Search Results (4,938)

This study investigates the environmental impact of combined missile and drone attacks on Kyiv, the capital of Ukraine, with a focus on the release of particulate matter (PM) into the urban atmosphere. These military strikes frequently result in the destruction of residential and industrial infrastructure, as well as fires, leading to acute increases in ambient concentrations of fine particulate matter (PM2.5). Observational data were collected between 1 and 30 June 2025 using a distributed network of low-cost air quality monitoring stations aggregated by the SaveEcoBot platform. The optical particle counters, based on light scattering technology, enable real-time monitoring of airborne particulate fractions of PM2.5 along with meteorological parameters and gas pollutants. The study period included two significant attacks (10 and 17 June), during which the temporal and spatial dynamics of PM2.5 concentrations were analyzed in comparison to baseline levels observed under non-attack conditions. Raw concentrations of PM2.5 up to 241 μg/m³ were observed in the epicenters of air-strike-induced fires, while smog plumes covered half of the city area. Elevated PM2.5 concentrations were recorded during and for several hours following the attacks and corresponding air raid alerts. The findings show days of PM2.5 exceedances above the World Health Organization (WHO) daily threshold of 15 μg/m³. These results underscore the acute environmental and public health hazards posed by military assaults on urban centers. Furthermore, this research highlights the role of citizen-driven environmental monitoring as a valuable tool for both scientific documentation and potential evidentiary support in assessing the environmental impacts of warfare. Full article

China’s rapid economic growth since its reform and opening-up has come at the cost of worsening atmospheric pollution. This study investigates the spatiotemporal evolution and driving mechanisms of PM_2.5 concentrations in Shandong province, a key industrial region, during 2014–2023, using comprehensive air quality monitoring, meteorological observations, and socioeconomic datasets. Through spatial analysis and geodetector methods, we identify that (1) The annual PM_2.5 concentration decreases significantly by 50.9%; spatially, heterogeneity is observed with the western urban agglomeration experiencing more severe pollution, while the eastern coastal urban agglomeration exhibits better air quality. (2) Gravity model analysis shows that the centroids of PM_2.5 pollution undergo distinct migration phases. (3) PM_2.5 levels show a distinct seasonal pattern, peaking in winter at a level 143.7% higher than the summer average. (4) The meteorological driving factors are primarily air temperature (r = 0.511) and wind speed (r = −0.487), while the socioeconomic factors are tertiary industry production (r = −0.971), particulate matter emissions (r = 0.956), and sulfur dioxide emissions (r = 0.938). Concurrently, the combined effect of tertiary industry production and PM emissions account for 99.5% of PM_2.5 variability. Notably, we validate an Environmental Kuznets Curve relationship (R² = 0.805) between economic development and air quality improvement, demonstrating that clean production policy integration can reconcile environmental and economic objectives. These findings provide empirical evidence supporting circular economy strategies for air pollution mitigation in industrializing regions. Full article

Indoor exposure to polybrominated diphenyl ethers (PBDEs), particularly those bound to fine particulate matter (PM₁, particles < 1 µm), may pose a health concern, especially in light of prolonged indoor occupancy and the capacity of ultrafine particles to reach the lower respiratory tract. This study investigates indoor exposure to PBDEs associated with PM₁ in residential homes in Zagreb, Croatia, across warm and cold seasons. BDE-47 was consistently detected in all samples, while BDE-183 was consistently absent. Elevated concentrations and increased detection frequencies of BDE-99 and BDE-100 were observed during the colder season. Consequently, total PBDE (ΣPBDE) levels in the cold season were approximately 2.5 times higher than in the warm season. Although estimated daily inhalation intakes were below established oral reference doses, the potential for deep pulmonary deposition and systemic distribution underscores the need for further investigation. These findings represent the first reported data on indoor PM₁-associated PBDEs in Europe, emphasizing the impact of seasonal dynamics on inhalation exposure due to variation on indoor contaminant levels. Full article

Background/Objectives: Predicting whether a compound is subject to active transport is crucial in drug development. We propose a simple threshold for passive membrane permeability (P_m), derived from the cell’s energy limitation, to identify compounds unlikely to be actively effluxed. Results: By considering fundamental cellular energy constraints, our approach provides a mechanistic rationale for why compounds with very high passive permeability in combination with low applied concentration will not undergo active efflux. This moves beyond the empirical observation (such as in previous systems that associate fast-permeating, poorly soluble compounds with low transporter activity) by grounding the prediction in the cell’s energetic limitations. For MDCK (Madin–Darby canine kidney) cells, this threshold—normalized to the applied compound concentration (C_ext)—was determined to be P_m×C_ext = 10^−1.7 cm/s×µM. Methods: To derive this threshold, we conducted an extensive analysis of literature-reported efflux ratios (ERs) in MDCKII cells overexpressing efflux transporters (MDR1, BCRP, MRP2; 294 datapoints across 136 unique compounds). Concentration-dependent measurements for Amprenavir, Eletriptan, Loperamide, and Quinidine—chosen because these borderline compounds exhibited the highest P_m×C_ext while still being actively effluxed—enabled the most accurate determination of the threshold. Literature ER values were re-evaluated through the experimental determination of reliable P_m values, as well as newly measured ER values with MDCK efflux assays. Conclusions: The results of these assays and the re-evaluation allowed us to reclassify all but three outliers (compounds with ER > 2.5 and log(P_m×C_ext) > −1.7). In contrast, more than 60% of the compounds analyzed without significant ER values (123 compounds) fell above the threshold, in strong agreement with our theory of an energy limitation to active transport. This permeability threshold thus provides a simple and broadly applicable criterion to identify compounds for which active efflux is energetically not feasible and may serve as a practical tool for early drug discovery and optimization, pending further validation in practical applications. Full article

Clean air is listed by the United Nations under several Sustainable Development Goals. Particulate matter (PM_2.5) and ground-level ozone (O₃) are pollutants with severe public health and environmental impacts. In China, multiple fine-scale datasets integrating ground monitors, satellites, and chemical transport models have been developed to estimate PM_2.5 and O₃ concentrations, but differences between the fine-scale datasets complicate applications in exposure and policy research. This study presents the first systematic intercomparison of five PM_2.5 datasets (V5.GL.03, Ma et al. 2021, Huang et al. 2021, CHAP, TAP) and two O₃ datasets (CHAP, TAP) from 2014 to 2023, evaluated against ground-based observations at national, regional, and provincial levels. We present both operational (single time point) and dynamic (change over time) evaluations to understand how model results compare with observations for each year, and quantify the performances of the models in assessing long term changes in air quality. Results show nationwide declines in PM_2.5 (by 22.1 µgm⁻³; regional range: 8.4–30.1 µgm⁻³) and O₃ (by 28.5 µgm⁻³; regional range: 19.3–34.3 µgm⁻³). Operational and dynamic evaluation shows that CHAP consistently has higher R² (greater than 0.7 in all regions) and lower errors (less than 3.7 µgm⁻³ in all regions) compared to other datasets across most years and regions for PM_2.5. The same is true for TAP for O₃ (R² greater than 0.3 and ME less than 28.6 µgm⁻³ in all regions). However, the model performances vary spatially and temporally in alignment with several factors ranging from the number of observational monitors in a location, to recent changes in pollutant concentration levels, to extreme meteorological conditions. For example, higher predictive errors (>3.6 µgm⁻³) in operational evaluations are observed in all datasets for PM_2.5 in the sparsely monitored northwest region. Similarly, we find higher errors (ME > 28.5 µgm⁻³) in all O₃ datasets in the densely populated northern region, especially in the heavily industrialized Beijing–Tianjin–Hebei (BTH) area. Full article

We here present a novel and sensitive methodology for determining the melting point (MP) of Bovine Serum Albumin (BSA) from micromolar to picomolar concentration levels under label-free conditions. At 1 pM we could model the melting with a sharp Gaussian. However, from the transient state observed during the melting process by using a simple exponential decay model, we determined a time constant of 67 s. We applied this methodology by studying a 3.3 pM sample of a botulinum toxin A (BoNT-A) (stabilized with 2.8 nanomolar denatured Human Serum Albumin (HSA)). We were able to determine the Tm of BoNT-A in the presence of approximately 1000-fold more concentrated HSA. This method enables the detection of protein melting transitions at picomolar concentrations without the use of a fluorescence dye. Its sensitivity and simplicity make it a valuable analytical tool for studying protein stability in diluted pharmaceutical formulations. This method is useful for correlating thermal conformational changes with catalytic function. Full article

This study aims to evaluate and compare the performance of Autoencoders (AEs) and Sparse Autoencoders (SAEs) in forecasting the next-hour concentration levels of various air pollutants—specifically NO₂(t + 1), PM₁₀(t + 1), and SO₂(t + 1)—in the Bay of Algeciras, a highly complex region located in southern Spain. Hourly data related to air quality, meteorological conditions, and maritime traffic were collected from 2017 to 2019 across multiple monitoring stations distributed throughout the bay, enabling the analysis of diverse forecasting scenarios. The output variable was segmented into four distinct, non-overlapping quartiles (Q1–Q4) to capture different concentration ranges. AE models demonstrated greater accuracy in predicting moderate pollution levels (Q2 and Q3), whereas SAE models achieved comparable performance at the lower and upper extremes (Q1 and Q4). The results suggest that stacking AE layers with varying degrees of sparsity—culminating in a supervised output layer—can enhance the model’s ability to forecast pollutant concentration indices across all quartiles. Notably, Q4 predictions, representing peak concentrations, benefited from more complex SAE architectures, likely due to the increased difficulty associated with modelling extreme values. Full article

Pluriannual time series of fine particle concentrations suspended in the atmosphere are often lacking. Such data is necessary in evaluating the efficiency of policies aiming to improve air quality in megacities. In this work, a recently developed empirical method is applied over the megacities of Paris, Cairo, and New Delhi. The method utilizes observations of the aerosol optical depth, Angström Exponent, and atmospheric precipitable water as inputs to estimate the PM10. The modeled values validated against their respective reference measurements exhibited the best performance at daily, weekly, and monthly averages when using inputs of the AERONET. When exploiting inputs of the CAMS and MERRA-2 reanalyses, the results were found to be satisfactory with MERRA-2 on the monthly scale. This allows the reconstruction of the variability of the PM10 for the last 45 years. Analysis shows that average annual PM10 concentration has decreased from 40 to 20 µg·m⁻³ in Paris, increased from 70 to 250 µg·m⁻³ in New Delhi, and stayed relatively stable (around 100 µg·m⁻³) in Cairo. Provided that at least one year of PM10 measurements are available to calibrate the empirical method, the method herein is replicable over other megacities around the world. Full article

Objectives: Rapid detection and quantification of nucleic acids are essential for on-site diagnosis of pathogens. To provide an alternative to current methods that require bulky instruments and long reaction times, we developed a digital nucleic acid amplification method suitable for point-of-care applications. Methods: The method combines compartmentalization in micrometer-sized microchambers with recombinase polymerase amplification (RPA) and the Mango fluorescent aptamer system. Fluorescence microscopy was used to acquire images of microchambers. Single molecules of target DNA sequences were detected as fluorescence-positive chambers in the image and quantified by counting these chambers. Results: Detection and quantification were achieved within 8 and 22 min, respectively. The measurable concentration range was approximately 4 fM to 40 pM, demonstrating a wide dynamic range. Furthermore, the successful detection of five different pathogen-derived DNA sequences confirmed the versatility of the approach. Conclusions: Because the reaction proceeds isothermally within a compact microdevice, the system requires minimal instrumentation. These features make it a promising platform for nucleic acid measurement in point-of-care testing. Full article

A tiered approach is presented for evaluating occupational risks during liquid deposition modelling (LDM) using ceramic materials for manufacturing complex geometries in construction. The ceramic paste is comprised of kaolin/zeolite powders mixed with deionised water at a specific ratio. The tiered occupational risk analysis covered (i) the material evaluation and information gathering, (ii) on-site exposure measurements to ultrafine and micro-size particles, and (iii) morphological and toxicological analyses of raw and collected air samples. Results indicated an increase in PM4 (particle diameter < 4 μm) concentrations during powder preparation, reaching up to 1 mg/m³ during powder preparation, although below the corresponding substance-specific and general dust occupational exposure limit and with no increased exposure to ultrafine particles, as supported by morphological analysis. In toxicity assessment, reactive oxygen species production (ROS) reached approximately 300% for 50 μg/mL raw kaolin powder, while inducing high upregulation of TNF-α and IL-6 mRNA expression genes, indicating activation of pro-inflammatory pathways. Airborne samples resulted in cell viability reduction by ~50% at 40 μg/mL, showing significance (p-value < 0.001). Translating these findings to human risk remains difficult, yet the findings highlight an urgent requirement for continuous exposure surveillance, tailored toxicity evaluations, and robust protective strategies throughout ceramic manufacturing. Full article

This study utilizes ambient air quality monitoring data from 13 prefecture-level cities in Heilongjiang Province to systematically analyze the pollution characteristics and dynamic evolution of ozone (O₃) and non-methane hydrocarbons (NMHCs). The findings reveal that overall air quality in Heilongjiang Province has improved substantially in recent years. The concentrations of SO₂, NO₂, PM₁₀, PM_2.5 and CO in 2023 decreased significantly compared with 2015, with an average reduction of 38.7%. However, O₃ concentrations have continued to rise, indicating that O₃ pollution has become an increasingly pressing environmental concern. On an annual scale, the monthly average O₃ concentration in 2023 displayed a “clear single-peak” pattern, reaching its maximum in June, at a concentration of 139 μg/m³. In contrast, the monthly average NMHC concentration exhibited a “distinct double-peak” pattern, with elevated levels in January and December, at 59.4 and 48.35 μg/m³, respectively. From an hourly perspective, the highest O₃ concentrations across the 13 cities occurred between 11:00 and 17:00, while NMHC concentrations showed an opposite trend. Furthermore, during the heating season (October to April of the following year), O₃ and NMHC concentrations increased by 0.78 and 1.56 times, respectively, compared with the non-heating season. In terms of ambient air quality levels, both O₃ and NMHC concentrations exhibited a gradual upward trend under conditions of “excellent”, “good”, and “light pollution”. However, under “moderate pollution”, “heavy pollution”, and “severe pollution” levels, O₃ and NMHC concentrations exhibited irregular patterns, likely due to the interaction of multiple complex factors. O₃ pollution follows a “central concentration and peripheral diffusion” pattern, reflecting the combined influence of human activities and natural conditions. In contrast, NMHC concentrations display pronounced spatial heterogeneity, with low levels in the west and high levels in the east, primarily driven by regional differences in industrial structure and environmental conditions. In summary, this study aims to elucidate the spatiotemporal distribution characteristics of O₃ and NMHC pollution in Heilongjiang Province and their complex relationship with air quality levels, providing a scientific basis for future pollution prevention and control strategies. Subsequent research should focus on identifying the underlying causes of pollution to develop more precise and effective mitigation measures, thereby continuously improving ambient air quality in the province. Full article

The concentration of air pollutants could be affected by climate change in industrial park zones in Hidalgo state, Mexico (IPHSs). The goals of this work were: (a) to describe the aerosols’ behavior (PM₁₀ and PM_2.5) and air pollutants (SO₂, NO₂, O₃, and CO) in the IPHSs and (b) determine the climate variable behavior regarding the presence in IPHSs. The methodology consisted of structuring the time series of climate variables and air pollutants in six analysis regions. Afterwards, an annual average calculation, a count of days exceeding the allowed limits set by the official Mexican norms, an analysis of annual behavior by season, the Sen slope calculation, and correlation among variables were performed. Results demonstrated that Zone 2 is the most polluted, exceeding the allowed limits in the annual average (PM₁₀ > 36 μg/m³, PM_2.5 > 10 μg/m³, and NO₂ > 0.021 ppm) and having more than 1000, 96, and 11 days where the daily limit was exceeded in PM₁₀, PM_2.5, and SO₂, respectively. The minimum concentrations of the pollutants were observed during the summer–autumn seasons, coinciding with the highest precipitation. Regarding the correlations, the pollutants are negatively and statistically significantly correlated with precipitation (ranging from −0.81 to −0.43); meanwhile, the maximum temperature (ranging from +0.41 to +0.51) and evaporation (ranging from +0.39 to +0.54) are positively and statistically significantly correlated. In conclusion, the results could suggest that the presence of pollutants in the atmosphere may be influenced by the behavior of nearby regional climatic conditions in the IPHSs. Full article

Urban air pollution in Kazakhstan poses persistent risks; this study synthesizes measured concentrations, source evidence, and policy responses to inform mitigation in cold, inversion-prone cities. We compile national monitoring (Kazhydromet), community PM_2.5 sensors, emissions inventories and recent CEMS provisions, and appraise modeling approaches (Gaussian screening, Eulerian CTMs, and data-driven forecasting). Seasonal descriptive comparisons are performed for Astana using 56,944 observations (2023–2024), partitioned into heating and non-heating periods, and published receptor apportionment is integrated. Across major cities, annual PM_2.5 generally exceeds WHO guidelines and winter stagnation drives episodes. In Astana, the heating season means rose relative to non-heating equivalents—PM_2.5 12.3 vs. 10.6 μg m⁻³ (+16%) and SO₂ 21.9 vs. 14.8 μg m⁻³ (+23%)—while NO was unchanged; higher means but lower medians indicate episodic winter peaks. Receptor analyses attribute large shares of PM_2.5 to traffic (spark-ignition engines 30% and diesel 7%) and coal-related contributions including secondary nitrate (15%), consistent with power/heat and vehicle dominance. Evidence supports prioritizing clean heating (coal-to-gas and efficiency), transport emission controls, and dense monitoring to enable accountability within Kazakhstan’s Environmental Code and decarbonization strategy. A tiered modeling workflow can quantify intervention impacts and deweather trends; the near-term focus should be on reducing winter exposures. Full article

Understanding how organic amendments affect microbial carbon use efficiency (CUE) and necromass C (MNC) is crucial for understanding soil organic C (SOC) formation and accrual in paddy fields, but the underlying mechanisms remain largely unclear. In this study, the microbial CUE, MNC, and microbial community composition, as well as SOC fractions and chemical composition, were measured under long-term organic amendments: rice straw (RS), green manure (GM), and pig manure (PM) in paddy soils. Four treatments were included: (1) chemical fertilizers (CF); (2) CF plus RS (CF + RS); (2) CF plus GM (CF + GM); and (4) CF plus PM (CF + PM). The CUE, MNC, and microbial community were determined by ¹⁸O-H₂O incubation, amino sugars levels, and phospholipid fatty acids (PLFAs) content, respectively. Results showed that SOC, particulate organic C (POC), and mineral-associated organic C (MAOC) concentrations were significantly increased by organic amendments compared with chemical fertilization alone. The O-alkyl C decreased, but aromatic C increased with long-term organic amendments, suggesting enhanced SOC hydrophobicity. GM and PM inputs significantly enhanced microbial CUE, but straw return did not affect microbial CUE compared to CF. Microbial growth and C uptake increased by 25.2–42.4% and 19.8–30.0% under organic amendments relative with CF. Microbial respiration was increased by RS and GM amendments. Turnover time was more rapid in CF + RS and CF + GM than in CF and CF + PM. Compared to CF, organic amendments increased the MNC concentration due to the increase in microbial biomass. In addition, CF + RS and CF + GM enhanced the MNC contribution to SOC, but PM had no effect, suggesting that PM contributed more organic C from non-microbial sources. The SOC, POC, and MAOC increased with microbial CUE and MNC, indicating that microbial traits play a crucial role in SOC accrual. Higher microbial CUE and biomass explained the increased MNC accumulation under organic amendments. Our study highlights the crucial role of microbe-mediated processes in SOC accrual under long-term organic amendments in paddy soils. Our findings show that organic amendments are an effective management practice for accumulating more SOC in paddy soils. Full article

CoFe₂O₄ loaded onto red brick powder (CoFe₂O₄@RBP) was synthesized via coprecipitation followed by post-calcination and employed as a heterogeneous catalyst to activate peroxymonosulfate (PMS) for the degradation of methylene blue (MB), thereby valorizing red brick demolition waste within a circular economy pathway and aligning the study with sustainability-oriented resource recovery. The effects of pH, PMS concentration, catalyst dosage, and coexisting substances on MB removal were systematically investigated. Complete MB removal was achieved within 30 min, and the apparent rate constant for the CoFe₂O₄@RBP/PMS system was 0.22 min⁻¹—slightly lower than that of CoFe₂O₄/PMS—while Co leaching was markedly reduced. The process performed well across a broad pH range (3.0–9.0). EPR and radical-quenching experiments indicate that SO₄•⁻ and HO• play a minor role, whereas the Co(II)–PMS complex is primarily responsible for MB degradation; accordingly, common coexisting species (SO₄²⁻, Cl⁻, NO₃⁻, humic acid) exert negligible effects. The catalyst also maintained strong durability across numerous repetitions. These results highlight a cost-efficient route to PMS activation by coupling CoFe₂O₄ with construction waste-derived supports. Full article