Environmental Pollution最新文献

{"title":"High pollution and health risk of antibiotic resistance genes in rural domestic sewage in southeastern China: A study combining national-scale distribution and machine learning","authors":"Bingbing Feng ,&nbsp;Juan Chen ,&nbsp;Chao Wang ,&nbsp;Peifang Wang ,&nbsp;Han Gao ,&nbsp;Bo Zhang ,&nbsp;Jingjing Zhang ,&nbsp;Shunqing Zhang ,&nbsp;Jingjing Fu","doi":"10.1016/j.envpol.2025.126865","DOIUrl":"10.1016/j.envpol.2025.126865","url":null,"abstract":"<div><div>Rural domestic sewage has emerged as an important reservoir of antibiotic resistance genes (ARGs) under rapid urbanization, while the national-scale geographical patterns and risks of ARGs remaining unclear. We investigated ARG pollution in rural domestic sewage across 39 sites in 22 Chinese provinces using metagenomic sequencing, identifying 702 ARG subtypes across 21 types. Multidrug resistance genes were predominant in the shared ARGs, accounting for 58.96 % of the total ARG abundance. Host bacteria analysis revealed <em>Klebsiella pneumoniae</em> and <em>Escherichia coli</em> were the main pathogenic-resistant bacteria. Southeastern China exhibited the highest level of ARG pollution in rural domestic sewage, followed by south-central, northern, and western. This ARG pollution was primarily caused by human/animal feces based on ARG indicators. Partial least-squares path model and partial redundancy analysis highlighted antibiotics as the primary driver, explaining 24.16 % of ARG variation, with sulfamethazine, norfloxacin, and ofloxacin identified as priority control targets. Risk assessment by calculating the risk index indicated 24.58 % of detected ARGs posed potential health threats, particularly multidrug resistance. Machine learning models predicted higher ARG risks in rural domestic sewage from southeastern China with intensive human activity. This study underscores the crucial impact of antibiotics in ARG proliferation and risk in rural domestic sewage.</div></div>","PeriodicalId":311,"journal":{"name":"Environmental Pollution","volume":"383 ","pages":"Article 126865"},"PeriodicalIF":7.6,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144677712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coupling fine-grained nighttime Earth observation and optimal buffer for mobility-oriented measures of high-quality outdoor nighttime light exposure","authors":"Yang Liu ,&nbsp;Mei-Po Kwan ,&nbsp;Qiming Zheng ,&nbsp;Peifeng Ma","doi":"10.1016/j.envpol.2025.126861","DOIUrl":"10.1016/j.envpol.2025.126861","url":null,"abstract":"<div><div>Earth observations can well facilitate the modeling of human living environments but still need to be coupled with proper geographic information system (GIS) techniques to fully unpack their power for human health services. In this study, we investigated the buffer zone with optimal size as the proper contextual unit for the high-quality measurements of people's exposure to outdoor artificial light at night (ALAN) using SDGSAT-1 glimmer data and the mobility-oriented research paradigm. A large sample set with comprehensive socio-demographic attributes and self-reported health statuses was collected from 940 participants in Hong Kong through a stratified scheme. Participants' trajectories were delineated from GPS-equipped smartphones, while Hong Kong's nightscape was delineated from SDGSAT-1 images at a spatial resolution of 10 m. We derived participants' exposures to outdoor ALAN along their nighttime trajectories using a range of buffer sizes from 10 m to 100 m. We employed binary logistic regression to evaluate the quality of exposure measurements by modeling people's overall health outcomes. Our results clearly showed the U-shaped <em>p</em>-value curves along the gradient of buffer size in two representative communities, which indicates the existence of an optimal buffer size at 70 m in pertinent geographic contexts. We also observed that improper settings of contextual units cannot adequately capture the high-quality environmental exposure, and the spatial non-stationary issues may further complicate the quality issues in exposure measures. Our results provide essential insights into a range of health geography, epidemiological, and public health studies that need Earth observation data for accurate environmental exposure measures.</div></div>","PeriodicalId":311,"journal":{"name":"Environmental Pollution","volume":"383 ","pages":"Article 126861"},"PeriodicalIF":7.6,"publicationDate":"2025-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144677722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Arsenic contamination of rainfed versus irrigated rice","authors":"Ben Ingram ,&nbsp;Muhammad Ashraful Habib ,&nbsp;Sarah E. Johnson-Beebout ,&nbsp;Cecilia Acuin ,&nbsp;Ron Corstanje ,&nbsp;Robert W. Simmons ,&nbsp;Guy J.D. Kirk","doi":"10.1016/j.envpol.2025.126856","DOIUrl":"10.1016/j.envpol.2025.126856","url":null,"abstract":"<div><div>Arsenic (As) contamination of rice remains a major human health issue in Asia. Most research has been on irrigated rice. However much of the projected increase in global rice demand over coming decades must be met by rainfed lowland systems, for which As relations are poorly understood. We present the most comprehensive survey to date of As in rice in farmers’ fields across Bangladesh, covering both irrigated and rainfed systems. We collected rice grain and soil at 943 sites in the three rice growing seasons: irrigated Boro, rainfed Aus, and longer-duration rainfed Aman. Grain As concentrations increased in the order Aman ≪ Boro &lt; Aus with 2, 25 and 41 % of the sites exceeding permitted thresholds, respectively. The greater concentration in Aus than Boro challenges the accepted wisdom that contaminated irrigation water is the main source of As. The main growth and grain filling periods, when most As is taken up, coincide in Aus with the peak of the monsoon rains, suggesting a link between rainfall and high grain As. We suggest this is due to stronger soil reducing conditions and hence As solubility during peak rainfall. We discuss implications for rainfed lowland rice across Asia and mitigation options.</div></div>","PeriodicalId":311,"journal":{"name":"Environmental Pollution","volume":"383 ","pages":"Article 126856"},"PeriodicalIF":7.6,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144664524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing rice (Oryza sativa L.) resilience to cadmium stress through nanoparticle and rhizobacterial strategies: A sustainable approach to heavy metal remediation","authors":"Fu Chen ,&nbsp;Xuyue Pan ,&nbsp;Zhanbin Luo ,&nbsp;Xueying Duan ,&nbsp;Ming Zou ,&nbsp;Jing Ma","doi":"10.1016/j.envpol.2025.126847","DOIUrl":"10.1016/j.envpol.2025.126847","url":null,"abstract":"<div><div>Soil contamination with toxic heavy metals such as cadmium (Cd) is becoming a serious global problem due to rapid industrial and agriculture expansion. Although nanoparticles (NPs) and plant growth-promoting rhizo-bacteria (PGPR) are the major protectants to alleviate metal toxicity. A pot experiment was conducted under controlled conditions by using sand, mixed with different levels of Cd i.e., 0, 50, and 100 mg kg⁻¹ together with the application of FeO–NPs (50 and 100 mg L⁻¹) and <em>B. megaterium</em> (5 and 10 ppm) levels to monitor different growth, gaseous exchange, oxidative stress, antioxidative responses, minerals accumulation, organic acid exudation patterns of <em>O. sativa</em> seedlings. Our results depicted that Cd exposure significantly reduced plant biomass, photosynthetic efficiency, and mineral uptake, while increasing malondialdehyde (MDA), H₂O₂, and electrolyte leakage, indicating oxidative stress. Antioxidant enzymes (SOD, POD, CAT, and APX) were enhanced at 50 mg kg⁻¹ Cd but declined at 100 mg kg⁻¹. Cd stress also suppressed anthocyanins and soluble proteins while increasing Cd accumulation in roots and shoots. Application of FeO–NPs and <em>B. megaterium</em> mitigated these adverse effects by improving growth, photosynthesis, antioxidant defenses, mineral uptake, and reducing oxidative damage and organic acid exudation. These treatments also lowered Cd retention in plant tissues. Research findings, therefore, suggested that application of FeO–NPs and <em>B. megaterium</em> can ameliorate Cd toxicity in <em>O. sativa</em> seedlings and resulted in improved plant growth and composition under metal stress as depicted by balanced exudation of organic acids.</div></div>","PeriodicalId":311,"journal":{"name":"Environmental Pollution","volume":"383 ","pages":"Article 126847"},"PeriodicalIF":7.6,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144664519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distribution, sources, and ecological risks of heavy metal contamination at the sediment-water interface in the Dongjiang Basin based on in situ high-resolution measurements","authors":"Weijie Li ,&nbsp;Mengdi Yang ,&nbsp;Kang Liao ,&nbsp;Jianle Wang ,&nbsp;Zhiwei Huang ,&nbsp;Hailong Zeng ,&nbsp;Huaiyang Fang ,&nbsp;Hong Deng","doi":"10.1016/j.envpol.2025.126853","DOIUrl":"10.1016/j.envpol.2025.126853","url":null,"abstract":"<div><div>As a critical drinking water source for over 40 million people in southern China, the Dongjiang River faces growing ecological threats from sediment-derived heavy metals (HMs: As, Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn). This pioneering study is the first to integrate DGT, HR-Peeper, and BCR techniques, achieving three breakthroughs: (1) millimeter-scale resolution mapping of SWI dynamics, (2) a mechanistic assessment of mobility and bioavailability through DIFS modeling and flux calculations, and (3) a quantitative source apportionment that combines lead isotopes with machine learning–enhanced multivariate statistics (PCA-PMF-RF). Key findings demonstrate the following: (i) the accumulation of HMs downstream, (ii) Cd as the predominant risk factor despite moderate pollution levels, and (iii) Mn-Cd release as a previously underestimated threat, evidenced by positive diffusion fluxes and kinetic parameters. Using Pb isotopes and multivariate statistics (PCA-PMF-RF), we identified three dominant sources: natural/agricultural (42.6 %), industrial (18.9 %), and composite anthropogenic (38.5 %). This multi-methodological framework sets new standards for SWI studies and provides actionable data for watershed management.</div></div>","PeriodicalId":311,"journal":{"name":"Environmental Pollution","volume":"383 ","pages":"Article 126853"},"PeriodicalIF":7.6,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144664521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of natural rainfall and solidifying agents on solidified river sludge: Environmental characteristics","authors":"Mengyi Wei ,&nbsp;Junjie Shen ,&nbsp;Suqing Wu ,&nbsp;Xiangyong Zheng ,&nbsp;Min Zhao ,&nbsp;Sihong Liu ,&nbsp;Liujiang Wang ,&nbsp;Chunzhen Fan ,&nbsp;Noriyuki Yoshida ,&nbsp;Hongbin Cui","doi":"10.1016/j.envpol.2025.126850","DOIUrl":"10.1016/j.envpol.2025.126850","url":null,"abstract":"<div><div>Application of solidified dredged sludge for constructing ecological slope protection represents a vital strategy for sustainable utilization of river sludge. Evaluating the environmental characteristics of solidified river sludge under prolonged exposure to natural conditions is essential for assessing its ecological safety and practical applicability. In this study, conventional cement (CC) and a novel composite solidifying agent (GCP) were employed to stabilize river sludge. Impact of natural rainfall erosion on the physicochemical properties and environmental characteristics of the solidified sludge was examined. Particular focus was placed on the release patterns of water pollutants, including nitrogen, phosphorus, and heavy metals from both types of solidified sludge under natural rainfall exposure. The results showed that rainfall erosion reduced the strength and pH of the solidified sludge, affected the immobilization effect of heavy metals, nitrogen, phosphorus, and promoted their release. Compared with CC, GCP exhibited better immobilization effects on pollutants and a stronger buffering capacity against rainfall erosion. The compressive strength of the GCP solidified sludge (GCPSS) after rainfall erosion was 1.35 times greater than that of the CC solidified sludge (CCSS). The concentrations of total phosphorous and nitrogen in the GCPSS decreased significantly under the action of multiple rainfall events. <em>Cynodon dactylon</em> cultivated on the GCPSS demonstrated superior growth performance, accompanied by greater microbial diversity and abundance. Notably, the populations of <em>Pseudolabrys</em>, <em>Gaiella</em>, and <em>Bacillus</em> were enriched, contributing positively to soil stability. In contrast, the microbial community in the CCSS exhibited no significant variation. These findings are important for assessing the feasibility and environmental safety of utilizing solidified river sludge in the construction of ecological slope protection.</div></div>","PeriodicalId":311,"journal":{"name":"Environmental Pollution","volume":"383 ","pages":"Article 126850"},"PeriodicalIF":7.6,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144652171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Antibiotic resistant bacteria (ARB) and genes (ARGs) in urban wastewater treatment plants: influencing factors, mechanisms, and removal efficiency","authors":"Chimdi Muoghalu, Herbert Cirrus Kaboggoza, Swaib Semiyaga, Sarah Lebu, Chenchen Lui, Charles Niwagaba, Faridah Nansubuga, Musa Manga","doi":"10.1016/j.envpol.2025.126851","DOIUrl":"https://doi.org/10.1016/j.envpol.2025.126851","url":null,"abstract":"Urban wastewater treatment plants (UWWTPs) are major sources of antibiotic-resistant bacteria (ARB) and genes (ARGs) in the environment. Mitigating their impact requires understanding their sources, proliferation factors, and treatment mechanisms. While several studies have examined ARB and ARG concentrations and persistence post-effluent discharge, there is limited research on how intrinsic, environmental, and operational factors influence their prevalence. Notably, comprehensive decision-making tools for technology selection are lacking. We critically reviewed the sources of ARGs and ARB, factors influencing their fate, and the effectiveness of treatment processes. Our review highlights recent advances in monitoring and optimization and presents a decision matrix to guide selection of treatment technologies. Domestic wastewater had the highest relative ARG abundance while hospital wastewater, though lower in relative abundance, harbors greater ARG diversity. Due to their adaptability, ARGs persist even after organic and nutrient (energy source) removal, as bacterial lysis releases intracellular ARGs, which convert to extracellular ARGs. The fate of ARB and ARG depends on the form of organic matter – soluble or suspended - in the wastewater with soluble organic matter aiding removal via adsorption and complexation. Conventional primary and secondary treatment processes are less effective than advanced methods like chlorine disinfection and UV radiation, though efficiency varies with ARG type, reaction time, dosage. Combining different advanced treatments can improve ARG removal. Future research should explore pretreating different wastewater before discharge to UWWTP, bacteriophage roles in ARG transmission, and ARB sensitivity to advanced treatment. By comprehensively examining ARB and ARG fate, effective treatment processes can be better targeted.","PeriodicalId":311,"journal":{"name":"Environmental Pollution","volume":"18 1","pages":""},"PeriodicalIF":8.9,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144664578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrodynamics and dissolved organic matter regulate partitioning behaviour of heavy metals in seawater in a human-impacted subtropical estuary","authors":"Ling Zhang ,&nbsp;Yunchao Wu ,&nbsp;Jia Yang ,&nbsp;Pengju Li ,&nbsp;Zhixin Ni ,&nbsp;Xiaoping Huang","doi":"10.1016/j.envpol.2025.126854","DOIUrl":"10.1016/j.envpol.2025.126854","url":null,"abstract":"<div><div>The partitioning behaviour of heavy metals (HMs) plays a crucial role in influencing their mobility and pollution risks in estuaries. However, this process remains poorly understood in dynamic estuaries subject to intense anthropogenic and terrestrial inputs, which substantially alter the hydrodynamics and organic matter characteristics. Here, we performed our study in the Pearl River Estuary, which records serious anthropogenic activities and contains vibrant hydrodynamic processes, via runoff alteration and organic matter component shift, with the aim of probing the partitioning mechanisms of HMs between the particulate and dissolved phases in the water column. Results indicated that the terrestrial and anthropogenic inputs via runoff primarily controlled the levels and distributions of HMs. Partition coefficients (<em>K</em>_<em>d</em>) of HMs were higher along the estuarine west coast and near river outlets, where stronger turbulence from currents and runoff prevailed. Offshore, <em>K</em>_<em>d</em> values decreased due to mixing of freshwater and seawater. Salt wedge-induced water stratification facilitated the retention of most HMs in the particulate phase, and had a moderate impact on metal partitioning during summer. Terrestrially derived humic-like organic components further induced the partitioning of most HMs towards the particulate phase during this season. Intense hydrodynamic mixing during winter favoured metal partitioning into the dissolved phase, increasing metal mobility and associated risks, particularly for As, Pb and Cr. Moreover, anthropogenically derived protein-like components promoted the presence of particulate phase HMs under reduced runoff conditions. This study advances the understanding of metal transfer, transformation and pollution risks in dynamic, human-impacted estuarine environments.</div></div>","PeriodicalId":311,"journal":{"name":"Environmental Pollution","volume":"383 ","pages":"Article 126854"},"PeriodicalIF":7.6,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144652169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal variation of mercury and selenium in starfish from a contaminated coastal ecosystem","authors":"Gang Ni ,&nbsp;Le Chao ,&nbsp;Jiansong Chu ,&nbsp;Jiachen Sun","doi":"10.1016/j.envpol.2025.126857","DOIUrl":"10.1016/j.envpol.2025.126857","url":null,"abstract":"<div><div>Jiaozhou Bay (JZB), a hotspot for mercury (Hg) methylation and pollution in the Yellow Sea, faces rising Hg levels due to anthropogenic activities. However, seasonal Hg accumulation in benthic fauna remains understudied. This study investigated seasonal variations in Hg and selenium (Se) in Northern Pacific Seastar (NPS), and explored how carbon source (δ¹³C) and trophic position (δ¹⁵N) influence their accumulation. We observed distinct seasonal accumulation patterns for Hg and Se in NPS from JZB: MeHg and THg concentrations were significantly higher in summer and fall/winter than in spring, while Se levels were lowest in summer. Comparisons with two open sea sites showed that MeHg levels in NPS from JZB were significantly higher than those at Hailv Island (Weihai) and Changdao Archipelago (Yantai), while Se levels were lower than both sites. The MeHg:THg ratio and Se concentrations were positively correlated with δ¹³C, whereas MeHg, MeHg:THg and Se showed negative correlations with δ¹⁵N. The two Hg health risk assessment criteria, Se:Hg molar ratio and Se health benefit value (HBV_Se) showed that Se presented in molar excess of Hg in all NPS, potentially offsetting Hg toxicity risks. The relationships between the two risk criteria and body weight, δ¹³C and δ¹⁵N in NPS, suggest that starfish with diets less influenced by terrestrial discharge, lower trophic levels, and smaller body sizes were more protected by Se. Our findings highlight NPS as a potentially valuable bioindicator of Hg–Se interactions in this MeHg pollution hotspot and underscore the need for further research on seasonal Hg sources and Hg methylation dynamics in JZB.</div></div>","PeriodicalId":311,"journal":{"name":"Environmental Pollution","volume":"383 ","pages":"Article 126857"},"PeriodicalIF":7.6,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144652172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative and mechanistic study of the effect of river valley topography on urban scale pollution dispersion","authors":"Ying Wang ,&nbsp;Yuxuan Hao ,&nbsp;Yanyan Zhou ,&nbsp;Jianxiong Liu ,&nbsp;Yanfei Dong ,&nbsp;Jiaxin Long ,&nbsp;Wei Li","doi":"10.1016/j.envpol.2025.126848","DOIUrl":"10.1016/j.envpol.2025.126848","url":null,"abstract":"<div><div>This study investigates the influence of complex terrain on air pollution dispersion during a valley-basin pollution episode in Lanzhou, northwestern China, using the WRF-CALPUFF modeling system and terrain-modified sensitivity experiments to quantify these topographic effects and reveal their underlying mechanisms. Results indicate that orographic features increase NO₂ concentrations in urban areas by approximately 30 % on average, while channeling effects enhance ventilation and reduce pollutants in northwestern valleys. Analysis of atmospheric dynamics and thermodynamics reveals that thermally-induced local circulations combined with topographic stagnation create recirculation zones that effectively trap pollutants, as evidenced by recirculation factor analysis showing pronounced accumulation in these zones compared to well-ventilated areas. Valley heat deficit (VHD) demonstrates a strong correlation with NO₂ levels (R = 0.77), where elevated VHD coincides spatially with recirculation zones and pollution hotspots. The study identifies a critical VHD threshold of 1.4 MJ/m², beyond which pollution episodes occur due to suppressed vertical mixing from enhanced atmospheric stability and restricted horizontal transport from terrain-induced flow blockage. These findings highlight how the combined effects of thermal stabilization and flow obstruction work synergistically to sustain pollution accumulation in mountainous regions. The research establishes a comprehensive framework that elucidates the coupled dynamic-thermodynamic mechanisms through which terrain characteristics modulate pollution dispersion patterns, offering valuable insights into boundary layer processes and airflow dynamics during pollution events, with important implications for understanding urban air quality deterioration in complex terrain environments.</div></div>","PeriodicalId":311,"journal":{"name":"Environmental Pollution","volume":"383 ","pages":"Article 126848"},"PeriodicalIF":7.6,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144664525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}