Urbanization affects the quality of the air,which has drastically degraded in the past decades.Air quality level is determined by measures of several air pollutant concentrations.To create awareness among people,an au...Urbanization affects the quality of the air,which has drastically degraded in the past decades.Air quality level is determined by measures of several air pollutant concentrations.To create awareness among people,an automation system that forecasts the quality is needed.The COVID-19 pandemic and the restrictions it has imposed on anthropogenic activities have resulted in a drop in air pollution in various cities in India.The overall air quality index(AQI)at any particular time is given as the maximum band for any pollutant.PM2.5 is a fine particulate matter of a size less than 2.5 micrometers,the inhalation of which causes adverse effects in people suffering from acute respiratory syndrome and other cardiovascular diseases.PM2.5 is a crucial factor in deciding the overall AQI.The proposed forecasting model is designed to predict the annual PM2.5 and AQI.The forecasting models are designed using Seasonal Autoregressive Integrated Moving Average and Facebook’s Prophet Library through optimal hyperparameters for better prediction.An AQI category classification model is also presented using classical machine learning techniques.The experimental results confirm the substantial improvement in air quality and greater reduction in PM2.5 due to the lockdown imposed during the COVID-19 crisis.展开更多
Indoor Air Quality(IAQ)has been an area of growing concern with the increasing knowledge of health hazards associated with contaminants,particularly in high occupancy buildings where residents may be exposed to high l...Indoor Air Quality(IAQ)has been an area of growing concern with the increasing knowledge of health hazards associated with contaminants,particularly in high occupancy buildings where residents may be exposed to high levels of nuisance dust and other contaminants.Leadership and Energy in Environmental Design(LEED®)certification,which is awarded to buildings that prioritize sustainability and efficient resource use,has been increasingly sought in new construction.As LEED-certified buildings become more commonplace,it is worthwhile to consider whether these new building practices improve IAQ for its occupants.This study compares particulate matter(PM)concentrations in 12 LEED-certified buildings to 12 analogous non-LEED certified buildings on the University of Utah campus.Real-time air sampling was conducted in each building for PM measurements and a Wilcoxon signed rank test was conducted to compare PM levels.A statistically significant difference was found between LEED certification and PM concentrations,with LEED-certified buildings containing,on average,approximately half the PM of their non-LEED counterparts.These findings suggest that LEED certification is worth the financial investment,as it may lead to improved IAQ for residents.However,further research on other contaminants is warranted,including the characterization and comparison of formaldehyde and carbon dioxide levels.展开更多
Monitoring of PM10 and PM2.5 concentrations frequently is essential for assessing air quality and informing pollution control strategies. This study examines the effect of height on PM2.5 distribution in Hanoi using E...Monitoring of PM10 and PM2.5 concentrations frequently is essential for assessing air quality and informing pollution control strategies. This study examines the effect of height on PM2.5 distribution in Hanoi using EPA-standard methods at five rooftop locations on high-rise buildings. Results from Phase 1 (pre-pollution period) indicate a nearly 50% reduction in PM2.5 concentration, decreasing from 34.76 μg/m3 at 40 m to 13.95 μg/m3 at 336 m. In contrast, Phase 2 (pollution wave) showed relatively stable PM2.5 concentrations across heights, likely influenced by cold air masses and wind speed. MLR and MNLR analyses reveal the significant impact of meteorological factors and PM10 on PM2.5 levels, with the MNLR model accounting for 80% - 94% of the variance, outperforming the MLR model’s 50% - 80%. Employing UAVs, Lidar, and synchronized meteorological data is proposed as an advanced approach to enhance the accuracy of height-based dust concentration assessments.展开更多
Quantitative information on mass concentrations and other characteristics, such as spatial distribution, seasonal variation, indoor/outdoor （I/O） ratio, correlations and sources, of indoor and outdoor PM2.5 and elem...Quantitative information on mass concentrations and other characteristics, such as spatial distribution, seasonal variation, indoor/outdoor （I/O） ratio, correlations and sources, of indoor and outdoor PM2.5 and elemental components in Guangzhou City were provided. Mass concentration of PM2.5 and elemental components were determined by standard weight method and proton-induced X-ray emission （PIXE） method. 18 elements were detected, the results showed positive results. Average indoor and outdoor PM2.5 concentrations in nine sites were in the range of 67.7-74.5μg/m^3 for summer period, and 109.9-123.7 μg/m^3 for winter period, respectively. The sum of 18 elements average concentrations were 5362.6-5533.4 ng/m^3 for summer period, and 8416.8-8900.6 ng/m^3 for winter period, respectively. Average concentrations of PM2.5 and element components showed obvious spatial characteristic, that the concentrations in roadside area and in industrial plant area were higher than those in generic urban area. An obvious seasonal variation characteristic was found for PM2.5 and elemental components, that the concentrations in winter were higher than that in summer. The I/O ratio of PM2.5 and some elemental components presented larger than 1 sometimes. According to indoor/outdoor correlation of PM2.5 and element concentrations, it was found that there were often good relationships between indoor and outdoor concentrations. Enrichment factors were calculated to evaluate anthropogenic versus natural elements sources.展开更多
The pollution of particulate matter less than 2.5μm （PM2.5） is a serious environmental problem in Beijing. The annual average concentration of PM2.5 in 2001 from seasonal monitor results was more than 6 times that ...The pollution of particulate matter less than 2.5μm （PM2.5） is a serious environmental problem in Beijing. The annual average concentration of PM2.5 in 2001 from seasonal monitor results was more than 6 times that of the U,S, national ambient air quality standards proposed by U.S. EPA. The major contributors to mass of PM2.5 were organics, crustal elements and sulfate. The chemical composition of PM2.5 varied largely with season, but was similar at different monitor stations in the same season. The fine particles （PM2.5） cause atmospheric visibility deterioration through light extinction, The mass concentrations of PM2.5 were anti-correlated to the visibility, the best fits between atmospheric visibility and the mass concentrations of PM2.5 were somehow different： power in spring, exponential in summer, logarithmic in autumn, power or exponential in winter. As in each season the meteorological parameters such as air temperature and relative humidity change from day to day, probably the reason of above correlations between PM2.5 and visibility obtained at different seasons come from the differences in chemical compositions of PM2.5.展开更多
China’s past economic growth has substantially relied on fossil fuels,causing serious air pollution issues.Decoupling economic growth and pollution has become the focus in developing ecological civilization in China....China’s past economic growth has substantially relied on fossil fuels,causing serious air pollution issues.Decoupling economic growth and pollution has become the focus in developing ecological civilization in China.We have analyzed the three-decade progress of air pollution controls in China,highlighting a strategic transformation from emission control toward air quality management.Emission control of sulfur dioxide(SO2)resolved the deteriorating acid rain issue in China in 2007.Since 2013,control actions on multiple precursors and sectors have targeted the reduction of the concentration of fine particulate matter(PM2.5),marking a transition to an air-quality-oriented strategy.Increasing ozone(O3)pollution further requires O3 and PM2.5 integrated control strategies with an emphasis on their complex photochemical interactions.Fundamental improvement of air quality in China,as a key indicator for the success of ecological civilization construction,demands the deep de-carbonization of China’s energy system as well as more synergistic pathways to address air pollution and global climate change simultaneously.展开更多
基金funded by grant number 14-INF1015-10 from the National ScienceTechnology,and Innovation Plan(MAARIFAH)+1 种基金the King Abdul-Aziz City for Science and Technology(KACST)Kingdom of Saudi Arabia.We thank the Science and Technology Unit at Umm Al-Qura University for their continued logistics support.
文摘Urbanization affects the quality of the air,which has drastically degraded in the past decades.Air quality level is determined by measures of several air pollutant concentrations.To create awareness among people,an automation system that forecasts the quality is needed.The COVID-19 pandemic and the restrictions it has imposed on anthropogenic activities have resulted in a drop in air pollution in various cities in India.The overall air quality index(AQI)at any particular time is given as the maximum band for any pollutant.PM2.5 is a fine particulate matter of a size less than 2.5 micrometers,the inhalation of which causes adverse effects in people suffering from acute respiratory syndrome and other cardiovascular diseases.PM2.5 is a crucial factor in deciding the overall AQI.The proposed forecasting model is designed to predict the annual PM2.5 and AQI.The forecasting models are designed using Seasonal Autoregressive Integrated Moving Average and Facebook’s Prophet Library through optimal hyperparameters for better prediction.An AQI category classification model is also presented using classical machine learning techniques.The experimental results confirm the substantial improvement in air quality and greater reduction in PM2.5 due to the lockdown imposed during the COVID-19 crisis.
文摘Indoor Air Quality(IAQ)has been an area of growing concern with the increasing knowledge of health hazards associated with contaminants,particularly in high occupancy buildings where residents may be exposed to high levels of nuisance dust and other contaminants.Leadership and Energy in Environmental Design(LEED®)certification,which is awarded to buildings that prioritize sustainability and efficient resource use,has been increasingly sought in new construction.As LEED-certified buildings become more commonplace,it is worthwhile to consider whether these new building practices improve IAQ for its occupants.This study compares particulate matter(PM)concentrations in 12 LEED-certified buildings to 12 analogous non-LEED certified buildings on the University of Utah campus.Real-time air sampling was conducted in each building for PM measurements and a Wilcoxon signed rank test was conducted to compare PM levels.A statistically significant difference was found between LEED certification and PM concentrations,with LEED-certified buildings containing,on average,approximately half the PM of their non-LEED counterparts.These findings suggest that LEED certification is worth the financial investment,as it may lead to improved IAQ for residents.However,further research on other contaminants is warranted,including the characterization and comparison of formaldehyde and carbon dioxide levels.
文摘Monitoring of PM10 and PM2.5 concentrations frequently is essential for assessing air quality and informing pollution control strategies. This study examines the effect of height on PM2.5 distribution in Hanoi using EPA-standard methods at five rooftop locations on high-rise buildings. Results from Phase 1 (pre-pollution period) indicate a nearly 50% reduction in PM2.5 concentration, decreasing from 34.76 μg/m3 at 40 m to 13.95 μg/m3 at 336 m. In contrast, Phase 2 (pollution wave) showed relatively stable PM2.5 concentrations across heights, likely influenced by cold air masses and wind speed. MLR and MNLR analyses reveal the significant impact of meteorological factors and PM10 on PM2.5 levels, with the MNLR model accounting for 80% - 94% of the variance, outperforming the MLR model’s 50% - 80%. Employing UAVs, Lidar, and synchronized meteorological data is proposed as an advanced approach to enhance the accuracy of height-based dust concentration assessments.
基金Project supported by the Foundation of Research Grants Council of Hong Kong (No. PolyU 5145/03E) the National Natural Science Foundation of China (No. 40121303).
文摘Quantitative information on mass concentrations and other characteristics, such as spatial distribution, seasonal variation, indoor/outdoor （I/O） ratio, correlations and sources, of indoor and outdoor PM2.5 and elemental components in Guangzhou City were provided. Mass concentration of PM2.5 and elemental components were determined by standard weight method and proton-induced X-ray emission （PIXE） method. 18 elements were detected, the results showed positive results. Average indoor and outdoor PM2.5 concentrations in nine sites were in the range of 67.7-74.5μg/m^3 for summer period, and 109.9-123.7 μg/m^3 for winter period, respectively. The sum of 18 elements average concentrations were 5362.6-5533.4 ng/m^3 for summer period, and 8416.8-8900.6 ng/m^3 for winter period, respectively. Average concentrations of PM2.5 and element components showed obvious spatial characteristic, that the concentrations in roadside area and in industrial plant area were higher than those in generic urban area. An obvious seasonal variation characteristic was found for PM2.5 and elemental components, that the concentrations in winter were higher than that in summer. The I/O ratio of PM2.5 and some elemental components presented larger than 1 sometimes. According to indoor/outdoor correlation of PM2.5 and element concentrations, it was found that there were often good relationships between indoor and outdoor concentrations. Enrichment factors were calculated to evaluate anthropogenic versus natural elements sources.
基金The General Project of the Beijing Municipal Natural Science Foundation (No. 8012009) and the Key Project of the BeijingMunicipal Sciences & Technology Commission (No. H020620190091-H020620250230)
文摘The pollution of particulate matter less than 2.5μm （PM2.5） is a serious environmental problem in Beijing. The annual average concentration of PM2.5 in 2001 from seasonal monitor results was more than 6 times that of the U,S, national ambient air quality standards proposed by U.S. EPA. The major contributors to mass of PM2.5 were organics, crustal elements and sulfate. The chemical composition of PM2.5 varied largely with season, but was similar at different monitor stations in the same season. The fine particles （PM2.5） cause atmospheric visibility deterioration through light extinction, The mass concentrations of PM2.5 were anti-correlated to the visibility, the best fits between atmospheric visibility and the mass concentrations of PM2.5 were somehow different： power in spring, exponential in summer, logarithmic in autumn, power or exponential in winter. As in each season the meteorological parameters such as air temperature and relative humidity change from day to day, probably the reason of above correlations between PM2.5 and visibility obtained at different seasons come from the differences in chemical compositions of PM2.5.
基金the National Key Research Development Program of China(2016YFC0208901 and 2017YFC0212100)the National Natural Science Foundation of China(71722003 and 71690244)。
文摘China’s past economic growth has substantially relied on fossil fuels,causing serious air pollution issues.Decoupling economic growth and pollution has become the focus in developing ecological civilization in China.We have analyzed the three-decade progress of air pollution controls in China,highlighting a strategic transformation from emission control toward air quality management.Emission control of sulfur dioxide(SO2)resolved the deteriorating acid rain issue in China in 2007.Since 2013,control actions on multiple precursors and sectors have targeted the reduction of the concentration of fine particulate matter(PM2.5),marking a transition to an air-quality-oriented strategy.Increasing ozone(O3)pollution further requires O3 and PM2.5 integrated control strategies with an emphasis on their complex photochemical interactions.Fundamental improvement of air quality in China,as a key indicator for the success of ecological civilization construction,demands the deep de-carbonization of China’s energy system as well as more synergistic pathways to address air pollution and global climate change simultaneously.
