNPs) to mimic rotavirus attenuation and transport in coastal and alluvial sands. Chitosan nanoparticles were synthesized and coupled with a DNA tracer. Compared to rotavirus, DCNPs had similar size (79 ± 7.2 nm vs. 72.5 nm) and buoyant density (1.65 ± 0.07 g/cm³ vs. 1.36-1.40 g/cm³) but a less negative zeta potential (-20.61 ± 1.94 mV vs. -29.77 ± 0.86 mV) and lower hydrophobicity (0% vs. 44%). Filtration experiments (flow rate 1.26-1.27 ml/min, pH 6.0, electrical conductivity 224-226 μs/cm) showed that DCNPs approximated rotavirus attenuation in coastal and alluvial sands (p ≥ 0.07). Repeated dosing of rotavirus and DCNPs caused removal efficiencies to decline in the sand media. Both entities displayed faster and less dispersive transport than a nonreactive solute tracer (NaCl) in sand media. This preliminary study suggested that DCNPs can approximately mimic rotavirus attenuation and transport in coastal and alluvial sands. However, further validation under diverse experimental conditions is necessary. This includes varying flow rates, pH levels, ionic strengths, and the presence of multivalent cations (e.g., Ca²⁺ and Mg²⁺) and organic matter. DCNPs, made from a nontoxic, biocompatible, and biodegradable natural biopolymer, hold promise as a safe tool for assessing rotavirus attenuation and transport in sand filtration water treatment and aquifer filtration processes.

Anticoagulant rodenticides (ARs) are widely used for pest control, resulting in their pervasive presence in the environment and posing significant toxicological risks to a range of predatory and scavenging species. Our study mainly aimed to evaluate AR exposure and effects in nestlings of eagle owl (Bubo bubo) from the Region of Murcia (southeastern Spain). We analysed ARs in blood samples (n=106) using high-performance liquid chromatography-triple quadrupole (HPLC-TQ), assessed the influence of potential anthropogenic (presence of livestock farms, landfills and human population density) and environmental (land uses and proximity to watercourses) variables, and measured prothrombin time (PT) and plasma biochemical parameters as biomarkers of effects. Our results showed the presence of AR residues in 91.5% of the nestlings, with 70.8% exhibiting multiple ARs (up to six compounds in a single individual). Second-generation ARs (SGARs) were the most prevalent compounds. The analysis of biochemical parameters indicated that the sampled individuals were in good physiological condition. Although PT was positively correlated with total AR concentration (ΣARs), the relationship was not significant (Rho= 0.04; p= 0.49). Regarding environmental factors, higher ΣARs were associated with the most urbanised study site and the presence of landfills, likely due to the increased availability of rodent prey. The prevalence of two SGARs (brodifacoum and difenacoum) was linked to closer proximity to riverbeds, suggesting a contamination pathway associated with inland aquatic ecosystems, where these AR compounds may concentrate due to water scarcity. This study underscores the widespread exposure of eagle owls to ARs and highlights the importance of effective monitoring and management of these pollutants to protect conservation-concern wildlife in Mediterranean semiarid regions.

Studies have shown that mercury (Hg) exposure during pregnancy is associated with adverse birth outcomes (ABO) in infants, but the association between the two has not been systematically summarized. Therefore, we conducted a systematic review and meta-analysis of existing observational studies on the association between maternal Hg exposure (MHE) during pregnancy and ABO in infants to evaluate the association between them. We comprehensively searched all relevant literature published in three electronic databases (Web of Science, PubMed, Embase) from 2004 to June 2024. According to the heterogeneity, fixed effect model (I² ≤ 50 %) or random effect model (I² > 50 %) was used to pool the associated effect values. The results showed a positive association between MHE and low birth weight (LBW) (OR = 1.079, 95 % CI: 1.032-1.128) and no statistically significant association between and preterm birth (PTB) (OR = 1.044, 95 % CI: 0.956-1.140) and small-for-gestational-age (SGA) (OR = 1.006, 95 % CI: 0.983-1.030). In addition, each 10-fold increase in MHE during pregnancy was associated with abnormal Birth Anthropometrics. These findings suggest that MHE is a risk factor for LBW and is associated with abnormal anthropometric measurements at birth. However, there is insufficient evidence for Hg exposure and SGA, PTB. Further population-based studies are warranted to investigate these associations.

To identify the key factors for managing and controlling potential toxic elements (PTEs) in surface dust of urban community playgrounds, this study comprehensively analyzed the content, pollution characteristics, health risks, and sources of commonly concerned PTEs in surface dust of Xi'an community playgrounds. The average levels of Cd, Hg, Cu, Cr, Ba, Zn, and Pb in the dust were 2.2, 0.27, 1.4×10², 2.1×10², 1.7×10³, 2.9×10², 1.5×10² mg kg^-1, respectively, exceeding the soil background values. The main sources of PTEs in the dust were natural sources, weathering of entertainment facilities and building materials, traffic emissions, and industrial sources, accounting for 24.9%, 45.7%, 18.1%, and 11.3%, respectively. The contamination and ecological risk of PTEs in the dust were elevated, with Cd and industrial sources being the primary contributors. The non-carcinogenic risks for different age groups were within a safe range, but the cancer risk was high, especially for toddlers and the elderly. It is worth noting that the cancer risk calculated based on the minimum values of key exposure parameters for toddlers, preschool children, children, and teenagers exceeded the acceptable level. According to the results of source-oriented health risk assessment, the traffic sources have been identified as the main contributors of health risk, and Ni is a particularly concerned PTE. These findings can provide scientific basis for controlling PTEs pollution in community playgrounds and provide guidance for protecting residents' health.

Increased levels of p-aminobenzoic acid in aquatic environments, primarily utilized as UV filter in sunscreens, poses a serious threat to human and ecosystem health, while there is a dearth of exhaustive researches pertaining to the efficient and cost-effective elimination of p-aminobenzoic acid. Herein, a Ti/SnO₂-Sb/CNT-α-PbO₂/CNT-Ce-β-PbO₂, referred to Ti/CNT/CNT-Ce-PbO₂ electrode was constructed by incorporating CNTs into the middle layer of PbO₂ electrode, and simultaneously doping CNTs and Ce in the active layer. A series of tests signify that the target electrode is successfully fabricated, which exhibits higher particle density and smaller particle size, as well as exceptional degradation performance for p-aminobenzoic acid with a degradation rate of 99.7% within 30 min coupling with peroxymonosulfate activation. The optimal degradation performance was observed at a PMS dosage of 0.07 g, Na₂SO₄ concentration of 0.05 mol L^-1, current density of 120 mA cm^-2, and initial pH value of 6.94. Capture experiments, electron spin resonance test, liquid chromatography-mass spectrometry analysis, toxicity assessment and theoretical calculation were performed to clarify the main activate radicals, degradation pathways and intermediate toxicity. This study provides a new anode material, and conducted the first exploration of electrocatalysis integrating peroxymonosulfate activation for degradation p-aminobenzoic acid.