Umakant L. Karna, Khem N. Poudyal, Babu R. Tiwari, Binod K. Bhattarai
{"title":"A comparative study of the UV index between OMI and ground-based measurements in Nepal","authors":"Umakant L. Karna, Khem N. Poudyal, Babu R. Tiwari, Binod K. Bhattarai","doi":"10.1007/s44273-025-00072-1","DOIUrl":"10.1007/s44273-025-00072-1","url":null,"abstract":"<div><p>The study on solar ultraviolet radiation (UVR) is essential for understanding the solar status of any location, which enables the determination of the level of exposure to solar UV radiation and the necessary precautions to be taken at that location. The measurement of solar UV radiation and its validation are increasingly prevalent worldwide, using various ground-based observations and satellite estimates. This paper compares the Ozone Monitoring Instrument (OMI)/Aura satellite solar ultraviolet index (UVI) with the ground-based UVI measurements at Biratnagar, Pokhara, Kathmandu, and Lukla in Nepal using data from 2009 to 2012. Trend analysis of UVI using moving averages, a box plot of overpass UVI and Total Ozone Column (TOC) to analyze their trends, and a scatter plot for comparison of OMI overpass UVI with ground-based UVI. Statistical tools were used to compare the datasets for UVI in all-sky conditions. The results show that satellite estimates tended to overestimate ground-based UVI levels, with a mean bias, relative bias, MAPE, RMSE, correlation coefficient, and standard deviation of error corresponding to 0.92, 1.9, 28.44, 1.6, 0.69, and 1.44 for UVI, respectively. The result also shows that the altitude effect is found to be (6.5-8.8) %/km approximately.</p></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":"19 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-025-00072-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145778889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Catalytic role of atmospheric constituents in the formation of 6PPD-Quinone in a Korean Metropolitan Region","authors":"Hajeong Jeon, Dong-Hoon Ko, Myoungki Song, Min-Suk Bae","doi":"10.1007/s44273-025-00075-y","DOIUrl":"10.1007/s44273-025-00075-y","url":null,"abstract":"<div>\u0000 \u0000 <p>N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine quinone (6PPD-quinone) is an oxidation product of the tire antioxidant 6PPD and has recently emerged as a toxic environmental contaminant. Although the transformation of 6PPD to 6PPD-quinone through ozone has been documented, the influence of other atmospheric constituents as catalysts remains inadequately characterized. This study assessed whether specific airborne elements promote the conversion of 6PPD to 6PPD-quinone. From 7 to 26 June 2024, total suspended particles were sampled at the National Institute of Environmental Research in Incheon, Republic of Korea. The elemental composition of collected samples was determined using energy-dispersive X-ray fluorescence, while 6PPD-quinone levels were measured by liquid chromatography–tandem mass spectrometry. Particle number and volume concentrations were recorded in parallel with a scanning mobility particle sizer and an optical particle sizer, along with real-time detection of black carbon, nitrogen dioxide, and ozone. Mean daytime 6PPD-quinone concentrations were measured at 0.12 ± 0.08 ng m<sup>− 3</sup>, displaying significant temporal variability (0.001–0.519 ng m<sup>− 3</sup>). Multivariate regression analysis identified bromine and vanadium as principal predictors of 6PPD-quinone abundance. Notably, strong correlations with particle characteristics indicated that these elements may act not only as markers of emissions but also as catalysts facilitating atmospheric transformation of 6PPD. This study offers the first mechanistic insight in Korea into the contribution of traffic-associated elements to 6PPD-quinone formation, which has important implications for urban air quality management and the assessment of ecological risks.</p>\u0000 </div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":"19 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-025-00075-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145729610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chaehyeong Park, Seoyeong Choe, Min Young Song, Sung‑Kyun Shin, Hajeong Jeon, Dong-Hoon Ko, Myoungki Song, Min-Suk Bae
{"title":"Nighttime waste wood burning and its impact on urban air quality: multi-Year measurements in central Seoul, Gwanghwamun, South Korea","authors":"Chaehyeong Park, Seoyeong Choe, Min Young Song, Sung‑Kyun Shin, Hajeong Jeon, Dong-Hoon Ko, Myoungki Song, Min-Suk Bae","doi":"10.1007/s44273-025-00074-z","DOIUrl":"10.1007/s44273-025-00074-z","url":null,"abstract":"<div>\u0000 \u0000 <p>This study examines variations in PM<sub>2.5</sub> mass, chemical composition, and oxidative potential (OP) at Gwanghwamun Square, Seoul, using intensive 3-h integrated sampling campaigns performed in September 2020 and 2022. The mean PM<sub>2.5</sub> concentrations declined significantly from 20.66 µg/m<sup>3</sup> in 2020 to 12.04 µg/m<sup>3</sup> in 2022, indicating a 42% reduction in overall particle mass. Despite this progress, the mass-normalized oxidative potential (DTTm) remained statistically unchanged (0.04 ± 0.04 vs. 0.03 ± 0.05 µM/µg, showing that particle toxicity per unit mass did not decrease. However, organic aerosol components exhibited marked increases in 2022. Organic carbon (OC) and water-soluble organic carbon (WSOC) increased by 22% and 82%, respectively, and primary organic carbon (POC) experienced more than a twofold rise. Levoglucosan (LEVO) concentrations grew by 37%, especially during nighttime periods, and the levoglucosan-to-POC ratio (LEVO/POC) surpassed 35 × 10<sup>− 3</sup> µg/µg at night, providing clear evidence of intensified biomass burning contributions. Annual flammable waste wood generation increased substantially in 2022, further supporting the conclusion that nighttime waste wood combustion contributed to higher organic aerosol levels and persistent OP values. These findings emphasize that reducing PM<sub>2.5</sub> mass alone is inadequate; targeted interventions to control nighttime biomass burning are essential for lowering health-relevant aerosol toxicity in urban Seoul.</p>\u0000 </div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":"19 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-025-00074-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145674958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Comparative analysis of polycyclic aromatic sulfur heterocycles (PASHs) in PM2.5 from Xi’an, China and Yokohama, Japan: pollution characteristics and source attribution","authors":"Kaixu Chen, Weidong Jing, Zhenxing Shen, Tomoaki Okuda","doi":"10.1007/s44273-025-00069-w","DOIUrl":"10.1007/s44273-025-00069-w","url":null,"abstract":"<div><p>Polycyclic aromatic sulfur heterocycles (PASHs) sulfur-containing analogues of polycyclic aromatic hydrocarbons (PAHs) are emerging atmospheric pollutants of concern due to their potential toxicity and environmental persistence. This study presents the first comparative analysis of PASHs in PM<sub>2.5</sub> between two representative East Asian cities: Xi’an, China, and Yokohama, Japan. Ambient PM<sub>2.5</sub> samples were collected from July 2022 to July 2023, and four PASHs compounds were quantified using gas chromatography tandem mass spectrometry (GC–MS/MS). Concentrations, seasonal variations, and emission sources were systematically analyzed. The results showed that the annual mean PASHs concentration in Xi’an (156.6 pg/mg) was significantly higher than that in Yokohama (102.6 pg/mg). Source apportionment using the Positive Matrix Factorization (PMF) model identified four major pollution sources in each city, revealing notable differences in source composition between the two countries. This study advances the understanding of the atmospheric behavior and origins of PASHs in East Asian urban environments and highlights cross-regional differences in their pollution profiles.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":"19 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-025-00069-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145612825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Koichi Watanabe, Nanami Maki, Michiyo Chatani, Chisato Maki, Ayami Nakanishi, Yuki Wasada, Taisei Akahori, Ryoga Ono, Yuta Yamazaki, Chiharu Mori
{"title":"Peroxide concentrations measured over a rural site in the Hokuriku district, coastal region of the Sea of Japan, central Japan, during early summer using a helicopter","authors":"Koichi Watanabe, Nanami Maki, Michiyo Chatani, Chisato Maki, Ayami Nakanishi, Yuki Wasada, Taisei Akahori, Ryoga Ono, Yuta Yamazaki, Chiharu Mori","doi":"10.1007/s44273-025-00071-2","DOIUrl":"10.1007/s44273-025-00071-2","url":null,"abstract":"<div><p>Atmospheric concentrations of peroxides (hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) and methyl hydroperoxide (MHP)), formaldehyde (HCHO), ozone (O<sub>3</sub>), and sulfur dioxide (SO<sub>2</sub>) were measured using a helicopter over Imizu City, Toyama Prefecture, central Japan in early summer (May and June) from 2022 to 2024. The impact of transboundary air pollution was relatively small during the observation days. H<sub>2</sub>O<sub>2</sub> concentrations were higher in the high-altitude atmosphere than on the ground and were sufficiently high relative to SO<sub>2</sub>, similar to the H<sub>2</sub>O<sub>2</sub> concentrations previously measured in mid-summer (August), suggesting that the potential for sulfur dioxide oxidation is high over central Japan during warm seasons. HCHO concentrations in the high-altitude atmosphere were high due to the influence of air pollution from domestic urban areas. The measurement results in this study were compared with the results of a series of helicopter observations previously conducted over Toyama Prefecture, and the characteristics of the oxidizing capacity in the atmosphere over central Japan are discussed.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":"19 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-025-00071-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145612438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A new hybrid multivariate prediction model based on wavelet transform convolution for PM2.5 prediction","authors":"Xinbiao Lu, Wentao Zhang, Gaofan Zhan, Wen Wu, Changjiang Han, Xiaolong Wu","doi":"10.1007/s44273-025-00067-y","DOIUrl":"10.1007/s44273-025-00067-y","url":null,"abstract":"<div><p>With the rapid development of industry and urbanization, air pollution has become a global environmental issue, with PM2.5 attracting widespread attention due to its severe impact on human health and the environment. Therefore, accurate prediction of PM2.5 concentration is crucial for environmental protection and public health. However, the nonlinear and multivariate characteristics of PM2.5 data pose challenges to prediction accuracy. To address this issue, we propose an innovative hybrid multivariate prediction model called WTCrossformer, which integrates wavelet transform convolution (WTC) to better extract local features and reduce the impact of noise on predictions. Additionally, the model employs dimension segment-wise embedding (DSW) and two-stage attention (TSA) mechanisms to capture temporal and cross-variable correlations in multivariate PM2.5 data, leveraging a hierarchical encoder-decoder structure to generate prediction results. This paper selects a multivariate time-series dataset from the UCI Machine Learning Repository. There are a total of 13 variables in this dataset, which details the air pollutant situations and meteorological conditions at 12 monitoring stations in the Beijing area over a 5-year period. Comparative experiments carried out on multiple PM2.5 datasets indicate that the model achieves relatively high prediction accuracy. It can accurately predict the trends of PM2.5 concentration, offering effective guidance for people’s daily life and health. Ablation experiments further confirm that the introduction of the WTC module significantly enhances the prediction accuracy. Our research provides strong technical support for environmental monitoring and pollution prediction.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":"19 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-025-00067-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145560849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Black carbon and its radiative effect with role in Urban Heat Island (UHI) over India: a review","authors":"Sunayana, Nahar Singh, Papiya Mandal","doi":"10.1007/s44273-025-00062-3","DOIUrl":"10.1007/s44273-025-00062-3","url":null,"abstract":"<div><p>Black carbon (BC) is a major pollutant entering the human body through PM<sub>2.5</sub> and posing major health effects. India lying in the Asia region is a major contributor to BC emissions from the combustion of biofuels. BC present in the atmosphere is a pollutant deteriorating air quality and is a light-absorbing aerosol (LAA), thus playing a dual role. In India, several studies have been published quantifying BC concentration. The optical measurement of BC has been carried out at multiple locations in India, and its radiative effect has been studied using the Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART) model. This review is an attempt to collate those studies that have measured BC and estimated its radiative effect. The BC levels, spectral Aerosol Optical Depth (AOD), single scattering albedo (SSA) and direct radiative forcing (DRF) at the top of the atmosphere (TOA), at the surface (SUR) and heat within the atmosphere (ATM) for 20 years (2002 to 2023) have been analysed. It was found that many studies for performing DRF calculations have not used BC measurements and have used AOD analysis to characterise the sources of aerosols as direct BC measurements are not required to estimate the DRF. The selection of AOD wavelength 500 nm or 550 nm is not clear in the literature for BC-RF calculations and needs to be standardised for DRF. IPCC AR6 has estimated Effective Radiative Forcing (ERF) due to BC with temperature and surface feedbacks, and future studies for ERF need to use climate models with tools like WRF-Chem. The source of BC is mostly from fossil fuel or biomass burning during the winter season, while it is dust aerosols during the summer. Biomass burning, use of traditional cook stoves and aerosol episodes contribute to the warming of the ambient environment. Beijing, China, has reduced ATM forcing in the summer when compared to Delhi, India, and has reduced the fraction of heat exerted in the atmosphere. The interactions of BC-UHI are not studied yet in India, and with the ARFINET network, an attempt can be made in this direction. The Urban Pollution Island (UPI)-Urban Heat Island (UHI) review identified PM<sub>2.5</sub> contributing to UHI intensity during the summer and winter in metro cities, while BC-UHI interactions are not dealt with in detail.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":"19 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-025-00062-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145456702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Microplastics and health hazards: gastrointestinal risk assessment across a multi-species perspective","authors":"Shiv Basant Kumar, Jey Kumar Pachiyappan, Sudharsanavasan Chandrasekar, Veera Venkata Satyanarayana Reddy Karri, Praveen Thaggikuppe Krishnamurthy, Jawahar Natarajan, Thava Palaniami, Gowthamarajan Kuppusamy","doi":"10.1007/s44273-025-00068-x","DOIUrl":"10.1007/s44273-025-00068-x","url":null,"abstract":"<div><p>Plastic is now a globally acknowledged pollutant. The current annual production of plastic worldwide is over 400 million tonnes, of which more than 40% is contributed by single-use plastic, resulting in plastic waste. This plastic garbage degrades into finer particles termed microplastics (less than 1 mm) and nano-plastics (less than 1 µm), together known as micro-nano-plastics (MNPs). Because of their endurance, they may remain in the environment for several decades, and their low density can easily be dispersed by wind and sea waves, often traveling thousands of kilometers. Due to these characteristics, MNPs are omnipresent now. Humans get exposed to these MNPs regularly, mainly through ingestion, inhalation, and dermal contact. Huge quantities of MNPs have been reported in the ocean around the globe, and through this, they enter the seafood and further into humans. Additionally, MNPs have been detected in processed food and beverages such as beer, tea bags, and table salt. Once MNPs enter the body, they accumulate in the tissues, enter the bloodstream, and affect various cellular pathways. So, the hazard assessment results from various studies on MPs and NPs are diverse and sometimes conflicting, most likely due to the use of research models and the diversity of the MNPs (varying size, shape, and composition). Therefore, considering these parameters this review will thoroughly evaluate the possible impact of MNP exposure on the gastrointestinal system and further amplifications on human health.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":"19 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-025-00068-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145168215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Seasonal variation and temperature-dependent emission of volatile organic compounds from a commercial swine shed in Japan","authors":"Nobuyuki Tanaka, Kaho Nishimura, Akane Miyazaki, Hiroshi Hayami","doi":"10.1007/s44273-025-00066-z","DOIUrl":"10.1007/s44273-025-00066-z","url":null,"abstract":"<div><p>To quantify and characterize the emissions of volatile organic compounds (VOCs) from swine sheds—a major source of atmospheric pollutants—this study investigated VOC concentrations and emission rates in a commercial swine facility in Okinawa, Japan, across four seasons. Average VOC concentrations at the exhaust outlet Ranged from 480 to 750 µg m⁻<sup>3</sup> with limited seasonal variation. Volatile fatty acids (VFAs), particularly acetic acid (31–38%), consistently dominated the VOC profile, followed by p-cresol, acetaldehyde, acetone, and ethanol. VFAs also made the largest contributions to both the OH radical reactivity (OHR) and ozone formation potential (OFP), indicating their significance in secondary pollutant formation. VOC emission rates (ERs) Ranged from 1.1 to 2.8 mg h⁻<sup>1</sup> kg⁻<sup>1</sup> and exhibited an exponential increase with temperature. The derived temperature–ER regression model was consistent with previous findings from other swine facilities, suggesting its broader applicability. Using this model, we estimated that annual VOC emissions from Japanese commercial swine sheds amount to approximately 10,000 tons, equivalent to 1.8% of the nation’s total VOC emissions. These findings highlight the livestock sector as a non-negligible contributor to national VOC inventories and suggest that mitigation strategies should account for animal husbandry emissions.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":"19 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-025-00066-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145062239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}