Pub Date : 2024-10-28DOI: 10.1016/j.aeaoa.2024.100302
The regulation of ship emissions has become more restrictive due to their significant impact on global air quality, particularly in coastal regions. According to the International Maritime Organization (IMO) regulations, current restrictions mainly limit the sulfur content of the fuel mass to 0.5 % and 0.1 % respectively. In compliance with these regulations, exhaust SO2 cleaning systems (scrubbers) and new low-sulfur fuels are increasingly used. For comprehensive monitoring of ship emissions, advanced measurement techniques are demanded. Our study reports on the results of a land-based field campaign conducted in the port of Rostock, Germany. The chosen location strategically positions the measurement setup to capture all incoming and outgoing ships passing within a distance of up to 2 km. Potential ship exhaust plumes are indicated by rapid changes in particle number and size distribution monitored by an optical particle sizer (OPS) and a scanning mobility particle sizer (SMPS). Additionally, single-particle mass spectrometry (SPMS) was used to qualitatively characterize ambient single-particles (0.2–2.5 μm) by their chemical signatures. In a one-week time span, the exhaust plumes of 73 ships were identified. The high sensitivity of SPMS to transition metals and polycyclic aromatic hydrocarbons (PAH) in individual particles make it possible to distinguish between different marine fuels.
{"title":"Detection and analysis of ship emissions using single-particle mass spectrometry: A land-based field study in the port of rostock, Germany","authors":"","doi":"10.1016/j.aeaoa.2024.100302","DOIUrl":"10.1016/j.aeaoa.2024.100302","url":null,"abstract":"<div><div>The regulation of ship emissions has become more restrictive due to their significant impact on global air quality, particularly in coastal regions. According to the International Maritime Organization (IMO) regulations, current restrictions mainly limit the sulfur content of the fuel mass to 0.5 % and 0.1 % respectively. In compliance with these regulations, exhaust SO<sub>2</sub> cleaning systems (scrubbers) and new low-sulfur fuels are increasingly used. For comprehensive monitoring of ship emissions, advanced measurement techniques are demanded. Our study reports on the results of a land-based field campaign conducted in the port of Rostock, Germany. The chosen location strategically positions the measurement setup to capture all incoming and outgoing ships passing within a distance of up to 2 km. Potential ship exhaust plumes are indicated by rapid changes in particle number and size distribution monitored by an optical particle sizer (OPS) and a scanning mobility particle sizer (SMPS). Additionally, single-particle mass spectrometry (SPMS) was used to qualitatively characterize ambient single-particles (0.2–2.5 μm) by their chemical signatures. In a one-week time span, the exhaust plumes of 73 ships were identified. The high sensitivity of SPMS to transition metals and polycyclic aromatic hydrocarbons (PAH) in individual particles make it possible to distinguish between different marine fuels.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530891","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}
Pub Date : 2024-10-26DOI: 10.1016/j.aeaoa.2024.100303
The impact of ambient air pollution on human health, particularly fine particulate matter (PM2.5) and tropospheric ozone (O3), is a critical global concern. Atmospheric chemical transport models (CTMs) are widely used to predict air pollutant concentrations and assess associated health risks. However, there is a need to better understand how the horizontal resolution of these models influences their accuracy, especially in future assessments. In this study, we compared the performance of global low-resolution CTMs with high-resolution nested simulations for estimating O3 and PM2.5 concentrations. The models were validated against observational data to determine their accuracy across different spatial scales and to evaluate their suitability for future scenario assessments. Our findings demonstrate that while the nested-grid simulations improved the reproducibility of regional observations, especially in areas with complex topography or localized emissions, the overall global-scale performance of the model did not significantly benefit from higher resolution. Additionally, the differences in global health and agricultural impacts between low- and high-resolution simulations were minor and within the range of uncertainty typically associated with emission inventories and CTMs. However, for specific regional studies or policy applications, higher resolution may offer improved accuracy. Ultimately, the current low-spatial-resolution model provides sufficient accuracy for many global-scale applications, but the choice of resolution should be carefully considered depending on the specific objectives of the study especially in future scenario.
{"title":"Comparison of global air pollution impacts across horizontal resolutions","authors":"","doi":"10.1016/j.aeaoa.2024.100303","DOIUrl":"10.1016/j.aeaoa.2024.100303","url":null,"abstract":"<div><div>The impact of ambient air pollution on human health, particularly fine particulate matter (PM<sub>2.5</sub>) and tropospheric ozone (O<sub>3</sub>), is a critical global concern. Atmospheric chemical transport models (CTMs) are widely used to predict air pollutant concentrations and assess associated health risks. However, there is a need to better understand how the horizontal resolution of these models influences their accuracy, especially in future assessments. In this study, we compared the performance of global low-resolution CTMs with high-resolution nested simulations for estimating O<sub>3</sub> and PM<sub>2.5</sub> concentrations. The models were validated against observational data to determine their accuracy across different spatial scales and to evaluate their suitability for future scenario assessments. Our findings demonstrate that while the nested-grid simulations improved the reproducibility of regional observations, especially in areas with complex topography or localized emissions, the overall global-scale performance of the model did not significantly benefit from higher resolution. Additionally, the differences in global health and agricultural impacts between low- and high-resolution simulations were minor and within the range of uncertainty typically associated with emission inventories and CTMs. However, for specific regional studies or policy applications, higher resolution may offer improved accuracy. Ultimately, the current low-spatial-resolution model provides sufficient accuracy for many global-scale applications, but the choice of resolution should be carefully considered depending on the specific objectives of the study especially in future scenario.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553881","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}
Pub Date : 2024-10-25DOI: 10.1016/j.aeaoa.2024.100300
This research thoroughly examined the emissions of primary fine particle and precursors of secondary particles (VOCs, SO2 and NOx) originating from the petroleum refinery operation. The central aim was to quantify the emission factors of fine particulate matter and analyze their spatial dispersion and source contributions, in order to evaluate their environmental impacts.
The VOCs emission measurement appeared that the wastewater treatment plant unit was the most significant source of VOCs emissions, with pentane, cyclopentane, and propane being the dominant VOCs species released. The study employed the secondary organic aerosol potential (SOAP), sulfur oxidation ratio (SOR), and nitrogen oxidation ratio (NOR) methodologies to calculate the emissions of secondary PM2.5. The combustion stacks were the principal contributor to secondary PM2.5 emissions, with SO2 being the predominant secondary PM2.5 precursor species contributing to fine particulate matter, accounting for 82.5% of the total secondary PM2.5 emissions. The overall emission factor for the refinery was determined to be 0.31 g secondary PM2.5 per kg of refined crude oil. Furthermore, the analysis indicated that the combustion stacks were the primary contributors to PM2.5 concentrations at all receptor sites, accounting for 64.4%–80.8% of the total contribution, followed by the wastewater treatment unit and storage tanks. The study underscored the importance of focusing on secondary PM2.5 precursor emissions to effectively reduce emissions and environmental concentrations of PM2.5, highlighting the potential for more effective management and mitigation strategies targeting these precursors.
{"title":"Manifesting the hidden pollutants: Quantifying emissions and environmental impact of petroleum refinery on PM2.5","authors":"","doi":"10.1016/j.aeaoa.2024.100300","DOIUrl":"10.1016/j.aeaoa.2024.100300","url":null,"abstract":"<div><div>This research thoroughly examined the emissions of primary fine particle and precursors of secondary particles (VOCs, SO<sub>2</sub> and NO<sub>x</sub>) originating from the petroleum refinery operation. The central aim was to quantify the emission factors of fine particulate matter and analyze their spatial dispersion and source contributions, in order to evaluate their environmental impacts.</div><div>The VOCs emission measurement appeared that the wastewater treatment plant unit was the most significant source of VOCs emissions, with pentane, cyclopentane, and propane being the dominant VOCs species released. The study employed the secondary organic aerosol potential (SOAP), sulfur oxidation ratio (SOR), and nitrogen oxidation ratio (NOR) methodologies to calculate the emissions of secondary PM2.5. The combustion stacks were the principal contributor to secondary PM2.5 emissions, with SO<sub>2</sub> being the predominant secondary PM2.5 precursor species contributing to fine particulate matter, accounting for 82.5% of the total secondary PM2.5 emissions. The overall emission factor for the refinery was determined to be 0.31 g secondary PM2.5 per kg of refined crude oil. Furthermore, the analysis indicated that the combustion stacks were the primary contributors to PM2.5 concentrations at all receptor sites, accounting for 64.4%–80.8% of the total contribution, followed by the wastewater treatment unit and storage tanks. The study underscored the importance of focusing on secondary PM2.5 precursor emissions to effectively reduce emissions and environmental concentrations of PM2.5, highlighting the potential for more effective management and mitigation strategies targeting these precursors.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553880","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}
Pub Date : 2024-10-22DOI: 10.1016/j.aeaoa.2024.100299
Roof openings are typically fitted to naturally ventilated dairy building (NVDB) for better ventilation but their impact on air pollutant emission calculations has not been fully considered. Particulate matter (PM) emission rate (ER) for NVDB rely on the total ventilation rate (VR), outdoor PM concentration and average indoor PM concentration sampled either under the roof (Roof Sampling) or in the cubicle area (Cubicle Sampling), which may show large deviations due to its spatiotemporal variation of PM concentrations and complex airflow patterns. This study utilised a novel ER calculation method (Joint Sampling) that computes the respective emission from the roof and sidewall openings by matching each outlet's VR and PM concentration. By year-round field measurements of PM2.5 and the total suspended particulates (TSP), results showed that annual average ERs of PM2.5 and TSP were 10.8 mg h−1 cow−1 and 45.7 mg h−1 cow−1 for Roof Sampling, 12.7 mg h−1 cow−1 and 40.7 mg h−1 cow−1 for Cubicle Sampling, and 11.7 mg h−1 cow−1 and 45.9 mg h−1 cow−1 for Joint Sampling. Considering the Joint Sampling results were relatively true, Roof Sampling exhibited a maximum underestimate of PM2.5 emissions of 20.8% when sidewall curtains were fully opened, whilst Cubicle Sampling demonstrated a maximum overestimate of TSP of 10.2% when the aperture was closed. Using Joint Sampling, the roof opening contributed 39.3% and 24.4% of the annual PM2.5 and TSP emissions. When sidewall openings are partially or fully closed, the Joint Sampling calculation is preferable to estimate the ER of PM.
{"title":"Quantifying particulate matter emission rates from naturally ventilated dairy buildings by considering roof opening contributions","authors":"","doi":"10.1016/j.aeaoa.2024.100299","DOIUrl":"10.1016/j.aeaoa.2024.100299","url":null,"abstract":"<div><div>Roof openings are typically fitted to naturally ventilated dairy building (NVDB) for better ventilation but their impact on air pollutant emission calculations has not been fully considered. Particulate matter (<em>PM</em>) emission rate (ER) for NVDB rely on the total ventilation rate (<em>VR</em>), outdoor PM concentration and average indoor <em>PM</em> concentration sampled either under the roof (Roof Sampling) or in the cubicle area (Cubicle Sampling), which may show large deviations due to its spatiotemporal variation of <em>PM</em> concentrations and complex airflow patterns. This study utilised a novel <em>ER</em> calculation method (Joint Sampling) that computes the respective emission from the roof and sidewall openings by matching each outlet's <em>VR</em> and <em>PM</em> concentration. By year-round field measurements of <em>PM</em><sub>2.5</sub> and the total suspended particulates (<em>TSP</em>), results showed that annual average ERs of <em>PM</em><sub>2.5</sub> and <em>TSP</em> were 10.8 mg h<sup>−1</sup> cow<sup>−1</sup> and 45.7 mg h<sup>−1</sup> cow<sup>−1</sup> for Roof Sampling, 12.7 mg h<sup>−1</sup> cow<sup>−1</sup> and 40.7 mg h<sup>−1</sup> cow<sup>−1</sup> for Cubicle Sampling, and 11.7 mg h<sup>−1</sup> cow<sup>−1</sup> and 45.9 mg h<sup>−1</sup> cow<sup>−1</sup> for Joint Sampling. Considering the Joint Sampling results were relatively true, Roof Sampling exhibited a maximum underestimate of <em>PM</em><sub>2.5</sub> emissions of 20.8% when sidewall curtains were fully opened, whilst Cubicle Sampling demonstrated a maximum overestimate of <em>TSP</em> of 10.2% when the aperture was closed. Using Joint Sampling, the roof opening contributed 39.3% and 24.4% of the annual <em>PM</em><sub>2.5</sub> and <em>TSP</em> emissions. When sidewall openings are partially or fully closed, the Joint Sampling calculation is preferable to estimate the <em>ER</em> of <em>PM</em>.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530890","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}
Pub Date : 2024-10-05DOI: 10.1016/j.aeaoa.2024.100298
The decarbonization of air transportation requires novel propulsion concepts in order to replace fossil kerosene powered gas turbines. Within various options, H2 based propulsion is one of the most promising candidates, at least for regional and short haul routes. However, despite the potential to reduce CO2 emissions to zero, those aircraft can still have a significant climate impact due to increased contrail formation caused by higher water emission when using H2 as a propellant. In order to understand potential changes in the climate impact of H2 powered air traffic, it is crucial to evaluate how the potential for contrail formation and the potential contrail cirrus cover would change under representative atmospheric conditions. To this end, we developed a tool which uses several years of meteorological reanalysis data (ERA-5 and MERRA-2) in combination with contrail formation conditions adjusted to H2 gas turbine and H2 Fuel Cell propulsion in order to investigate their regional and seasonal variation. Contrail formation conditions for three different propulsion settings (kerosene gas turbine, H2 gas turbine and H2 fuel cell) are calculated to obtain global statistics of potential contrail cover and potential contrail cirrus cover over 12 years. For H2 based propulsion contrails are more likely to form due to the increased water vapor emission. However, this does not necessarily translate into the climatically relevant potential for contrail cirrus formation. Focusing on three hot spots of regional air traffic, we find that the difference between kerosene and H2 scenarios has a strong systematic dependency on season, altitude and latitude. Maximum differences in potential contrail cirrus cover are found in the transition region from typically no-contrail to contrail forming conditions at a potential contrail cover around 50%. In contrast, less to no difference in potential contrail cirrus cover is found at very high (close to 100%) or rather low potential contrail cover. This study demonstrates, that the question whether H2 powered air traffic produces more climate relevant contrail cirrus can not be parameterized by a simple factor but rather strongly depends on the propulsion type, season, region and flight altitude.
{"title":"Regional and seasonal impact of hydrogen propulsion systems on potential contrail cirrus cover","authors":"","doi":"10.1016/j.aeaoa.2024.100298","DOIUrl":"10.1016/j.aeaoa.2024.100298","url":null,"abstract":"<div><div>The decarbonization of air transportation requires novel propulsion concepts in order to replace fossil kerosene powered gas turbines. Within various options, H<sub>2</sub> based propulsion is one of the most promising candidates, at least for regional and short haul routes. However, despite the potential to reduce CO<sub>2</sub> emissions to zero, those aircraft can still have a significant climate impact due to increased contrail formation caused by higher water emission when using H<sub>2</sub> as a propellant. In order to understand potential changes in the climate impact of H<sub>2</sub> powered air traffic, it is crucial to evaluate how the potential for contrail formation and the potential contrail cirrus cover would change under representative atmospheric conditions. To this end, we developed a tool which uses several years of meteorological reanalysis data (ERA-5 and MERRA-2) in combination with contrail formation conditions adjusted to H<sub>2</sub> gas turbine and H<sub>2</sub> Fuel Cell propulsion in order to investigate their regional and seasonal variation. Contrail formation conditions for three different propulsion settings (kerosene gas turbine, H<sub>2</sub> gas turbine and H<sub>2</sub> fuel cell) are calculated to obtain global statistics of potential contrail cover and potential contrail cirrus cover over 12 years. For H<sub>2</sub> based propulsion contrails are more likely to form due to the increased water vapor emission. However, this does not necessarily translate into the climatically relevant potential for contrail cirrus formation. Focusing on three hot spots of regional air traffic, we find that the difference between kerosene and H<sub>2</sub> scenarios has a strong systematic dependency on season, altitude and latitude. Maximum differences in potential contrail cirrus cover are found in the transition region from typically no-contrail to contrail forming conditions at a potential contrail cover around 50%. In contrast, less to no difference in potential contrail cirrus cover is found at very high (close to 100%) or rather low potential contrail cover. This study demonstrates, that the question whether H<sub>2</sub> powered air traffic produces more climate relevant contrail cirrus can not be parameterized by a simple factor but rather strongly depends on the propulsion type, season, region and flight altitude.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424953","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}
Pub Date : 2024-10-01DOI: 10.1016/j.aeaoa.2024.100297
The concentrations of PM2.5, PM10, O3 and NO2 in Urumqi People's Park were monitored by mobile monitoring in July and October 2023, and the temporal and spatial changes of pollutant concentrations in urban parks and their influencing factors were analyzed. The results show that park can effectively reduce PM and NO2 concentration, increase O3 concentration. PM concentration in the park was higher in the morning than the noon. O3 and NO2 concentration is lower in the morning than the noon. The concentration within the park was lower than that outside the park. The mitigative effect of pollutants in the park was better in summer than in autumn. The concentration of PM in the park showed a high value aggregation, and PM2.5 and PM10 showed the same spatial distribution in the high value cluster, and the pollution of both showed homology in summer. O3 and NO2 concentrations tend to accumulate at low value cluster. Pollutants are affected by the local environment. PM2.5 concentration is greatly affected by wind speed and distance from water, O3 concentration is greatly affected by temperature and average distance from road. The closer to the road, the higher the concentration of NO2. Attention should be paid to the landscape design of the buffer zone of 30–50 m with the high pollution area. This study can provide reference for park planning and design.
{"title":"Mobile monitoring of air pollutant concentration in the park of Urumqi, China","authors":"","doi":"10.1016/j.aeaoa.2024.100297","DOIUrl":"10.1016/j.aeaoa.2024.100297","url":null,"abstract":"<div><div>The concentrations of PM<sub>2.5</sub>, PM<sub>10</sub>, O<sub>3</sub> and NO<sub>2</sub> in Urumqi People's Park were monitored by mobile monitoring in July and October 2023, and the temporal and spatial changes of pollutant concentrations in urban parks and their influencing factors were analyzed. The results show that park can effectively reduce PM and NO<sub>2</sub> concentration, increase O<sub>3</sub> concentration. PM concentration in the park was higher in the morning than the noon. O<sub>3</sub> and NO<sub>2</sub> concentration is lower in the morning than the noon. The concentration within the park was lower than that outside the park. The mitigative effect of pollutants in the park was better in summer than in autumn. The concentration of PM in the park showed a high value aggregation, and PM<sub>2.5</sub> and PM<sub>10</sub> showed the same spatial distribution in the high value cluster, and the pollution of both showed homology in summer. O<sub>3</sub> and NO<sub>2</sub> concentrations tend to accumulate at low value cluster. Pollutants are affected by the local environment. PM<sub>2.5</sub> concentration is greatly affected by wind speed and distance from water, O<sub>3</sub> concentration is greatly affected by temperature and average distance from road. The closer to the road, the higher the concentration of NO<sub>2</sub>. Attention should be paid to the landscape design of the buffer zone of 30–50 m with the high pollution area. This study can provide reference for park planning and design.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424952","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}
Pub Date : 2024-09-25DOI: 10.1016/j.aeaoa.2024.100293
Few studies have considered the real-world impact of changes in traffic signal timings on air pollution and pedestrian exposure with most only drawing their conclusion from vehicle emission models alone. Here, we consider two distinct cycle timings at a junction in London, UK, model the impact using a traffic microsimulation and a NOx emissions model, and compare these results with NOx and other air pollution measurements collected during a two-week field study at the junction.
Our models predict that extending the cycle time leads to a 23% decrease in NOx emissions within a 15 m radius of the junction itself. When the wind direction was such that our sensors were downwind of the junction a 21% decrease in traffic and background-adjusted NOx concentrations were seen, suggesting that the intervention was successful. However, when the sensors were upwind of the junction, we observed an increase of 23% in adjusted NOx concentrations. Similar patterns were found for the other pollutants NO2, lung deposited surface area, black carbon and CO2 we measured. This indicates that meteorology was by far the greatest determinant of roadside concentrations during our two-week study period.
Looking at pedestrian exposure for pedestrians waiting to cross the road, we found that their NOx exposure increased by 46% as waiting times to cross the road increased and that potential small reductions in air pollution were offset by increases in waiting times on the main road.
The study demonstrates the need to go beyond assessing the impact of hyper-local traffic interventions on vehicle emissions. Real-world trials over extended periods are required to evaluate the impact of meteorology and changes to air pollution concentrations and pedestrian exposures.
{"title":"Vehicle emission models alone are not sufficient to understand full impact of change in traffic signal timings","authors":"","doi":"10.1016/j.aeaoa.2024.100293","DOIUrl":"10.1016/j.aeaoa.2024.100293","url":null,"abstract":"<div><div>Few studies have considered the real-world impact of changes in traffic signal timings on air pollution and pedestrian exposure with most only drawing their conclusion from vehicle emission models alone. Here, we consider two distinct cycle timings at a junction in London, UK, model the impact using a traffic microsimulation and a NO<sub>x</sub> emissions model, and compare these results with NO<sub>x</sub> and other air pollution measurements collected during a two-week field study at the junction.</div><div>Our models predict that extending the cycle time leads to a 23% decrease in NO<sub>x</sub> emissions within a 15 m radius of the junction itself. When the wind direction was such that our sensors were downwind of the junction a 21% decrease in traffic and background-adjusted NO<sub>x</sub> concentrations were seen, suggesting that the intervention was successful. However, when the sensors were upwind of the junction, we observed an increase of 23% in adjusted NO<sub>x</sub> concentrations. Similar patterns were found for the other pollutants NO<sub>2</sub>, lung deposited surface area, black carbon and CO<sub>2</sub> we measured. This indicates that meteorology was by far the greatest determinant of roadside concentrations during our two-week study period.</div><div>Looking at pedestrian exposure for pedestrians waiting to cross the road, we found that their NO<sub>x</sub> exposure increased by 46% as waiting times to cross the road increased and that potential small reductions in air pollution were offset by increases in waiting times on the main road.</div><div>The study demonstrates the need to go beyond assessing the impact of hyper-local traffic interventions on vehicle emissions. Real-world trials over extended periods are required to evaluate the impact of meteorology and changes to air pollution concentrations and pedestrian exposures.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432362","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}
Pub Date : 2024-09-12DOI: 10.1016/j.aeaoa.2024.100296
Atmospheric particles can undergo aging as they are transported over long distances and mix with particles from other sources. This can lead to the accumulation of pollutants and the formation of complex aerosol mixtures with diverse chemical and physical properties. To investigate the process of aging in ambient atmosphere, 24h sampling of PM2.5 aerosol particles on Quartz microfiber filter with a tin substrate was carried out from November 2020 to March 2021 at CSIR-National Physical Laboratory, New Delhi (28°38'10″ N and 77°10′17" E), using fine particle sampler. Based on the observations of weather and meteorological parameters, a few episodic cases have been selected, and samples were analyzed at bulk and individual particle level. The objective of the present study is to investigate the aging characteristics of aerosols, enabling us to understand the mixing of aerosols (at both bulk and individual particle levels) and the variation in fresh and deformed (aged with other species) graphitic content in the episodic cases. The Raman Spectroscopy technique employed measures the intensity of graphitic (G band; around 1580 cm−1) and disordered graphitic (D band; around 1320 cm−1) content of aerosols. Individual particle microscopic observations reveal the occurrence of open chain fractals of black carbon in variable monomer sizes, sometimes agglomerated with metals like Cu, Cr, Ca etc., along with the presence of S- rich and organic aerosols while the Raman Spectrum (bulk sample analysis) highlights graphitic and disordered (when graphite interacts with other chemical species) graphitic intensities. Comparing the intensities of heavy haze and moderate haze with non-haze days (for comparison purpose, March 23, 2021 with the lowest PM2.5 concentration ∼ 62 μg/m3, has been considered as a non-haze day), it was observed that the intensities recorded on haze days were 45 to 200 times higher for the G band and 43 to 93 times higher for the D band; while for moderate haze days, the intensities were 4 to 61 times higher for the G band and 2 to 29 times higher for the D band. These findings suggest chemical processing of BC during haze days.
{"title":"Insights into chemical aging of urban aerosols over Delhi, India","authors":"","doi":"10.1016/j.aeaoa.2024.100296","DOIUrl":"10.1016/j.aeaoa.2024.100296","url":null,"abstract":"<div><div>Atmospheric particles can undergo aging as they are transported over long distances and mix with particles from other sources. This can lead to the accumulation of pollutants and the formation of complex aerosol mixtures with diverse chemical and physical properties. To investigate the process of aging in ambient atmosphere, 24h sampling of PM<sub>2.5</sub> aerosol particles on Quartz microfiber filter with a tin substrate was carried out from November 2020 to March 2021 at CSIR-National Physical Laboratory, New Delhi (<span><span>28°38'10″ N and 77°10′17\" E</span><svg><path></path></svg></span>), using fine particle sampler. Based on the observations of weather and meteorological parameters, a few episodic cases have been selected, and samples were analyzed at bulk and individual particle level. The objective of the present study is to investigate the aging characteristics of aerosols, enabling us to understand the mixing of aerosols (at both bulk and individual particle levels) and the variation in fresh and deformed (aged with other species) graphitic content in the episodic cases. The Raman Spectroscopy technique employed measures the intensity of graphitic (G band; around 1580 cm<sup>−1</sup>) and disordered graphitic (D band; around 1320 cm<sup>−1</sup>) content of aerosols. Individual particle microscopic observations reveal the occurrence of open chain fractals of black carbon in variable monomer sizes, sometimes agglomerated with metals like Cu, Cr, Ca etc., along with the presence of S- rich and organic aerosols while the Raman Spectrum (bulk sample analysis) highlights graphitic and disordered (when graphite interacts with other chemical species) graphitic intensities. Comparing the intensities of heavy haze and moderate haze with non-haze days (for comparison purpose, March 23, 2021 with the lowest PM<sub>2.5</sub> concentration ∼ 62 μg/m<sup>3</sup>, has been considered as a non-haze day), it was observed that the intensities recorded on haze days were 45 to 200 times higher for the G band and 43 to 93 times higher for the D band; while for moderate haze days, the intensities were 4 to 61 times higher for the G band and 2 to 29 times higher for the D band. These findings suggest chemical processing of BC during haze days.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590162124000637/pdfft?md5=3745a010e0be247a3ab8816fee5916fc&pid=1-s2.0-S2590162124000637-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142311905","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}
Pub Date : 2024-08-01DOI: 10.1016/j.aeaoa.2024.100283
Nitrous oxide (N2O) emissions from organic waste and animal slurry contribute to climate change and endanger our ecosystems. For the development of efficient mitigation technologies, in-depth knowledge of emission processes is needed. This can be obtained by non-destructive, temporal measurements of in-situ soil profiles and the transformation of ammonium (NH4+) during events of emissions. Planar optode imaging is a non-destructive measuring method that can be used to visualize spatiotemporal changes of ammonia (NH3) and pH in soil systems. In this study, soil amended with dairy processing sludge (DPS) was incubated in static chambers for 23 days, and GHG emissions, NH3 concentrations and pH in the soil were measured simultaneously over time. The aim was to investigate the potential of applying different planar optodes to provide information that gives insight into processes of N2O emissions. The DPS was applied to the soil as a surface layer (SL), with untreated soil as a control (CK). We were able to measure N2O emissions while monitoring spatiotemporal changes of soil pH and NH3 concentrations. The visualized microscale heterogeneity of the soil contributed to a better understanding of N2O emission processes. While technical challenges (e.g., humidity sensitivity of the NH3 optode and airtightness of the chambers) still need to be overcome, the method is a promising non-destructive method to study soil processes after application of different types of soil amendments.
{"title":"Tracing N2O from dairy processing sludge amended soil with visualizing microscale heterogeneity of NH3 and pH (Short Communication)","authors":"","doi":"10.1016/j.aeaoa.2024.100283","DOIUrl":"10.1016/j.aeaoa.2024.100283","url":null,"abstract":"<div><p>Nitrous oxide (N<sub>2</sub>O) emissions from organic waste and animal slurry contribute to climate change and endanger our ecosystems. For the development of efficient mitigation technologies, in-depth knowledge of emission processes is needed. This can be obtained by non-destructive, temporal measurements of in-situ soil profiles and the transformation of ammonium (NH<sub>4</sub><sup>+</sup>) during events of emissions. Planar optode imaging is a non-destructive measuring method that can be used to visualize spatiotemporal changes of ammonia (NH<sub>3</sub>) and pH in soil systems. In this study, soil amended with dairy processing sludge (DPS) was incubated in static chambers for 23 days, and GHG emissions, NH<sub>3</sub> concentrations and pH in the soil were measured simultaneously over time. The aim was to investigate the potential of applying different planar optodes to provide information that gives insight into processes of N<sub>2</sub>O emissions. The DPS was applied to the soil as a surface layer (SL), with untreated soil as a control (CK). We were able to measure N<sub>2</sub>O emissions while monitoring spatiotemporal changes of soil pH and NH<sub>3</sub> concentrations. The visualized microscale heterogeneity of the soil contributed to a better understanding of N<sub>2</sub>O emission processes. While technical challenges (e.g., humidity sensitivity of the NH<sub>3</sub> optode and airtightness of the chambers) still need to be overcome, the method is a promising non-destructive method to study soil processes after application of different types of soil amendments.</p></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590162124000509/pdfft?md5=8577931ea0ccd95cc4a04027af74e7c1&pid=1-s2.0-S2590162124000509-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141951976","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}
Pub Date : 2024-08-01DOI: 10.1016/j.aeaoa.2024.100288
PAHs have been recognised as a major menace to living-beings as well as environment. Several researchers have extensively claimed regarding death-defying nature of PAHs and its derivatives. However, these studies have only considered the ambient air which is a composition of automobile exhausts, industrial emissions etc. as major source of harmful air pollutants. Indoor air quality (IAQ) is an overlooked area since, although many researchers in recent times have been working on the chemistry and composition of IAQ, yet, source determination and nature of pollutants is still a comprehensive area to be explored. With the above stated objective, the present study emphases on 16 USEPA specified PAHs which are allied with particulate matter. Both PM as well as PAHs are some very common and treacherous chemical contaminant accountable for more than a million death globally. PAHs are organic compound which are either attached to PM of various sizes or can exist in gaseous form. Current work precises the concentration of PAHs associated with fine PM i.e., PM2.5 in indoor environment of south Asian precinct, further, using receptor modelling technique for determination indoor sources responsible for the emanation of specific PAHs. The toxicity equivalent quotient i.e., TEQ evaluated in the study demonstrations that the highest toxicity among all PAHs is exhibited by BaP followed by InP, BKF, BbF. Seasonal variations in the concentration of PAHs and their respective sources were also established using PMF models, which depicted the domination of 3-ring PAHs in winter with 42% contribution in outdoors, whereas, four-ring PAHs dominion in indoors. Similarly, in summer two-ring accounted for 35% in outdoors, and three-ring PAHs contributed highest with 26.8% in indoors. In monsoon PAHs with two-ring contributed highest with 45.2% in outdoors, whereas, 2-ring PAHs contributed 38.3% in indoors. Also, IDW mapping and molecular diagnostic ratio were assessed for an intense study on distribution of PAHs in the locality and the source apportionment purpose respectively. To the best of our knowledge, the study is first of its kind in this part of the world where, majority of the countries are either developing or under-developed and hence at greater risk to the noxious effects which are often overlooked. The study will provide a clear picture regarding the indoor sources of the PAHs and further help the further professionals to build a credible and pragmatic mitigation technique accordingly.
{"title":"Distribution assessment and source apportionment of particulate bound-PAHs in indoor air of south Asian precinct using IDW and PMF receptor model: A comprehensive study","authors":"","doi":"10.1016/j.aeaoa.2024.100288","DOIUrl":"10.1016/j.aeaoa.2024.100288","url":null,"abstract":"<div><p>PAHs have been recognised as a major menace to living-beings as well as environment. Several researchers have extensively claimed regarding death-defying nature of PAHs and its derivatives. However, these studies have only considered the ambient air which is a composition of automobile exhausts, industrial emissions etc. as major source of harmful air pollutants. Indoor air quality (IAQ) is an overlooked area since, although many researchers in recent times have been working on the chemistry and composition of IAQ, yet, source determination and nature of pollutants is still a comprehensive area to be explored. With the above stated objective, the present study emphases on 16 USEPA specified PAHs which are allied with particulate matter. Both PM as well as PAHs are some very common and treacherous chemical contaminant accountable for more than a million death globally. PAHs are organic compound which are either attached to PM of various sizes or can exist in gaseous form. Current work precises the concentration of PAHs associated with fine PM i.e., PM<sub>2.5</sub> in indoor environment of south Asian precinct, further, using receptor modelling technique for determination indoor sources responsible for the emanation of specific PAHs. The toxicity equivalent quotient i.e., TEQ evaluated in the study demonstrations that the highest toxicity among all PAHs is exhibited by BaP followed by InP, BKF, BbF. Seasonal variations in the concentration of PAHs and their respective sources were also established using PMF models, which depicted the domination of 3-ring PAHs in winter with 42% contribution in outdoors, whereas, four-ring PAHs dominion in indoors. Similarly, in summer two-ring accounted for 35% in outdoors, and three-ring PAHs contributed highest with 26.8% in indoors. In monsoon PAHs with two-ring contributed highest with 45.2% in outdoors, whereas, 2-ring PAHs contributed 38.3% in indoors. Also, IDW mapping and molecular diagnostic ratio were assessed for an intense study on distribution of PAHs in the locality and the source apportionment purpose respectively. To the best of our knowledge, the study is first of its kind in this part of the world where, majority of the countries are either developing or under-developed and hence at greater risk to the noxious effects which are often overlooked. The study will provide a clear picture regarding the indoor sources of the PAHs and further help the further professionals to build a credible and pragmatic mitigation technique accordingly.</p></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590162124000558/pdfft?md5=f1627fca3ac306dc955a72e89268dc07&pid=1-s2.0-S2590162124000558-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142095651","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}
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