Pub Date : 2026-04-01Epub Date: 2026-01-17DOI: 10.1016/j.atmosenv.2026.121806
Mohammadamin Vahidi Ghazvini, Joseph K. Vaughan, Jun Meng, Ana Carla Fernandez Valdes, Von P. Walden
In this study, the forecast period of AIRPACT5 (Air Indicator Report for Public Awareness and Community Tracking) model was extended from two days to three days, and the accuracy of the third-day forecasts was subsequently evaluated. Two primary pollutants, PM2.5 and O3, were considered for validation. The model's third-day forecasts were compared with observed data from AirNow monitoring stations, as well as with the model's first and second-day forecasts. The evaluation covered a nine-month period from December 2023 to August 2024, encompassing the winter, spring, and summer seasons. Additionally, the model domain was categorized into urban, suburban and rural areas, and results were analyzed separately for each category. The comparison indicates that the performance trends of the third-day forecasts closely align with those of the first and second days. For PM2.5, model predictions were generally consistent with observational data, particularly in rural areas and across all seasons except during the wildfire season. In the case of O3, model performance was satisfactory in the summer but showed significant discrepancies in winter, especially in rural regions.
本研究将AIRPACT5 （Air Indicator Report for Public Awareness and Community Tracking）模型的预测周期从2天延长至3天，并对第三天预测的准确性进行了评估。两种主要污染物PM2.5和O3被考虑用于验证。该模型的第三天预报与AirNow监测站的观测数据以及该模型的第一天和第二天预报进行了比较。评估涵盖了从2023年12月到2024年8月的9个月，包括冬季、春季和夏季。此外，将模型域划分为城市、郊区和农村地区，并对每个类别的结果分别进行分析。比较表明，第三天预测的表现趋势与第一天和第二天的预测密切一致。对于PM2.5，模型预测总体上与观测数据一致，特别是在农村地区和除野火季节外的所有季节。在O3的情况下，模型在夏季的表现令人满意，但在冬季，特别是在农村地区，表现出显著的差异。
{"title":"Extension of AIRPACT5 forecasting to Day3 and evaluation of PM2.5 and ozone predictions across winter, spring and summer (2023–2024)","authors":"Mohammadamin Vahidi Ghazvini, Joseph K. Vaughan, Jun Meng, Ana Carla Fernandez Valdes, Von P. Walden","doi":"10.1016/j.atmosenv.2026.121806","DOIUrl":"10.1016/j.atmosenv.2026.121806","url":null,"abstract":"<div><div>In this study, the forecast period of AIRPACT5 (Air Indicator Report for Public Awareness and Community Tracking) model was extended from two days to three days, and the accuracy of the third-day forecasts was subsequently evaluated. Two primary pollutants, PM<sub>2.5</sub> and O<sub>3</sub>, were considered for validation. The model's third-day forecasts were compared with observed data from AirNow monitoring stations, as well as with the model's first and second-day forecasts. The evaluation covered a nine-month period from December 2023 to August 2024, encompassing the winter, spring, and summer seasons. Additionally, the model domain was categorized into urban, suburban and rural areas, and results were analyzed separately for each category. The comparison indicates that the performance trends of the third-day forecasts closely align with those of the first and second days. For PM<sub>2.5</sub>, model predictions were generally consistent with observational data, particularly in rural areas and across all seasons except during the wildfire season. In the case of O<sub>3</sub>, model performance was satisfactory in the summer but showed significant discrepancies in winter, especially in rural regions.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"370 ","pages":"Article 121806"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146075942","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}
Pub Date : 2026-04-01Epub Date: 2026-01-21DOI: 10.1016/j.atmosenv.2026.121823
Mateo Kalinowski , Guido N. Rimondino , María P. Rostagno , Fabio E. Malanca
Anhydrides are widely used in industrial processes. Propionic anhydride (PA) and butyric anhydride (BA) are considered to be high production volume chemicals, with a total production in the order of thousands of tonnes. This study presents the rate coefficients for PA and BA with chlorine atoms for the first time: (3.8 ± 0.8) × 10−12 and (11 ± 2) × 10−12 cm3 molecule−1 s−1, respectively. The rate coefficients for the reactions of PA and BA with •OH radicals were estimated using Linear-Free-Energy-Relationships (LFER): 3.5 × 10−13 cm3 molecule−1 s−1 and 7.9 × 10−13 cm3 molecule−1 s−1, respectively. From here, the calculated atmospheric lifetimes (33 and 15 days, for PA and BA, respectively) indicate that, once emitted, they could be transported by air masses having a regional impact.
Moreover, the main photooxidation products, both in the presence and absence of NO2 were identified by infrared spectroscopy: CH3CH2C(O)OH, CH3CH2C(O)OC(O)C(O)CH3, CH3CH2C(O)OC(O)CH2C(O)H, CH3C(O)C(O)OONO2, CH3C(O)OONO2 and CO2 for PA; and CH3CH2CH2C(O)OH, CH3CH2CH2C(O)OC(O)CH2CH2C(O)H, CH3CH2CH2C(O)OC(O)CH2C(O)H, CH3CH2C(O)OONO2, CH3CH2C(O)C(O)OONO2 and CO2 for BA. Computational studies were used to support the experimental identification of the products.
Atmospheric degradation of PA and BA produces carboxylic acids that can partition into the aqueous phase of clouds and fog, affecting atmospheric processes having environmental impacts. In addition, the degradation of PA and BA in regions polluted with nitrogen dioxide leads to the formation of peroxyacyl nitrates, which can be transported long distances from their source of production, polluting remote areas.
{"title":"Kinetic and mechanistic studies of the atmospheric degradation of organic anhydrides","authors":"Mateo Kalinowski , Guido N. Rimondino , María P. Rostagno , Fabio E. Malanca","doi":"10.1016/j.atmosenv.2026.121823","DOIUrl":"10.1016/j.atmosenv.2026.121823","url":null,"abstract":"<div><div>Anhydrides are widely used in industrial processes. Propionic anhydride (PA) and butyric anhydride (BA) are considered to be high production volume chemicals, with a total production in the order of thousands of tonnes. This study presents the rate coefficients for PA and BA with chlorine atoms for the first time: (3.8 ± 0.8) × 10<sup>−12</sup> and (11 ± 2) × 10<sup>−12</sup> cm<sup>3</sup> molecule<sup>−1</sup> s<sup>−1</sup>, respectively. The rate coefficients for the reactions of PA and BA with <sup>•</sup>OH radicals were estimated using Linear-Free-Energy-Relationships (LFER): 3.5 × 10<sup>−13</sup> cm<sup>3</sup> molecule<sup>−1</sup> s<sup>−1</sup> and 7.9 × 10<sup>−13</sup> cm<sup>3</sup> molecule<sup>−1</sup> s<sup>−1</sup>, respectively. From here, the calculated atmospheric lifetimes (33 and 15 days, for PA and BA, respectively) indicate that, once emitted, they could be transported by air masses having a regional impact.</div><div>Moreover, the main photooxidation products, both in the presence and absence of NO<sub>2</sub> were identified by infrared spectroscopy: CH<sub>3</sub>CH<sub>2</sub>C(O)OH, CH<sub>3</sub>CH<sub>2</sub>C(O)OC(O)C(O)CH<sub>3</sub>, CH<sub>3</sub>CH<sub>2</sub>C(O)OC(O)CH<sub>2</sub>C(O)H, CH<sub>3</sub>C(O)C(O)OONO<sub>2</sub>, CH<sub>3</sub>C(O)OONO<sub>2</sub> and CO<sub>2</sub> for PA; and CH<sub>3</sub>CH<sub>2</sub>CH<sub>2</sub>C(O)OH, CH<sub>3</sub>CH<sub>2</sub>CH<sub>2</sub>C(O)OC(O)CH<sub>2</sub>CH<sub>2</sub>C(O)H, CH<sub>3</sub>CH<sub>2</sub>CH<sub>2</sub>C(O)OC(O)CH<sub>2</sub>C(O)H, CH<sub>3</sub>CH<sub>2</sub>C(O)OONO<sub>2</sub>, CH<sub>3</sub>CH<sub>2</sub>C(O)C(O)OONO<sub>2</sub> and CO<sub>2</sub> for BA. Computational studies were used to support the experimental identification of the products.</div><div>Atmospheric degradation of PA and BA produces carboxylic acids that can partition into the aqueous phase of clouds and fog, affecting atmospheric processes having environmental impacts. In addition, the degradation of PA and BA in regions polluted with nitrogen dioxide leads to the formation of peroxyacyl nitrates, which can be transported long distances from their source of production, polluting remote areas.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"370 ","pages":"Article 121823"},"PeriodicalIF":3.7,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171212","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}
Pub Date : 2026-03-15Epub Date: 2026-01-17DOI: 10.1016/j.atmosenv.2026.121808
Beata Górka-Kostrubiec, Katarzyna Dudzisz
Indoor dust (ID) is a key indicator of indoor air quality, reflecting both human activity and the infiltration of outdoor pollutants. This study integrates magnetic, geochemical, and microscopic methods to identify pollution sources by characterizing magnetic particles (MPs) in ID collected from residential locations in the Warsaw metropolitan area. Fine (<0.071 mm) and coarse (0.071–1.0 mm) dust fractions were analyzed alongside road dust (RD) and wood ash to differentiate between indoor and outdoor contributions. Magnetite was identified as the primary magnetic mineral, accompanied by metallic Fe and/or iron-based alloys. Decomposition of isothermal remanent magnetization acquisition curves revealed two main coercivity components in ID, while RD and ash exhibited distinct magnetic signatures. Scanning electron microscopy identified technogenic MPs, such as ferrospheres and abrasion-derived flakes, while geochemical analyses highlighted associations between Fe and heavy metals (e.g., Zn, Pb). Cluster analysis indicated both anthropogenic (traffic, biomass combustion, industry) and natural (soil, crustal) origins. Based on these findings, potentially toxic metals were correlated with their likely sources: sulfur from coal burning; zinc, copper, and lead from vehicle emissions; calcium from construction activities; and chromium from indoor sources such as chrome-plated surfaces. Variations in dust composition among apartments—especially in the fine fraction mass and magnetic properties—underscore the influence of ventilation, proximity to traffic, and resident behavior. This study confirms that magnetic methods provide a nondestructive, cost-effective approach for tracking external pollutants in ID and underscores their potential as a screening tool for assessing urban environmental health risks.
{"title":"Integration of magnetic methods and chemical elemental analysis to differentiate the sources of dust in the indoor environment","authors":"Beata Górka-Kostrubiec, Katarzyna Dudzisz","doi":"10.1016/j.atmosenv.2026.121808","DOIUrl":"10.1016/j.atmosenv.2026.121808","url":null,"abstract":"<div><div>Indoor dust (ID) is a key indicator of indoor air quality, reflecting both human activity and the infiltration of outdoor pollutants. This study integrates magnetic, geochemical, and microscopic methods to identify pollution sources by characterizing magnetic particles (MPs) in ID collected from residential locations in the Warsaw metropolitan area. Fine (<0.071 mm) and coarse (0.071–1.0 mm) dust fractions were analyzed alongside road dust (RD) and wood ash to differentiate between indoor and outdoor contributions. Magnetite was identified as the primary magnetic mineral, accompanied by metallic Fe and/or iron-based alloys. Decomposition of isothermal remanent magnetization acquisition curves revealed two main coercivity components in ID, while RD and ash exhibited distinct magnetic signatures. Scanning electron microscopy identified technogenic MPs, such as ferrospheres and abrasion-derived flakes, while geochemical analyses highlighted associations between Fe and heavy metals (e.g., Zn, Pb). Cluster analysis indicated both anthropogenic (traffic, biomass combustion, industry) and natural (soil, crustal) origins. Based on these findings, potentially toxic metals were correlated with their likely sources: sulfur from coal burning; zinc, copper, and lead from vehicle emissions; calcium from construction activities; and chromium from indoor sources such as chrome-plated surfaces. Variations in dust composition among apartments—especially in the fine fraction mass and magnetic properties—underscore the influence of ventilation, proximity to traffic, and resident behavior. This study confirms that magnetic methods provide a nondestructive, cost-effective approach for tracking external pollutants in ID and underscores their potential as a screening tool for assessing urban environmental health risks.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"369 ","pages":"Article 121808"},"PeriodicalIF":3.7,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036625","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}
Pub Date : 2026-03-15Epub Date: 2026-01-19DOI: 10.1016/j.atmosenv.2026.121800
Dong Ding , Kai Kang , Shaofang Li , Tianfang Xing , Wenjie Yang , Liuqiao Sun , Xinxin Liu , Yao Chen , Mingyi Xue , Zengli Yu , Zhan Gao
Background
Globally, the increasing frequency of extreme heat events and ozone pollution incidents has significantly intensified public health risks. However, empirical evidence regarding their synergistic impacts remains limited in central China.
Methods
A two-stage analysis was conducted using data from 121 counties in Henan (2013–2019). Quasi-Poisson generalized additive models were used to assess county-specific associations, adjusting for PM2.5, RH, and temporal trends. The combined effect of air temperature (non-linear) and ozone (linear) was captured through multiplicative interaction terms. Random-effects meta-analyses were applied to pool the results. Subgroup analyses examined differences by age, sex, marital status, and cause of death.
Results
During the study period, 1,280,429 deaths were recorded. Both high temperatures and elevated ozone levels were associated with increased mortality. Their joint effects were stronger than individual exposures. At high ozone levels, mortality risk increased by 2 percentage points (from 9.3 % to 11.3 %) between temperature distribution percentiles 75th and 99th. Under high-temperature conditions (31.4 °C, 90th percentile), a 10 μg/m3 elevation in ozone was associated with a 0.94 % (95 % CI: 0.49 %–1.38 %) increase in mortality. Older adults, females, other marital statuses (including unmarried, divorced, or widowed), and those with cardiovascular or respiratory diseases were more susceptible to its effects.
Conclusion
High temperature and ozone synergistically increase mortality risk. Targeted interventions are needed to protect vulnerable groups under climate change.
{"title":"Joint impact of heat and ozone exposure on mortality in Henan, central China","authors":"Dong Ding , Kai Kang , Shaofang Li , Tianfang Xing , Wenjie Yang , Liuqiao Sun , Xinxin Liu , Yao Chen , Mingyi Xue , Zengli Yu , Zhan Gao","doi":"10.1016/j.atmosenv.2026.121800","DOIUrl":"10.1016/j.atmosenv.2026.121800","url":null,"abstract":"<div><h3>Background</h3><div>Globally, the increasing frequency of extreme heat events and ozone pollution incidents has significantly intensified public health risks. However, empirical evidence regarding their synergistic impacts remains limited in central China.</div></div><div><h3>Methods</h3><div>A two-stage analysis was conducted using data from 121 counties in Henan (2013–2019). Quasi-Poisson generalized additive models were used to assess county-specific associations, adjusting for PM<sub>2</sub>.<sub>5</sub>, RH, and temporal trends. The combined effect of air temperature (non-linear) and ozone (linear) was captured through multiplicative interaction terms. Random-effects meta-analyses were applied to pool the results. Subgroup analyses examined differences by age, sex, marital status, and cause of death.</div></div><div><h3>Results</h3><div>During the study period, 1,280,429 deaths were recorded. Both high temperatures and elevated ozone levels were associated with increased mortality. Their joint effects were stronger than individual exposures. At high ozone levels, mortality risk increased by 2 percentage points (from 9.3 % to 11.3 %) between temperature distribution percentiles 75th and 99th. Under high-temperature conditions (31.4 °C, 90th percentile), a 10 μg/m<sup>3</sup> elevation in ozone was associated with a 0.94 % (95 % CI: 0.49 %–1.38 %) increase in mortality. Older adults, females, other marital statuses (including unmarried, divorced, or widowed), and those with cardiovascular or respiratory diseases were more susceptible to its effects.</div></div><div><h3>Conclusion</h3><div>High temperature and ozone synergistically increase mortality risk. Targeted interventions are needed to protect vulnerable groups under climate change.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"369 ","pages":"Article 121800"},"PeriodicalIF":3.7,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036627","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}
Pub Date : 2026-03-15Epub Date: 2026-01-16DOI: 10.1016/j.atmosenv.2026.121807
Cheonwoong Kang , Hyunjun Shin , Hyunjeong Seo , Hanjin Yoo , Ki-Joon Jeon
Effective management of volatile organic compounds (VOCs) in large, dense industrial complexes remains a critical challenge, as conventional monitoring methods are often too slow, limited in spatial coverage, and insufficiently resolved to pinpoint specific emission sources among thousands of facilities. This study introduces and validates a novel, multi-stage methodological framework which synergistically combines mobile Selected Ion Flow Tube Mass Spectrometry (SIFT-MS) with drone-based systems to enable rapid and precise source identification. The methodology begins with a wide-area mobile SIFT-MS survey, utilizing spatial statistics (Getis-Ord Gi∗) to identify hotspots, followed by targeted drone deployment for high-resolution aerial screening. This multi-stage approach successfully resolved distinct chemical signatures from adjacent sources that were not separable by ground-based monitoring alone. For instance, the framework differentiated a xylene- and ethylbenzene-rich profile near chemical manufacturing facilities, a MEK (methyl ethyl ketone)-rich profile near paint production, and a toluene- and acrolein-rich profile originating from a painting facility. The quantitative reliability of the drone-based sampling was validated through concurrent ground-level measurements, which demonstrated a high consistency in capturing the unique chemical signature at each location. This study demonstrates that the integrated mobile-drone framework provides a scientifically robust and efficient approach for characterizing industrial VOC emissions. By progressing from broad spatial screening to precise, evidence-based source identification, the methodology offers a powerful tool for targeted air quality management and has strong potential for application in highly complex industrial environments worldwide.
{"title":"Advancing VOC management: A mobile and drone-based approach for industrial emission monitoring","authors":"Cheonwoong Kang , Hyunjun Shin , Hyunjeong Seo , Hanjin Yoo , Ki-Joon Jeon","doi":"10.1016/j.atmosenv.2026.121807","DOIUrl":"10.1016/j.atmosenv.2026.121807","url":null,"abstract":"<div><div>Effective management of volatile organic compounds (VOCs) in large, dense industrial complexes remains a critical challenge, as conventional monitoring methods are often too slow, limited in spatial coverage, and insufficiently resolved to pinpoint specific emission sources among thousands of facilities. This study introduces and validates a novel, multi-stage methodological framework which synergistically combines mobile Selected Ion Flow Tube Mass Spectrometry (SIFT-MS) with drone-based systems to enable rapid and precise source identification. The methodology begins with a wide-area mobile SIFT-MS survey, utilizing spatial statistics (Getis-Ord Gi∗) to identify hotspots, followed by targeted drone deployment for high-resolution aerial screening. This multi-stage approach successfully resolved distinct chemical signatures from adjacent sources that were not separable by ground-based monitoring alone. For instance, the framework differentiated a xylene- and ethylbenzene-rich profile near chemical manufacturing facilities, a MEK (methyl ethyl ketone)-rich profile near paint production, and a toluene- and acrolein-rich profile originating from a painting facility. The quantitative reliability of the drone-based sampling was validated through concurrent ground-level measurements, which demonstrated a high consistency in capturing the unique chemical signature at each location. This study demonstrates that the integrated mobile-drone framework provides a scientifically robust and efficient approach for characterizing industrial VOC emissions. By progressing from broad spatial screening to precise, evidence-based source identification, the methodology offers a powerful tool for targeted air quality management and has strong potential for application in highly complex industrial environments worldwide.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"369 ","pages":"Article 121807"},"PeriodicalIF":3.7,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145996217","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}
Pub Date : 2026-03-15Epub Date: 2026-01-13DOI: 10.1016/j.atmosenv.2026.121804
Yumeng Li , Xin Su , Lunche Wang , Lan Feng , Xiaoyu Ma , Ming Zhang , Shikuan Jin
PM2.5 and PM10 pollution in China's Beijing-Tianjin-Hebei (BTH) region poses severe environmental and health risks, yet sparse ground monitoring networks constrain high-resolution and spatial assessments despite policy-driven air quality improvements. This study developed a stacking ensemble machine learning model integrating multi-source data with 2014–2024 national station observations to generate gap-free 1 km daily PM2.5 and PM10 grids across the BTH region. The ensemble model, integrating multiple machine learning models, performs comparably to or better than existing single models, achieving high accuracy (R2 = 0.935 and 0.916, RMSE = 12.8 and 22.4 μg/m3 for PM2.5 and PM10 under 10-fold cross-validation) and spatial generalization (R2 = 0.89 and 0.87 for PM2.5 and PM10 under leave-one-station-out validation). The products captured a 56.3 % decline (from 81.4 to 35.6 μg/m3) in PM2.5 and a 50.9 % reduction (from 136.7 to 67.1 μg/m3) in PM10 from 2014 to 2024, followed by stabilization with interannual fluctuations in recent years. The analysis results indicate that anthropogenic emissions are the dominant factor driving the reduction in PM. Over 70 % of regions exhibit significant improvements in air quality, affirming the efficacy of the Air Pollution Prevention and Control Action Plan. In summary, the ensemble model delivers high accuracy and strong spatial generalization, supporting PM2.5 and PM10 mapping and policy impact analysis across the entire BTH areas.
{"title":"Efficient stacking ensemble machine learning for 1 km daily PM2.5 and PM10 mapping in Beijing-Tianjin-Hebei","authors":"Yumeng Li , Xin Su , Lunche Wang , Lan Feng , Xiaoyu Ma , Ming Zhang , Shikuan Jin","doi":"10.1016/j.atmosenv.2026.121804","DOIUrl":"10.1016/j.atmosenv.2026.121804","url":null,"abstract":"<div><div>PM<sub>2</sub>.<sub>5</sub> and PM<sub>10</sub> pollution in China's Beijing-Tianjin-Hebei (BTH) region poses severe environmental and health risks, yet sparse ground monitoring networks constrain high-resolution and spatial assessments despite policy-driven air quality improvements. This study developed a stacking ensemble machine learning model integrating multi-source data with 2014–2024 national station observations to generate gap-free 1 km daily PM<sub>2</sub>.<sub>5</sub> and PM<sub>10</sub> grids across the BTH region. The ensemble model, integrating multiple machine learning models, performs comparably to or better than existing single models, achieving high accuracy (R<sup>2</sup> = 0.935 and 0.916, RMSE = 12.8 and 22.4 μg/m<sup>3</sup> for PM<sub>2</sub>.<sub>5</sub> and PM<sub>10</sub> under 10-fold cross-validation) and spatial generalization (R<sup>2</sup> = 0.89 and 0.87 for PM<sub>2</sub>.<sub>5</sub> and PM<sub>10</sub> under leave-one-station-out validation). The products captured a 56.3 % decline (from 81.4 to 35.6 μg/m<sup>3</sup>) in PM<sub>2</sub>.<sub>5</sub> and a 50.9 % reduction (from 136.7 to 67.1 μg/m<sup>3</sup>) in PM<sub>10</sub> from 2014 to 2024, followed by stabilization with interannual fluctuations in recent years. The analysis results indicate that anthropogenic emissions are the dominant factor driving the reduction in PM. Over 70 % of regions exhibit significant improvements in air quality, affirming the efficacy of the Air Pollution Prevention and Control Action Plan. In summary, the ensemble model delivers high accuracy and strong spatial generalization, supporting PM<sub>2</sub>.<sub>5</sub> and PM<sub>10</sub> mapping and policy impact analysis across the entire BTH areas.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"369 ","pages":"Article 121804"},"PeriodicalIF":3.7,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145996223","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}
To examine decadal changes in aerosol pollution, trends, hotspots, and aerosol types across the Indo-Gangetic Plain (IGP), north-east India (NEI), and the Himalayas, a 25-year (2000–2024) analysis was conducted using MODIS and MERRA-2 datasets. The highest aerosol loading and trend (MODIS AOD) occurred over the lower IGP (0.71 ± 0.09; 0.016 yr−1), followed by the middle IGP (0.65 ± 0.10; 0.009 yr−1), upper IGP (0.51 ± 0.10; 0.003 yr−1), and NEI (0.40 ± 0.10; 0.008 yr−1). Within the Himalayas, the central region showed the highest AOD (0.24 ± 0.09) with low trends (0.001–0.003 yr−1). Significant rising trends were observed in SO42−AOD over the lower IGP (0.006 yr−1) and OCAOD over NEI (0.004 yr−1). AOD across the entire IGP and NEI increased by more than 20 % in the 2010s relative to the 2000s. Notably, SO42−AOD increased by ∼30–40 % over the lower IGP, while OCAOD rose by over 50 % in NEI and the eastern Himalayas, with an additional 30–40 % rise during 2020–2024. Bangladesh, the lower IGP, and NEI consistently emerged as hotspots of carbonaceous and sulphate aerosols, shifting into highly polluted zones after 2020. The upper and middle IGP for the western and central Himalayas and NEI and the lower IGP acted as major source regions. Clean-continental and biomass/urban aerosols dominated the Himalayas, whereas anthropogenic aerosols prevailed over the IGP and NEI, with notable increases across the Himalayas after 2020. These insights can guide targeted mitigation strategies for the IGP and vulnerable Himalayan regions.
为了研究印度-恒河平原（IGP）、印度东北部（NEI）和喜马拉雅地区气溶胶污染的年代际变化、趋势、热点和气溶胶类型，利用MODIS和MERRA-2数据集进行了25年（2000-2024）分析。最高气溶胶负荷和趋势（MODIS AOD）出现在较低IGP(0.71±0.09;0.016 yr - 1)，其次是中等IGP(0.65±0.10;0.009 yr - 1)，较高IGP（0.51±0.10;0.003 yr - 1）和NEI（0.40±0.10;0.008 yr - 1）。在喜马拉雅地区，中部地区AOD最高（0.24±0.09），趋势较低（0.001 ~ 0.003 yr−1）。SO42 - AOD在IGP较低的地区呈显著上升趋势（0.006 yr - 1）， OCAOD在NEI地区呈显著上升趋势（0.004 yr - 1）。与2000年代相比，2010年代整个IGP和NEI的AOD增长了20%以上。值得注意的是，在IGP较低的地区，SO42−AOD增加了~ 30 - 40%，而NEI和喜马拉雅东部的OCAOD增加了50%以上，在2020-2024年期间还增加了30 - 40%。IGP较低的孟加拉国和NEI一直是碳质和硫酸盐气溶胶的热点地区，在2020年之后转变为高污染地区。喜马拉雅西部和中部的上、中部IGP和NEI以及下IGP是主要的源区。清洁大陆气溶胶和生物质/城市气溶胶在喜马拉雅地区占主导地位，而人为气溶胶在IGP和NEI中占主导地位，2020年后喜马拉雅地区的气溶胶显著增加。这些见解可以指导针对IGP和喜马拉雅脆弱地区的有针对性的缓解战略。
{"title":"Decadal shifts in aerosol hotspots and source attribution over IGP, north-east India and Himalayas: A 25-year (2000–2024) study","authors":"Soumen Raul, Monami Dutta , Sauryadeep Mukherjee , Abhijit Chatterjee","doi":"10.1016/j.atmosenv.2026.121810","DOIUrl":"10.1016/j.atmosenv.2026.121810","url":null,"abstract":"<div><div>To examine decadal changes in aerosol pollution, trends, hotspots, and aerosol types across the Indo-Gangetic Plain (IGP), north-east India (NEI), and the Himalayas, a 25-year (2000–2024) analysis was conducted using MODIS and MERRA-2 datasets. The highest aerosol loading and trend (MODIS AOD) occurred over the lower IGP (0.71 ± 0.09; 0.016 yr<sup>−1</sup>), followed by the middle IGP (0.65 ± 0.10; 0.009 yr<sup>−1</sup>), upper IGP (0.51 ± 0.10; 0.003 yr<sup>−1</sup>), and NEI (0.40 ± 0.10; 0.008 yr<sup>−1</sup>). Within the Himalayas, the central region showed the highest AOD (0.24 ± 0.09) with low trends (0.001–0.003 yr<sup>−1</sup>). Significant rising trends were observed in SO<sub>4</sub><sup>2−</sup><sub>AOD</sub> over the lower IGP (0.006 yr<sup>−1</sup>) and OC<sub>AOD</sub> over NEI (0.004 yr<sup>−1</sup>). AOD across the entire IGP and NEI increased by more than 20 % in the 2010s relative to the 2000s. Notably, SO<sub>4</sub><sup>2−</sup><sub>AOD</sub> increased by ∼30–40 % over the lower IGP, while OC<sub>AOD</sub> rose by over 50 % in NEI and the eastern Himalayas, with an additional 30–40 % rise during 2020–2024. Bangladesh, the lower IGP, and NEI consistently emerged as hotspots of carbonaceous and sulphate aerosols, shifting into highly polluted zones after 2020. The upper and middle IGP for the western and central Himalayas and NEI and the lower IGP acted as major source regions. Clean-continental and biomass/urban aerosols dominated the Himalayas, whereas anthropogenic aerosols prevailed over the IGP and NEI, with notable increases across the Himalayas after 2020. These insights can guide targeted mitigation strategies for the IGP and vulnerable Himalayan regions.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"369 ","pages":"Article 121810"},"PeriodicalIF":3.7,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036626","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}
Pub Date : 2026-03-15Epub Date: 2026-01-20DOI: 10.1016/j.atmosenv.2026.121809
Jinwen Li , Shaoxun Guo , Yongcheng Jia , Tianzeng Chen , Wei Ma , Veli-Matti Kerminen , Tuukka Petäjä , Markku Kulmala , Hui Li , Yongchun Liu
Coupling effects among different components of atmospheric particulate matter (PM) may influence the oxidative potential (OP) of PM, whereas the mechanism remains unclear. In this study, we investigate the OP of binary organics/inorganics mixtures, typically present in PM, using a dithiothreitol assay under dark conditions. The binary mixture of 2-methoxyphenol (2-MET, a typical biomass burning marker) and FeCl3 shows a 23 times increase in OP (380 pmol min−1·μg−1) compared to the individual species. A synergistic mechanism has been revealed through comprehensive characterization of reactive oxygen species (ROS) and relevant intermediates, by ROS probe technology, spectroscopy, and mass spectrometry. Mass spectrometry indicates that diphenyl-p-benzoquinones, like 5,5′-dihydroxy-3,3′-dimethoxy-[1,1′-bi(cyclohexane)]-2,2′,5,5′-tetraene-4,4′-dione, can be produced in the presence of Fe3+, subsequently promoting ROS formation (·OH and ·O2−) through free radical chain reaction induced by semiquinone. The OP achieves a maximum when the mass ratio of 2-MET to FeCl3 is 1.0 at 37°C. It persists around 60% of the initial OP over 31 h, which indicates the possible contribution of the mixture of methoxyphenol and Fe(III) to environmental persistent free radicals in the atmosphere. Our findings provide a new insight into the non-linear dependence of PM oxidative toxicity on composition and meaningful guidance for future PM health risk reduction.
{"title":"Enhanced oxidative potential of methoxyphenol in the presence of Fe(III) in the atmosphere: Effects and mechanisms","authors":"Jinwen Li , Shaoxun Guo , Yongcheng Jia , Tianzeng Chen , Wei Ma , Veli-Matti Kerminen , Tuukka Petäjä , Markku Kulmala , Hui Li , Yongchun Liu","doi":"10.1016/j.atmosenv.2026.121809","DOIUrl":"10.1016/j.atmosenv.2026.121809","url":null,"abstract":"<div><div>Coupling effects among different components of atmospheric particulate matter (PM) may influence the oxidative potential (OP) of PM, whereas the mechanism remains unclear. In this study, we investigate the OP of binary organics/inorganics mixtures, typically present in PM, using a dithiothreitol assay under dark conditions. The binary mixture of 2-methoxyphenol (2-MET, a typical biomass burning marker) and FeCl<sub>3</sub> shows a 23 times increase in OP (380 pmol min<sup>−1</sup>·μg<sup>−1</sup>) compared to the individual species. A synergistic mechanism has been revealed through comprehensive characterization of reactive oxygen species (ROS) and relevant intermediates, by ROS probe technology, spectroscopy, and mass spectrometry. Mass spectrometry indicates that diphenyl-p-benzoquinones, like 5,5′-dihydroxy-3,3′-dimethoxy-[1,1′-bi(cyclohexane)]-2,2′,5,5′-tetraene-4,4′-dione, can be produced in the presence of Fe<sup>3+</sup>, subsequently promoting ROS formation (·OH and ·O<sub>2</sub><sup>−</sup>) through free radical chain reaction induced by semiquinone. The OP achieves a maximum when the mass ratio of 2-MET to FeCl<sub>3</sub> is 1.0 at 37°C. It persists around 60% of the initial OP over 31 h, which indicates the possible contribution of the mixture of methoxyphenol and Fe(III) to environmental persistent free radicals in the atmosphere. Our findings provide a new insight into the non-linear dependence of PM oxidative toxicity on composition and meaningful guidance for future PM health risk reduction.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"369 ","pages":"Article 121809"},"PeriodicalIF":3.7,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036628","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}
Pub Date : 2026-03-15Epub Date: 2026-01-14DOI: 10.1016/j.atmosenv.2026.121803
Po-Hao Feng , I-Jung Liu , Rachel Chien , Kang-Yun Lee , Kuan-Yuan Chen , Wen-Te Liu , Ying-Ying Chen , Yen-Ling Chen , Kun-Ta Lee , Shu-Chuan Ho , Arnab Majumdar , Jiunn-Horng Kang , Wun-Hao Cheng , Sheng-Ming Wu , Cheng-Yu Tsai
Rapid decline in lung function is a key phenotype of chronic obstructive pulmonary disease (COPD) and is associated with disease progression and a poor prognosis. However, time-specific dynamics of pollutant exposure and their impacts on this phenotype remain unclear. In this retrospective cohort study, we investigated how period-specific particulate matter (PM) exposure relates to lung function rapid decline in individuals with COPD. Clinical and individual factors and ambient PM exposures were collected, and participants were categorized into rapid-decline and non-rapid-decline groups based on forced expiratory volume in 1 s (FEV1) trajectories. A modified exponentially weighted moving average approach was used for estimating PM2.5 and PM10 exposure levels across the baseline, early follow-up, and late follow-up periods. Regression and machine learning models assessed period-specific effects, with variable importance evaluated via Shapley additive explanation. The rapid-decline group had significantly higher baseline lung function but greater annual FEV1 reductions than the non-rapid-decline group (both p < 0.01). After adjusting for confounding factors, PM exposures were associated with FEV1 declines (PM2.5: −280.62 to −267.38 mL/year; PM10: −305.15 to −246.89 mL/year, all p < 0.01) and increased odds ratio of rapid FEV1 decline (PM2.5: 1.76–1.95; PM10: 1.62–1.96, all p < 0.05), particularly evident in models emphasizing the baseline and late follow-up periods. Baseline PM2.5 and PM10 exposures, and age were identified as the most influential predictors. These findings suggest that period-specific PM exposure may critically contribute to the development of lung function rapid decline in COPD. Considering environmental, temporal, and individual-level factors may help improve disease management.
{"title":"Impacts of period-specific particulate matter exposure on COPD phenotypes: Rapid lung function decline","authors":"Po-Hao Feng , I-Jung Liu , Rachel Chien , Kang-Yun Lee , Kuan-Yuan Chen , Wen-Te Liu , Ying-Ying Chen , Yen-Ling Chen , Kun-Ta Lee , Shu-Chuan Ho , Arnab Majumdar , Jiunn-Horng Kang , Wun-Hao Cheng , Sheng-Ming Wu , Cheng-Yu Tsai","doi":"10.1016/j.atmosenv.2026.121803","DOIUrl":"10.1016/j.atmosenv.2026.121803","url":null,"abstract":"<div><div>Rapid decline in lung function is a key phenotype of chronic obstructive pulmonary disease (COPD) and is associated with disease progression and a poor prognosis. However, time-specific dynamics of pollutant exposure and their impacts on this phenotype remain unclear. In this retrospective cohort study, we investigated how period-specific particulate matter (PM) exposure relates to lung function rapid decline in individuals with COPD. Clinical and individual factors and ambient PM exposures were collected, and participants were categorized into rapid-decline and non-rapid-decline groups based on forced expiratory volume in 1 s (FEV<sub>1</sub>) trajectories. A modified exponentially weighted moving average approach was used for estimating PM<sub>2.5</sub> and PM<sub>10</sub> exposure levels across the baseline, early follow-up, and late follow-up periods. Regression and machine learning models assessed period-specific effects, with variable importance evaluated via Shapley additive explanation. The rapid-decline group had significantly higher baseline lung function but greater annual FEV<sub>1</sub> reductions than the non-rapid-decline group (both <em>p</em> < 0.01). After adjusting for confounding factors, PM exposures were associated with FEV<sub>1</sub> declines (PM<sub>2.5</sub>: −280.62 to −267.38 mL/year; PM<sub>10</sub>: −305.15 to −246.89 mL/year, all <em>p</em> < 0.01) and increased odds ratio of rapid FEV<sub>1</sub> decline (PM<sub>2.5</sub>: 1.76–1.95; PM<sub>10</sub>: 1.62–1.96, all <em>p</em> < 0.05), particularly evident in models emphasizing the baseline and late follow-up periods. Baseline PM<sub>2.5</sub> and PM<sub>10</sub> exposures, and age were identified as the most influential predictors. These findings suggest that period-specific PM exposure may critically contribute to the development of lung function rapid decline in COPD. Considering environmental, temporal, and individual-level factors may help improve disease management.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"369 ","pages":"Article 121803"},"PeriodicalIF":3.7,"publicationDate":"2026-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146036630","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}
Pub Date : 2026-03-01Epub Date: 2026-01-02DOI: 10.1016/j.atmosenv.2025.121770
Se-In Hong , Jeffrey L. Collett Jr. , Young-Ji Han
This study examines the role of volatile organic compounds (VOCs) in ozone (O3) formation in a medium-sized residential city in South Korea. Using continuous measurements of 53 VOC species and photochemically adjusted initial concentrations (PICs), we assessed VOC transformations and their impact on O3 production. Results show that alkenes, particularly isoprene, cis-2-butene, and propene, are dominant contributors to O3 formation, with their influence intensifying under high O3 conditions. PIC of total VOCs (36.1 ppb) were significantly higher than measured concentrations (8.3 ppb), highlighting the extent of photochemical degradation. Ozone formation potential (OFP) analysis showed that metrics based on consumed VOCs better captured O3 variability than those based on measured concentrations, underscoring the importance of accounting for photochemical processing. Positive Matrix Factorization (PMF) identified distinct VOC sources: while LPG/natural gas usage (23.3 %) and coal combustion (22.4 %) dominated measured VOCs, solvent usage (16.2 %) and biogenic emissions (25.7 %) contributed more substantially when PICs were considered. Regional transport also played a key role, suggesting that aged and photochemically processed air masses significantly influence downwind O3 levels. These findings demonstrate the need to prioritize the control of anthropogenic alkenes and aromatic compounds, while also considering the influence of biogenic emissions. Policy measures should incorporate photochemical transformations into source attribution frameworks to support more effective and targeted O3 mitigation strategies.
{"title":"Reconstructing initial VOC concentrations to reveal their role in ozone formation","authors":"Se-In Hong , Jeffrey L. Collett Jr. , Young-Ji Han","doi":"10.1016/j.atmosenv.2025.121770","DOIUrl":"10.1016/j.atmosenv.2025.121770","url":null,"abstract":"<div><div>This study examines the role of volatile organic compounds (VOCs) in ozone (O<sub>3</sub>) formation in a medium-sized residential city in South Korea. Using continuous measurements of 53 VOC species and photochemically adjusted initial concentrations (PICs), we assessed VOC transformations and their impact on O<sub>3</sub> production. Results show that alkenes, particularly isoprene, cis-2-butene, and propene, are dominant contributors to O<sub>3</sub> formation, with their influence intensifying under high O<sub>3</sub> conditions. PIC of total VOCs (36.1 ppb) were significantly higher than measured concentrations (8.3 ppb), highlighting the extent of photochemical degradation. Ozone formation potential (OFP) analysis showed that metrics based on consumed VOCs better captured O<sub>3</sub> variability than those based on measured concentrations, underscoring the importance of accounting for photochemical processing. Positive Matrix Factorization (PMF) identified distinct VOC sources: while LPG/natural gas usage (23.3 %) and coal combustion (22.4 %) dominated measured VOCs, solvent usage (16.2 %) and biogenic emissions (25.7 %) contributed more substantially when PICs were considered. Regional transport also played a key role, suggesting that aged and photochemically processed air masses significantly influence downwind O<sub>3</sub> levels. These findings demonstrate the need to prioritize the control of anthropogenic alkenes and aromatic compounds, while also considering the influence of biogenic emissions. Policy measures should incorporate photochemical transformations into source attribution frameworks to support more effective and targeted O<sub>3</sub> mitigation strategies.</div></div>","PeriodicalId":250,"journal":{"name":"Atmospheric Environment","volume":"368 ","pages":"Article 121770"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922711","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}
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