{"title":"Spatio-temporal variation of aerosol optical depth and black carbon mass concentration over five airports across Bangladesh: emphasis on effect of COVID-19 lockdown","authors":"Khaled Shaifullah Joy, Shahid Uz Zaman, Md. Riad Sarkar Pavel, Md. Safiqul Islam, Abdus Salam","doi":"10.1007/s44273-024-00038-9","DOIUrl":"10.1007/s44273-024-00038-9","url":null,"abstract":"<div><p>Globally, the COVID-19 outbreak has had a devastating impact on both health and economy. In contrast, the reduction in anthropogenic emissions has resulted in a major improvement in air quality. In this study, US National Aeronautics and Space Administration (NASA) satellite datasets and related reanalysis model data were used with validation using ground-based data to evaluate the effects of aviation-based emissions on aerosol optical depth (AOD) and black carbon (BC). The contributions from five airports in Bangladesh were assessed during the pre-lockdown (01 Jan to 22 March), lockdown (23 March to 30 May), and post-lockdown (31 May to 30 Aug) periods in 2019 and 2020. The study’s findings show that during the 2020 lockdown, AOD and BC concentrations significantly decreased at all five airports. The overall decline of AOD was ~ 18.5% (13.1% to 22.8%) and BC was ~ 18.1% (16.6% to 22.2%) in 2020 compared to 2019. The three international airports that were examined—Dhaka, Chattagram, and Sylhet—showed an average reduction of about ~ 9.7%, while Jashore and Barisal—two domestic airports—saw a minor increase in AOD of ~ 0.8% over the same period. However, the average BC concentration at both international and domestic airports dropped by ~ 9.8% and ~ 10.2%, respectively. This is the first study to use reanalysis datasets in Bangladesh to evaluate air pollution levels and aviation-based emissions. The results highlight the significant impact of reduced aviation activity on air quality and provide valuable insights for future air pollution management strategies.</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":"18 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00038-9.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141802461","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":"Large-eddy simulation of the effects of a tower structure on wind velocity and drag coefficient","authors":"Takenobu Michioka","doi":"10.1007/s44273-024-00036-x","DOIUrl":"10.1007/s44273-024-00036-x","url":null,"abstract":"<div><p>A large-eddy simulation was implemented for the flow around a cylindrical observation tower to investigate the effects of the tower structure on wind speed and drag coefficient. The mean wind velocity accelerates above the tower because flow separation occurs at the leading edge of the top of the tower. The drag coefficient is strongly linked to the Reynolds shear stress. Above the tower, the Reynolds shear stresses change from negative to positive within the recirculation zone and return to a negative value in the latter half of the tower because of the steep velocity gradients near the top of the tower. The change in the Reynolds shear stress results in an inaccurate drag coefficient. When one anemometer is used, a location at over 10 m above the top of the tower is suitable for measuring the drag coefficient accurately. When two anemometers are used, the Reynolds shear stress can be measured more accurately. Although the effects of the tower on the drag coefficient are not entirely removed, the use of two anemometers is a promising approach to estimate the drag coefficient in a tower.</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":"18 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00036-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141654654","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":"Possible detection of atmospheric bioaerosol via LiDAR: a wavelength-based simulation study","authors":"Juseon Shin, Youngmin Noh","doi":"10.1007/s44273-024-00035-y","DOIUrl":"10.1007/s44273-024-00035-y","url":null,"abstract":"<div><p>This study explores potential of LiDAR technology to rapidly detect aerosolized biological terror agents in the atmosphere. It assesses the application by simulating extinction coefficients and the Ångström exponent at various wavelengths (266, 1064, 1571, and 2000 nm), focusing on differentiating bioaerosols from typical atmospheric particles. The simulation analysis evaluates changes in aerosol distributions and related extinction coefficient and Ångström exponent shifts under clean, normal, and bad atmospheric conditions. The findings indicate that the 1064 nm wavelength effectively detects bioaerosol presence, with a combination of 1064 nm and 1571 nm providing optimal Ångström exponent use for particle size differentiation. This dual-wavelength approach is highlighted as a practical method for bioaerosol detection, showcasing a significant sensitivity to variations in particle quantity and size, which are critical in biological threat scenarios. In conclusion, the study offers guidance for selecting LiDAR wavelengths for biological agent detection systems. While providing a theoretical framework for practical applications, it also underlines the need for further experimental work to confirm findings and fine-tune technology for real-world monitoring and threat management. This research contributes to the development of effective monitoring strategies against the backdrop of biological terror threats.</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":"18 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00035-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141674108","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":"Air quality monitoring device to mitigate the spread of COVID-19 in educational buildings","authors":"Diego Quiroga, Sergio Diaz, Homero F. Pastrana","doi":"10.1007/s44273-024-00033-0","DOIUrl":"10.1007/s44273-024-00033-0","url":null,"abstract":"<div><p>The COVID-19 pandemic brought significant consequences on healthcare systems, economy, and politics. Nowadays, we know that the pathogen responsible for COVID-19 is transmitted mainly by aerosol droplets exhaled by infected individuals, which remain suspended in indoor air. There has been widespread interest in monitoring the <span>(CO_2)</span> levels in indoor spaces since an infected patient exhales <span>(CO_2)</span> and infectious aerosols when breathing. So, we designed and built an Air Quality Monitoring Device (AQMD) that measures and analyzes the levels of <span>(CO_2)</span> and particulate matter in the classrooms of a university with the aim of mitigating the spread of COVID-19. We divided the AQMD design into 2 phases: (i) data measurement and (ii) estimation of infection risk. Specifically, we measured the air quality in 3 classrooms of a university during different types of activities. Using these data, we calculated the recommended <span>(CO_2)</span> threshold for our classroom setting and estimated the probability of COVID-19 infection of a susceptible person. Our research shows that indoor <span>(CO_2)</span> concentrations and the probability of COVID-19 infection are influenced mainly by the type of activity and the number of windows open; besides, the number of students does not significantly impact the indoor <span>(CO_2)</span> concentrations levels because the range of students in the test scenario (18 to 31) was relatively small.</p></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":"18 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00033-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141374063","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":"Dry deposition of nitric acid gas by long-term measurement above and below a forest canopy","authors":"Zhaojie Wu, Mao Xu, Atsuyuki Sorimachi, Hiroyuki Sase, Makoto Watanabe, Kazuhide Matsuda","doi":"10.1007/s44273-024-00034-z","DOIUrl":"10.1007/s44273-024-00034-z","url":null,"abstract":"<div><p>Reactive nitrogen negatively affects terrestrial ecosystems by excessive deposition. Nitric acid gas (HNO<sub>3</sub>), a component of reactive nitrogen, is readily deposited on ground surfaces due to its high reactivity. However, there have been recent cases in which suppressed deposition fluxes, including upward fluxes, were observed above forests. As the mechanisms of HNO<sub>3</sub> dry deposition on forest surfaces are not fully understood, the accuracy of dry deposition estimates remains uncertain. To reduce uncertainties in the estimation, we investigated dry deposition of HNO<sub>3</sub> by 1-year measurement in a forest. We measured the vertical profiles of HNO<sub>3</sub>, nitrate, and sulfate in PM<sub>2.5</sub> in a deciduous forest in suburban Tokyo (FM Tama). We observed their concentrations above the forest canopy (30 m) and near the forest floor (2 and 0.2 m) using the denuder/filter pack from October 2020 to September 2021. The HNO<sub>3</sub> concentration decreased significantly from 30 to 2 m. However, the decrease in HNO<sub>3</sub> was not as significant, and occasionally, emission profiles were produced between 2 and 0.2 m. This was likely caused by HNO<sub>3</sub> generated by the volatilization of NH<sub>4</sub>NO<sub>3</sub> near the forest floor, which was warmed by sunlight during daytime in both leafy and leafless periods. Conversely, HNO<sub>3</sub> concentrations at 30 m were much higher than those at 2 m and 0.2 m, indicating that the forest acted as a sink for HNO<sub>3</sub> from a long-term perspective. It is presumed that HNO<sub>3</sub>, generated just above the forest canopy, could cause an upward flux if a temperature difference of several degrees occurs between 25 and 20 m.</p></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":"18 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00034-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141385494","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}
Na Ra Youn, Sang-Jin Lee, Tuyet Nam Thi Nguyen, Ho-Young Lee, Hye Kyung Cho, Chang-Keun Song, Sung-Deuk Choi
{"title":"Seasonal variation, source identification, and health risk assessment of atmospheric polycyclic aromatic hydrocarbons (PAHs) in Ulsan, South Korea","authors":"Na Ra Youn, Sang-Jin Lee, Tuyet Nam Thi Nguyen, Ho-Young Lee, Hye Kyung Cho, Chang-Keun Song, Sung-Deuk Choi","doi":"10.1007/s44273-024-00032-1","DOIUrl":"10.1007/s44273-024-00032-1","url":null,"abstract":"<div><p>Gaseous and particulate 21 PAHs were monitored at a residential site in Ulsan, South Korea, over three seasons (December 2013–August 2014). The mean concentrations of Σ<sub>21</sub> PAHs were highest in winter (16.2 ± 8.2 ng/m<sup>3</sup>), followed by spring (8.37 ± 4.53 ng/m<sup>3</sup>) and summer (6.23 ± 2.53 ng/m<sup>3</sup>). The mean gaseous concentration of Σ<sub>21</sub> PAHs (7.39 ± 4.39 ng/m<sup>3</sup>) was 2.7 times higher than that of particulate PAHs (2.70 ± 3.38 ng/m<sup>3</sup>). To identify the sources of PAHs (both types of sources and their areas), diagnostic ratios, principal component analysis, and concentration-weighted trajectory (CWT) were used. The results showed that pyrogenic sources (e.g., coal combustion) were the primary emission sources of PAHs in winter and spring. In summer, the influence of both coal and heavy oil combustion was dominant, suggesting that PAHs could be transported from industrial areas of Ulsan (e.g., petrochemical and nonferrous industrial complexes) by seasonal winds. Regarding emission source areas, the CWT analysis revealed that in winter and spring, PAHs in Ulsan could be attributed to emissions from regional areas, e.g., China and North Korea. The PAH concentrations were also used to assess the health risks associated with the inhalation of these compounds for adults aged 18–70. The results showed that the cancer risks from Σ<sub>19</sub> PAHs and Σ<sub>13</sub> PAHs did not exceed the guideline set by the US EPA (10<sup>−6</sup>), indicating no cancer risks for this target group. However, it is worth noting that certain PAHs, which are not listed as priority PAHs by the US EPA, make significant contributions to the benzo[a]pyrene equivalent and the associated cancer risks. Therefore, it is necessary to investigate not only the priority PAHs but also other PAH species to fully evaluate their effect on human health.</p></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":"18 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00032-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140694903","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":"Spatiotemporal aerosol prediction model based on fusion of machine learning and spatial analysis","authors":"Kwon-Ho Lee, Seong-Hun Pyo, Man Sing Wong","doi":"10.1007/s44273-024-00031-2","DOIUrl":"10.1007/s44273-024-00031-2","url":null,"abstract":"<div><p>This study examined long-term aerosol optical thickness (AOT) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) to quantify aerosol conditions on the Korean Peninsula. Time-series machine learning (ML) techniques and spatial interpolation methods were used to predict future aerosol trends. This investigation utilized AOT data from Terra MODIS and meteorological data from Automatic Weather System (AWS) in eight selected cities in Korea (Gangneung, Seoul, Busan, Wonju, Naju, Jeonju, Jeju, and Baengyeong) to assess atmospheric aerosols from 2000 to 2021. A machine-learning-based AOT prediction model was developed to forecast future AOT using long-term observations. The accuracy analysis of the AOT prediction results revealed mean absolute error of 0.152 ± 0.15, mean squared error of 0.048 ± 0.016, bias of 0.002 ± 0.011, and root mean squared error of 0.216 ± 0.038, which are deemed satisfactory. By employing spatial interpolation, gridded AOT values within the observation area were generated based on the ML prediction results. This study effectively integrated the ML model with point-measured data and spatial interpolation for an extensive analysis of regional AOT across the Korean Peninsula. These findings have substantial implications for regional air pollution policies because they provide spatiotemporal AOT predictions.</p></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":"18 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00031-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140222244","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":"Assessment of WRF-CO2 simulated vertical profiles of CO2 over Delhi region using aircraft and global model data","authors":"Srabanti Ballav, Prabir K. Patra, Manish Naja, Sandipan Mukherjee, Toshinobu Machida","doi":"10.1007/s44273-024-00030-3","DOIUrl":"10.1007/s44273-024-00030-3","url":null,"abstract":"<div><p>High-resolution regional model simulation of CO<sub>2</sub> may be more beneficial to reduce the uncertainty in estimation of CO<sub>2</sub> source and sink via inverse modeling. However, the study of atmospheric CO<sub>2</sub> transport with regional models is rare over India. Here, weather research and forecasting chemistry model adjusted for CO<sub>2</sub> (WRF-CO<sub>2</sub>) is used for simulating vertical profile of CO<sub>2</sub> and its assessment is performed over Delhi, India (27.4–28.6° N and 77–96° E) by comparing aircraft observations (CONTRAIL) and a global model (ACTM) data. During August and September, the positive vertical gradient (~ 13.4 ppm) within ~ 2.5 km height is observed due to strong CO<sub>2</sub> uptake by newly growing vegetation. A similar pattern (~ 4 ppm) is noticed in February due to photosynthesis by newly growing winter crops. The WRF-CO<sub>2</sub> does not show such steep increasing slope (capture up to 5%) during August and September but same for February is estimated ~ 1.7 ppm. Generally, CO<sub>2</sub> is quite well mixed between ~ 2.5 and ~ 8 km height above ground which is well simulated by the WRF-CO<sub>2</sub> model. During stubble burning period of 2010, the highest gradient within 2.5 km height above ground was recorded in October (− 9.3 ppm), followed by November (− 7.6 ppm). The WRF-CO<sub>2</sub> and ACTM models partially capture these gradients (October − 3.3 and − 2.7 ppm and November − 3.8 and − 4.3 ppm respectively). A study of the seasonal variability of CO<sub>2</sub> indicates seasonal amplitudes decrease with increasing height (amplitude is ~ 21 ppm at the near ground and ~ 6 ppm at 6–8 km altitude bin). Correlation coefficients (CC) between the WRF-CO<sub>2</sub> model and observation are noted to be greater than 0.59 for all the altitude bins. In contrast to simulated fossil CO<sub>2</sub>, the biospheric CO<sub>2</sub> is in phase with observed seasonality, having about 80% at the lowest level and gradually declines with height due to mixing processes, reaching around 60% at the highest level. The model simulation reveals that meteorology plays a significant role of the horizontal and vertical gradient of CO<sub>2</sub> over the region.</p></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":"18 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00030-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142410617","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}
Shin-Young Park, Hye-Won Lee, Jaymin Kwon, Sung-Won Yoon, Cheol-Min Lee
{"title":"Proposal of a methodology for prediction of heavy metals concentration based on PM2.5 concentration and meteorological variables using machine learning","authors":"Shin-Young Park, Hye-Won Lee, Jaymin Kwon, Sung-Won Yoon, Cheol-Min Lee","doi":"10.1007/s44273-024-00029-w","DOIUrl":"10.1007/s44273-024-00029-w","url":null,"abstract":"<div><p>In this study, we developed a prediction model for heavy metal concentrations using PM<sub>2.5</sub> concentrations and meteorological variables. Data was collected from five sites, encompassing meteorological factors, PM<sub>2.5</sub>, and 18 metals over 2 years. The study employed four analytical methods: multiple linear regression (MLR), random forest regression (RFR), gradient boosting, and artificial neural networks (ANN). RFR was the best predictor for most metals, and gradient boosting and ANN were optimal for certain metals like Al, Cu, As, Mo, Zn, and Cd. Upon evaluating the final model’s predicted values against the actual measurements, differences in the concentration distribution between measurement locations were observed for Mn, Fe, Cu, Ba, and Pb, indicating varying prediction performances among sites. Additionally, Al, As, Cd, and Ba showed significant differences in prediction performance across seasons. The developed model is expected to overcome the technical limitations involved in measuring and analyzing heavy metal concentrations. It could further be utilized to obtain fundamental data for studying the health effects of exposure to hazardous substances such as heavy metals.</p></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":"18 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00029-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140426627","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":"PM2.5-bound polycyclic aromatic hydrocarbons (PAHs): quantification and source prediction studies in the ambient air of automobile workshop using the molecular diagnostic ratio","authors":"Gregory E. Onaiwu, Ikhazuagbe H. Ifijen","doi":"10.1007/s44273-024-00027-y","DOIUrl":"10.1007/s44273-024-00027-y","url":null,"abstract":"<div><p>The presence of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere has been linked to health concerns, including cancer. Automobile workshops are significant contributors to PAH emissions due to their operations. Hence, this investigation aimed to identify and quantify the sources of PM2.5-bound PAHs in the ambient air of automobile workshops in Benin City, Nigeria, using molecular diagnostic ratios. PM2.5 samples were collected from 60 automobiles over 1 year, during the rainy (April to November) and dry (December to March) seasons of 2019. Sample collection utilized a low-volume air sampler with quartz filter paper, and extraction was performed using a 1:1 mixture of acetone and dichloromethane. The analysis involved an HP Agilent Technology 6890 Gas Chromatography (GC) system with a flame ionization detector. The annual average concentrations of PM2.5-bound PAHs in Benin City were 269.87 ± 249.32 ng/m<sup>3</sup> (dry season) and 216.30 ± 204.89 ng/m<sup>3</sup> (wet season). Molecular diagnostic ratios, such as Fl/(Fl + Py), An/(An + Phe), BaP/(BaP + Chry), BbF/BkF, InP/(InP + BghiP), and BaA/(BaA + Chr), aided in identifying PAH sources. Gasoline combustion, diesel combustion, traffic emissions, and emissions from automobile panel welders were found to be the primary sources of PAHs near vehicle workshops. These findings provide crucial insights for developing effective strategies to reduce emissions and protect public health in the air surrounding automobile workshops in Benin City.</p></div>","PeriodicalId":45358,"journal":{"name":"Asian Journal of Atmospheric Environment","volume":"18 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s44273-024-00027-y.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140447999","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}