scholarly journals A Functional Data Analysis Approach for the Detection of Air Pollution Episodes and Outliers: A Case Study in Dublin, Ireland

Mathematics ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 225 ◽  
Author(s):  
Javier Martínez Torres ◽  
Jorge Pastor Pérez ◽  
Joaquín Sancho Val ◽  
Aonghus McNabola ◽  
Miguel Martínez Comesaña ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Nitrogen Oxide ◽  
Functional Data ◽  
Ground Level ◽  
Control Measures ◽  
Urban Site ◽  
Air Pollution Control ◽  
Limit Values ◽  
Pollution Episodes

Ground level concentrations of nitrogen oxide (NOx) can act as an indicator of air quality in the urban environment. In cities with relatively good air quality, and where NOx concentrations rarely exceed legal limits, adverse health effects on the population may still occur. Therefore, detecting small deviations in air quality and deriving methods of controlling air pollution are challenging. This study presents different data analytical methods which can be used to monitor and effectively evaluate policies or measures to reduce nitrogen oxide (NOx) emissions through the detection of pollution episodes and the removal of outliers. This method helps to identify the sources of pollution more effectively, and enhances the value of monitoring data and exceedances of limit values. It will detect outliers, changes and trend deviations in NO2 concentrations at ground level, and consists of four main steps: classical statistical description techniques, statistical process control techniques, functional analysis and a functional control process. To demonstrate the effectiveness of the outlier detection methodology proposed, it was applied to a complete one-year NO2 dataset for a sub-urban site in Dublin, Ireland in 2013. The findings demonstrate how the functional data approach improves the classical techniques for detecting outliers, and in addition, how this new methodology can facilitate a more thorough approach to defining effect air pollution control measures.

scholarly journals Using Costs and Health Benefits to Estimate the Priority of Air Pollution Control Action Plan: A Case Study in Taiwan

2020 ◽  
Vol 10 (17) ◽  
pp. 5970
Author(s):  
Hsin-Chih Lai ◽  
Min-Chuan Hsiao ◽  
Je-Liang Liou ◽  
Li-Wei Lai ◽  
Pei-Chih Wu ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Pollution Control ◽  
Action Plan ◽  
Health Benefits ◽  
Control Measures ◽  
Cost Ratio ◽  
Air Pollution Control ◽  
Kriging Method ◽  
Quality Modeling

A comparative analysis was conducted between the costs and health benefits of the Air Pollution Control Action Plan (APCAP), which can be implemented in any country to improve air quality and human health. In this study, air quality modeling was used to simulate several scenarios and implement the Kriging method to describe the PM2.5 reduction concentration instantly. Then, health benefits were estimated using the environmental benefit mapping and analysis program (BenMAP) with results from the air quality modeling and Kriging method. To estimate the priority of APCAP, 14 pollution control measures that cover point, mobile, and area sources of air pollution in Taiwan were analyzed. The results indicate that the health benefits of the Taiwan APCAP (TAPCAP) are generally greater than the technical costs. Thus, the implementation of this strategy may result in net benefits. In addition, the benefit-to-control cost ratio for health for the 14 pollution control measures was calculated. The results provide evidence to prioritize the implementation of air quality policies with a higher benefit-cost ratio.

scholarly journals Ambient Air Quality in the Czech Republic: Past and Present

Atmosphere ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 214 ◽  
Author(s):  
Iva Hůnová
Keyword(s):  
Air Pollution ◽  
Czech Republic ◽  
Air Quality ◽  
Transition Period ◽  
Ground Level ◽  
Ambient Air ◽  
Ambient Air Pollution ◽  
Ambient Air Quality ◽  
Limit Values ◽  
Pollution Impacts

Based on an analysis of related core papers and reports, this review presents a historical perspective on ambient air pollution and ambient air quality development in the modern-day Czech Republic (CR) over the past seven decades, i.e., from the 1950s to the present. It offers insights into major air pollution problems, reveals the main hot spots and problematic regions and indicates the principal air pollutants in the CR. Air pollution is not presented as a stand-alone problem, but in the wider context of air pollution impacts both on human health and the environment in the CR. The review is arranged into three main parts: (1) the time period until the Velvet Revolution of 1989, (2) the transition period of the 1990s and (3) the modern period after 2000. Obviously, a major improvement in ambient air quality has been achieved since the 1970s and 1980s, when air pollution in the former Czechoslovakia culminated. Nevertheless, new challenges including fine aerosol, benzo[a]pyrene and ground-level ozone, of which the limit values are still vastly exceeded, have emerged. Furthermore, in spite of a significant reduction in overall emissions, the atmospheric deposition of nitrogen, in particular, remains high in some regions.

scholarly journals Effects of air pollution control measures on air quality improvement in Guangzhou, China

2019 ◽  
Vol 244 ◽  
pp. 127-137 ◽  
Author(s):  
Meifang Yu ◽  
Yun Zhu ◽  
Che-Jen Lin ◽  
Shuxiao Wang ◽  
Jia Xing ◽  
...  
Keyword(s):  
Air Pollution ◽  
Quality Improvement ◽  
Air Quality ◽  
Pollution Control ◽  
Control Measures ◽  
Air Pollution Control ◽  
Air Quality Improvement

scholarly journals Assessment of the Effect of the Three-Year Action Plan to Fight Air Pollution on Air Quality and Associated Health Benefits in Sichuan Basin, China

2021 ◽  
Vol 13 (19) ◽  
pp. 10968
Author(s):  
Juihui Chen ◽  
Xiaoqiong Feng ◽  
Yonghui Zhu ◽  
Ling Huang ◽  
Min He ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Pollution Control ◽  
Emission Reduction ◽  
Sichuan Basin ◽  
Action Plan ◽  
Control Measures ◽  
Air Pollution Control ◽  
Premature Deaths ◽  
Pm2.5 Concentration

To continuously improve air quality, after implementation of the “Clean Air Action Plan, 2013–2017” (CAAP), the “Three-year Action Plan to Fight Air Pollution” (TYP) was further conducted from 2018 to 2020. However, the effectiveness of the TYP remains unclear in one of the major city-clusters of China, the Sichuan Basin. In this study, the bottom-up method was used to quantify the emission reduction during TYP based on the emissions inventory in Sichuan Basin in 2017 and the air pollution control measures adopted from 2018 to 2020 in each city. The reduction of PM2.5 concentration and the avoided premature deaths due to implementation of air pollution control measures were assessed by using an integrated meteorology and air quality modeling system and a concentration-response algorithm. Emissions of SO2, NOx, PM2.5, and VOCs in the Sichuan Basin have been reduced by 42.6, 105.2, 40.2, and 136.6 Gg, respectively. The control of non-electricity industry contributed significantly to the emission reduction of all pollutants, accounting for 26–49%. In addition, the control of mobile sources contributes the most to NOx reductions, accounting for 57%. The results illustrate that the focus of air pollution control in Sichuan Basin is still industrial sources. We also found that the emission reduction of NOx, PM2.5, and VOCs in Chengdu is significantly higher than that of other cities, which were about 3.4~15.4 times, 2.2~40.1 times, and 4.3~24.4 times that of other cities, respectively. In Sichuan Basin, the average reduction rate of PM2.5 concentration due to air pollution control measures was 5% on average, with the highest contributions from industry, mobile source, and dust emission control. The decrease rate in each city ranges between 1~10%, and the decreasing ratios in Dazhou (10%), Chengdu (8%), and Zigong (7%) are relatively higher. The number of premature deaths avoided due to air pollution control measures in Sichuan Basin is estimated to be 22,934. Chengdu and Dazhou have benefitted most from the air pollution control measures, with 6043 and 2713 premature deaths avoided, respectively. Our results indicate that the implementation of TYP has achieved remarkable environmental and health benefits.

scholarly journals Science–Policy Interplay: Improvement of Air Quality from 2008 to 2014 in Beijing and the Scientific Approach to Achieve APEC Blue

2016 ◽  
Vol 97 (4) ◽  
pp. 553-559 ◽  
Author(s):  
Zhanshan Wang ◽  
Yunting Li ◽  
Tian Chen ◽  
Dawei Zhang ◽  
Lingjun Li ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Pollution Control ◽  
Control Policy ◽  
Air Pollutant ◽  
Control Measures ◽  
Asia Pacific ◽  
Great Effort ◽  
Air Pollution Control ◽  
Scientific Approach

Abstract The Beijing government has made great effort to solve the air pollution problem in recent years. In this paper, the major air pollution control measures and the air quality improvement from 2008 to 2014 in Beijing were represented. With the implementation of a series of unconventional and high–air pollutant reduction measures in Beijing and the surrounding area, good air quality during both the 2008 Olympic Games and the 2014 Asia–Pacific Economic Cooperation (APEC) conference was guaranteed. Notably, a new scientific approach was applied to formulate air pollution control policy during the APEC conference. In addition to the established measures, two periods of enhanced and targeted reduction measures were implemented according to the forecast in advance. Finally, suggestions for improving air quality in Beijing were offered on the basis of the monitoring results and analyses during the APEC conference.

scholarly journals Impact of air pollution control measures and regional transport on carbonaceous aerosols in fine particulate matter in urban Beijing, China: insights gained from long-term measurement

2019 ◽  
Vol 19 (13) ◽  
pp. 8569-8590 ◽  
Author(s):  
Dongsheng Ji ◽  
Wenkang Gao ◽  
Willy Maenhaut ◽  
Jun He ◽  
Zhe Wang ◽  
...  
Keyword(s):  
Air Pollution ◽  
Particulate Matter ◽  
Air Quality ◽  
Pollution Control ◽  
Fine Particulate Matter ◽  
Control Measures ◽  
Air Pollution Control ◽  
Heavy Duty ◽  
Potential Source ◽  
Fine Particulate

Abstract. As major chemical components of airborne fine particulate matter (PM2.5), organic carbon (OC) and elemental carbon (EC) have vital impacts on air quality, climate change, and human health. Because OC and EC are closely associated with fuel combustion, it is helpful for the scientific community and policymakers assessing the efficacy of air pollution control measures to study the impact of control measures and regional transport on OC and EC levels. In this study, hourly mass concentrations of OC and EC associated with PM2.5 were semi-continuously measured from March 2013 to February 2018. The results showed that annual mean OC and EC concentrations declined from 14.0 to 7.7 µg m−3 and from 4.0 to 2.6 µg m−3, respectively, from March 2013 to February 2018. In combination with the data of OC and EC in previous studies, an obvious decreasing trend in OC and EC concentrations was found, which was caused by clean energy policies and effective air pollution control measures. However, no obvious change in the ratios of OC and EC to the PM2.5 mass (on average, 0.164 and 0.049, respectively) was recorded, suggesting that inorganic ions still contributed a lot to PM2.5. Based on the seasonal variations in OC and EC, it appeared that higher OC and EC concentrations were still observed in the winter months, with the exception of winter of 2017–2018. Traffic policies executed in Beijing resulted in nighttime peaks of OC and EC, caused by heavy-duty vehicles and heavy-duty diesel vehicles being permitted to operate from 00:00 to 06:00 (China standard time, UTC+8, for all times throughout the paper). In addition, the fact that there was no traffic restriction in weekends led to higher concentrations on weekends compared to weekdays. Significant correlations between OC and EC were observed throughout the study period, suggesting that OC and EC originated from common emission sources, such as exhaust of vehicles and fuel combustion. OC and EC levels increased with enhanced SO2, CO, and NOx concentrations while the O3 and OC levels were enhanced simultaneously when O3 concentrations were higher than 50 µg m−3. Non-parametric wind regression analysis was performed to examine the sources of OC and EC in the Beijing area. It was found that there were distinct hot spots in the northeast wind sector at wind speeds of approximately 0–6 km h−1, as well as diffuse signals in the southwestern wind sectors. Source areas further away from Beijing were assessed by potential source contribution function (PSCF) analysis. A high-potential source area was precisely pinpointed, which was located in the northwestern and southern areas of Beijing in 2017 instead of solely in the southern areas of Beijing in 2013. This work shows that improvement of the air quality in Beijing benefits from strict control measures; however, joint prevention and control of regional air pollution in the regions is needed for further improving the air quality. The results provide a reference for controlling air pollution caused by rapid economic development in developing countries.

scholarly journals Impact of air pollution control measures and regional transport on carbonaceous aerosols in fine particulate matter in urban Beijing, China: Insights gained from long-term measurement

2019 ◽  
Author(s):  
Dongsheng Ji ◽  
Wenkang Gao ◽  
Willy Maenhaut ◽  
Jun He ◽  
Zhe Wang ◽  
...  
Keyword(s):  
Air Pollution ◽  
Particulate Matter ◽  
Air Quality ◽  
Pollution Control ◽  
Fine Particulate Matter ◽  
Control Measures ◽  
Air Pollution Control ◽  
Heavy Duty ◽  
Potential Source ◽  
Fine Particulate

Abstract. As major chemical components of airborne fine particulate matter (PM2.5), organic carbon (OC) and elemental carbon (EC) have vital impacts on air quality, climate change, and human health. Because OC and EC are closely associated with fuel combustion, it is helpful for the scientific community and policymakers assessing the efficacy of air pollution control measures to study on the impact of the control measures and regional transport on the OC and EC levels. In this study, hourly mass concentrations of OC and EC associated with PM2.5 were semi-continuously measured from March 2013 to February 2018. The results showed that annual mean OC and EC concentrations declined from 14.0 to 7.7 μg/m3 and from 4.0 to 2.6 μg/m3, respectively, from March 2013 to February 2018. In combination with the data of OC and EC in previous studies, an obvious decreasing trend in OC and EC concentrations was found, which was caused by clean energy policies and effective air pollution control measures. However, no obvious change in the ratios of OC and EC to the PM2.5 mass (on average, 0.164 and 0.049, respectively) was recorded, suggesting that inorganic ions still contributed a lot to PM2.5. Based on the seasonal variations of OC and EC, it appeared that higher OC and EC concentrations were still observed in the winter months, with the exception of winter of 2017–2018. Traffic policies executed in Beijing resulted in nighttime peaks of OC and EC, caused by heavy-duty vehicles and heavy-duty diesel vehicles being permitted to operate from 0:00 to 6:00. In addition, the fact that there was no traffic restriction in weekends led to higher concentrations in weekends compared to weekdays. Significant correlations between OC and EC were observed throughout the study period, suggesting that OC and EC originated from common emission sources, such as exhaust of vehicles and fuel combustion. OC and EC levels increased with enhanced SO2, CO and NOx concentrations while the O3 and OC levels enhanced simultaneously when O3 concentrations were higher than 50 μg/m3. Nonparametric wind regression analysis was performed to examine the sources of OC and EC in the Beijing area. It was found that there were distinct hot spots in the northeast wind sector at wind speeds of approximately 5 km/h, as well as diffuse signals in the southwestern wind sectors, highlighting probable trans-boundary transport from highly industrialized regions upwind of the Hebei province, such as Baoding, Shijiazhuang and Handan, which were the most polluted cities in China. This was consistent with their higher potential as source areas, as determined by the potential source contribution function (PSCF) analysis. A high-potential source area was precisely pinpointed, which was located in the northwestern and southern areas of Beijing in 2017 instead of solely in the southern areas of Beijing in 2013. This work shows that improvement of the air quality in Beijing benefits from strict control measures; however, joint prevention and control of regional air pollution in the regions is needed for further improving the air quality. The results provide a reference for controlling air pollution caused by rapid economic development in developing countries.

scholarly journals Five-Year Analysis of Air Pollution in Istanbul Including Also the Impact of the COVID-19 Pandemic

2021 ◽  
Author(s):  
Nilüfer Aykaç ◽  
Pınar Pazarlı Bostan ◽  
Sabri Serhan Olcay ◽  
Berker Öztürk
Keyword(s):  
Air Pollution ◽  
Particulate Matter ◽  
Air Quality ◽  
Nitrogen Oxide ◽  
Air Pollutants ◽  
World Health ◽  
Limit Values ◽  
Public Data ◽  
Health Organization ◽  
The Impact

INTRODUCTION: Particulate matter, sulfur dioxide, ozone, and nitrogen oxide compounds are the main air pollutants. The purpose of this research is to analyze the five-year air quality of Istanbul and examine the effect of movement restrictions due to the COVID-19 pandemic on pollutants. METHODS: The public data of the National Air Quality Observation Network has been utilized. The research has been conducted based on the five-year daily averages of PM10, NO2, and NOx pollutants for Istanbul between 2016 - 2020. The data of stations which measured for 75% and more throughout the year has been used. The effect of lockdowns enforced due to COVID-19 was revealed by comparing data of pollutants from April and May of 2020 to the same period in 2019. RESULTS: There were 12 stations between 2016 – 2018, and 39 stations in 2019 and 2020 which measured particulate matter and nitrogen oxide compounds. Only 9 stations reached the standard of measuring pollution for 75% and more throughout the year. The PM10, NO2, and NOx levels measured by all the 9 stations between 2016 - 2020 are above the limit values set by the World Health Organization (WHO). The lockdowns in 2020 have not been helping improvements in air pollution issue. However, there have been regressions of 33.4%, 59.6%, and 52.6% in the overall average particulate matter, nitrogen oxide, and nitrogen dioxide concentrations during the lockdowns between 23-26 of April, 1-3 of May, and 23-26 of May, respectively. DISCUSSION AND CONCLUSION: The air pollution issue in Istanbul has not improved in a meaningful and significant manner for the last five years. There is a significant deficiency in measuring traffic pollution. It has been found that two days long lockdowns and physical movement restrictions due to COVID-19 have significantly contributed to a significant regression in the overall concentration of air pollutants.

scholarly journals Variations of ground-level O<sub>3</sub> and its precursors in Beijing in summertime between 2005 and 2011

2014 ◽  
Vol 14 (1) ◽  
pp. 1019-1050 ◽  
Author(s):  
Q. Zhang ◽  
B. Yuan ◽  
M. Shao ◽  
X. Wang ◽  
S. Lu ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Ground Level ◽  
Ozone Production ◽  
Urban Site ◽  
Large Contribution ◽  
Beijing City ◽  
Ground Level Ozone ◽  
Quality Controls ◽  
Ozone Precursors

Abstract. Increased levels of ground-level ozone (O3), reflecting the oxidative capacity of the atmosphere, are of increasing concern. High levels of total oxidants (Ox = O3 + NO2) have been persistently observed as a feature of Beijing's air pollution. Beijing is a typical global mega-city requiring the enforcement of stringent air quality controls as rapid economic growth continues. To evaluate the effect of air quality controls in recent years, ground-based on-line measurements at an urban site were conducted in summer and the variations in O3 with simultaneous changes in NOx and volatile organic compounds (VOCs) between 2005 and 2011 were analyzed. Both NOx and anthropogenic VOCs in Beijing decreased over the study period, 1.4 ppbv yr−1 and 1.6 ppbv yr−1 respectively, the VOCs reactivity, in term of OH loss rate showed an indistinct statistical trend due to the large contribution from naturally emitted isoprene. Meanwhile, the daytime average O3 concentrations increased significantly at an annual rate 2.6 ppbv yr−1, around 5% yr−1 between 2005 and 2011. Considering the influence of NO titration effect and the increasing in regional background in the North China Plain (NCP), the main reason for such an increase in oxidants was local photochemistry. A simplified model was used to evaluate the effect of changes in the levels of ozone precursors on ozone production, we found that between 2001 and 2006, the production rate of total oxidants, P(Ox) increased rapidly due to increased VOC levels and decreasing of NO2, while from 2006 to2011, P(Ox) remained high though, decreased slightly as a~consequence of the decrease in both VOC reactivity (5% yr−1) and NOx (4% yr−1). Measurements have shown that the air pollution control efforts of Beijing city were effective in cutting ozone precursors, but even led to higher ground-level ozone. Therefore, putting ozone as the target for air quality, a faster reduction of VOCs, especially the reactive VOCs, will be needed to go together with NOx emission control programs.

scholarly journals Variations of ground-level O<sub>3</sub> and its precursors in Beijing in summertime between 2005 and 2011

2014 ◽  
Vol 14 (12) ◽  
pp. 6089-6101 ◽  
Author(s):  
Q. Zhang ◽  
B. Yuan ◽  
M. Shao ◽  
X. Wang ◽  
S. Lu ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Urban Areas ◽  
Ground Level ◽  
Oxidative Capacity ◽  
Ozone Production ◽  
Urban Site ◽  
Ground Level Ozone ◽  
Quality Controls ◽  
Ozone Precursors

Abstract. Elevated ground-level ozone (O3), reflecting atmospheric oxidative capacity, are of increasing concern. High levels of total oxidants (Ox= O3 + NO2) have been persistently observed as a feature of Beijing's air pollution. Beijing is a well-known megacity requiring the enforcement of stringent air quality controls as rapid economic growth continues. To evaluate the effect of air quality controls in recent years, ground-based on-line measurements at an urban site were conducted in summer and the variations in O3 with simultaneous changes in NOx and volatile organic compounds (VOCs) between 2005 and 2011 were analyzed. Both NOx and total VOCs in Beijing decreased over the study period, 1.4 ppbv yr−1 and 1.6 ppbv yr−1, respectively. However, VOCs reactivity, in terms of OH loss rate, showed an indistinct statistical trend due to unsteady variations from naturally emitted isoprene, though some anthropogenic species showed decreasing trends, such as pentane, benzene and toluene. Meanwhile, daytime average O3 increased rapidly at an annual rate of 2.6 ppbv yr−1, around 5% yr−1 between 2005 and 2011. Considering the influence of NO titration effect and elevated regional ozone background in the North China Plain (NCP), the main reason for such an increase in oxidants was subject to "local" photochemistry. A simplified model was used to evaluate the effect of changes in the levels of ozone precursors on ozone production. We found that between 2001 and 2006, the production rate of total oxidants, P(Ox) increased rapidly due to increased VOC levels and decreasing NO2, while from 2006 to 2011 P(Ox) remained high, though decreased slightly as a consequence of the decrease in both VOC reactivity (−5% yr−1) and NOx (−4% yr−1). Observations have shown that Beijing's efforts to control air pollution were somehow effective in cutting ozone precursors, but still left higher ground-level ozone. We surmised that it resulted from potential contributions from OVOCs and regional transport near Beijing. Therefore, Beijing needs deeper cooperation with adjacent provinces to control ozone pollution together. To impel this kind of joint prevention and control program, ground-level ozone should become a mandatory index for air quality management, and a faster reduction of VOCs, especially reactive VOCs, in urban areas, should coordinate with national NOx emission control programs.

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