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.

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 Subtle Changes or Dramatic Perceptions of Air Pollution in Sydney during COVID-19

Environments ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 2
Author(s):  
Peter Brimblecombe ◽  
Yonghang Lai
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
New South ◽  
Human Mobility ◽  
Ground Level ◽  
Physical Reality ◽  
Social Perceptions ◽  
Search Terms ◽  
South Wales ◽  
Significant Difference

The COVID-19 pandemic made it critical to limit the spread of the disease by enforcing human isolation, restricting travel and reducing social activities. Dramatic improvements to air quality, especially NO2, have often characterised places under COVID-19 restrictions. Air pollution measurements in Sydney in April 2019 and during the lockdown period in April 2020 show reduced daily averaged NO2 concentrations: 8.52 ± 1.92 and 7.85 ± 2.92 ppb, though not significantly so (p1~0.15) and PM2.5 8.91 ± 4.94 and 7.95 ± 2.64 µg m−3, again a non-significant difference (p1~0.18). Satellite imagery suggests changes that parallel those at ground level, but the column densities averaged over space and time, in false-colour, are more dramatic. Changed human mobility could be traced in increasing times spent at home, assessed from Google Mobility Reports and mirrored in decreased traffic flow on a major road, suggesting compliance with the restrictions. Electricity demand for the State of New South Wales was low under lockdown in early April 2020, but it recovered rapidly. Analysis of the uses of search terms: bushfires, air quality, haze and air pollution using Google Trends showed strong links between bushfires and pollution-related terms. The smoke from bushfires in late 2019 may well have added to the general impression of improved air quality during lockdown, despite only modest changes in the ground level measurements. This gives hints that successful regulation of air quality requires maintaining a delicate balance between our social perceptions and the physical reality.

scholarly journals Environmental and Air Pollution Factors Affecting Allergic Eye Disease in Children and Adolescents in India

2021 ◽  
Vol 18 (11) ◽  
pp. 5611
Author(s):  
Anthony Vipin Das ◽  
Sayan Basu
Keyword(s):  
Air Pollution ◽  
Children And Adolescents ◽  
Temporal Pattern ◽  
Environmental Parameters ◽  
Ground Level ◽  
Significant Negative Correlation ◽  
Eye Disease ◽  
Cross Sectional ◽  
Recent Onset ◽  
Ground Level Ozone

The aim of this study was to describe the correlation between the meteorological and air pollution parameters with the temporal pattern of presentation of recent onset allergic eye disease (AED). This cross-sectional hospital-based study included new patients (≤21 years of age) presenting between January 2016 and August 2018 from the district of Hyderabad with a clinical diagnosis of AED and an acute exacerbation of recent onset of symptoms of less than 3 months duration. Correlation analysis was performed with the local environmental rainfall, temperature, humidity, windspeed, and air pollution. Of the 25,354 new patients hailing from the district of Hyderabad, 2494 (9.84%) patients were diagnosed with AED, of which 1062 (4.19%) patients had recent onset of symptoms. The mean monthly prevalence in this cohort was 4.13%, and the month of May (6.09%) showed the highest levels. The environmental parameters of humidity (r2 = 0.83/p = < 0.0001) and rainfall (r2 = 0.41/p = 0.0232) showed significant negative correlation, while temperature (r2 = 0.43/p = 0.0206) and ground-level ozone (r2 = 0.41/p = 0.0005) showed significant positive correlation with the temporal pattern of AED in the population. An increase in rainfall and humidity was associated with a lower prevalence, and an increase of temperature and ground-level ozone was associated with a higher prevalence of AED cases during the year among children and adolescents.

scholarly journals Regional Features of Long-Term Exposure to PM2.5 Air Quality over Asia under SSP Scenarios Based on CMIP6 Models

2021 ◽  
Vol 18 (13) ◽  
pp. 6817
Author(s):  
Sungbo Shim ◽  
Hyunmin Sung ◽  
Sanghoon Kwon ◽  
Jisun Kim ◽  
Jaehee Lee ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
East Asia ◽  
Climate Model ◽  
Fine Particulate Matter ◽  
Coupled Model ◽  
Surface Air Temperature ◽  
Quality Controls ◽  
Quality Guidelines

This study investigates changes in fine particulate matter (PM2.5) concentration and air-quality index (AQI) in Asia using nine different Coupled Model Inter-Comparison Project 6 (CMIP6) climate model ensembles from historical and future scenarios under shared socioeconomic pathways (SSPs). The results indicated that the estimated present-day PM2.5 concentrations were comparable to satellite-derived data. Overall, the PM2.5 concentrations of the analyzed regions exceeded the WHO air-quality guidelines, particularly in East Asia and South Asia. In future SSP scenarios that consider the implementation of significant air-quality controls (SSP1-2.6, SSP5-8.5) and medium air-quality controls (SSP2-4.5), the annual PM2.5 levels were predicted to substantially reduce (by 46% to around 66% of the present-day levels) in East Asia, resulting in a significant improvement in the AQI values in the mid-future. Conversely, weak air pollution controls considered in the SSP3-7.0 scenario resulted in poor AQI values in China and India. Moreover, a predicted increase in the percentage of aged populations (>65 years) in these regions, coupled with high AQI values, may increase the risk of premature deaths in the future. This study also examined the regional impact of PM2.5 mitigations on downward shortwave energy and surface air temperature. Our results revealed that, although significant air pollution controls can reduce long-term exposure to PM2.5, it may also contribute to the warming of near- and mid-future climates.

scholarly journals Real Time Air Quality Index from Various Locations

2020 ◽  
Vol 9 (2) ◽  
pp. 368-372
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Real Time ◽  
Environmental Protection Agency ◽  
Quality Index ◽  
Ground Level ◽  
Air Quality Index ◽  
Time Data ◽  
Open Government Data ◽  
Government Data

The surveys regarding air pollution shows that there has been a hasty growth due to the emission of fuels and exhaust gases from factories. The Air Quality Index (AQI) has been launched to note the contemporary status of the air quality. The intent of AQI is to aid every individual know how the regional air quality will make an impact on them. The Environmental Protection Agency assess the AQI for five major air pollutants namely Nitrogen dioxide (NO2), ground-level ozone (O3), particle pollution (PM10, PM2.5), carbon monoxide (CO), and sulphur dioxide (SO2). The intent of the project is to congregate real-time Air Quality Index from distinct monitoring stations across India, analysing the data and reporting on it. Collect the real-time data using the API key provided by Open Government Data (OGD) platform India. This is done by making use of Microsoft Business Intelligence (MSBI) and Power BI Tools to transform, analyse and visualize the data. This project can be utilized to develop various programs like Ozone today in Europe and in mobile applications which acts as an alert system that can protect people from air pollution.

scholarly journals The impacts of precursor reduction and meteorology on ground-level ozone in the Greater Toronto Area

2014 ◽  
Vol 14 (15) ◽  
pp. 8197-8207 ◽  
Author(s):  
S. C. Pugliese ◽  
J. G. Murphy ◽  
J. A. Geddes ◽  
J. M. Wang
Keyword(s):  
Health Hazard ◽  
Ground Level ◽  
Ozone Production ◽  
Ground Level Ozone ◽  
Ozone Concentrations ◽  
Greater Toronto Area ◽  
High Solar Radiation ◽  
Linear Effects ◽  
Human Health Hazard ◽  
Ozone Levels

Abstract. Tropospheric ozone (O3) is a major component of photochemical smog and is a known human health hazard, as well as a damaging factor for vegetation. Its precursor compounds, nitrogen oxides (NOx) and volatile organic compounds (VOCs), have a variety of anthropogenic and biogenic sources and exhibit non-linear effects on ozone production. As an update to previous studies on ground-level ozone in the Greater Toronto Area (GTA), we present an analysis of NO2, VOC and O3 data from federal and provincial governmental monitoring sites in the GTA from 2000 to 2012. We show that, over the study period, summertime 24 h VOC reactivity and NO2 midday (11:00–15:00) concentrations at all sites decreased significantly; since 2000, all sites experienced a decrease in NO2 of 28–62% and in measured VOC reactivity of at least 53–71%. Comparing 2002–2003 to 2011–2012, the summed reactivity of OH towards NO2 and a suite of measured VOCs decreased from 8.6 to 4.6 s−1. Ratios of reactive VOC pairs indicate that the effective OH concentration experienced by primary pollutants in the GTA has increased significantly over the study period. Despite the continuous decrease in precursor levels, ozone concentrations are not following the same pattern at all stations; it was found that the Canada-wide Standard for ozone continues to be exceeded at all monitoring stations. Additionally, while the years 2008–2011 had consistently lower ozone levels than previous years, 2012 experienced one of the highest recorded summertime ozone concentrations and a large number of smog episodes. We demonstrate that these high ozone observations in 2012 may be a result of the number of days with high solar radiation, the number of stagnant periods and the transport of high ozone levels from upwind regions.

Air Pollution, Air Quality, and Climate Change

Heat Advisory ◽  
2016 ◽  
Author(s):  
Alan H. Lockwood
Keyword(s):  
Climate Change ◽  
Air Pollution ◽  
Carbon Monoxide ◽  
Air Quality ◽  
Quality Standards ◽  
Ambient Air ◽  
Ozone Production ◽  
Atmospheric Water ◽  
Particulate Pollution ◽  
Volatile Organic

The effects of climate change on air quality are difficult to model due to the large number of unpredictable variables. Hotter temperatures favor ozone production. Higher atmospheric water content may blunt this effect in some regions. Higher levels of natural volatile organic compounds (VOCs), such as terpenes from plants, are likely to act synergistically with anthropogenic VOCs to favor ozone production. Droughts increase wildfire risks that produce particulate pollution and carbon monoxide, a VOC involved in ozone production. Some models predict increased ozone concentrations in many urban settings. Future revisions of National Ambient Air Quality Standards, a process driven by politics and science, should consider these effects.

scholarly journals A Mobile Air Pollution Monitoring Data Set

Data ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 2 ◽  
Author(s):  
Matthew Adams ◽  
Denis Corr
Keyword(s):  
Air Pollution ◽  
Urban Air Pollution ◽  
Ground Level ◽  
Pollution Monitoring ◽  
Mobile Platform ◽  
Data Set ◽  
Air Pollution Monitoring ◽  
Ground Level Ozone ◽  
Instrument Response ◽  
Capture Technique

Air pollution was observed in Hamilton, Ontario, Canada using monitors installed in a mobile platform from November 2005 up to November 2016. The dataset is an aggregation of several project specific monitoring days, which attempted to quantify air pollution spatial variation under varying conditions or in specific regions. Pollutants observed included carbon monoxide, nitric oxide, nitrogen dioxide, total nitrogen oxides, ground-level ozone, particulate matter concentrations for size cuts of 10 µm, 2.5 µm and 1 µm, and sulfur dioxide. Observations were collected over 114 days, which occurred in varying seasons and months. During sampling, the mobile platform travelled at an average speed of 27 km/h. The samples were collected as one-minute integrated samples and are prepared as line-segments, which include an offset for instrument response time. Sampling occurred on major freeways, highways, arterial and residential roads. This dataset is shared in hopes of supporting research on how to best utilize air pollution observations obtained with mobile air pollution platforms, which is a growing technique in the field of urban air pollution monitoring. We conclude with limitations in the data capture technique and recommendations for future mobile monitoring studies.

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.

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