Environmental Pollution最新文献

The widespread utilization of antibiotics in livestock has promoted the accumulation and diffusion of antibiotics and antibiotic resistance in agricultural soils and crops. Here we investigated the mechanisms of antibiotic uptake and accumulation in swine wastewater (SW)-treated radish (Raphanus sativus L.) and subsequent impacts on endophyte antibiotic resistance. Under SW treatments, exposure to 500 μg/L sulfamethazine (SMZ) and enrofloxacin (EFX) significantly affected radish biomass, with SMZ causing 63.0% increases and EFX causing 36.3% decreases relative to the untreated control. EFX uptake by radish were from 5 to 100-folds over SMZ. Passive diffusion through anion channel proteins on cell membranes was an important route for SMZ uptake, while both passive diffusion and energy-dependent processes contributed to the uptake of EFX. Bacterial community was time-dependent as a function of both antibiotics and SW, the bacterial alpha diversity in liquid solution co-treated with antibiotics and SW increased over time. The abundance of antibiotic resistance genes (ARGs) in the roots was positively correlated with ARGs in the Hoagland's solution under antibiotic-alone treatments. EFX co-exposure with SW enhanced the dissemination of ARGs from swine wastewater into plant roots, and significant correlations existed between ARGs and integrons in both Hoagland's solution and roots. These findings increased our understanding of the fate of antibiotics in crops and their subsequent impacts on antibiotic resistance of endophytic bacteria.

Groundwater pollution from valley type landfills is concerning, and natural attenuation by contaminants is increasingly relied upon. However, the reliability of natural attenuation in such complex sites has been called into question due to incomplete understanding of their attenuation mechanisms. Therefore, we conducted field investigations, monitoring analyses, mathematical statistics, and machine learning techniques to elucidate the natural attenuation mechanisms of pollutants within bedrock fissures at a prototypical valley type landfill located in the east Yanshan Mountains, China. Our results indicate that 50% of the monitored indicators showed extreme pollution in bedrock fissure aquifers, due to seepage from the valley type landfill site. Ammonia nitrogen, arsenic, cadmium, lead, iron, manganese, and mercury were among the contaminants that could pose serious risks to human health. Pollutant concentrations in bedrock fissure aquifers were lower during the rainy season compared to the dry season as the aquifer was rapidly recharged by strong rainfall runoff. The initial concentration of bedrock fissure water generally increased during the flow through the landfill. However, significant natural attenuation of total dissolved solids, oxygen consumption, ammonia, cadmium, and lead occurred after passing through the landfill (p < 0.05), with attenuation coefficients of 0.0041 m^-1, 2.56 × E^-5m^-2, 4.18 × E^-5m^-2、0.0015 m^-0.99, and 6.83 × E^-33 m^-12.49, respectively. The driving mechanisms for natural attenuation include physical migration, leaching, microbiological degradation, and adsorption, primarily occurring within 600-650 m downstream of the landfill boundary. This study makes fundamental contribution to the understanding of the migration and natural attenuation process of leachate pollutants in bedrock fissure aquifer, which will provide a scientific basis for implementation of natural attenuation strategies in complex site remediation. Future research should examine more precise evidence of natural attenuation feasibility in complex sites in conjunction with monitoring networks.

GenX, a substitute for perfluorooctanoic acid, has demonstrated potential enterotoxicity. The enterotoxic effects of GenX and effective interventions need further investigation. In the present study, the mice were administered GenX (2 mg/kg/day) with or without inulin supplementation (5 g/kg/day) for 12 weeks. Histopathological assessments revealed that GenX induced colonic gland atrophy, inflammatory cell infiltration, a reduction in goblet cell numbers, and decreased mucus secretion. Furthermore, a significant decrease in the protein levels of ZO-1, occludin, and claudin-5 indicated compromised barrier integrity. Transcriptomic analysis identified 2645 DEGs, which were mapped to 39 significant pathways. The TGF-β, BMP6, and β-catenin proteins were upregulated in the intestinal mucosa following GenX exposure, indicating activation of the TGF-β pathway. Conversely, the protein expression of PAK3, CyclinD2, contactin1, and Jam2 decreased, indicating disruptions in cell cycle progression and cell adhesion. Inulin cotreatment ameliorated these GenX-induced alterations, partially through modulating the MAPK pathway, as evidenced by the upregulation of the cell cycle and cell adhesion proteins. Collectively, these findings suggested that GenX exposure triggered intestinal injury in mice by activating the TGF-β pathway and disrupting proteins crucial for the cell cycle and cell adhesion, whereas inulin supplementation mitigated this injury by modulating the MAPK pathway.

Honey bees provide vital pollination services to agricultural crops and wild plants worldwide. Unfortunately, the misuse and overuse of pesticides in agricultural production have led to an increase in incidents harming honey bees in recent years. Among the commonly utilized bee species in beekeeping are Apis cerana and Apis mellifera, with wild A. cerana populations widely dispersed in forests, contributing substantially to ecosystem balance. Yet, the impact of paraquat, a toxic herbicide, on A. cerana remains largely unexplored. This study aims to address this gap by examining acute exposure endpoints based on mortality represented by median lethal doses (LD₅₀ values) of paraquat, survival rates, and gene expression patterns between the A. cerana and A. mellifera. The findings revealed that A. cerana exhibits greater sensitivity to paraquat compared to A. mellifera. The acute oral LD₅₀ values for A. cerana were 5.85, 1.74, and 1.21 μg/bee at 24, 48, and 72 h, respectively, whereas the corresponding values for A. mellifera were 104.00, 11.00, and 6.41 μg/bee. Further, the study demonstrated significant upregulation of the detoxification (antioxidative) enzymes SOD1, CAT, and LLDH-X2 in both A. mellifera and A. cerana following exposure to the lethal dose of paraquat. However, SOD2 expression was notably downregulated in both species, indicating potential mitochondrial damage. These findings suggest that while honey bees initiate activate defense mechanisms against oxidative damage, paraquat exposure may still impair mitochondrial function. Paraquat was found to be moderately toxic to A. mellifera but highly toxic to A. cerana, indicating the importance of screening multiple bee species when assessing the risks of chemical exposure. This research provides a rare comparative analysis of chemical stress effects on morbidity and gene expression in two different honey bee species, establishing a foundational framework for risk assessment and the regulation of herbicide risks to pollinating insects.

Microplastic (MP) pollution in water has become one of the most important global problems of our time. The development of appropriate and rapid analysis techniques is of great importance at the beginning of the studies aimed at solving this problem. In the presented study, in order to perform the qualitative and quantitative analysis of MP forms of polyamide (PA), polyethylene (PE), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET), which are known to be most abundant in water, in a fast and easy way, new Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy methods were tried to be developed by utilizing chemometric methods. While principal component analysis (PCA) was applied for qualitative analyses, partial least squares (PLS) models were created for quantitative analyses. Raw, 1st, and 2nd order derivatives of all spectra and their spectra with different levels of smoothing points were taken and 24 different chemometric models were created for each MP. In interpreting the statistical performances of the developed PCA and PLS models, different parameters were used. According to the obtained results, the qualitative discrimination of all polymer types was successfully achieved. It was determined that the PLS models developed for the quantitative determination of mixtures consisting of different concentrations of MP types could not be at the desired level. However, it was determined that the PLS models developed for PA, PE, PP, and PET, where the normal spectrum was used, could give quantitatively accurate results, albeit partially.

Electronic waste (e-waste) dismantling and dumpsite processes are major sources of organophosphate flame retardant and plasticiser emissions and may pose potentially adverse effects on environment and human health. In 20 outdoor dust and 49 soil samples collected from four e-waste dismantling and three e-waste dumpsites in two States of Nigeria (Lagos and Ogun), we identified 13 alternative plasticisers (APs), 7 legacy phthalate plasticisers (LPs), and 17 organophosphorus flame retardants (OPFRs) for the first time in African e-waste streams. In the samples from dismantling sites, the range (median) concentrations of ∑₁₃APs, ∑₇LPs, and ∑₁₇OPFRs were 11-2747 μg/g (144 μg/g), 11-396 μg/g (125 μg/g), and 0.2-68 μg/g (5.5 μg), in dust respectively and 1.8-297 μg/g (55 μg/g), 1.3-274 μg/g (48.5 μg/g), and 1.6-62 μg/g (1.6 μg/g), in soil respectively. Results for soil samples from e-waste dumpsites were (6.6-195 μg/g (23.7 μg/g), 6.0-295 μg/g (54.8), and 0.4-42.3 μg/g (9.0 μg/g) for ∑₁₃APs, ∑₇LPs, and ∑₁₇OPFRs respectively. Overall, concentrations of APs were significantly higher at the dismantling sites (p = 0.005) compared to dumpsites, levels of LPs were higher at dismantling sites but not significant, while OPFR concentrations were significantly higher in dumpsite samples (p = 0.005). Plasticisers were found to be major contributors to pollution at e-waste dismantling sites, while OPFRs were associated with both automobile dismantling and e-waste dumpsite processes. Following particle size fractionation of selected soil samples, higher concentrations of targeted compounds were observed in the smaller mesh (180 μm) soil sieve fraction. For dust, the total median estimated daily intake via ingestion and dermal adsorption (EDI_ing and EDI_derm) ranged from 43 to 74 ng/kg bw/day and 0.4-0.7 ng/kg bw/day, respectively. Correspondingly, 4.6-45 ng/kg bw/day and 0.015-0.57 ng/kg bw/day were the values found for soil, respectively. According to these results, the targeted chemicals do not appear to pose a non-carcinogenic risk to e-waste workers through ingestion or dermal contact of bio-accessible fractions of the chemicals. Human biomonitoring campaigns are recommended in the Nigerian e-waste environment considering the elevated concentration levels found for the majority of targeted compounds and that risk parameters required for exposure assessment were only available for a limited number of compounds.

In solid backfill coal mining, recycled coal gangue aggregate (RCGA) is subject to the combined effects of overlying strata stress and leaching by mine water in the goaf. This process causes heavy metals to be leached and released from RCGA, which can lead to groundwater contamination. In this study, the release patterns of heavy metals in RCGA under the coupled effects of stress, solution pH, and solution flow rate were investigated, and the interactions between RCGA and the surrounding environment were explored. The findings indicate that: (1) The combined action of effective stress and mine water promotes the leaching of heavy metals. Specifically, the leaching of Pb, Zn, and Mn of RCGA is primarily influenced by the pH value of the leaching solution, while the leaching of Cu and Cr of RCGA is more closely related to the stress level; (2) Acidic environments accelerate the release of carbonate-bound fraction (CAR) in elements, facilitating the transformation of Fe/Mn oxide-bound fraction (XXI) into soluble forms; (3) The leaching ratios (Lr) of heavy metals follow the order: L_rZn > L_rPb > L_rMn > L_rCu > L_rCr. This research provides guidance for the safe application of RCGA in solid backfill coal mining.

Perfluorinated compounds (PFCs) can induce immunotoxicity effect via binding with proteins. Immunoglobulin G (IgG) is a common four chain monomer protein in serum, and plays an important role in long-term body fluid immunity. Whether PFCs can bind with IgG and further induce immunotoxicity is not clear. Herein, fluorescence quenching assay was used to verify the PFCs-IgG binding interactions. The occurrence of fluorescence quenching phenomenon suggested that PFCs could bind to IgG. Linear fitting curves demonstrated that the binding constants (K_A) for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) were 2.51 × 10⁶ L/mol and 1.58 × 10⁵ L/mol, respectively. UV-vis spectral analysis results showed that the PFCs-IgG interactions mainly proceeded via the intercalation binding mode. Fourier transform infrared spectroscopy results revealed that PFCs preferentially bound to the C=O/N-H of IgG structure. Circular dichroism results revealed that PFCs-IgG binding induced the decrease of α-helix. Moreover, hydrogen bonds and van der Waals force dominated PFCs-IgG binding interactions. This binding process was a stable process, and its stability depended on the number of hydrogen bonds formation. This study reveals the mechanism of interaction between PFCs and IgG at the molecular level, providing a theoretical basis for the immunotoxic mechanism of PFCs.

Maternal exposure to various metallic and non-metallic elements has been linked to the occurrence of orofacial clefts (OFCs), yet there remains a dearth of comprehensive research on the potential ramifications of simultaneous exposure to multiple elements. In this study, we investigated the individual and combined effects of element exposure on OFCs in a cohort of 168 pregnant women (49 cases and 119 controls) in the Shanxi province of northern China from 2010 to 2015. Cord serum samples were obtained from all participants to analyze the levels of 32 elements using inductively coupled plasma-mass spectrometry. The study examined the independent correlation between element concentrations and OFCs using two machine screening models, Boruta and Least Absolute Shrinkage and Selection Operator. Bayesian kernel machine regression (BKMR) was utilized to determine the combined effects of key exposure elements on OFCs and to clarify the interaction between exposed elements through the generalized additive model (GAM). The screening models identified lead (Pb), tin (Sn), iron (Fe), and cesium (Cs) as the most significant risk factors for OFC development in offspring. In the BKMR model, the probability of OFCs increased with higher overall levels of these risk elements, with Pb emerging as the primary contributor to the combined effect of the mixture. The findings of the GAM indicated that the combined exposure to Pb and Sn had a synergistic effect on the risk of developing OFCs. Analysis of elemental exposure in umbilical cord serum suggested that Pb exposure may have detrimental effects on OFC development in offspring, which may be further intensified by a synergistic interaction between Sn and Pb in the occurrence of OFCs.

Microplastics (MPs) are widely detected in the soil of the Qinghai-Tibet Plateau with increasing economic activities. However, studies concerning the driving factors affecting the presence of these surface soil MPs for the typical regions with different geographic conditions are still lacking. Here we chose three representative regions (Ali, Yushu, and Haixi) from east to west across the plateau to investigate the distribution and further explore the contributing factors of surface soil MPs. The Spearman rank correlation, Geodetector, Random Forest Regression and Principal Component Analysis were used to unveil how the driving factors influence MPs distribution across the plateau. The results revealed that the MPs abundance, type, size, color and polymer across the Ali, Yushu, and Haixi were different. Microplastic abundance was inversely correlated with the distance from roads and residential areas, but was positively related to precipitation. Moreover, traffic elements were the primary source of MPs pollution in the Ali and Yushu but residential activities were the leading source of MPs contamination in the Haixi. Besides, backward trajectory simulations suggested that atmospheric transport may also contribute to the presence of soil MPs in the representative regions. These results further indicated that different regions may require different measures for controlling MPs pollution in surface soil. This study provides new insights into the distribution and source of MPs and further offers valuable methodology for future research aimed at uncover driving factors contributing MPs pollution across different regions with various geographical conditions.