Average Concentrations Of SO2 Research Articles

Spatiotemporal variation of atmospheric pollution and its plausible sources in an industrial populated city, Bay of Bengal, Paradip, India

This study examines the possible sources of ambient pollutants and seasonal variations within the nine selected stations, including the residential, commercial, and industrial sites from January 2016 to December 2018 in Paradip city. The particulate matter (PM) like PM10 and PM2.5 and gaseous pollutants like sulphur dioxide (SO2), nitrogen dioxide (NO2), and ammonia (NH3) samples were collected in four different seasons such as pre-monsoon, monsoon, post-monsoon, and winter. The seasonal average concentrations of PM10 and PM2.5 showed the highest levels in winter and the lowest in monsoon. The seasonal average concentrations of SO2, NO2, and NH3 were within the permissible limits at all the sites. The seasonal air quality index (AQI) shows that industrial sites were under the “severe air pollution” category in the winter season while all residential and commercial sites (except AG) under the “light air pollution” category in all seasons. The correlation such as, PM10 with PM2.5 and SO2 with NO2, showed a significant positive relation in all seasons. Principal component analysis (PCA) identified two major factors, with a total variance of 47.995% and 25.821%, respectively. Hierarchical cluster analysis (HCA) was used to explain the pollutants dispersion and spatial variations.

Impact of emissions from a single urban source on air quality estimated from mobile observation and WRF-STILT model simulations

For industrial cities, quantifying the influence of a given emission source on air quality is very important for making a detailed control strategy to the emissions. By taking use of the mobile observations and WRF-STILT model simulations, this study analyzes the air pollution characteristics and air quality influences from an industrial emission source in Xinji, China. During the study period, the hourly average concentrations of smoke, SO2, and NOx emitted from the industrial source are 1.01, 22.04, and 26.22 mg/m3, respectively. The mobile observations show that with the increase of distance from the emission source, the concentration of air pollutants increases first and then decreases. The peak values of PM2.5, SO2, and NOx appear at the distance of around 0–3 km away from the emission source, among which PM2.5 and SO2 increase first and then decrease before stabilizing, while NOx is interfered by emissions from the traffic along the roads. Within the distance of 3 km, the emission source has obvious influence on the air quality with contribution rate 10–48% at night time and 3–23% at day time. The simulation results of WRF-STILT also support the observed gradient change characteristics of air pollutants, suggesting that this industrial emission source is an important pollution source for regions around it. Our results further show that the meteorological conditions play an important role on the transport capacity of industrial emissions. The results of this study provide support for quantifying the scope of influence of fixed emission sources, especially in industrial cities.

The impact of energy-intensive industries on air quality in China’s industrial agglomerations

Understanding the driving forces of regional air pollution and its mechanism has gained much attention in academic research, which can provide scientific policy-making basis for economy-environment sustainability in China. Being an important energy and industrial base, the North China Plain region has been experiencing severe air pollution. Therefore, understanding the relationship between industrialization and air quality in this region is of great importance for air quality improvement. In this study, the average annual concentrations of SO2, NO2 and PM10 in 47 sample cities at and above the prefecture level in the North China Plain region from 2007 to 2016 were used to illustrate the spatiotemporal characteristics of air pollution within this region. Furthermore, panel data model, panel vector autoregression model, and impulse response function were used to explore the correlation and driving mechanism between energy-intensive industries and regional air quality. The results show that: first, overall air quality improved in the study area between 2007 and 2016, with a significant greater fall in concentration of SO2 than that of NO2 and PM10; second, provincial border areas suffered from severe air pollution and showed an apparent spatial agglomeration trend of pollution; and third, the test results from different models all proved that energy-intensive industries such as the chemical, non-metallic mineral production, electric and thermal power production and supply industries, had a significant positive correlation with concentrations of air pollutants, and indicated an obvious short-term impulse response effect. It concludes that upgradation of industrial structure, especially that of energy-intensive industries, plays a very important role in the improvement of regional air quality, which is recommended to be put in top priority for authorities. Therefore, policies as increasing investments in technological innovation in energy-intensive industries, deepening cooperation in environmental governance between different provinces and cities, and strengthening supervision and entry restrictions are suggested.

Trend of atmosphreic PM_(2. 5) and their components in two districts of Lanzhou City from 2015 to 2019

To analyse the variation of the fine particulate matter(PM_(2. 5)) concentration and its chemical composition in two districts of Lanzhou City from 2015 to 2019. From January 2015 to December 2019, two sampling points, namely residential district(Chengguan District) and industrial district(Xigu District) were selected in Lanzhou City, to collect PM_(2. 5) samples, and the mass concentrations, metals and metalloid elements, water-soluble ions and polycyclic aromatic hydrocarbons(PAHs) contents were determined. A total of 838 samples were collected in Chengguan District and Xigu District in Lanzhou City during 2015-2019, the average annual mass concentration and the daily average concentration of the PM_(2. 5) were decreasing year by year(P<0. 05). The higher metal content in PM_(2. 5) were Al, Pb, Mn and As during 2015-2019. Sb, Al, As, Cd, Cr, Pb, Mn and Tl element content were higher in 2015 and 2016 than in other years(P<0. 05), the average annual concentration of As were 7. 92 and 8. 63 ng/m~3 respectively, which exceeded the reference concentration limit of the ambient air quality standard. The average annual mass concentration of Cr from 2015 to 2019 was much higher than the annual average reference concentration limit of the ambient air quality standard. From 2015 to 2019, except for 2018, the highest average concentration of PAHs in atmospheric PM_(2. 5) in the two districts of Lanzhou City was Ant, B(b)F and I(cd)P mass concentration were highest in 2015, N(a)P, FI, Ace, Phe, Ant, Flu, Pyr, B(k)F and B(a)P mass concentration were highest in 2017, Acy, Chr and B(ghi)P mass concentration were highest in 2018(P<0. 05). From 2017 to 2018, the average annual content of B(a)P in the two districts of Lanzhou City were 1. 16 and 1. 11 ng/m~3, respectively, which exceeded the annual average concentration limit of the ambient air quality standard. The concentration of Cl~- in PM_(2. 5) in the two districts of Lanzhou City was decreasing year by year, the annual average concentrations of SO~2-_4, NO~-_3 and NH~+_4 from 2017 to 2019 showed a downward trend year by year. SO~2-_4, Cl~- of both districts were the highest in 2015, and NO~-_3, NH~+_4 were the highest in 2017(P<0. 05). The air quality of Lanzhou City has been improved obviously, but the pollution problem is still serious.

Atmospheric Pollution Impact Assessment of Brick and Tile Industry: A Case Study of Xinmi City in Zhengzhou, China

The brick and tile industry was selected to investigate the impact of pollutants emitted from such industry on air quality. Based on the 2018 Zhengzhou City Census data and combined with field sampling and research visits, an emission inventory of the brick and tile industry in Xinmi City was established using the emission factor method. Based on the established emission inventory, the concentrations of SO2, NOX, and PM2.5 emitted by 31 brick and tile enterprises were then predicted using the CALPUFF model (California puff model, USEPA), which had been evaluated for accuracy, and the simulation results were compared with the observed results to obtain the impact of pollutant emissions from the brick and tile industry on air pollution in the simulated region. Results show that SO2, NOX, and PM2.5 emissions from the brick and tile industry in the study area in 2018 were 564.86 tons, 513.16 tons, and 41.01 tons, respectively. The CALPUFF model can simulate the characteristics of meteorological changes and pollutant concentration trends, and the correlation coefficient of the fit curve between the pollutant observed data and the simulated data was higher than 0.8, which can reproduce the impact of key industrial point sources on air quality well. The simulated concentration values and spatial and temporal distribution characteristics of SO2, NOX, PM2.5 in spring, summer, autumn, and winter were obtained from the model simulations. The contribution of pollutant emissions from the brick and tile industry to the monthly average concentrations of SO2, NOX, and PM2.5 in the simulated region were 6.58%, 5.38%, and 1.42%, respectively, with the Housing Administration monitoring station as the receptor point. The brick and tile industry should increase the emission control measures of SO2 and NOX, and at the same time, the emission control of PM2.5 cannot be slackened.

Impact of suspending traffic management plan in Tehran on air quality and COVID-19 mortality and morbidity

Introduction: The novel coronavirus disease 2019, namely COVID-19, has been known as a global pandemic by the World Health Organization (WHO). To prevent of COVID-19 spread, most countries including Iran have implemented many preventive measures. This study aimed to evaluate the effect of implementation (Phase-01)/non- implementation (Phase-02) of the traffic plan on confirmed cases, suspected cases, and mortality cases by COVID-19 as well as on air quality in Tehran.
 Materials and methods: Daily data of confirmed COVID-19 cases, suspected COVID-19 cases, mortality COVID-19 cases, air pollutants concentration and meteorological variables were obtained from 26 February, 2020 to 5August, 2020 in Tehran megacity and data were compared during the period’s implementation /non-implementation of traffic plan in Tehran.
 Results: Our results showed that the non-implementation of traffic plan has been effective in reducing the number of daily confirmed cases, suspected cases and mortality by COVID-19. Also, the average concentration of PM10, PM2.5, NO2 , O3 , SO2 and CO have reduced significantly during nonimplementation traffic plan phase.
 Conclusion: Our findings indicate that there is a significant association between non-implementation traffic plan and reduce risk of COVID-19 infection.

A model-based exploratory study of sulfur dioxide dispersions from concentrated animal feeding operations in the Southeastern United States

ABSTRACT In the Southeastern U. S. there are Concentrated Animal Feeding Operations (CAFOs) that emit a variety of gases, including SO2. Sulfur is emitted as reduced sulfur compounds and can react in the atmosphere to produce SO2. It is expected that the concentration and spread of SO2 emissions from these sources would differ between wet and dry periods. In this research, SO2 emissions from locations representing CAFOs and its dispersion over the southeastern U.S. were simulated through sensitivity experiments using the Weather Research and Forecasting-Chemistry (WRF- Chem) model. Simulations were performed for dry periods and precipitation events that occurred over western Kentucky between July 7 and 13 July 2012. The study found that spatial coverage of SO2 dispersion originating from these locations was reduced during precipitation events and expanded during dry periods. The average concentration of SO2 over the study area was also higher during the breaks between precipitation events than during precipitation. The highest concentrations of SO2 exceeding 1,000 pptv remained within close range of the emission locations for the majority of the simulations, except for when local surface wind speeds were high. Most emissions from the locations remained limited to the surface and lower levels of the atmosphere (850 mb).

The association between gaseous pollutants and non-accidental mortality: a time series study.

To evaluate the effects of gaseous pollutants (SO2, NO2) on non-accidental mortality of residents in Hefei city, we collected non-accidental deaths, air pollutants and meteorological data of Hefei city from 2014 to 2017. After controlling confounding factors with Poisson generalized additive model, we analyzed the relationship between air pollutants and non-accidental mortality and used subgroup analysis to identify susceptible groups. The number of non-accidental deaths during the study period was 42,116, with an average of 28.83 per day. The average concentrations of SO2 and NO2 were 16.08μg/m3 and 39.10μg/m3, respectively. In the single-pollutant model, every 10μg/m3 increase in SO2 and NO2 concentrations was significantly associated with non-accidental mortality, and there was a significant lag effect. SO2 increased the risk of non-accidental death by 4.93% (95% CI: 1.94% ~ 8.00%) at lag0-3. In addition, male, the elderly, non-elderly and low-education people were more susceptible (P < 0.05). NO2 increased the risk of non-accidental death by 2.11% (95% CI: 1.18% ~ 3.05%) at lag0-1 and had an effect on all subgroups (P < 0.05). For every 10μg/m3 increase in SO2 and NO2, the two-pollutant model showed that the risk of non-accidental death, respectively, increased by 3.34% (95% CI: 0.29% ~ 6.50%) and 1.82% (95% CI: 0.85% ~ 2.79%), suggesting that the effect was weakened. Our study suggested that SO2 and NO2 were associated with non-accidental mortality, and there were lag effects. Therefore, environmental management should be strengthened and health protection education should be carried out for different groups.

Assessment of Some Pollutant Gases in Selected Cities in Crude Oil-Rich Delta State Nigeria

Delta state is one of the petroleum-producing states in Nigeria where upstream and downstream exploration activities tend to pollute the environment. While soil and water pollution are regularly monitored, there is a dearth of information on the impact of exploration and related industries on air quality. This study investigated the levels of pollutant gases including ozone, nitrogen dioxide, sulphur dioxide, hydrogen sulphide and ammonia in ambient air samples selected cities (Warri, Ughelli, Sapele and Ugbenu) in Delta state, Nigeria. The concentration of the gases was determined using air sampling instruments equipped with appropriate sensors for selective to each gas. Meteorological parameters were also obtained concurrently during sampling. The results obtained showed that the average concentrations of SO₂, H₂S and NH₃ were all below the National ambient air quality standard (NAAQS) and Federal ministry of environment (FMEnv) regulatory limits. However, the mean concentration of O₃ and NO₂ obtained exceeded the NAAQS and FMEnv regulatory limits of 0.007 ppm, 0.05 ppm and 0.04 ppm – 0.06 ppm respectively. Ugbenu, the control station did not record any value for the pollutant gases. This is as a result of non-availability of industrial activities that emit these pollutant gases in the area. There was a clear seasonal variation, with higher values recorded mostly in the dry season. The field data agreed with global model data on the pollutant gases. The information from this study provides information on the level of these pollutant gases and how the various industrial process may impact their concentration in this region.

Air Quality, Atmospheric Variables and Spread of COVID-19 in Delhi (India): An Analysis

Based on a time series analysis of the criteria pollutants, meteorological parameters, and COVID-19 positive cases, this paper explores the impact of epidemic prevention and control actions on air quality for five different periods of COVID-19 outbreak in Delhi, India. The study found that under the epidemic control measure during 11 May-19 June 2020, the average concentrations of atmospheric air pollutants PM2.5, PM10, NO2, and CO were reduced to 42.15 µg m-3, 128.68 µg m-3, 27.31 ppb, and 0.83 ppm respectively, and were 73.85%, 46.48%, 63.43%, and 50.18% lower than the pre-COVID-19 level of January 2020, respectively. The steep fall of PM2.5, NO2, and CO was due to a drastic reduction in vehicular emission, but PM10 did not fall below the National Ambient Air Quality Standard. Between January 2020 to 11 May -19 June 2020 period, the pollutants O3 and SO2 increased significantly by 217.33% and 57.58 % respectively. The rise of SO2 in Delhi was due to long-distance transfer, power plant emissions, and biomass burning. The sharp increase of O3 happened due to accumulation in the atmosphere. During the peak COVID-19 phase (9 April –10 May 2020) Delhi had unprecedented improved AQI classes of II and III only. However, the pivotal pollutants in terms of their cumulative contribution to the AQI classes were PM10 and O3. Low RH and low-temperature situations exhibited positive correlations with the new COVID-19 infection cases in Delhi. Comparatively lower NO2 level in the air demonstrated a significant negative correlation with new COVID-19 cases while average SO2 concentration in the air, when increased to 24.05 ppb, showed a negative correlation with new COVID-19 cases in Delhi. This study indicated a possibility of O3 exhibiting a positive correlation with new COVID-19 cases under the condition of comparatively low temperature and low humidity.

Multiple Air Quality Monitoring Evidence of the Impacts of Large-scale Social Restrictions during the COVID-19 Pandemic in Jakarta, Indonesia

Air pollution is a top contributor to global mortality. Air quality issues abound in developing Asian countries, but during COVID-19 lockdowns, urban air quality improved due to the reduction in public mobility and fuel consumption. In Indonesia, the Large-Scale Social Restriction (LSSR) program was implemented to prevent the wider spread of COVID-19, especially in large urban areas. It was not a total lockdown program but had the purpose of reducing urban public mobility. This study investigated the effects of social restrictions on air quality in Jakarta, Indonesia. Data were obtained from our long-term monitoring of fine (PM2.5) and coarse particulate matter (PM2.5-10) and compositions collected at a site in South Jakarta. Other data were obtained from the environmental protection agency’s (EPA’s) air quality monitoring station in Central Jakarta including PM10, PM2.5, SO2, NO2, CO, and O3. The aerosol optical depth (AOD) in Jakarta measured by a sun photometer and satellite data were used to assess the spatial distribution of AOD across Jakarta. During the first LSSR implementation period from 15 March to 30 May 2020, there were decreased average SO2, CO, NO, NO2, and NOx concentrations of 40 to 60% compared to the same period in 2019. However, O3 increased by 33% likely due to reduction in NOx emissions. The PM2.5 decline reached ~40%, but a similar decline was not observed for PM10. Elemental and black carbon concentration data showed reductions that ranged from 30% to more than 50%. Consistent with the PM observations, both ground and satellite based AOD showed reductions in the aerosol column burden over the city. The ground based AOD values showed moderate correlations with PM2.5. The results confirmed that significant reduction in public mobility was highly associated with the improvement of local air quality which useful to derive future control strategies.

Sulfur dioxide and exacerbation of allergic respiratory diseases: A time-stratified case-crossover study.

Background:Strong epidemiological evidence suggests that air pollution plays a significant role in the exacerbation of allergic respiratory diseases. This study aimed to assess the potential relationship between daily levels of sulfur dioxide (SO2) and emergency department (ED) visits for allergic diseases.Materials and Methods:Data regarding ED visits for allergic respiratory diseases were routinely collected from the EDs in the Zlatibor district, and the General Hospital, Užice. The daily average concentrations of SO2 were obtained from the regional automatic air quality monitoring stations. All data were collected from June 2012 to July 2014. A time-stratified case-crossover design was used. Crude odds ratios (ORs) and ORs adjusted for weather conditions were calculated using conditional logistic regression.Results:Statistically significant associations were seen between 0-day lagged exposure to SO2 and ED visits for all allergic diseases (OR = 1.62; 95% confidence interval [CI]: 1.05–2.48; P = 0.028) and between 2-day lagged exposure to SO2 and ED visits for asthma with allergic rhinitis (OR = 2.00; 95% CI: 1.03–3.88; P = 0.042). These results were adjusted for temperature, temperature2, and humidity.Conclusion:Our results suggest that short-term exposure to SO2 conferred an increased risk of ED visits for allergic respiratory diseases, particularly for asthma with concomitant allergic rhinitis.

Ambient air pollution and emergency department visits among children and adults in Casablanca, Morocco.

This study presents the relationships between ambient air pollutants and morbidity and emergency department visits among children and adults performed in Great Casablanca, the most populated and economic region in Morocco. This research was analyzed using conditional Poisson model for the period 2011–2013. In the period of study, the daily average concentrations of SO2, NO2, O3 and PM10 in Casablanca were 209.4 µg/m3, 61 µg/m3, 113.2 µg/m3 and 75.1 µg/m3, respectively. In children less than 5 years old, risk of asthma could be increased until 12% per 10 µg/m3 increase in NO2, PM10, SO2 and O3. In children over 5 years and adults, an increase of 10 µg/m3 air pollutant can cause an increase until 3% and 4% in respiratory consultations and acute respiratory infection, respectively. Similarly, impact on emergency department visits due to respiratory and cardiac illness was established. Our results suggest a not negligible impact on morbidity of outdoor air pollution by NO2, SO2, O3, and PM10.

COVID-19 Outbreak in Lombardy, Italy: An Analysis of the Short-Term Role of Air Pollution and Meteorological Factors

Background: Short-term exposure to air pollution, as well as to climate variables could be linked to a higher incidence of respiratory viral diseases. The objective of the study is to assess the short-term impact of air pollution and climate on COVID19 incidence in Lombardy (Italy), during the initial outbreak.Methods: The daily number of COVID19 cases in Lombardy from February 25th to March 10th 2020, and the daily average concentrations of particulate matter (PM10, PM2·5), O3, SO2, and NO2 together with climate variables (temperature, relative humidity – RH%, wind speed, precipitation), were analyzed. A mixed model with a logarithm transformation as link function was applied to evaluate the relationship between all the variables. Additionally, change points (Break Points; BP) in the relationship between incident cases and air pollution or climatic factors were estimated.Findings: The analysis showed a two-phase effect of PM10 on COVID19 incidence, with a negative association at the beginning of the examined period and a positive one later on, while a positive relationship was observed for O3. The COVID19 spread in Lombardy showed to be influenced positively by RH%, and negatively by wind speed. A BP at 40 µg/m3 was observed for PM10 at lag8, and for O3 at lags 3-8 and 10.Interpretation: PM10, O3, RH% and wind speed showed a short-term association with the COVID19 incidence. Air pollution and climate conditions should be considered as part of an integrated approach when containment measures against SARS-CoV-2 are adopted.Funding: The study did not receive any fund.Declaration of Interests: The Authors declare no conflict of interest.

Susceptibility of individuals with chronic obstructive pulmonary disease to respiratory inflammation associated with short-term exposure to ambient air pollution: A panel study in Beijing

BackgroundChronic obstructive pulmonary disease (COPD) is a leading cause of death worldwide. There is no clear evidence of whether COPD patients are more susceptible to respiratory inflammation associated with short-term exposure to air pollutants than those without COPD. ObjectivesThis study directly compared air pollutant-associated respiratory inflammation between COPD patients and healthy controls. MethodsThis study is based on the COPDB panel study (COPD in Beijing). Fractional exhaled nitric oxide (FeNO) was repeatedly measured in 53 COPD patients and 82 healthy controls at up to four clinical visits. Concentrations of carbon monoxide (CO), nitrogen monoxide, nitrogen dioxide (NO2), sulfur dioxide (SO2), fine particulate matter (PM2.5), black carbon (BC), ultrafine particles (UFPs), and accumulated-mode particles (Acc) were monitored continuously at a fixed-site monitoring station. Linear mixed-effects models were used to compare the associations between ln-transformed FeNO and average 1–23 h concentrations of air pollutants before the clinical visits. ResultsFeNO was positively associated with interquartile range (IQR) increases in average concentrations of CO, NO2, SO2, BC, UFPs, and Acc in all participants, with the strongest associations in different time-windows (range from 6.6% for average 1 h NO2 exposure to 32.1% for average 7 h SO2 exposure). Associations between FeNO and average 13–23 h PM2.5 exposure differed significantly according to COPD status. Increases in FeNO associated with average 1–2 h NO exposure were significant in COPD patients (range 8.9–10.2%), while the associations were nonsignificant in healthy controls. Associations between FeNO and average 1–23 h CO and SO2 exposure tended to be higher in COPD patients than in healthy controls, although the differences were not significant. UFPs-associated respiratory inflammation was robust in both subgroups. ConclusionsCOPD patients are more susceptible to respiratory inflammation following PM2.5, NO, CO, and SO2 exposure than individuals without COPD.

Air quality status and trends over large cities in South America

Air pollution is one of the most persistent environmental issues in South America, with exposure to air pollutants being associated with increased mortality and morbidity. According to estimates of the World Health Organization (WHO), in 2016, 91 % of the global population lived in cities that exceeded the WHO PM2.5 annual guideline (10 μg/m3). In Latin America and the Caribbean, other studies affirm that approximately 100 million people are exposed to poor air quality, exceeding WHO guidelines. This study presents a review of long-term (annual) and short-term (daily) concentrations of nitrogen dioxide (NO2), sulfur dioxide (SO2), particulate matter (PM10 and PM2.5), carbon monoxide (CO), and ozone (O3), collected between 2010 and 2017 by the automatic monitoring networks of 11 metropolitan areas of South America, including three of global 33 megacities (Rio de Janeiro, São Paulo, and Buenos Aires), and three from all 34 largest cities in the world (Bogotá, Lima, and Santiago). Despite efforts to monitor air quality, in some cities, the information on air quality provided by environmental authorities still has poor publicity and presentation, making it difficult to take action for critical air pollution episodes. Annual particulate matter (PM2.5 and PM10) monitored in all cities (2010-2017) exceeded the World Health Organization Air Quality Guidelines (WHO-AQG). The annual NO2 guideline was exceeded at least in one city between 2010 and 2017, except in 2014. Most average daily concentrations of SO2 in South America were below the WHO-AQG. Still, Vitória, Rio de Janeiro, and Belo Horizonte Metropolitan Areas presented values over WHO guidelines, and for the two last cities, over intermediate standards of Brazilian national legislation. Most of the ozone concentration (8 -h running average) was below WHO-AQG, but Rio de Janeiro, São Paulo, and Belo Horizonte presented exceedances of this limit between 2010 and 2017. Although some cities in South America have their pollutant concentrations reduced since 2010 (PM2.5, for example), such as São Paulo, Vitória, and Bogotá, the region does not report a trend in the same direction, with the WHO guidelines and national or local standards being continuously exceeded.

Pollutant concentration measurement and emission factor analysis of highway tunnel with mainly HGVs in mountainous area

In recent years, with the rapid growth of traffic flow in highway tunnels, the in-tunnel environmental pollution problem has aroused widespread concern in China. Previous studies mainly focused on the emission factors in tunnels dominated by passenger cars (PCs) and light commercial vehicles (LCVs). However, this study concentrated on the characteristics of traffic flow dominated by heavy-goods vehicles (HGVs), environmental monitoring and assessment in highway tunnels in mountainous areas. To explore the emission characteristics of vehicle pollutants in highway tunnels in such regions, a field measurement was conducted in Qinling No. 3 Tunnel in China, focusing on the traffic volume, air velocity, and pollutant concentration. Measurement results show that the average daily traffic volume in Qinling No. 3 Tunnel is 22,218 pcu/d, with the HGVs comprising more than 65%. The average air velocity in case tunnel reaches 5.09 m/s. The average concentrations of NH3, SO2, CO, and NOx in the tunnel are 4.54 ppm, 0.06 ppm, 6.22 ppm, and 4.39 ppm, respectively. The single vehicle emission rates of measured pollutants are calculated based on collected data, among which, the emission factor of NOx is the largest (average: 9.37 g/(km·veh)), while that of SO2 is the lowest (0.09 g/(km·veh)). The results show that the dilution of NO2 in the tunnel should be considered in the ventilation design of highway tunnels.

Measurement report: Statistical modelling of long-term trends of atmospheric inorganic gaseous species within proximity of the pollution hotspot in South Africa

Abstract. South Africa is considered an important source region of atmospheric pollutants, which is compounded by high population and industrial growth. However, this region is understudied, especially with regard to evaluating long-term trends of atmospheric pollutants. The aim of this study was to perform statistical modelling of SO2, NO2 and O3 long-term trends based on 21-, 19- and 16-year passive sampling datasets available for three South African INDAAF (International Network to study Deposition and Atmospheric Chemistry in Africa) sites located within proximity of the pollution hotspot in the industrialized north-eastern interior in South Africa. The interdependencies between local, regional and global parameters on variances in SO2, NO2 and O3 levels were investigated in the model. Average monthly SO2 concentrations at Amersfoort (AF), Louis Trichardt (LT) and Skukuza (SK) were 9.91, 1.70 and 2.07 µg m−3, respectively, while respective mean monthly NO2 concentrations at each of these sites were 6.56, 1.46 and 2.54 µg m−3. Average monthly O3 concentrations were 50.77, 58.44 and 43.36 µg m−3 at AF, LT and SK, respectively. Long-term temporal trends indicated seasonal and inter-annual variability at all three sites, which could be ascribed to changes in meteorological conditions and/or variances in source contribution. Local, regional and global parameters contributed to SO2 variability, with total solar irradiation (TSI) being the most significant factor at the regional background site LT. Temperature (T) was the most important factor at SK, located in the Kruger National Park, while population growth (P) made the most substantial contribution at the industrially impacted AF site. Air masses passing over the source region also contributed to SO2 levels at SK and LT. Local and regional factors made more substantial contributions to modelled NO2 levels, with P being the most significant factor explaining NO2 variability at all three sites, while relative humidity (RH) was the most important local and regional meteorological factor. The important contribution of P on modelled SO2 and NO2 concentrations was indicative of the impact of increased anthropogenic activities and energy demand in the north-eastern interior of South Africa. Higher SO2 concentrations, associated with lower temperatures, as well as the negative correlation of NO2 levels to RH, reflected the influence of pollution build-up and increased household combustion during winter. The El Niño–Southern Oscillation (ENSO) made a significant contribution to modelled O3 levels at all three sites, while the influence of local and regional meteorological factors was also evident. Trend lines for SO2 and NO2 at AF indicated an increase in SO2 and NO2 concentrations over the 19-year sampling period, while an upward trend in NO2 levels at SK signified the influence of growing rural communities. Marginal trends were observed for SO2 at SK, as well as SO2 and NO2 at LT, while O3 remained relatively constant at all three sites. SO2 and NO2 concentrations were higher at AF, while the regional O3 problem was evident at all three sites.

Inventory and Distribution Characteristics of China's Thermal Power Emissions Under Ultra-Low Reconstruction

This study updates a bottom-up high-resolution emission inventory and estimates the concentrations, emission factors, emissions, and performance values of China's power plants, based on the data from continuous emission monitoring systems and environmental statistics in 2018. The results show that the ultra-low emission policy has significant effects: the average concentrations of SO2, NOx, and PM in thermal power plants were 37.57, 56.71, and 7.41 mg ·m-3, respectively in 2018, which were 58.71%, 43.12%, and 60.79% lower than those in 2015. The average emission factors of SO2, NOx, and PM from coal-fired units in China were 0.3, 0.48, and 0.06 g ·kg-1, respectively, which were 55.2%, 36.84%, and 62.5% lower than those in 2015. The total emissions of SO2, NOx, PM, and PM2.5in thermal power plants were 721.4, 1183.8, 149.0, and 135.9 kt ·a-1, respectively, down by 41.32%, 19.29%, 48.12%, and 40.39% from 2015.

Impacts of nationwide lockdown due to COVID-19 outbreak on air quality in Bangladesh: a spatiotemporal analysis.

In Bangladesh, a nationwide lockdown was imposed on 26 March 2020, due to the COVID-19 pandemic. Due to restricted emissions, it was hypothesized that the air quality has been improved during lockdown throughout the country. The study is intended to assess the impact of nationwide lockdown measures on air quality in Bangladesh. We analyzed satellite data for four different air pollutants (NO2, SO2, CO, and O3) to assess the changes in the atmospheric concentrations of pollutants in major cities as well as across the country. In this study, the concentrations of NO2, SO2, CO, and O3 from 1 February to 30 May of the year 2019 and 2020 were analyzed. The average SO2 and NO2 concentrations were decreased by 43 and 40%, respectively, while tropospheric O3 were found to be increased with a maximum of > 7%. Among the major cities, Dhaka, Gazipur, Chattogram, and Narayanganj were found to be more influenced by the restricted emissions. In Dhaka, NO2 and SO2 concentrations were decreased approximately by 69 and 67%, respectively. Our analysis reveals that NO2 concentrations are highly correlated with the regional COVID-19 cases (r = 0.74). The study concludes that the lockdown measures significantly reduced air pollution because of reduced vehicular and industrial emissions in Bangladesh.Electronic supplementary materialThe online version of this article (10.1007/s11869-020-00940-5) contains supplementary material, which is available to authorized users.