Srishti Singh, Pratyush Agrawal, P. Kulkarni, H. Gautam, Meenakshi Kushwaha, V. Sreekanth
In this study, we combined state-of-the-art data modelling techniques (machine learning [ML] methods) and data from state-of-the-art low-cost particulate matter (PM) sensors (LCSs) to improve the accuracy of LCS-measured PM 2.5 (PM with aerodynamic diameter less than 2.5 microns) mass concentrations. We collocated nine LCSs and a reference PM 2.5 instrument for 9 months, covering all local seasons, in Bengaluru, India. Using the collocation data, we evaluated the performance of the LCSs and trained around 170 ML models to reduce the observed bias in the LCS-measured PM 2.5 . The ML models included (i) Decision Tree, (ii) Random Forest (RF), (iii) eXtreme Gradient Boosting, and (iv) Support Vector Regression (SVR). A hold-out validation was performed to assess the model performance. Model performance metrics included (i) coefficient of determination (R 2 ), (ii) root mean square error (RMSE), (iii) normalised RMSE, and (iv) mean absolute error. We found that the bias in the LCS PM 2.5 measurements varied across different LCS types (RMSE = 8– 29 µ g m –3 ) and that SVR models performed best in correcting the LCS PM 2.5 measurements. Hyperparameter tuning improved the performance of the ML models (except for RF). The performance of ML models trained with significant predictors (fewer in number than the number of all predictors, chosen based on recursive feature elimination algorithm) was comparable to that of the ‘all predictors’ trained models (except for RF). The performance of most ML models was better than that of the linear models. Finally, as a research objective, we introduced the collocated black carbon mass concentration measurements into the ML models but found no significant improvement in the model performance.
{"title":"Multiple PM Low-Cost Sensors, Multiple Seasons’ Data, and Multiple Calibration Models","authors":"Srishti Singh, Pratyush Agrawal, P. Kulkarni, H. Gautam, Meenakshi Kushwaha, V. Sreekanth","doi":"10.4209/aaqr.220428","DOIUrl":"https://doi.org/10.4209/aaqr.220428","url":null,"abstract":"In this study, we combined state-of-the-art data modelling techniques (machine learning [ML] methods) and data from state-of-the-art low-cost particulate matter (PM) sensors (LCSs) to improve the accuracy of LCS-measured PM 2.5 (PM with aerodynamic diameter less than 2.5 microns) mass concentrations. We collocated nine LCSs and a reference PM 2.5 instrument for 9 months, covering all local seasons, in Bengaluru, India. Using the collocation data, we evaluated the performance of the LCSs and trained around 170 ML models to reduce the observed bias in the LCS-measured PM 2.5 . The ML models included (i) Decision Tree, (ii) Random Forest (RF), (iii) eXtreme Gradient Boosting, and (iv) Support Vector Regression (SVR). A hold-out validation was performed to assess the model performance. Model performance metrics included (i) coefficient of determination (R 2 ), (ii) root mean square error (RMSE), (iii) normalised RMSE, and (iv) mean absolute error. We found that the bias in the LCS PM 2.5 measurements varied across different LCS types (RMSE = 8– 29 µ g m –3 ) and that SVR models performed best in correcting the LCS PM 2.5 measurements. Hyperparameter tuning improved the performance of the ML models (except for RF). The performance of ML models trained with significant predictors (fewer in number than the number of all predictors, chosen based on recursive feature elimination algorithm) was comparable to that of the ‘all predictors’ trained models (except for RF). The performance of most ML models was better than that of the linear models. Finally, as a research objective, we introduced the collocated black carbon mass concentration measurements into the ML models but found no significant improvement in the model performance.","PeriodicalId":7402,"journal":{"name":"Aerosol and Air Quality Research","volume":"1 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70295386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shengli Zhu, Zhaowen Wang, Kai Qu, Jun Xu, Ji Zhang, Haiyi Yang, Wenxin Wang, X. Sui, Minghua Wei, Houfeng Liu
Based on the PM 2.5 concentration in the autumn and winter of 2015–2019, the characteristics of urban air pollution in the eastern monsoon region of China were discussed. The spatial distribution and interregional influence of fine particle pollution under different synoptic weather and topography in the eastern monsoon region of China were illustrated. According to synoptic systems, regional PM 2.5 pollution episodes were classified into three categories, including Uniform Pressure field (UP, 60.00%), Pre-High Pressure (PreHP, 30.91%) and Inverted-Trough (IT, 9.09%). The K-Means algorithm combined with the HYSPLIT backward trajectory clustering analysis indicated four clusters under UP controlled, and under weak pressure field was responsible for the elevation of PM 2.5 concentration, where the Beijing-Tianjin-Hebei and its surrounding areas were the most polluted region. For PreHP, four clusters eased after cold front. For IT, three clusters were ascertained, and the severe PM 2.5 pollution area was in the central and southern of the North China Plain. This study provided a scientific basis for the joint prevention of PM 2.5 pollution based on topographic and meteorological characteristics in Eastern China.
{"title":"Spatial Characteristics and Influence of Topography and Synoptic Systems on PM2.5 in the Eastern Monsoon Region of China","authors":"Shengli Zhu, Zhaowen Wang, Kai Qu, Jun Xu, Ji Zhang, Haiyi Yang, Wenxin Wang, X. Sui, Minghua Wei, Houfeng Liu","doi":"10.4209/aaqr.220393","DOIUrl":"https://doi.org/10.4209/aaqr.220393","url":null,"abstract":"Based on the PM 2.5 concentration in the autumn and winter of 2015–2019, the characteristics of urban air pollution in the eastern monsoon region of China were discussed. The spatial distribution and interregional influence of fine particle pollution under different synoptic weather and topography in the eastern monsoon region of China were illustrated. According to synoptic systems, regional PM 2.5 pollution episodes were classified into three categories, including Uniform Pressure field (UP, 60.00%), Pre-High Pressure (PreHP, 30.91%) and Inverted-Trough (IT, 9.09%). The K-Means algorithm combined with the HYSPLIT backward trajectory clustering analysis indicated four clusters under UP controlled, and under weak pressure field was responsible for the elevation of PM 2.5 concentration, where the Beijing-Tianjin-Hebei and its surrounding areas were the most polluted region. For PreHP, four clusters eased after cold front. For IT, three clusters were ascertained, and the severe PM 2.5 pollution area was in the central and southern of the North China Plain. This study provided a scientific basis for the joint prevention of PM 2.5 pollution based on topographic and meteorological characteristics in Eastern China.","PeriodicalId":7402,"journal":{"name":"Aerosol and Air Quality Research","volume":"1 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70295423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dayaram Bhoyar Priyanka, Pooja Kamdi, Amit P. Bafana, P. Devara, Servana Sivanesan, Amrit Kumar, K. Krishnamurthi
Bioaerosols (or biological aerosols) consist of aerosol particles that originate biologically either as fully active component or as whole or part of inactive fragments. They are ubiquitously present in the atmospheric environment. They are the least investigated pollutants due to their complex structure and composition. The effects of bioaerosols, originating due to the processes, such as wastewater management, handling of sludge, composting, municipal solid waste
{"title":"Prevalence, Dispersion and Nature of Bioaerosols over a Solid Landfill Site in Central India","authors":"Dayaram Bhoyar Priyanka, Pooja Kamdi, Amit P. Bafana, P. Devara, Servana Sivanesan, Amrit Kumar, K. Krishnamurthi","doi":"10.4209/aaqr.220431","DOIUrl":"https://doi.org/10.4209/aaqr.220431","url":null,"abstract":"Bioaerosols (or biological aerosols) consist of aerosol particles that originate biologically either as fully active component or as whole or part of inactive fragments. They are ubiquitously present in the atmospheric environment. They are the least investigated pollutants due to their complex structure and composition. The effects of bioaerosols, originating due to the processes, such as wastewater management, handling of sludge, composting, municipal solid waste","PeriodicalId":7402,"journal":{"name":"Aerosol and Air Quality Research","volume":"1 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70295521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The emission of fine particulate matter (PM 2.5 ) in dry season from the open biomass burning has caused a long-term negative impact on residents’ health in Northern Thailand. This study takes Chiang Mai and Chiang Rai provinces in Northern Thailand as the study areas to identify pollution episodes, analyze PM 2.5 source trajectories, and finally propose pollution control strategies accordingly. PM 2.5 levels during 2019–2021 of three representative air pollution monitoring stations (i.e., Chaing Mai-35T, Chiang Rai-57T, and Mae Sai-73T) in these two provinces were collected and analyzed. The Air Quality Index (AQI) defined by PM 2.5 level higher than 91 µ g m –3 causing serious adverse health effects was adopted to define periods having pollution levels, and the days of the air pollution episodes were identified. Based on these episodes, we applied the backward trajectory model to identify the sources of pollutants. Results showed that PM 2.5 levels were significantly higher between February to April compared with other months during 2019– 2021 at all three monitoring stations, indicating the severity of PM 2.5 episode during the dry season. The backward trajectory demonstrated that air mass transported through the Northern Thailand or nearby mountain areas (categorized as long-or short-transport-distance) contributed up to 21.6% and 75.9% of the total air mass, respectively. Although residents in these mountainous areas are accustomed to the biomass burning, we suggested that there should be urgent needs for the improvement of the long-term air quality in these two provinces. Therefore, this study proposes some control strategies including improvement of prevention knowledge, increase of the risk perception, cultivation of the protection behavior, and intensification of the social influence. In addition to reducing biomass burning pollution, this improvement plan also has a co-benefit of achieving resources recycling concomitantly. Providing effective management strategies may reduce the adverse health effects to Thai residents.
{"title":"Strategy Design of PM2.5 Controlling for Northern Thailand","authors":"Karuna Jainontee, Prapat Pongkiatkul, Ying-Lin Wang, Roy J.F. Weng, Yi-Ting Lu, Ting Wang, Wang-Kun Chen","doi":"10.4209/aaqr.220432","DOIUrl":"https://doi.org/10.4209/aaqr.220432","url":null,"abstract":"The emission of fine particulate matter (PM 2.5 ) in dry season from the open biomass burning has caused a long-term negative impact on residents’ health in Northern Thailand. This study takes Chiang Mai and Chiang Rai provinces in Northern Thailand as the study areas to identify pollution episodes, analyze PM 2.5 source trajectories, and finally propose pollution control strategies accordingly. PM 2.5 levels during 2019–2021 of three representative air pollution monitoring stations (i.e., Chaing Mai-35T, Chiang Rai-57T, and Mae Sai-73T) in these two provinces were collected and analyzed. The Air Quality Index (AQI) defined by PM 2.5 level higher than 91 µ g m –3 causing serious adverse health effects was adopted to define periods having pollution levels, and the days of the air pollution episodes were identified. Based on these episodes, we applied the backward trajectory model to identify the sources of pollutants. Results showed that PM 2.5 levels were significantly higher between February to April compared with other months during 2019– 2021 at all three monitoring stations, indicating the severity of PM 2.5 episode during the dry season. The backward trajectory demonstrated that air mass transported through the Northern Thailand or nearby mountain areas (categorized as long-or short-transport-distance) contributed up to 21.6% and 75.9% of the total air mass, respectively. Although residents in these mountainous areas are accustomed to the biomass burning, we suggested that there should be urgent needs for the improvement of the long-term air quality in these two provinces. Therefore, this study proposes some control strategies including improvement of prevention knowledge, increase of the risk perception, cultivation of the protection behavior, and intensification of the social influence. In addition to reducing biomass burning pollution, this improvement plan also has a co-benefit of achieving resources recycling concomitantly. Providing effective management strategies may reduce the adverse health effects to Thai residents.","PeriodicalId":7402,"journal":{"name":"Aerosol and Air Quality Research","volume":"10 23 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70295758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pitakchon Ponsawansong, T. Prapamontol, K. Rerkasem, S. Chantara, Kraichat Tantrakarnapa, S. Kawichai, Guoxing Li, Cao Fang, Xiaochuan Pan, Yanlin Zhang
Dithiothreitol (DTT) assay is an acellular technique used to investigate the oxidative potential (OP) of chemical substances bound on PM, which may potentially lead to oxidative stress after exposure. In this study, the source contributions of 16 high priority polycyclic aromatic hydrocarbons (PAHs), designated by the United States Environmental Protection Agency (U.S. EPA), and 10 species of water-soluble inorganic ions bound on PM 2.5 and their OP were investigated using DTT assay. The 24-hr ambient PM 2.5 samples were collected throughout 2018–2019 and the analyzed OP was compared during haze episodes, which generally occurs in the dry season, and non-haze rainy season in the Chiang Mai-Lamphun basin. During haze episodes, DTTv activity was positively correlated with 4–5 rings PAHs including fluoranthene (Fla) pyrene (Pyr), benzo[a]anthracene (BaA), chrysene (Chr), benzo[b]fluoranthene (BbF) and benzo[k]fluoranthene (BkF) with coefficient ranging from 0.327 to 0.545, p = 0.002 to 0.009 (Pearson’s correlation). Inorganic ions, particularly NH 4+ , SO 42– , and NO 3– , which are the tracers of secondary inorganic aerosol (SIA), were positively correlated with DTTv activity (r = 0.394 to 0.659. p = 0.000 to 0.047; Spearman’s correlation). Positive matrix factorization (PMF) indicated the biomass burning factor had the highest contribution (57.9%) to PM 2.5 during haze episodes, followed by SIA (26.2%), and vehicle exhausts (7.8%). Furthermore, multiple linear regression (MLR) showed that biomass burning was the highest contributor to DTTv (43.0%). These results suggest that during haze episodes, higher levels of PM 2.5 and its chemical compositions play a crucial role on OP, particularly DTTv activity, which may induce oxidative stress in human body.
{"title":"Sources of PM2.5 Oxidative Potential during Haze and Non-haze Seasons in Chiang Mai, Thailand","authors":"Pitakchon Ponsawansong, T. Prapamontol, K. Rerkasem, S. Chantara, Kraichat Tantrakarnapa, S. Kawichai, Guoxing Li, Cao Fang, Xiaochuan Pan, Yanlin Zhang","doi":"10.4209/aaqr.230030","DOIUrl":"https://doi.org/10.4209/aaqr.230030","url":null,"abstract":"Dithiothreitol (DTT) assay is an acellular technique used to investigate the oxidative potential (OP) of chemical substances bound on PM, which may potentially lead to oxidative stress after exposure. In this study, the source contributions of 16 high priority polycyclic aromatic hydrocarbons (PAHs), designated by the United States Environmental Protection Agency (U.S. EPA), and 10 species of water-soluble inorganic ions bound on PM 2.5 and their OP were investigated using DTT assay. The 24-hr ambient PM 2.5 samples were collected throughout 2018–2019 and the analyzed OP was compared during haze episodes, which generally occurs in the dry season, and non-haze rainy season in the Chiang Mai-Lamphun basin. During haze episodes, DTTv activity was positively correlated with 4–5 rings PAHs including fluoranthene (Fla) pyrene (Pyr), benzo[a]anthracene (BaA), chrysene (Chr), benzo[b]fluoranthene (BbF) and benzo[k]fluoranthene (BkF) with coefficient ranging from 0.327 to 0.545, p = 0.002 to 0.009 (Pearson’s correlation). Inorganic ions, particularly NH 4+ , SO 42– , and NO 3– , which are the tracers of secondary inorganic aerosol (SIA), were positively correlated with DTTv activity (r = 0.394 to 0.659. p = 0.000 to 0.047; Spearman’s correlation). Positive matrix factorization (PMF) indicated the biomass burning factor had the highest contribution (57.9%) to PM 2.5 during haze episodes, followed by SIA (26.2%), and vehicle exhausts (7.8%). Furthermore, multiple linear regression (MLR) showed that biomass burning was the highest contributor to DTTv (43.0%). These results suggest that during haze episodes, higher levels of PM 2.5 and its chemical compositions play a crucial role on OP, particularly DTTv activity, which may induce oxidative stress in human body.","PeriodicalId":7402,"journal":{"name":"Aerosol and Air Quality Research","volume":"1 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70296784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Optical Performance of Sodium Tungsten Bronze Particles in Transparent Matrix: An Ensemble Particle Modeling Study","authors":"Hao Tu, Da-Ren Chen","doi":"10.4209/aaqr.230085","DOIUrl":"https://doi.org/10.4209/aaqr.230085","url":null,"abstract":"Abstract","PeriodicalId":7402,"journal":{"name":"Aerosol and Air Quality Research","volume":"1 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70297218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tsrong-Yi Wen, S. Chantara, J. Jalaludin, Puji Lestari, A. D. Syafei, T. V. Pham, Y. Tsai
This paper consists of several topics on aerosol and air pollution in South Eastern Asia countries, including exposure and health effects of aerosol in Malaysia, characteristics/sources of particulate matter (PM) in Surabaya, Indonesia, size fraction of polycyclic aromatic hydrocarbons (PAHs) in Chiang Mai, Thailand, and removal of PMs using sodium hydroxyl and electrostatic precipitator (ESP) in Vietnam. Findings in Malaysia indicated that exposure to PM was associated with respiratory symptoms such as phlegm, coughing, wheezing and chest tightness among children in urban areas. Characterization of PM 2.5 and PM 2.5-10 samples collected in an industrial area in Surabaya, Indonesia showed that the highest levels of individual elements in PM 2.5 were S, Na, Si and K, and in PM 2.5-10 were Si, Ca, Cl, Na, and Mg. The main potential sources of PM 2.5 were diesel vehicle emission, a mixture of Cu industry and biomass combustion, metal industries using Ni, and construction, with contributions of 33%, 24.1%, 11.4%, and 7.9%, respectively. Meanwhile, main sources of PM 2.5-10 were soil dust and port industry, construction, road dust, and sea salt, with contributions of 32%, 28.8%, 14%, and 10%, respectively. In Chiang Mai, the highest PM mass and PAHs concentrations were found in the finest particle sizes (0.65 µ m – 0.43 µ m) in periods of intensive open burning (IOB) and low open burning (LOB), in both urban and rural areas, and the PAHs concentration (5.10 ng m – 3 ) in the fine fraction accounted for 45% to 47% and 32% to 37% during IOB and LOB periods, respectively. The study of particle removal from a charcoal kiln in Vietnam using a water and sodium hydroxyl solution sprayed in a top-down direction with fine droplets showed a removal efficiency of total dust of about 47.5% on average, while an ESP removed PM with high collection efficiency and low-pressure drop.
{"title":"Overview of Aerosol and Air Pollution in South Eastern Asia Countries","authors":"Tsrong-Yi Wen, S. Chantara, J. Jalaludin, Puji Lestari, A. D. Syafei, T. V. Pham, Y. Tsai","doi":"10.4209/aaqr.230055","DOIUrl":"https://doi.org/10.4209/aaqr.230055","url":null,"abstract":"This paper consists of several topics on aerosol and air pollution in South Eastern Asia countries, including exposure and health effects of aerosol in Malaysia, characteristics/sources of particulate matter (PM) in Surabaya, Indonesia, size fraction of polycyclic aromatic hydrocarbons (PAHs) in Chiang Mai, Thailand, and removal of PMs using sodium hydroxyl and electrostatic precipitator (ESP) in Vietnam. Findings in Malaysia indicated that exposure to PM was associated with respiratory symptoms such as phlegm, coughing, wheezing and chest tightness among children in urban areas. Characterization of PM 2.5 and PM 2.5-10 samples collected in an industrial area in Surabaya, Indonesia showed that the highest levels of individual elements in PM 2.5 were S, Na, Si and K, and in PM 2.5-10 were Si, Ca, Cl, Na, and Mg. The main potential sources of PM 2.5 were diesel vehicle emission, a mixture of Cu industry and biomass combustion, metal industries using Ni, and construction, with contributions of 33%, 24.1%, 11.4%, and 7.9%, respectively. Meanwhile, main sources of PM 2.5-10 were soil dust and port industry, construction, road dust, and sea salt, with contributions of 32%, 28.8%, 14%, and 10%, respectively. In Chiang Mai, the highest PM mass and PAHs concentrations were found in the finest particle sizes (0.65 µ m – 0.43 µ m) in periods of intensive open burning (IOB) and low open burning (LOB), in both urban and rural areas, and the PAHs concentration (5.10 ng m – 3 ) in the fine fraction accounted for 45% to 47% and 32% to 37% during IOB and LOB periods, respectively. The study of particle removal from a charcoal kiln in Vietnam using a water and sodium hydroxyl solution sprayed in a top-down direction with fine droplets showed a removal efficiency of total dust of about 47.5% on average, while an ESP removed PM with high collection efficiency and low-pressure drop.","PeriodicalId":7402,"journal":{"name":"Aerosol and Air Quality Research","volume":"1 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70297384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Catherine A Fitton, B. Cox, M. Stewart, James Chalmers, J. Belch
This study, from the Tayside Pollution Research Programme (TPRP), aims to investigate the effects of air pollution on respiratory hospital admissions in adults and children < 16 y of age, over a 14-year period, in Dundee, Scotland (population circa 148,270). We conducted a case-crossover study using routinely collected healthcare records from Ninewells Hospital, Dundee, Scotland from 2004 to 2017. Respiratory hospitalisation events were linked to daily nitric oxide gases (NO x , NO 2 , NO) extracted from publicly available data over this period. We used distributed lag models to allow for delayed effects of air pollutants up to 14 days. A total of 34,192 hospital admissions for a respiratory condition were included in this study (children = 9,501; adults = 24,691). Respiratory admissions in children were significantly associated with cumulative 14-day exposure to NO x (RR for a 10 µ g m –3 increase in concentration 1.020; 95% confidence interval 1.010–1.031), NO 2 (RR 1.086; 95% CI 1.036–1.139) and NO (RR 1.033; 95% CI 1.016–1.052). Similar estimates were observed for acute respiratory infection categories in children. Effects appeared to be somewhat delayed, with the largest estimates mostly observed around lag 6. No significant association was seen for respiratory admissions in adults. This study shows that both NO and NO 2 are associated with increased respiratory hospital admissions in children < 16 y of age, and that much more should be done to improve and enforce the established legal NO x pollution limits in cities for the sake of our children’s health.
这项研究来自泰赛德污染研究计划(TPRP)，旨在调查空气污染对苏格兰邓迪(人口约148,270)14年期间成人和16岁以下儿童呼吸系统住院的影响。我们使用2004年至2017年从苏格兰邓迪的Ninewells医院常规收集的医疗记录进行了病例交叉研究。从这一时期的公开数据中提取的每日一氧化氮气体(nox, NO 2, NO)与呼吸道住院事件有关。我们使用分布式滞后模型来考虑空气污染物长达14天的延迟效应。该研究共纳入34192例因呼吸系统疾病入院的患者(儿童= 9501;成人= 24,691)。儿童呼吸道入院与14天累积暴露于nox(浓度增加10 μ g -3时的RR为1.020)显著相关;95%可信区间1.010-1.031)，NO 2 (RR 1.086;95% CI 1.036-1.139)和NO (RR 1.033;95% ci 1.016-1.052)。在儿童急性呼吸道感染类别中也观察到类似的估计。效果似乎有些延迟，最大的估计大多在延迟6左右观察到。成人呼吸道入院未见显著相关性。这项研究表明，一氧化氮和二氧化氮都与16岁以下儿童因呼吸道疾病住院的人数增加有关，为了我们孩子的健康，我们应该做更多的工作来改善和执行城市中既定的法定一氧化氮污染限制。
{"title":"Respiratory Admissions Linked to Air Pollution in a Medium Sized City of the UK: A Case-crossover Study","authors":"Catherine A Fitton, B. Cox, M. Stewart, James Chalmers, J. Belch","doi":"10.4209/aaqr.230062","DOIUrl":"https://doi.org/10.4209/aaqr.230062","url":null,"abstract":"This study, from the Tayside Pollution Research Programme (TPRP), aims to investigate the effects of air pollution on respiratory hospital admissions in adults and children < 16 y of age, over a 14-year period, in Dundee, Scotland (population circa 148,270). We conducted a case-crossover study using routinely collected healthcare records from Ninewells Hospital, Dundee, Scotland from 2004 to 2017. Respiratory hospitalisation events were linked to daily nitric oxide gases (NO x , NO 2 , NO) extracted from publicly available data over this period. We used distributed lag models to allow for delayed effects of air pollutants up to 14 days. A total of 34,192 hospital admissions for a respiratory condition were included in this study (children = 9,501; adults = 24,691). Respiratory admissions in children were significantly associated with cumulative 14-day exposure to NO x (RR for a 10 µ g m –3 increase in concentration 1.020; 95% confidence interval 1.010–1.031), NO 2 (RR 1.086; 95% CI 1.036–1.139) and NO (RR 1.033; 95% CI 1.016–1.052). Similar estimates were observed for acute respiratory infection categories in children. Effects appeared to be somewhat delayed, with the largest estimates mostly observed around lag 6. No significant association was seen for respiratory admissions in adults. This study shows that both NO and NO 2 are associated with increased respiratory hospital admissions in children < 16 y of age, and that much more should be done to improve and enforce the established legal NO x pollution limits in cities for the sake of our children’s health.","PeriodicalId":7402,"journal":{"name":"Aerosol and Air Quality Research","volume":"1 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70297504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study performed surface treatment of Flumex, polyimide, and membrane-covered aramid (chosen as test substrates) by the C8-1833 water-repellent agent. Five key parameters (C8-1833 concentration, impregnation time, rolling residue rate, baking temperature, and baking time) were selected to investigate their effects on the filter media’s water-repellent grade and air permeability variation rate. Through an orthogonal optimization test, the optimal water-repellent process parameters were determined. Air and dust filter media test beds were employed to assess the anti-paste bag performance of water-repellent and membrane-covered filter media under high-humidity conditions. The results indicate that the water-repellent grade of the filter media was unaffected by the baking time during complete drying. At water- repellent agent concentrations of no less than 30 g L-1, impregnation times exceeding 3 s, baking temperatures exceeding 240℃, and rolling residue rates below 46%, both filter materials achieved a water-repellent grade 8. Under optimized processing conditions, the water-repellent grade of the filter media reached 8, and the contact angle was maximized, significantly enhancing the hydrophobicity. Both water-repellent and membrane-covered filter media delayed wet dust adhesion. However, in excessively high humidity of flue gas, sustained filtration performance of the filter media might not be achievable. In bag sticking or rapid condensation situations, the water-repellent filter material should be initially dried using high-temperature flue gas and subsequently restores its filtration performance through thorough dust cleaning.
本研究使用C8-1833拒水剂对Flumex、聚酰亚胺和膜覆盖芳纶(选择作为测试底物)进行表面处理。选择5个关键参数(C8-1833浓度、浸渍时间、滚渣率、焙烧温度、焙烧时间)考察其对滤料拒水等级和透气性变化率的影响。通过正交优化试验，确定了最佳拒水工艺参数。采用空气和粉尘过滤介质试验台，对高湿条件下防水性和膜覆盖过滤介质的防膏袋性能进行了评价。结果表明，在完全干燥过程中，滤料的防水性不受烘烤时间的影响。在防水剂浓度不低于30 g L-1、浸渍时间超过3 s、烘烤温度超过240℃、轧制残留率低于46%的条件下，两种过滤材料的防水性均达到8级。在优化的工艺条件下，滤料的防水性达到8级，接触角最大，疏水性显著增强。防水和膜覆盖的过滤介质延迟湿灰尘粘附。然而，在过高湿度的烟气中，过滤介质的持续过滤性能可能无法实现。在粘袋或快速凝结的情况下，防水过滤材料应首先使用高温烟气干燥，然后通过彻底的除尘恢复其过滤性能。
{"title":"Anti-paste Bag Performance of Water-repellent Filter Media in High-humidity Environments Considering Ultra-low Emissions","authors":"Zhongkai Yu, Erbao Guo, Xingcheng Liu, Yuemin Li","doi":"10.4209/aaqr.230148","DOIUrl":"https://doi.org/10.4209/aaqr.230148","url":null,"abstract":"This study performed surface treatment of Flumex, polyimide, and membrane-covered aramid (chosen as test substrates) by the C8-1833 water-repellent agent. Five key parameters (C8-1833 concentration, impregnation time, rolling residue rate, baking temperature, and baking time) were selected to investigate their effects on the filter media’s water-repellent grade and air permeability variation rate. Through an orthogonal optimization test, the optimal water-repellent process parameters were determined. Air and dust filter media test beds were employed to assess the anti-paste bag performance of water-repellent and membrane-covered filter media under high-humidity conditions. The results indicate that the water-repellent grade of the filter media was unaffected by the baking time during complete drying. At water- repellent agent concentrations of no less than 30 g L-1, impregnation times exceeding 3 s, baking temperatures exceeding 240℃, and rolling residue rates below 46%, both filter materials achieved a water-repellent grade 8. Under optimized processing conditions, the water-repellent grade of the filter media reached 8, and the contact angle was maximized, significantly enhancing the hydrophobicity. Both water-repellent and membrane-covered filter media delayed wet dust adhesion. However, in excessively high humidity of flue gas, sustained filtration performance of the filter media might not be achievable. In bag sticking or rapid condensation situations, the water-repellent filter material should be initially dried using high-temperature flue gas and subsequently restores its filtration performance through thorough dust cleaning.","PeriodicalId":7402,"journal":{"name":"Aerosol and Air Quality Research","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136258287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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