Atmospheric Environment最新文献

{"title":"Road-geometry and traffic predictors of roadside soil contamination: Insights from PCA and LASSO modeling","authors":"Mohammad Hossein Mirshekari ,&nbsp;Elham Chavoshi ,&nbsp;Atefeh Chamani ,&nbsp;Mozhgan Ahmadi Nadoushan","doi":"10.1016/j.atmosenv.2025.121569","DOIUrl":"10.1016/j.atmosenv.2025.121569","url":null,"abstract":"<div><div>Roadside environments are critical interfaces where transportation systems intersect with urban ecosystems, often acting as hotspots for the accumulation of potentially toxic elements (PTEs). In arid and semi-arid regions with aged vehicle fleets and fuel quality concerns, the persistence and dispersion of PTEs pose heightened environmental and public health risks. This study aimed to investigate the spatial patterns, potential sources, and environmental drivers of PTE concentrations (Pb, Cd, Zn, Cu, Ni, Cr) in roadside soils west of Isfahan City, Iran. Surface (0–2 cm) and background (30 cm) soils were collected from 209 stations, and analyzed using standard protocols with detection limits ranging from 0.1 to 1.0 ppm. Principal Component Analysis (PCA) identified two dominant components: PC1 (Zn, Cu, Cr) related to mechanical abrasion, and PC2 (Pb, Cd, Ni) linked to combustion sources. Least Absolute Shrinkage and Selection Operator (LASSO) regression and sensitivity analysis revealed that PC1 was primarily predicted by road slope and curvature, while PC2 was best explained by traffic volume and diesel vehicle proportion (R² = 0.561 and 0.686, respectively). The results highlight the dual role of structural and operational road factors in shaping PTE distribution in dryland cities, with implications for land-use planning and pollution mitigation in rapidly urbanizing regions.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"362 ","pages":"Article 121569"},"PeriodicalIF":3.7,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155844","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":"Reconciling volume- and mass-based hygroscopicity parameters: Insights from coupled H-TDMA–APM measurements","authors":"Ta-Chih Hsiao ,&nbsp;Ke-Ching Chen ,&nbsp;Jun-Fa Ye ,&nbsp;Si-Chee Tsay ,&nbsp;Neng-Huei Lin","doi":"10.1016/j.atmosenv.2025.121571","DOIUrl":"10.1016/j.atmosenv.2025.121571","url":null,"abstract":"<div><div>This study investigates aerosol hygroscopicity by reconciling volume-based (<strong>κᵥ</strong>) and mass-based (κ_m) hygroscopicity parameters through a dual-system approach combining a Hygroscopic Tandem Differential Mobility Analyzer (H-TDMA) and a Hygroscopic Differential Mobility Analyzer–Aerosol Particle Mass Analyzer (H-DMA-APM). The integrated system enables simultaneous measurement of size and mass growth factors for pure and internally mixed sub-100 nm NaCl and (NH₄)₂SO₄ particles under varying relative humidities (RH). Results show that <strong>κᵥ</strong> exhibits strong size dependence, declining by over 25 % as particle diameter decreases from 51.4 nm to 20.2 nm, attributed to curvature effects and morphology-induced artifacts. In contrast, κ_m shows a more stable trend across sizes, varying by less than 15 %, reflecting its robustness against morphological and curvature influences. However, κ_m did not consistently outperform <strong>κᵥ</strong> in predictive accuracy, likely due to the broader classification resolution of the APM system. While κ_m remains a theoretically superior parameter, <strong>κᵥ</strong>, when derived from high-resolution HTDMA systems, remains an effective predictor of hygroscopic growth. These findings highlight the importance of particle size, morphology, and instrumentation in characterizing aerosol hygroscopicity and advocate for the complementary use of <strong>κᵥ</strong> and κ_m in climate-relevant aerosol studies.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"362 ","pages":"Article 121571"},"PeriodicalIF":3.7,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145226976","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":"Modelling and forecasting of CERES-retrieved ultraviolet radiation and AOD using a seasonal-ARIMA model in urban regions of Indo-Gangetic Plain","authors":"Ankita Mall ,&nbsp;Sachchidanand Singh","doi":"10.1016/j.atmosenv.2025.121570","DOIUrl":"10.1016/j.atmosenv.2025.121570","url":null,"abstract":"<div><div>The Indo-Gangetic Plain (IGP), a densely populated and agriculturally productive region, experiences substantial emissions from industrial activities, vehicular traffic, and biomass burning. These emissions contribute to high aerosol loading and significant variability affecting the ultraviolet (UV) radiation, impacting air quality, climate, and public health. The present study employs Box-Jenkins, Seasonal Autoregressive Integrated Moving Average (SARIMA) model to analyze and forecast the ultraviolet radiation (UVA and UVB) and Aerosol Optical Depth (AOD) using data from the Clouds and the Earth's Radiant Energy System (CERES) over selected urban regions in the IGP. Time-series data from January 2005 to December 2020 (∼16 years) are utilized to capture seasonal patterns and long-term trends, enabling predictions for the next two years. Stationarity of UVA, UVB, and AOD data is tested using the Augmented Dickey-Fuller (ADF) test, followed by autocorrelation function (ACF) and partial autocorrelation function (PACF) analysis to determine the optimal model order. Model is fitted by estimating various parameters through maximum likelihood estimation (MLE) optimization techniques and found suitable with (1,1,1)(1,1,1)₁₂, considering a monthly seasonal factor for predicting UVA, UVB fluxes, and AOD. When SARIMA was used with exogenous variables for prediction of UVA, UVB and AOD it was found that different stations had different optimal configurations. The model validation involves error and comparative analyses. Error metrics, including mean absolute error (MAE), mean squared error (MSE), root mean squared error (RMSE), and mean absolute percentage error (MAPE) in the predicted data, indicate low errors. Comparative analysis shows strong agreement between modelled and CERES data, with significant correlation metrics such as the R-squared coefficient, Pearson correlation coefficient (r), degree of agreement (DOA), and Taylor skill score (TSS). Model accuracy is further assessed using normalized Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC), while model adequacy is evaluated through Ljung-Box and Jarque-Bera tests. Results indicate a strong seasonal dependence of UV radiation and AOD, with peaks during pre-monsoon and winter months, respectively. The SARIMA model effectively captures temporal variability and provides very good forecast for time series data valuable to researchers in air quality management and climate mitigation.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"362 ","pages":"Article 121570"},"PeriodicalIF":3.7,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145263103","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":"A novel integrated strategy for air quality monitoring in volcanic-hydrothermal, wetland, urban and industrial areas","authors":"R. Biagi ,&nbsp;A. Randazzo ,&nbsp;S. Venturi ,&nbsp;F. Capecchiacci ,&nbsp;O. Vaselli ,&nbsp;F. Tassi","doi":"10.1016/j.atmosenv.2025.121567","DOIUrl":"10.1016/j.atmosenv.2025.121567","url":null,"abstract":"<div><div>In the present era, environmental challenges are becoming increasingly prominent, necessitating innovative solutions that facilitate air quality monitoring and mitigation strategies aimed at safeguarding human health, the climate, and ecosystems. This study demonstrates how combining low-cost and high-tech stations (through integrated fixed and mobile monitoring) offers an effective and complementary approach. The strategy was applied in diverse environments (volcanic-hydrothermal areas, a wetland, and a CO₂ production plant), providing high spatial and temporal resolution data. Fixed low-cost stations, calibrated using machine-learning techniques, enabled continuous monitoring of key pollutants (CO₂, CH₄, PM_2.5, PM₁₀), depicting temporal variability linked to atmospheric dynamics, meteorological conditions, and emission strength. Their affordability allowed denser monitoring networks, enhancing spatial resolution and identifying critical areas that require long-term observation. This was especially effective in the wetland, where eutrophic zones emitting higher CH₄ levels were clearly identified. Mobile high-tech monitoring complemented fixed data by extending spatial coverage, with repeated transects allowing partial temporal tracking. An integrated analysis of pollutant concentrations, wind patterns, and isotopic ratios (δ¹³C of CO₂ and CH₄) enabled source apportionment, distinguishing between geogenic-hydrothermal and anthropogenic emissions, particularly in volcanic and industrial contexts. Despite its strengths, some limitations persist in the combination of the two approaches: (i) the drift over time and aging of low-cost sensors were not addressed, despite the necessity of their evaluation to ensure their proper use over longer monitoring periods; (ii) mobile monitoring lacks continuous temporal data and measurements are not simultaneous, limiting its effectiveness for tracking long-term trends and comparing pollutant levels across different areas.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"362 ","pages":"Article 121567"},"PeriodicalIF":3.7,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155786","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":"Source apportionment of PM2.5 and its oxidative potential in inland and coastal areas in Japan using positive matrix factorization with composite extraction","authors":"Siwei Wei ,&nbsp;Yuta Kamiya ,&nbsp;Yuta Kenzaki ,&nbsp;Takeshi Ohura ,&nbsp;Atsushi Matsuki ,&nbsp;Nozomu Tsuchiya ,&nbsp;Takayuki Kameda","doi":"10.1016/j.atmosenv.2025.121568","DOIUrl":"10.1016/j.atmosenv.2025.121568","url":null,"abstract":"<div><div>Fine particulate matter with a diameter ≤2.5 μm (PM_2.5) can penetrate the respiratory system and generate reactive oxygen species (ROS), posing a threat to human health. The ability to generate ROS can be represented by the oxidative potential (OP) of PM_2.5 in air. Herein, PM_2.5 was collected from Kyoto and Suzu, Japan, which are downwind regions in East Asia. Kyoto represents a typical densely populated urban center situated in one of Japan's plains, and Suzu is a remote coastal town. This pairing provides a representative framework for assessing OP-related health risks across different environmental settings in Japan. Composite extraction using water and methanol as solvents was used to extract the chemical components of samples, and the OP values of their water-soluble (OP_Ws-DTT) and methanol-soluble (OP_Ms-DTT) fractions were assessed via dithiothreitol (DTT) assay. The daily average of the total DTT consumption rate (OP_Ws-DTT + OP_Ms-DTT) was 436.8 ± 249.7 pmol/min/m³ in Kyoto and 141.0 ± 54.0 pmol/min/m³ in Suzu. The OP_Ms-DTT/OP_Ws-DTT ratio exceeded 30 % in both locations, indicating that methanol could effectively complement water in estimating the OP of PM_2.5. Positive matrix factorization analysis revealed seven pollution sources in Kyoto and six in Suzu. Biomass burning and secondary sulfate with soil were the main OP contributors in both locations. Kyoto (inland) and Suzu (coastal) were both influenced by marine aerosols. Additionally, transboundary pollution from northeast Asia was observed in Suzu. These results highlight significant differences in the OP-relevant PM_2.5 sources between locations and the variable, non-negligible contribution of water-insoluble components.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"362 ","pages":"Article 121568"},"PeriodicalIF":3.7,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155787","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 and optical properties of brown carbon and nitroaromatic compounds in PM2.5 in the urban area of Beijing","authors":"Zhongyi Yin ,&nbsp;Xingru Li ,&nbsp;Fangkun Wu ,&nbsp;Yang Yang ,&nbsp;Yuhu Zhang ,&nbsp;Zhuohui Yang ,&nbsp;Xin Gu ,&nbsp;Qing Zhao","doi":"10.1016/j.atmosenv.2025.121566","DOIUrl":"10.1016/j.atmosenv.2025.121566","url":null,"abstract":"<div><div>Nitroaromatic compounds (NACs) are important light-absorbing constituents of brown carbon (BrC), yet their seasonal characteristics, particle-size distributions, optical properties, and sources remain insufficiently resolved in highly polluted urban environments. This study presents a year-long field investigation of NACs in PM_2.5 in urban Beijing, focusing on their seasonal variations, size distributions, optical properties, and sources. Eight NAC species were quantified across four seasons, with winter showing the highest concentrations due to enhanced emissions and unfavorable meteorology. Size-resolved analysis revealed fine-mode dominance (0.43–1.1 μm), reflecting secondary formation from aromatic precursors and implying strong radiative and health relevance, while coarse-mode occurrence suggested contributions from primary biomass burning and heterogeneous processes. NACs exhibited distinct light-absorbing properties, with laboratory-calibrated mass absorption efficiency (MAE) and absorption Ångström exponent (AAE) confirming their role as contributors to methanol-soluble brown carbon (MSBrC). On annual average, NACs accounted for 2.7 ± 1.5 % (0.35–8.3 %) of MSBrC absorption at 365 nm, indicating that they are a non-negligible but limited contributor to BrC light absorption. Positive matrix factorization (PMF) identified biomass burning, coal combustion, vehicle emissions, dust, and secondary formation as major sources, with seasonal variations highlighting the importance of mixed combustion sources in summer and autumn. Overall, this work provides a comprehensive molecular- and size-resolved dataset that links NAC concentrations, optical properties, and source apportionment, offering new insights into the atmospheric role of NACs and their implications for urban air quality and radiative forcing.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"362 ","pages":"Article 121566"},"PeriodicalIF":3.7,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155843","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":"Atmospheric rare earth elements in a southeastern China metropolis: photoelectric source and associated health risk assessment","authors":"Wenkai Guan ,&nbsp;Ziang Li ,&nbsp;Yanli Liu ,&nbsp;Xinyi Xu ,&nbsp;Dongdong Zhu ,&nbsp;Hongwei Xiao ,&nbsp;Ruifeng Zhang","doi":"10.1016/j.atmosenv.2025.121565","DOIUrl":"10.1016/j.atmosenv.2025.121565","url":null,"abstract":"<div><div>Rare earth elements (REEs) are commonly used to trace sources and geochemical processes due to their coherent chemical properties and systematic variations. However, with the rapid expansion of their industrial applications, REEs have increasingly become emerging atmospheric pollutants, while their anthropogenic sources and associated health risks remain poorly understood. In this study, a year-long observation (April 2021–March 2022) of total suspended particles (TSP) and size-segregated aerosol was conducted in Nanchang, a major Chinese REE industry city. We found the average annual concentration of total REEs (ΣREE) was in the order of spring &gt; winter &gt; autumn &gt; summer. Most REEs showed low enrichment factors (EFs), suggesting a primarily crustal origin. However, the elevated Ce and Eu EFs, combined with positive Ce and Eu anomalies pattern, indicated anthropogenic influence. A significant positive correlation of Ce and Eu EFs across both TSP and size-segregated samples further suggests a common anthropogenic source. Photoelectric industry emissions were identified as the primary contributors to the observed anomalies, accounting for 39 % ± 18 % of Ce and 24 % ± 11 % of Eu annually. Notably, both Ce and Eu anomalies showed comparable degree across fine and coarse PM, demonstrating the unique particle size distribution characteristics of photoelectric Ce and Eu. While Ce inhalation showed no significant non-carcinogenic health risks in Nanchang, concerns should be raised for workers and residents near photoelectric industry sites due to high Ce exposure levels. Furthermore, the urgent establishment of threshold values for REEs, particularly Eu, is necessary given its notable enrichment.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"362 ","pages":"Article 121565"},"PeriodicalIF":3.7,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155825","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":"Urea-enhanced nucleation in the atmosphere: Mechanistic insights from MSA, SA, and ternary MSA-MA pathways","authors":"Zhongwei Cao,&nbsp;Xiuju Cai,&nbsp;Zirui Chen,&nbsp;Yongjun Hu,&nbsp;Shi Yin","doi":"10.1016/j.atmosenv.2025.121563","DOIUrl":"10.1016/j.atmosenv.2025.121563","url":null,"abstract":"<div><div>New particle formation (NPF) is a fundamental process governing atmospheric aerosol production and, consequently, climate and air quality. Despite the extensive study of acid-base interactions in nucleation, the role of organic nitrogen compounds, particularly urea, remains inadequately explored. Here, we employ quantum chemical calculations and kinetic simulations via the Atmospheric Cluster Dynamics Code (ACDC) to elucidate the mechanisms by which urea modulates nucleation processes. Our investigation reveals that urea, through its dual hydrogen-bonding capability and proton-accepting -C=O group, stabilizes clusters formed with methanesulfonic acid (MSA), sulfuric acid (SA), and nitric acid (NA). In binary systems, MSA-Urea clusters exhibit intermediate stability, higher than those of MSA-NH₃ but lower than MSA-MA. Notably, in ternary MSA-MA-Urea systems, urea markedly enhances nucleation rates, particularly under low-temperature conditions. These results indicate that urea can compensate for the low ambient concentrations of more potent bases such as methylamine (MA), thus playing a pivotal role in atmospheric nucleation. Our findings underscore the need to incorporate organic nitrogen chemistry into atmospheric models to improve predictions of aerosol formation and its broader climatic impacts.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"362 ","pages":"Article 121563"},"PeriodicalIF":3.7,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145155842","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":"Passive sampling of atmospheric polycyclic aromatic hydrocarbons by silicone wristbands during wildland fires","authors":"Jordina Gili ,&nbsp;Mar Viana ,&nbsp;Barend L. van Drooge","doi":"10.1016/j.atmosenv.2025.121564","DOIUrl":"10.1016/j.atmosenv.2025.121564","url":null,"abstract":"<div><div>Wildland fires, including both wildfires and prescribed burns, emit large quantities of smoke containing hazardous air pollutants such as polycyclic aromatic hydrocarbons (PAHs). Understanding PAHs concentrations in these smoke-filled environments is key to developing effective mitigation strategies to protect public health and safety. However, conventional measurement strategies are not always feasible in the highly dynamic and logistically complex settings of wildfire events. As a result, alternative approaches are needed, such as the use of silicone wristbands (SWBs) as passive air samplers. In this study, PAHs were analyzed in SWBs worn by firefighters during prescribed burns and wildfires. After deployment, extraction, and GC-MS/MS analysis, PAH air concentrations were calculated using a compound-specific kinetic uptake model. Personal exposure to PAHs was task-specific: wildfire operators and torchers, who ignite the fires, experienced the highest concentrations (mean sum of PAHs ≈ 5000 ng/m³), followed by liners, who manage fire boundaries (≈2000 ng/m³), while truck drivers exhibited the lowest exposure concentrations (≈100 ng/m³), likely due to their roles keeping them farther from the smoke-dense areas. Additionally, to evaluate the SWBs’ ability to capture particle-bound PAHs, PAH air concentrations measured in SWBs were compared with those obtained from PM_2.5 filter sampling. The findings highlight the utility of passive air sampling with SWBs in detecting PAHs and underscore their potential for monitoring exposure concentrations in complex atmospheric environments.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"362 ","pages":"Article 121564"},"PeriodicalIF":3.7,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145263232","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":"Organic and elemental carbon at a regional background site in South Africa","authors":"Johan P. Beukes ,&nbsp;Thapelo Sehloho ,&nbsp;Pieter G. van Zyl ,&nbsp;Petra Maritz ,&nbsp;Miroslav Josipovic ,&nbsp;Kerneels Jaars ,&nbsp;Ville Vakkari ,&nbsp;Markku Kulmala ,&nbsp;Lauri Laakso","doi":"10.1016/j.atmosenv.2025.121562","DOIUrl":"10.1016/j.atmosenv.2025.121562","url":null,"abstract":"<div><div>Atmospheric particulate matter (PM) contains a significant fraction of carbonaceous materials, which include organic- (OC) and elemental carbon (EC). These species significantly influence the global radiation balance and have negative health impacts. Although South Africa is an important emitter of carbonaceous aerosols, very little OC and EC studies have been published in the peer reviewed public domain. Therefore, the aim of this paper was augmenting the sparse OC and EC data for South Africa through a detailed assessment of an extensive dataset collected daily for 24 h over a period of 14 months at the regional background site, Welgegund. In total. 587 datasets were collected, which is the most comprehensive OC and EC dataset collected for this region. Seasonal OC and EC concentration patterns indicated significant contributions from open biomass burning in the months with highest fire frequencies, as well as contributions from household combustion during winter. In addition to these sources, the important influence of the industrial hub in the South African interior on OC and EC levels were also indicated. Meteorological conditions also contributed to increased OC and EC during the colder months. Since fire occurrences and population density decreased from east to west, OC and EC data associated with air masses mainly passing over eastern and western defined regions were compared. Although the differences were not as large as expected, statistical differences could be confirmed with air masses passing over the eastern region corresponding to higher OC and EC concentrations. Contextualization of OC and EC concentrations revealed OC and EC levels determined in this study were similar or slightly elevated compared to concentrations reported for other background sites. Furthermore, EC correlated well with equivalent black carbon (eBC), indicating that EC at this site can be used as a proxy for eBC at regional background sites.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"362 ","pages":"Article 121562"},"PeriodicalIF":3.7,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145263234","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}