Environmental Research最新文献

Coagulation could effectively remove microplastics (MPs). However, MPs coagulated sludge was still a hazardous waste that is difficult to degrade. Nitrogen-doped carbon composite (N-PSMPC) was prepared by carbonizing MPs coagulated aluminum sludge (MP-CA) doped with cheap urea in this study. Compared with the carbon material (PSMPC) produced by direct carbonization of MP-CA, N-PSMPC had a higher degree of defects, which could provide more active sites for peroxymonosulfate (PMS) activation. And then, the N-PSMPC was applied to the degradation of tetracycline hydrochloride (TC). The results showed that the N-PSMPC/PMS system exhibited excellent TC degradation performance at the pH range of 3-9, and the coexistence of CO₃^2- and HCO₃^- inhibited the TC degradation. Moreover, the graphite N, pyridine N and carbonyl group were identified as the primary catalytic active sites. Three TC degradation pathways were speculated based on the intermediates detected by liquid chromatography-mass spectrometry, and the degradation mechanism was dominated by the nonradical pathway. In addition, the analysis of TC and intermediates by toxicity assessment software showed that N-PSMPC/PMS system could mitigate the TC toxicity. This study will provide a novel approach for the resourceful utilization of MP-CA and provide technical support for the removal of MPs and TC in water.

The advancement of cellular networks requires updating measurement protocols to better study radiofrequency electromagnetic field (RF-EMF) exposure emitted from devices and base stations. This paper aims to present a novel activity-based microenvironmental survey protocol to measure environmental, auto-induced downlink (DL), and uplink (UL) RF-EMF exposure in the era of 5G. We present results when applying the protocol in Switzerland. Five study areas with different degrees of urbanization were selected, in which microenvironments were defined to assess RF-EMF exposure in the population. Three scenarios of data transmission were performed using a user equipment in flight mode (non-user), inducing DL traffic (max DL), or UL traffic (max UL). The exposimeter ExpoM-RF 4, continuously measuring 35 frequency bands ranging from broadcasting to Wi-Fi sources, was carried in a backpack and placed 30 cm apart from the user equipment. The highest median RF-EMF levels during the non-user scenario were measured in an urban business area (1.02 mW/m²). Here, DL and broadcasting bands contributed the most to total RF-EMF levels. Compared to the non-user scenario, exposure levels increased substantially during max DL due to the 5G band at 3.5 GHz with 50% of the median levels between 3.20 and 12.13 mW/m², mostly in urban areas. Note that the time-division nature of this band prevents distinguishing between exposure contribution from DL beamforming or UL signals emitted at this frequency. The highest levels were measured during max UL, especially in rural microenvironments, with 50% of the median levels between 12.08 and 37.50 mW/m². Mobile UL 2.1 GHz band was the primary contributor to exposure during this scenario. The protocol was successfully applied in Switzerland and used in nine additional countries. Inducing DL and UL traffic resulted in a substantial increase in exposure, whereas environmental exposure levels remained similar to previous studies. This data is important for epidemiological research and risk communication/management.

Exposure to fine particulate matter (PM_2.5) is recognized to induce atherosclerosis, but the underlying mechanisms are not fully understood. This study used ambient PM_2.5 samples collected in one of the highly polluted regions of Guanzhong Plain in China (2017-2020) and an ApoE^-/- mouse model to investigate the association between exposure to PM_2.5 and atherosclerosis. Despite a substantial decrease in the ambient concentration of PM_2.5 from 266.7 ± 63.9 to 124.4 ± 37.7 μg m^-3 due to the execution of a series of emission controls, cardiovascular toxicity due to exposure to PM_2.5 remained at a significantly high level compared with the Control group. Moreover, the result highlighted that biomass burning (BB) showed an increased contribution to PM_2.5 while most anthropogenic sources decreased. This study found that PM_2.5 exposure led to vascular oxidative stress and inflammation, accelerated atherosclerotic plaque growth, and altered vascular proliferation pathways. The latter two mechanisms provide new insights into how PM_2.5 enhanced the processes of atherosclerosis, promoted lipoprotein cholesterol (LDL-C) absorption in vascular cells, and directed stimulation of cell function factors (VEGF and MCP-1), which are highly associated by PI3K/AKT signaling pathway. Polycyclic aromatic hydrocarbons (PAHs) and their derivatives, and certain biomarkers showed strong correlations with bio-reactivity, while BB was identified as a major contributor to toxicity of PM_2.5. The findings offer new insights into the role of PM_2.5 promoting atherosclerosis and provide recommendations for controlling PM_2.5 pollution to prevent and treat the disease particularly for susceptible populations.

N-(1,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD) is an antioxidant commonly used in tire manufacturing, and its release into the environment has significantly increased due to rapid urbanization. When subjected to ozonation, 6PPD converts into the harmful pollutant 6PPD quinone (6PPDQ). These substances enter wastewater treatment plants (WWTPs) via stormwater runoff and pipelines, posing significant risks to the functional microorganisms. Anammox, a strictly controlled and sensitive microbial nitrogen removal process, is especially susceptible to the effects of the pollutants. This study investigates the comprehensive impact of 6PPD-Q and 6PPD on anammox communities based on characterization analysis and metagenomics. At environmental concentrations, 6PPD-Q at 200 ng/L-1000 ng/L led to the disintegration of anammox granules. Extended exposure to both 6PPD-Q and 6PPD significantly reduces the population of anammox bacteria (AnAOB). By utilizing organic matter from dead cells and incoming carbonate as a carbon source, the system evolved into a nitrogen metabolism network primarily focused on denitrification and dissimilatory nitrate reduction to ammonium (DNRA). This transformation was accompanied by a reshuffling of the microbial community and associated genes, resulting in an accumulation of NH₄⁺-N. These findings underscore the toxicity of 6PPD-Q and 6PPD to anammox and stress the importance of incorporating 6PPD into regulatory and preventive strategies.

Previous studies - primarily in high income countries - have shown that high prenatal temperatures are associated with adverse birth outcomes. However, these studies are mostly focused on average exposure across the full gestational period or short-term exposure immediately prior to delivery and may miss important sensitive windows of exposure in utero. Further, nearly all use ambient air temperature data, which neglect physiologically important interactions between air temperature and humidity. The Ghana Randomized Air Pollution and Health Study (GRAPHS) recruited pregnant individuals from 2013 to 2015 from communities in the Kintampo North Municipality and Kintampo South District of Ghana. We estimated daily maximum shaded wet bulb globe temperature (WBGTmax) and heat index (HImax) during pregnancy and examined associations with birth weight, birth length, head circumference, and incidence of low birth weight, preterm birth, and small for gestational age. Using linear regression analyses, trimester average models identified that higher WBGTmax in the first trimester was associated with larger head circumference; second trimester was associated with shorter birth length, lower birth weight and higher odds of preterm birth, and third trimester was associated with shorter gestational age and larger head circumference. Time-varying analyses using distributed lag nonlinear models find that, compared to the median, lower WBGTmax and HImax (25th percentile) during the first half of pregnancy was associated with higher birth weight and longer birth length. Compared to the median, lower WBGTmax and HImax (25th percentile) in the second half of pregnancy was associated with smaller head circumference while higher wet bulb globe temperature (75th percentile) was associated with larger head circumference. Overall, our study identified that higher WBGTmax and HImax are associated with pregnancy duration and newborn size. Given the overall trend in our study area of rising temperatures, these data suggest that adaptation strategies are urgently needed to protect child health.

Valuable nutrients such as ammonium and phosphate exist in teensy concentrations in marine-culture wastewater (MCW), causing their recovery challenging with inefficient conventional methods. Air gap membrane distillation (AGMD) is systematically explored for the first time to recover nutrients and pure water from low-nutrient MCW. This study assessed the AGMD performance in resource recovery by conducting a thorough investigation and optimization of various parameter conditions. Concerning the findings, AGMD satisfactorily inhibits ammonia transfer from the feed stream to the permeate stream by optimizing operating parameters specifically feed temperature and pH. A higher feed temperature improves water recovery, and feed pH is critical in nutrient recovery. In particular, high pH promotes the transformation and transport of ammonia through the membrane, whereas low pH inhibits ammonia transport, encouraging the creation of pure water. Maintaining an acidic feed solution decreases membrane fouling by increasing the solubility of calcium phosphate, hence boosting water recovery. Nevertheless, higher pH levels encourage fouling by allowing solid phosphate particles to form more readily. While at lower pH, ammonium phosphate fertilizers might be generated in the retentate solution by improving NH₄⁺ and PO₄^3- recovery under optimal conditions. The findings reveal that the AGMD system provides a novel method for treating MCW while also improving nutrient and pure water recovery.

Per- and polyfluoroalkyl substances (PFAS) are a class of ubiquitously detected chemicals, some of which are highly persistent and bioaccumulative in humans. Within the general population, dietary ingestion is considered a primary pathway for PFAS exposure, and seafood consumption specifically has been associated with higher serum PFAS concentrations. Proximity of residence to the ocean may influence dietary habits, particularly seafood consumption, and exposure to geographically specific PFAS sources such as sea spray aerosols (SSA). The objective of this study was to evaluate potential spatial trends in serum PFAS concentrations between Australian coastal and island populations compared to those with inland residency. Human sera were obtained from deidentified surplus pathology samples and pooled with respect to geographical location, sex (male or female), and age group (males: ≥15-<45 years, ≥45 years; females: ≥15-<45 years, ≥45-<60 years, ≥60 years) stratification criteria. Serum samples were then analysed for PFAS using High Performance Liquid Chromatography-Mass Spectrometry (HP LC-MS). A total of 13 of the 45 targeted PFAS were quantifiable in at least one pooled sample, including the detection of perfluorooctane sulfonate (PFOS) replacement compounds 5:3 fluorotelomer carboxylic acid (5:3 FTCA) and potassium 9-chlorohexadecafluoro-3-oxanonane-1-sulfonate (9Cl-F53B). Significant spatial trends were observed in males aged ≥45 years, with serum concentrations of PFOS, perfluorobutanoic acid (PFBA), perfluorodecanoic acid (PFDA) and perfluoroheptane sulfonic acid (PFHpS) demonstrated to be 32-77% higher in pooled samples from island locations compared with inland. A similar trend was observed for PFHpS in coastal locations. Whilst deidentification of samples limited inferences about exposure pathways associated with the observed trends, this study indicated the feasibility of utilising pooled samples for assessing spatial variations in serum PFAS concentrations between geographically distinct subpopulations.

Wetland restoration can promote the recovery of ecosystem services. However, an increasing number of reports indicate that phosphorus leaching risk occurs in downstream water bodies during the early stages of agricultural utilized wetland restoration, it is unclear that whether this phenomenon depend on temporal dynamics. Therefore, in this study, we used soil phosphorus fractions and stoichiometry as indicators to investigate soil phosphorus leaching and examine their evolution during both short- and long-term wetland restoration, aiming to identify the key driving factors. The results showed that only soil inorganic phosphorus (Pi) decreased during short-term restoration, while soil organic P (Po) increased during long-term restoration, which indicates that the restoration period can promote the transformation of Pi to Po. The soil total organic carbon: total P (C:P) and total nitrogen: total P (N:P) ratios did not differ during short-term wetland restoration, while C:P and N:P significantly increased under long-term wetland restoration (163% and 225%), demonstrating an increasing trend of P demand with increasing wetland restoration time. Finally, redundancy analysis showed that reactive iron (Fe_r) and pH were the dominant factors influencing soil P pools under short-term restoration. In contrast, TN, SOC, and pH were dominant factors driving P pools under long-term restoration, and changes in the dominant factors driving P pools also implied that organic carbon contributed to Po accumulation. Overall, these indicators show that wetland restoration improves soil P stability and reduces the potential for soil P release. The findings highlight the importance of incorporating soil P fraction analyses and stoichiometric evaluation into P management during wetland restorations.

The environment plays an important role in modulating susceptibility and severity of respiratory tract infections. Influenza is a significant zoonotic disease globally. Hydrogen sulfide (H₂S), a respiratory tract irritant and toxic gas, is ubiquitous in the environment. The interaction of environmental H₂S exposure and influenza is unknown. In this pilot study we tested the hypothesis that subchronic exposure to ambient H₂S worsens the outcome of influenza A virus (IAV) infection in mice. Male C57BL6 mice were exposed either to room air (RA), or to 5 or 10 ppm H₂S for 2 h, 5 days a week for 5 weeks, followed by a single exposure either to phosphate buffered saline (sham) or a sublethal IAV intranasal dose of 10 plaque-forming units and observed for up to 28 days post inoculation (DPI). 10 ppm H₂S alone suppressed growth. Mice challenged with IAV following exposure to 5 or 10 ppm H₂S were most severely affected and euthanized on DPI 6 to 7 or DPI 4, respectively. In contrast, mice exposed to RA and challenged with IAV only showed minor weight loss. Viral titer in lung homogenates was 11-fold higher in mice pre-exposed to 5 ppm H₂S and challenged with IAV compared to the RA-IAV group on DPI 3. BALF concentrations of TNF-α, IL-6, and IL-10 cytokines were significantly higher in mice exposed to H₂S and challenged with IAV compared to sham groups. Lung pathology was most severe in mice exposed to H₂S and challenged with IAV. Collectively, the study shows that mice subchronically exposed to low levels of H₂S overly reacted to a nonlethal dose of IAV, suffering severe lung injury and mortality. This suggests that communities and workers subchronically exposed to ambient H₂S concentrations used in this study or higher are at higher risk for developing very severe IAV infections and mortality.

The toxicity of chemical mixtures may be misestimated, as the assessment of individual chemicals may not adequately reflect their combined toxic effects. However, numerous combinations of chemicals and various interactions make it impossible to measure all possible mixtures. Computational toxicology can help to mitigate this issue, particularly with new methodologies that rely upon alternatives to animal testing. For cosmetic and personal care additives (CPCAs), the ever-increasing of consumption has triggered their complex co-existence in the aquatic environment. To assess their ecological risks, CPCAs experimentally mix at realistic low concentrations with multi-components and different combinations needs to be examined firstly. In this study, toxicity and interactions of multi-component CPCAs mixtures were analyzed taking Daphnia magna as model organism. Also, the contributions of components to the mixture toxicity at different effect levels were discussed. Apparently, the mixture toxicity is closely related to components proportion and impacted by dilution effect. Different forms of combined toxic effects occur in different effect levels. The more components, the less interactions, and the combined toxic effect tends to be additive. Then, Quantitative Structure-Activity Relationship (QSAR) models were developed and evaluated to predict the aquatic toxicity of CPCAs mixtures at various effect levels. The model performance at the median effect level is the best. The descriptors associated most to the toxicity response of CPCA multi-component mixtures are autocorrelation and radial distribution function (RDF), which provide structural information about the spatial distribution of electronic properties and atomic mass.