scholarly journals Impact of the COVID-19 Pandemic Lockdown on Air Pollution in 20 Major Cities around the World

Atmosphere ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1189
Author(s):  
Franck Fu ◽  
Kathleen L. Purvis-Roberts ◽  
Branwen Williams
Keyword(s):  
Air Quality ◽  
Ground Level ◽  
Transportation Industry ◽  
Asian Countries ◽  
Key Factors ◽  
Commercial Activities ◽  
The World ◽  
Pm2.5 And Pm10 ◽  
The Impact ◽  
Pm2.5 Emissions

In order to fight against the spread of COVID-19, the most hard-hit countries in the spring of 2020 implemented different lockdown strategies. To assess the impact of the COVID-19 pandemic lockdown on air quality worldwide, Air Quality Index (AQI) data was used to estimate the change in air quality in 20 major cities on six continents. Our results show significant declines of AQI in NO2, SO2, CO, PM2.5 and PM10 in most cities, mainly due to the reduction of transportation, industry and commercial activities during lockdown. This work shows the reduction of primary pollutants, especially NO2, is mainly due to lockdown policies. However, preexisting local environmental policy regulations also contributed to declining NO2, SO2 and PM2.5 emissions, especially in Asian countries. In addition, higher rainfall during the lockdown period could cause decline of PM2.5, especially in Johannesburg. By contrast, the changes of AQI in ground-level O3 were not significant in most of cities, as meteorological variability and ratio of VOC/NOx are key factors in ground-level O3 formation.

Law Librarianship and Legal Information Provision in the 21st Century

2008 ◽  
Vol 8 (1) ◽  
pp. 4-10 ◽  
Keyword(s):  
21St Century ◽  
Legal Education ◽  
Legal Profession ◽  
Information Provision ◽  
Key Factors ◽  
Legal Information ◽  
The Past ◽  
The World ◽  
The Future ◽  
The Impact

AbstractIn this analysis of the future of our profession, Barbara Tearle starts by looking at the past to see how much the world of legal information has evolved and changed. She considers the nature of the profession today and then identifies key factors which she believes will be of importance in the future, including the impact of globalisation; the potential changes to the legal profession; technology; developments in legal education; increasing commercialisation and changes to the law itself.

scholarly journals Entrainment and Mixing of Transported Ozone Layers: Implications for Surface Air Quality in the Western U.S.

2020 ◽  
Vol 237 ◽  
pp. 03012
Author(s):  
Christoph Senff ◽  
Andrew Langford ◽  
Raul Alvarez ◽  
Tim Bonin ◽  
Alan Brewer ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Air Quality ◽  
Mixed Layer ◽  
Las Vegas ◽  
Surface Ozone ◽  
Ground Level ◽  
San Joaquin Valley ◽  
Fire Emissions ◽  
Ozone Transport ◽  
The Impact

Recently, two air quality campaigns were conducted in the southwestern United States to study the impact of transported ozone, stratospheric intrusions, and fire emissions on ground-level ozone concentrations. The California Baseline Ozone Transport Study (CABOTS) took place in May – August 2016 covering the central California coast and San Joaquin Valley, and the Fires, Asian, and Stratospheric Transport Las Vegas Ozone Study (FAST-LVOS) was conducted in the greater Las Vegas, Nevada area in May – June 2017. During these studies, nearly 1000 hours of ozone and aerosol profile data were collected with the NOAA TOPAZ lidar. A Doppler wind lidar and a radar wind profiler provided continuous observations of atmospheric turbulence, horizontal winds, and mixed layer height. These measurements allowed us to directly observe the degree to which ozone transport layers aloft were entrained into the boundary layer and to quantify the resulting impact on surface ozone levels. Mixed layer heights in the San Joaquin Valley during CABOTS were generally below 1 km above ground level (AGL), while boundary layer heights in Las Vegas during FAST-LVOS routinely exceeded 3 km AGL and occasionally reached up to 4.5 km AGL. Consequently, boundary layer entrainment was more often observed during FAST-LVOS, while most elevated ozone layers passed untapped over the San Joaquin Valley during CABOTS.

scholarly journals Emission of fine particles (PM2.5) from residential biomass combustion in Croatia and how to reduce it

2020 ◽  
Vol 7 (2) ◽  
pp. 84-94
Author(s):  
Mirela Poljanac
Keyword(s):  
Air Quality ◽  
Human Health ◽  
Urban Areas ◽  
Fine Particles ◽  
Biomass Combustion ◽  
Rural And Urban Areas ◽  
Wood Burning ◽  
Rural And Urban ◽  
The Impact ◽  
Pm2.5 Emissions

Wood burning in residential appliances is very represented in the Republic of Croatia. It is a main or an additional form of heating for many households in rural and urban areas and is therefore an important source of air pollution. The choice of energy and the combustion appliance used in home have a significant impact on PM2.5 emissions. The paper informs the reader about PM2.5 emissions, their main sources and impacts on human health, environment, climate, air quality, and the reason why PM2.5 emissions from residential wood burning are harmful. Paper also gives an overview of spatial PM2.5 emission distribution in Croatia, their five air quality zones and four agglomerations. The paper analyses the sources and their contribution to PM2.5 emissions with the relevance of PM2.5 emissions from residential plants, the use of fuels in residential plants and their contribution to PM2.5 emissions and PM2.5 emissions by fuel combustion technologies in residential sector. Appropriate strategies, policies, and actions to reduce the impact of residential biomass (wood) burning on the environment, air quality and human health are considered.

scholarly journals Exploring Outdoor Solar Potential in High-Density Living: Analyzing Direct Sunlight Duration for Urban Agriculture in Seoul’s Residential Complexes

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2030
Author(s):  
Hyungkyoo Kim ◽  
Kyung Lee ◽  
Jae Lee ◽  
Saewon Lee
Keyword(s):  
South Korea ◽  
Urban Agriculture ◽  
Ground Level ◽  
High Density ◽  
Direct Sunlight ◽  
Residential Developments ◽  
The World ◽  
Feasible Solutions ◽  
The Impact ◽  
Diverse Density

Urban agriculture has become a favored activity in many cities around the world. This study explores how urban agriculture’s potential can be maximized in Seoul, South Korea, a city characterized by high-density residential complexes. It selects six existing residential complexes with representative site typologies and diverse density levels. The study’s aim is to assess the impact of various typology and density settings on percentages of ground-level surface with direct sunlight above certain thresholds during warmer seasons when crops can grow. DIVA-for-Rhino is used for simulation. The findings suggest that parallel typologies and lower density levels offer the best performance, while other combinations show mixed results. This study could benefit citizens and policymakers to facilitate urban agriculture practices around the world by suggesting feasible solutions for high-density residential developments.

scholarly journals COVID-19 and/with dengue infection: A curse in an overburdened healthcare system

2020 ◽  
pp. 004947552097594
Author(s):  
Prateek Kumar Panda ◽  
Indar Kumar Sharawat
Keyword(s):  
Health Care ◽  
Health Care Services ◽  
Emergency Services ◽  
Dengue Infection ◽  
History Taking ◽  
Asian Countries ◽  
Hospital Emergency ◽  
Care Services ◽  
The World ◽  
The Impact

While the world battles to wrestle with the impact of the COVID-19 pandemic, regions with endemic dengue fever are confronting the possibility of a double pandemic that could completely overpower health care services administrations. Simultaneous outbreaks of dengue and COVID-19, as well as probable cases of overlapping infections, have already started in Latin America and certain Asian countries. There, the healthcare framework is already overburdened and such a deadly duo may completely overwhelm hospital emergency services quite apart from a country’s economy. Precise epidemiological and contact history-taking joined with due attention to false-positive dengue serology and the chance of co-infections are key devices for frontline doctors to overcome this seemingly insurmountable challenge.

scholarly journals The Impact of COVID-19 Lockdowns on Air Quality—A Global Review

2021 ◽  
Vol 13 (18) ◽  
pp. 10212
Author(s):  
Abdullah Addas ◽  
Ahmad Maghrabi
Keyword(s):  
Air Quality ◽  
Web Of Science ◽  
Large Numbers ◽  
The World ◽  
The Uk ◽  
Google Search ◽  
The Impact ◽  
Tremendous Impact ◽  
Total Environment ◽  
The U.S

The outbreak of the COVID-19 pandemic has emerged as a serious public health threat and has had a tremendous impact on all spheres of the environment. The air quality across the world improved because of COVID-19 lockdowns. Since the outbreak of COVID-19, large numbers of studies have been carried out on the impact of lockdowns on air quality around the world, but no studies have been carried out on the systematic review on the impact of lockdowns on air quality. This study aims to systematically assess the bibliographic review on the impact of lockdowns on air quality around the globe. A total of 237 studies were identified after rigorous review, and 144 studies met the criteria for the review. The literature was surveyed from Scopus, Google Scholar, PubMed, Web of Science, and the Google search engine. The results reveal that (i) most of the studies were carried out on Asia (about 65%), followed by Europe (18%), North America (6%), South America (5%), and Africa (3%); (ii) in the case of countries, the highest number of studies was performed on India (29%), followed by China (23%), the U.S. (5%), the UK (4%), and Italy; (iii) more than 60% of the studies included NO2 for study, followed by PM2.5 (about 50%), PM10, SO2, and CO; (iv) most of the studies were published by Science of the Total Environment (29%), followed by Aerosol and Air Quality Research (23%), Air Quality, Atmosphere & Health (9%), and Environmental Pollution (5%); (v) the studies reveal that there were significant improvements in air quality during lockdowns in comparison with previous time periods. Thus, this diversified study conducted on the impact of lockdowns on air quality will surely assist in identifying any gaps, as it outlines the insights of the current scientific research.

scholarly journals IMPACT OF COVID-19 EVENT ON AIR POLLUTANTS OF PM2.5 AND PM10 IN JAKARTA, INDONESIA

2021 ◽  
Vol 56 (4) ◽  
pp. 117-140
Author(s):  
Nora Idiawati ◽  
Sepridawati Siregar
Keyword(s):  
Air Quality ◽  
Control Strategies ◽  
Dry Season ◽  
Capital City ◽  
Future Research ◽  
Air Pollution Control ◽  
Wet Season ◽  
Two Cities ◽  
Pm2.5 And Pm10 ◽  
The Impact

As the capital city of Indonesia, the Province of Jakarta encounter a problem seriously of decreasing air quality. This study analyzes the air quality of two cities in Jakarta Province, Central Jakarta and South Jakarta, from March to June 2016–2020, and the impact of COVID-19 epidemic prevention and control actions on air quality. The combined air quality index (AQI) for two cities from 2016–2019, in the wet season, indicated that it has the lowest AQI with an average of 79, and the highest AQI occurred in the dry season with averaged 118. The distribution of the six AQI classes for two cities in dry season were 2%, 24%, 63%, 11%, 0%, and 0%, and in wet season, they were 10%, 48%, 39%, 3%, 0%, and 0%, respectively. The concentrations for PM2.5 and PM10 in March, April, May, and June 2016–2019 and those for 2020 were also analyzed in this study. Based on the data from the two cities, during March, April, May, and June 2020, the average PM2.5 decreased by 23.6%, 39.5%, 41.5%, and 13.3%, respectively, and the average PM10 decreased by 22.2%, 29.9%, 36.9%, and 29.8%, respectively, compared with that in March, April, May, and June 2016–2019. It is obvious that air quality greatly improved during the COVID-19 epidemic. This study presents beneficial information to policymakers for developing scientific air pollution control strategies and is a useful reference for future research in improving urban air quality.

scholarly journals Review and prospect of maintenance technology for traction system of high-speed train

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Shaolong Xu ◽  
Chunyang Chen ◽  
Zhenjun Lin ◽  
Xiao Zhang ◽  
Jisheng Dai ◽  
...  
Keyword(s):  
High Speed ◽  
Research Direction ◽  
Maintenance Cost ◽  
High Speed Train ◽  
Transportation Industry ◽  
Key Factors ◽  
The World ◽  
High Speed Trains ◽  
Oil Crisis ◽  
Traction System

Abstract In the past few decades, high-speed trains have witnessed tremendous and vigorous development with the appearance of the oil crisis and industrialization, which became a significant trend in the transportation industry the world over. With the increase of high-speed railway mileage, the amount of high-speed train has grown sharply, the service life of the trains has increased gradually and the components of the vehicle traction system have become worn and aged as a result. Therefore, advanced maintenance technology and its application are key factors to reduce maintenance cost, human resource input and ensure safe, stable and reliable operation of trains. This paper summarizes and discusses the development, application mode, maintenance management and maintenance technology of high-speed railways of the major countries in the world, especially discusses the condition-based maintenance and the key technology of the traction electrical system, and offers the prospect of research direction and the development of traction maintenance technology.

scholarly journals Impact of Trade Openness on Food Security: Evidence from Panel Data for Central Asian Countries

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3012
Author(s):  
Zhilu Sun ◽  
Defeng Zhang
Keyword(s):  
Food Security ◽  
Panel Data ◽  
Trade Openness ◽  
Generalized Method Of Moments ◽  
Dynamic Panel Data ◽  
Asian Countries ◽  
Central Asian ◽  
The World ◽  
Central Asian Countries ◽  
The Impact

The problem of food insecurity has become increasingly critical across the world since 2015, which threatens the lives and livelihoods of people around the world and has historically been a challenge confined primarily to developing countries, to which the countries of Central Asia, as typical transition countries, cannot be immune either. Under this context, many countries including Central Asian countries have recognized the importance of trade openness to ensure adequate levels of food security and are increasingly reliant on international trade for food security. Using the 2001–2018 panel data of Central Asian countries, based on food security’s four pillars (including availability, access, stability, and utilization), this study empirically estimates the impact of trade openness and other factors on food security and traces a U-shaped (or inverted U-shaped) relationship between trade openness and food security by adopting a panel data fixed effect model as the baseline model, and then conducts the robustness test by using the least-squares (LS) procedure for the pooled data and a dynamic panel data (DPD) analysis with the generalized method of moments (GMM) approach, simultaneously. The results show that: (1) a U-shaped relationship between trade openness and the four pillars of food security was found, which means that beyond a certain threshold of trade openness, food security status tends to improve in Central Asian countries; (2) gross domestic product (GDP) per capita, GDP growth, and agricultural productivity have contributed to the improvement of food security. Employment in agriculture, arable land, freshwater withdrawals in agriculture, population growth, natural disasters, and inflation rate have negative impacts on food security; and (3) this study confirms that trade policy reforms can finally be conducive to improving food security in Central Asian countries. However, considering the effects of other factors, potential negative effects of trade openness, and vulnerability of global food trade network, ensuring reasonable levels of food self-sufficiency is still very important for Central Asian countries to achieve food security. Our research findings can provide scientific support for sustainable food system strategies in Central Asian countries.

scholarly journals Spatial and temporal representativeness of point measurements for nitrogen dioxide pollution levels in cities

2020 ◽  
Author(s):  
Ying Zhu ◽  
Jia Chen ◽  
Xiao Bi ◽  
Gerrit Kuhlmann ◽  
Ka Lok Chan ◽  
...  
Keyword(s):  
Air Quality ◽  
Nitrogen Dioxide ◽  
Satellite Data ◽  
World Health ◽  
Horizontal Distance ◽  
Street Level ◽  
The World ◽  
Mobile Measurements ◽  
The Impact ◽  
Monitoring Stations

Abstract. In many cities around the world the overall air quality is improving, but at the same time nitrogen dioxide (NO2) trends show stagnating values and in many cases could not be reduced below air quality standards recommended by the World Health Organization (WHO). Many large cities have built monitoring stations to continuously measure different air pollutants. While most stations follow defined rules in terms of measurement height and distance to traffic emissions, the question remains, how representative are those point measurements for the city-wide air quality. The question of the spatial coverage of a point measurement is important because it defines the area of influence and coverage of monitoring networks, determines how to assimilate monitoring data into model simulations or compare to satellite data with a coarser resolution, and is essential to assess the impact of the acquired data on public health. In order to answer this question, we combined different measurement data sets consisting of path averaging remote sensing data and in-situ point measurements in stationary and mobile setups from a measurement campaign that took place in Munich, Germany in June and July 2016. We developed an algorithm to strip temporal diversity and spatial patterns in order to construct a consistent NO2 pollution map for Munich. Continuous long-path differential optical absorption spectroscopy (LP DOAS) measurements were complemented with mobile cavity-enhanced (CE) DOAS, chemiluminescence (CL) and cavity attenuated phase shift (CAPS) instruments and were compared to monitoring stations and satellite data. In order to generate a consistent composite map, the LP DOAS diurnal cycle has been used to normalize for the time of the day dependency of the source patterns, so that spatial and temporal patterns can be analyzed separately. The resulting concentration map visualizes pollution hot spots at traffic junctions and tunnel exits in Munich, providing insights into the strong spatial variations. On the other hand, this database is beneficial to the urban planning and the design of control measures of environment pollution. Directly comparing on-street mobile measurements in the vicinity of monitoring stations resulted in a difference of 48 %. For the extrapolation of the monitoring station data to street level, we determined the influence of the measuring height and distance to the street. We found that a measuring height of 4m, at which the Munich monitoring stations measure, results in 16 % lower average concentrations than a measuring height of 1.5 m, which is the height of the inlet of our mobile measurements and a typical pedestrian breathing height. The horizontal distance of most stations to the center of the street of about 6 m also results in an average reduction of 13 % compared to street level concentration. A difference of 21 % in the NO2 concentrations remained, which could be an indication that city-wide measurements are needed for capturing the full range and variability of concentrations for assessing pollutant exposure and air quality in cities.

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