Atmospheric Environment: X最新文献

{"title":"Impacts of wildfire smoke aerosols on radiation, clouds, precipitation, climate, and air quality","authors":"Rahele Barjeste Vaezi ,&nbsp;Michael R. Martin ,&nbsp;Farnaz Hosseinpour","doi":"10.1016/j.aeaoa.2025.100322","DOIUrl":"10.1016/j.aeaoa.2025.100322","url":null,"abstract":"<div><div>Wildfires have become increasingly prevalent, impacting ecosystems, climate, and human health on a global scale. This review aims to present a comprehensive analysis of current knowledge on the environmental factors and conditions driving wildfires, the characteristics and transport of smoke emissions, along the broader impacts of wildfire smoke on the weather and climate. These impacts include changes in atmospheric radiation, cloud formation, atmospheric circulation, precipitation patterns, and air quality, as well as their effects on land cover, safety, and public health. Wildfire emissions include various pollutants such as particulate matter that alter the Earth's energy balance, reduce air quality, and impact cloud microphysics. Key interactions, such as the direct and indirect effects of smoke aerosols, affect cloud cover and lifetime, precipitation, atmospheric stability, and ultimately induce changes in weather and climate dynamics. Moreover, smoke transport extends the effects of wildfires thousands of kilometers beyond their sources, which reduces agricultural productivity, deteriorates human health, and threatens the environment. Advances in satellite retrievals and modeling techniques have improved the ability to monitor, analyze, and predict these complex interactions. Moreover, this review highlights the critical need for advancing research to more precisely quantify and project multi-scale trends in wildfire smoke and its far-reaching impact on public health, safety, infrastructure, and ecosystems. Developing more robust adaptation strategies and resilience measures is essential to effectively mitigate these complex, adverse effects on communities and the environment.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"26 ","pages":"Article 100322"},"PeriodicalIF":3.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143783855","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":"Influence factors on airborne pollen dispersal in a tropical island over China: morphology and meteorology","authors":"Mengyuan Pang,&nbsp;Ningyan Fu,&nbsp;Siyang Li","doi":"10.1016/j.aeaoa.2025.100323","DOIUrl":"10.1016/j.aeaoa.2025.100323","url":null,"abstract":"<div><div>Airborne pollen is an important primary biological aerosol particle in tropical regions, greatly impacting climate and human health. However, the pollen morphology in tropical areas, particularly their impact on pollen dispersal, remains unknown. To determine the relationship between the dispersal and morphology of airborne pollens, we collected the airborne pollen by Durham samplers at three vertical heights, including 1.5 m, ∼18.5 m, and ∼55 m in Haikou City, China. Pollen particles showed higher concentrations at higher heights above ground level. The quantitative analysis of single pollen particles based on the size index showed that the airborne pollen sizes in the tropics were mainly small (10–25 μm) (45.9%) and medium (25–50 μm) (32.2%). That's consistent with the pollen morphology of spring and summer flowering plants in the surrounding areas. The proportions of very small (&lt;10 μm) and small (10–25 μm) pollen particles increased significantly with the vertical height. The shape index showed the prominent shape of airborne pollen was subspheroidal/spheroidal (∼80%). The pollen concentration of other shapes, like prolate or oblate, slightly increased with height. The Pearson correlation analysis showed that local meteorological conditions had an important role in influencing pollen amounts, with some associations found to be statistically significant. Temperature variables had significant positive correlation with pollen amounts, especially the maximum temperature (r = 0.71, P &lt; 0.01). The rainfall and relative humidity exhibited a negative correlation with pollen concentration. Notably, pollen release was influenced by meteorological factors with a 1–7 day lagged effect. This study provided a near-ground vertical profile of tropical pollen concentration and morphology. These findings also offer a comprehensive understanding of how airborne pollen morphology and meteorological factors influence their transport and deposition characteristics on a tropical island.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"26 ","pages":"Article 100323"},"PeriodicalIF":3.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143783856","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":"Cement and brick factories contribute elevated levels of NO2 pollution in Nepal: Evidence of high-resolution view from space","authors":"Madhu S. Gyawali ,&nbsp;Lok N. Lamsal ,&nbsp;Sujan Neupane ,&nbsp;Bimal Gyawali ,&nbsp;Keshav Bhattarai ,&nbsp;Bradford Fisher ,&nbsp;Nickolay Krotkov ,&nbsp;Jos van Geffen ,&nbsp;Henk Eskes ,&nbsp;Shriram Sharma ,&nbsp;Cameron Brunt ,&nbsp;Rudra Aryal","doi":"10.1016/j.aeaoa.2025.100324","DOIUrl":"10.1016/j.aeaoa.2025.100324","url":null,"abstract":"<div><div>An upsurge in the pollution level in areas with a high concentration of brick and cement factories in Nepal is concerning. Nitrogen dioxide (NO₂), a key air quality indicator, can be effectively monitored from space. This study utilizes high-resolution satellite observations of NO₂ from the TROPOspheric Monitoring Instrument (TROPOMI). It examines the NO₂ distribution over areas with emerging sources of nitrogen oxides from brick and cement factories from 2018 to 2021. Rapid growth of brick and cement factories has turned the Lumbini-Butwal-Palpa corridor, in Midwest Nepal, more polluted than the capital city Kathmandu. Between 2019 and 2021, NO₂ levels in this corridor rose considerably, while it remained steady in the Kathmandu Valley. TROPOMI-derived NO₂ levels and inferred NO_x emissions over the corridor nearly doubled in the span of three years. Conversely, Kathmandu Valley exhibited no significant changes except in 2020 when NO₂ and NO_x levels declined. This drop coincided with COVID-19-related travel restrictions and other reduced activities. NO₂ pollution recorded by the Ozone Monitoring Instrument (OMI) from 2005 to 2019 shows an annual NO₂ increase of ∼3.5 % over both regions. A comparison between NO_x emissions from the 2018 EDGAR inventory and TROPOMI-derived estimates for 2019 reveal comparable values over the Lumbini-Butwal-Palpa corridor but around 35 % higher estimates over Kathmandu. This discrepancy over the capital city, as well as the rapid rise in emissions over the Lumbini-Butwal-Palpa corridor due to a large-scale development of cement and brick industries, highlights the need for timely updates in bottom-up emission inventory.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"26 ","pages":"Article 100324"},"PeriodicalIF":3.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143817089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Addressing underestimated carbon monoxide emissions in Taiwan using CMAQ and impacts on local ozone concentration","authors":"Chieh-Sen Tsai ,&nbsp;Ping-Chieh Huang ,&nbsp;Hsin-Chih Lai ,&nbsp;John C. Lin ,&nbsp;Hui-Ming Hung","doi":"10.1016/j.aeaoa.2025.100325","DOIUrl":"10.1016/j.aeaoa.2025.100325","url":null,"abstract":"<div><div>Emission inventories play a crucial role in understanding and managing air quality. This research centers on carbon monoxide (CO), a low-reactivity species with a lifetime of 2 months, acting as a tracer for local pollutants. The investigation delves into the potential uncertainties within its emissions and the impacts. CO is significantly underestimated in the current air quality model using Taiwan Emission Data System 9.0 (TEDS 9.0) for Taiwan. The present CMAQ simulation underestimates CO in Taiwan by a factor of ∼3 compared to observations. With the minimum root mean square error (RMSE) analysis between simulation and observation, the optimal emission correction factors are estimated as 2, 4, and 3.6 for northern, central, and southern Taiwan, respectively. The simulated underestimation of CO concentrations, coupled with relatively consistent NOx concentrations compared to observations, might indicate possible uncertainties in emission sources, especially for sources with high CO/NOx ratios, such as vehicles. This discrepancy further suggests the possibility of underestimating other combustion chemical species, such as volatile organic compounds (VOCs), which are not adequately quantified in the ambient environment. Our findings indicate that the adjustment would increase local O₃ concentration (up to 3 ppbv), with a minor decreased influence on NOx (less than 0.5 ppbv), underscoring the importance of accurate emission inventories in air quality modeling and the reassessment of the validity of CO and NOx emissions in a NOx-saturated environment. Our analysis of the potential emission sources highlights the importance of implementing stricter local emission controls and monitoring.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"26 ","pages":"Article 100325"},"PeriodicalIF":3.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143829188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of emissions from a turbojet engine running on sustainable aviation fuels, blends and conventional jet A1","authors":"Jana Moldanová ,&nbsp;Åsa M. Hallquist ,&nbsp;Michael Priestley ,&nbsp;Kristoffer Danèl ,&nbsp;Bengt Fallenius ,&nbsp;Omar Abdalal ,&nbsp;Annika Potter ,&nbsp;Bo Strandberg","doi":"10.1016/j.aeaoa.2025.100321","DOIUrl":"10.1016/j.aeaoa.2025.100321","url":null,"abstract":"<div><div>Aviation contributes to air pollution and significantly impacts climate change. Sustainable aviation fuels (SAFs) offer a potential solution to reduce CO₂ emissions with the possible co-benefit of reducing emissions of particles. This study evaluates emissions of a turbojet engine using conventional Jet A1 fuel, Biojet fuel (alcohol-to-jet synthetic kerosene with aromatics, ATJ-SKA), hydrotreated vegetable oil (HVO), and their blends. Emissions of particulate matter, gaseous pollutants (NOx, CO, total hydrocarbons, THC), polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs) and aldehydes were measured across different engine loads (Taxi, Cruise and Take-Off). The results show that SAFs, particularly neat Biojet and HVO, significantly reduced particle emissions, by 20 – &gt;99 % compared to Jet A1, especially in the Take-Off mode in case of the Biojet fuel. This reduction is likely connected to the differences in the chemical composition of the fuels including higher content of hydrogen and lower content of aromatics and naphthalenes. Emissions of VOCs, PAHs and aldehydes were reduced by 40–50 % in the Taxi mode, which has the highest emission factors and is also responsible for majority of emissions during the LTO cycle, while an increase was observed for the Take-Off mode. Biojet use exhibited improved engine performance at the Take-Off, but fuel blends showed mixed effects on efficiency. This study shows that SAFs present a promising route to reducing aviation's environmental footprint, with co-benefit of reduced impact on air pollution and non-CO₂ climate forcing from reduced particle emissions. Further research is required especially on impact of fuel blends on engine performance and emission characterization.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"26 ","pages":"Article 100321"},"PeriodicalIF":3.8,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143740115","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":"Estimation of the primary air pollutant emission levels of in-use gasoline vehicles and their influencing factors in Beijing, China","authors":"Yangyang Cui ,&nbsp;Yan Shen ,&nbsp;Lijun Zhu ,&nbsp;Huawei Yi ,&nbsp;Guanghan Huang ,&nbsp;Han Li ,&nbsp;Linzhen Qu ,&nbsp;Aijun Shi ,&nbsp;Yifeng Xue","doi":"10.1016/j.aeaoa.2024.100310","DOIUrl":"10.1016/j.aeaoa.2024.100310","url":null,"abstract":"<div><div>Gasoline vehicles (GVs) have become one of the main emission sources of NOx and volatile organic compounds (VOCs) in Beijing, and determining the pollutant emission levels of in-use GVs is crucial. In this study, we assessed the emission levels, exceedance rates, and factors influencing primary air pollutants (NO, CO, and hydrocarbons (HCs) from GVs, including 7.46 million GVs in Beijing from 2019 to 2023. We predicted the variation in the exceedance rate after implementing the standard b-limit and assessed the social stability risk. In general, the emissions of GVs in Beijing were relatively low. According to the simple driving mode conditions, the CO, HC and NO concentrations in the top 50% of the cumulative probability distributions of emissions were 0.04%, 10.3 ppm and 77.0 ppm, respectively, which account for only 1/10∼1/8 of the standard a-limit values. However, we found that the pollutant concentrations corresponding to the top 10% and 90% of the cumulative probability distributions significantly differed. For example, the NO concentrations in the top 10% were 220 times greater than those in the top 90%, namely, approximately 36.5% greater than the standard limit. The greater risk of exceeding the standards was related to the occurrence of carbon deposits on the valves and cylinder heads of engines, of which medium-duty trucks (MDTs) exhibited the highest rate of exceeding the standards (34.5%) due to vehicle deterioration under high-intensity use. GVs exhibited the highest exceedance rate among all the vehicle types, at 38.7%, whereas China VI vehicles exhibited an exceedance rate of only 0.2%. If the more stringent standard b-limit were implemented, the number of vehicles exceeding the standard would increase, and the exceedance rate of GVs under the standard b-limit would be slightly greater than that under the a-limit. Overall, the exceedance rate showed a decreasing trend with increasing emission stage, with the proportion of the exceedance rate at the different emission stages also varying.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"25 ","pages":"Article 100310"},"PeriodicalIF":3.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143158865","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":"On-Board measurement of emissions on a dual fuel LNG powered cruise ship: A sea trial study","authors":"Benoit Sagot ,&nbsp;Guilhem Giraudier ,&nbsp;François Decuniac ,&nbsp;Lise Lefebvre ,&nbsp;Aurelia Miquel ,&nbsp;Amandine Thomas","doi":"10.1016/j.aeaoa.2025.100313","DOIUrl":"10.1016/j.aeaoa.2025.100313","url":null,"abstract":"<div><div>The use of liquefied natural gas (LNG) in dual-fuel engines is expanding in the maritime industry, enabling compliance with sulfur and nitrogen oxide emissions regulations, while also reducing atmospheric emissions of particulate pollutants. LNG further allows for a reduction in direct CO₂ emissions compared to liquid fuels such as marine gas oil (MGO), which also helps meet greenhouse gas emission (GHG) reduction requirements in maritime transport. However, unburned methane emitted by dual-fueled engines remains an area for improvement. In this study, we monitored the atmospheric emissions of unburned methane, along with other gaseous and particulate pollutants, from a 4-stroke dual-fuel engine during sea trials of a new cruise ship, using both LNG and MGO fuels that these engines can operate on. During this ship's commissioning phase, we were able to perform measurements across a wide range of engine loads and confirm higher emission factors for unburned methane at low loads: the emission factor remains relatively stable at around 2.3 g.kWh⁻¹ between 60% and 95% engine load, but increases at lower loads, reaching 8.5 g.kWh⁻¹ at 25% load. For fine particulate emissions, characterized by the number of particles larger than 23 nm (PN₂₃), we established that switching from MGO to LNG results in a reduction factor of approximately 136 in PN₂₃ particles emitted by the engine at high load. The measured emission levels in MGO mode were relatively independent of engine load but tended to increase in LNG mode as engine load decreased. Based on our measurements of methane and CO₂, we propose a comparison of GHG emission levels as a function of engine load, which shows that switching from LNG to MGO at 75% load results in an 18% relative increase in CO₂ equivalent emissions. Finally, we had access to engine load monitoring (ELM) during commercial operation over a 3-month period. The load distribution obtained shows that the diesel-electric architecture, which adjusts the number of engines in operation and their load according to the vessel's energy demands, leads to a limitation in the use of the engine at low load. As a result, less than 7% of the engine operating time is spent at a load below 30%, a threshold beyond which the studied engine emits less than the default FuelEU value of 3.1%. When considering a usage-weighted average, based on the emission factors measured on board and the load distribution derived from the Engine Load Monitoring (ELM), we obtain an emission factor of 3.2 g.kWh⁻¹, or 1.7% of the fuel use. This value of 1.7% is lower than that specified by the FuelEU regulation, and it appears to be representative of the actual emissions of this vessel and its usage under operational conditions.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"25 ","pages":"Article 100313"},"PeriodicalIF":3.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143158868","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":"Investigating the effects of animal-specific δ15N-NH3 values volatilized from livestock waste on regional NH3 source partitioning","authors":"Dong Liu ,&nbsp;Zhi Quan ,&nbsp;Yingying Wang ,&nbsp;Kai Huang ,&nbsp;Quanping Zhang ,&nbsp;Linlin Song ,&nbsp;Shaonan Huang ,&nbsp;Yanzhi Wang ,&nbsp;Zhifeng Xun ,&nbsp;Deze Liu ,&nbsp;Chang Liu ,&nbsp;Yunting Fang ,&nbsp;Jianping Sun","doi":"10.1016/j.aeaoa.2025.100314","DOIUrl":"10.1016/j.aeaoa.2025.100314","url":null,"abstract":"<div><div>The natural ¹⁵N abundance of ammonia (δ¹⁵N-NH₃) emitted from livestock waste within a specific area (δ¹⁵N-NH₃-LW) can be used to estimate its contribution to atmospheric NH₃ through an isotope mixing model. However, the limited availability of reports on δ¹⁵N-NH₃-LW hinders the accuracy of regional NH₃ source partitioning. In this study, we conducted research in the suburbs of Shenyang, China, and combined our results (n = 71) with data from published literature (n = 56) to develop a δ¹⁵N-NH₃ spectrum emitted from cattle, pig, sheep, and poultry waste. We also explored the national and global spatial distribution of δ¹⁵N-NH₃-LW based on the proportion of NH₃ emissions from these four types of livestock waste. Our results showed that the δ¹⁵N-NH₃ values ranged from −59.9‰ to −7.7‰, with a mean value of −27.3‰. This value was significantly lower than that from non-agricultural sources, such as coal combustion and motor vehicle exhaust, but overlapped with values from fertilizer N volatilization. Specifically, the δ¹⁵N-NH₃ values emitted from cattle, pig, sheep, and poultry waste were −32.1 ± 15.9‰, −20.7 ± 7‰, −24.3 ± 5.9‰, and −19.1 ± 4.9‰, respectively. Considering regional differences in livestock farming structures, δ¹⁵N-NH₃-LW exhibited a gradual decreasing trend from Southeast to Northwest across China. For example, Fujian Province, located on the southeastern coast, exhibited the highest δ¹⁵N-NH₃-LW value of −19.8‰, owing to its high proportion of poultry farming, while the Tibet Autonomous Region, in the western inland, displayed the lowest δ¹⁵N-NH₃-LW value of −30.8‰, due to its high proportion of cattle farming. Globally, the δ¹⁵N-NH₃-LW value was highest in Southeast Asia (−23.4‰) and lowest in East Africa (−30.4‰). Overall, our study revealed significant spatial variation in δ¹⁵N-NH₃-LW at both national and global scales. To more accurately assess the regional contributions of NH₃ emissions from livestock waste, it is essential to use region-specific δ¹⁵N-NH₃-LW values for future NH₃ source partitioning.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"25 ","pages":"Article 100314"},"PeriodicalIF":3.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143158161","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":"Physicochemical characterization of welding and grinding fine particulates at a machinery plant: A comprehensive case study of workers’ health risk assessment","authors":"Po-Hsuan Yen ,&nbsp;Hsin-Nan Chung ,&nbsp;Wen-Hsi Cheng ,&nbsp;Chung-Shin Yuan ,&nbsp;Yu-Lun Tseng ,&nbsp;Chin-Ko Yeh ,&nbsp;Chang-Hua Lien ,&nbsp;Su-Wen Cheng","doi":"10.1016/j.aeaoa.2025.100319","DOIUrl":"10.1016/j.aeaoa.2025.100319","url":null,"abstract":"<div><div>Electric welding is a well-developed technology and an indispensable process in today's metal processing-related manufacturing industries. However, high-temperature operation could easily expose welding personnel to metal fume containing particle matters (PM) with aerodynamic diameters (<em>d</em>_<em>p</em>) ranging from sub-microns to microns. This investigation focused on a high-pressure vessel manufacturing factory in southern Taiwan, and workers in the same indoor factory building were divided into five similar exposure groups (SEGs), including design, layout/assembling, arc welding, grinding and pickling/painting, to implement personal sampling. According to the monitoring data on-site, high concentrations of PM are mainly found in the areas within 0.5 m of welding operations; the fume produced from ilmenite electrodes has the highest concentration of PM, and followed by those using high-fiber electrodes and high-tensile steel electrodes. Especially when welding with ilmenite electrodes at the current of 150 A, the concentrations of PM_2.5 and PM₁₀ reached the highest 1716 and 3024 μg/m³, respectively. The SEG of welding, who manually welded carbon steel and stainless steel, even exposed to submicron particles with <em>d</em>_<em>p</em> = 151–170 nm. Metal analysis of PM using inductively coupled plasma optical emission spectroscopy (ICP-OES) found that the cancer risk of cadmium (Cd) and chromium (Cr(VI)) in the SEG of pickling and painting was significantly the highest among all SEGs; the non-cancer risk (hazard index) of manganese (Mn) was high among all SEGs.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"25 ","pages":"Article 100319"},"PeriodicalIF":3.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143444946","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":"Emission characteristics of railway tread brakes","authors":"Daniel Fruhwirt ,&nbsp;Thomas Nöst ,&nbsp;Philipp Leonhardt ,&nbsp;Martin Leitner ,&nbsp;Peter Brunnhofer ,&nbsp;Gina Bode ,&nbsp;Sabrina Michael ,&nbsp;Johannes Rodler","doi":"10.1016/j.aeaoa.2025.100320","DOIUrl":"10.1016/j.aeaoa.2025.100320","url":null,"abstract":"<div><div>Braking of freight cars in rail transport mostly happens mechanically, as tread brakes are the only braking system. For this reason, non-exhaust particle (NEP) emissions can be expected. In order to quantify the emissions of such brakes, an extensive series of tests was conducted on a rail brake test bench at Graz University of Technology. The quantification of NEP emissions was done for grey cast iron as well as composite blocks and included the observation of emitted particle mass, particle size distribution, analysis of particle composition as well as the monitoring of gaseous substances. The test results indicated that grey cast iron brake shoes represent the highest emitter. PM10 emission factors for brake events were derived in the range of 2.65–28.66 g/km (km refers to braking distance). Iron and manganese were present in most of the tests. Barium and zinc could only be identified in tests with type K brake shoes.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"25 ","pages":"Article 100320"},"PeriodicalIF":3.8,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529618","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}