The Episode of National Lockdown in the Pandemic: Air Traffic Restriction as the Control Strategy and Its Impact on Existing Cases and Recovery Rate of Novel Coronavirus Disease in Megacities of China.

OBJECTIVE: The effectiveness of air traffic restriction in containing the spread of infectious diseases is full of controversy in prior literature. In January 2020, the Civil Aviation Administration of China (CAAC) announced air traffic restriction in response to the coronavirus disease (COVID-19) pandemic. This study's aim is to empirically examine the policy effectiveness. METHOD: The data from 2 third-party platforms are used in this investigation. The COVID-19 data from the platform DXY and the air traffic data from Airsavvi are matched to each other. The robust panel regression with controlling city effect and time effect is conducted. RESULTS: The curvilinear relations are found between the air traffic restriction and the existing cases, and the recovery rate (quadratic term = 9.006 and -0.967, respectively). As the strength of air traffic restriction is growing, the negative effect (-8.146) of air traffic restriction on the existing cases and the positive effect (0.961) of air traffic restriction on the recovery rate, respectively, begin decreasing. CONCLUSION: On the macro level, the air traffic restriction may help alleviate the growth of existing cases and help raise the recovery rate of COVID-19 in megacities of China, but both these effects will marginally recede as the restriction strength is intensifying.

Coronavírus: poluição em São Paulo cai 50% com a quarentena

Redução drástica na circulação de veículos, em consequência da quarentena para a contenção do novo coronavírus, teve como resultado a rápida diminuição da poluição atmosférica da cidade: concentração de monóxido de carbono cai cerca de 50% na cidade de São Paulo em uma semana. Os dados da Cetesb foram analisados especialmente para a Agência FAPESP por Maria de Fátima Andrade, professora do Instituto de Astronomia, Geofísica e Ciências Atmosféricas da Universidade de São Paulo (IAG-USP).

Spatiotemporal Variations and Driving Factors of Air Pollution in China.

In recent years, severe and persistent air pollution episodes in China have drawn wide public concern. Based on ground monitoring air quality data collected in 2015 in Chinese cities above the prefectural level, this study identifies the spatiotemporal variations of air pollution and its associated driving factors in China using descriptive statistics and geographical detector methods. The results show that the average air pollution ratio and continuous air pollution ratio across Chinese cities in 2015 were 23.1 ± 16.9% and 16.2 ± 14.8%. The highest levels of air pollution ratio and continuous air pollution ratio were observed in northern China, especially in the Bohai Rim region and Xinjiang province, and the lowest levels were found in southern China. The average and maximum levels of continuous air pollution show distinct spatial variations when compared with those of the continuous air pollution ratio. Monthly changes in both air pollution ratio and continuous air pollution ratio have a U-shaped variation, indicating that the highest levels of air pollution occurred in winter and the lowest levels happened in summer. The results of the geographical detector model further reveal that the effect intensity of natural factors on the spatial disparity of the air pollution ratio is greater than that of human-related factors. Specifically, among natural factors, the annual average temperature, land relief, and relative humidity have the greatest and most significant negative effects on the air pollution ratio, whereas human factors such as population density, the number of vehicles, and Gross Domestic Product (GDP) witness the strongest and most significant positive effects on air pollution ratio.

Socioeconomic Drivers of PM2.5 in the Accumulation Phase of Air Pollution Episodes in the Yangtze River Delta of China.

Recent studies in PM2.5 sources show that anthropogenic emissions are the main contributors to haze pollution. Due to their essential roles in establishing policies for improving air quality, socioeconomic drivers of PM2.5 levels have attracted increasing attention. Unlike previous studies focusing on the annual PM2.5 concentration (Cyear), this paper focuses on the accumulation phase of PM2.5 during the pollution episode (PMAE) in the Yangtze River Delta in China. This paper mainly explores the spatial variations of PMAE and its links to the socioeconomic factors using a geographical detector and simple linear regression. The results indicated that PM2.5 was more likely to accumulate in more developed cities, such as Nanjing and Shanghai. Compared with Cyear, PMAE was more sensitive to socioeconomic impacts. Among the twelve indicators chosen for this study, population density was an especially critical factor that could affect the accumulation of PM2.5 dramatically and accounted for the regional difference. A 1% increase in population density could cause a 0.167% rise in the maximal increment and a 0.214% rise in the daily increase rate of PM2.5. Additionally, industry, energy consumption, and vehicles were also significantly associated with PM2.5 accumulation. These conclusions could serve to remediate the severe PM2.5 pollution in China.

Sourcing methane and carbon dioxide emissions from a small city: Influence of natural gas leakage and combustion.

Natural gas leakage and combustion are major sources of methane (CH4) and carbon dioxide (CO2), respectively; however, our understanding of emissions from cities is limited. We mapped distribution pipeline leakage using a mobile CH4 detection system, and continuously monitored atmospheric CO2 and CH4 concentrations and carbon isotopes (δ13C-CO2 and δ13C-CH4) for one-year above Ithaca, New York. Pipeline leakage rates were low (<0.39 leaks mile-1), likely due to the small extent of cast iron and bare steel within the distribution pipeline system (2.6%). Our atmospheric monitoring demonstrated that the isotopic composition of locally emitted CO2 approached the δ13C range of natural gas combustion in winter, correlating to natural gas power generation patterns at Cornell's Combined Heat and Power Plant located 600 m southeast of the monitoring site. Atmospheric CH4 plumes were primarily of natural gas origin, were observed intermittently throughout the year, and were most frequent in winter and spring. No correlations between the timing of atmospheric natural gas CH4 plumes and Cornell Plant gas use patterns could be drawn. However, elevated CH4 and CO2 concentrations were observed coincident with high winds from the southeast, and the plant is the only major emission source in that wind sector. Our results demonstrate pipeline leakage rates are low in cities with a low extent of leak prone pipe, and natural gas power facilities may be an important source of urban and suburban emissions.

Toxic releases and risk disparity: a spatiotemporal model of industrial ecology and social empowerment.

Information-based regulations (IBRs) are founded on the theoretical premise that public participation in accomplishing policy goals is empowered by open access to information. Since its inception in 1988, the Toxics Release Inventory (TRI) has provided the framework and regulatory impetus for the compilation and distribution of data on toxic releases associated with industrial development, following the tenets of IBR. As TRI emissions are reputed to disproportionately affect low-income communities, we investigated how demographic characteristics are related to change in TRI emissions and toxicity risks between 1989 and 2002, and we sought to identify factors that predict these changes. We used local indicators of spatial association (LISA) maps and spatial regression techniques to study risk disparity in the Los Angeles urban area. We also surveyed 203 individuals in eight communities in the same region to measure the levels of awareness of TRI, attitudes towards air pollution, and general environmental risk. We discovered, through spatial lag models, that changes in gross and toxic emissions are related to community ethnic composition, poverty level, home ownership, and base 1989 emissions (R-square=0.034-0.083). We generated a structural equation model to explain the determinants of social empowerment to act on the basis of environmental information. Hierarchical confirmatory factor analysis (HCFA) supports the theoretical model that individual empowerment is predicted by risk perception, worry, and awareness (Chi-square=63.315, p=0.022, df=42). This study provides strong evidence that spatiotemporal changes in regional-scale environmental risks are influenced by individual-scale empowerment mediated by IBRs.

Enhanced nitrogen deposition over China.

China is experiencing intense air pollution caused in large part by anthropogenic emissions of reactive nitrogen. These emissions result in the deposition of atmospheric nitrogen (N) in terrestrial and aquatic ecosystems, with implications for human and ecosystem health, greenhouse gas balances and biological diversity. However, information on the magnitude and environmental impact of N deposition in China is limited. Here we use nationwide data sets on bulk N deposition, plant foliar N and crop N uptake (from long-term unfertilized soils) to evaluate N deposition dynamics and their effect on ecosystems across China between 1980 and 2010. We find that the average annual bulk deposition of N increased by approximately 8 kilograms of nitrogen per hectare (P < 0.001) between the 1980s (13.2 kilograms of nitrogen per hectare) and the 2000s (21.1 kilograms of nitrogen per hectare). Nitrogen deposition rates in the industrialized and agriculturally intensified regions of China are as high as the peak levels of deposition in northwestern Europe in the 1980s, before the introduction of mitigation measures. Nitrogen from ammonium (NH4(+)) is the dominant form of N in bulk deposition, but the rate of increase is largest for deposition of N from nitrate (NO3(-)), in agreement with decreased ratios of NH3 to NOx emissions since 1980. We also find that the impact of N deposition on Chinese ecosystems includes significantly increased plant foliar N concentrations in natural and semi-natural (that is, non-agricultural) ecosystems and increased crop N uptake from long-term-unfertilized croplands. China and other economies are facing a continuing challenge to reduce emissions of reactive nitrogen, N deposition and their negative effects on human health and the environment.

Mapping out a 'greener' future.

Addressing a 220-strong audience at London's Barts Hospital at the launch of a new NHS Sustainable Development Unit (NHS SDU) publication, Route Map for Sustainable Health, senior NHS and NHS SDU speakers highlighted the magnitude of the challenge faced by the service over the next 5-40 years in meeting its carbon reduction targets, and set out how the new "Route Map" could provide important pointers to help all in the healthcare arena operate more sustainably in the broadest sense. HEJ editor Jonathan Baillie reports.

Increase in tropospheric nitrogen dioxide over China observed from space.

Emissions from fossil fuel combustion and biomass burning reduce local air quality and affect global tropospheric chemistry. Nitrogen oxides are emitted by all combustion processes and play a key part in the photochemically induced catalytic production of ozone, which results in summer smog and has increased levels of tropospheric ozone globally. Release of nitrogen oxide also results in nitric acid deposition, and--at least locally--increases radiative forcing effects due to the absorption of downward propagating visible light. Nitrogen oxide concentrations in many industrialized countries are expected to decrease, but rapid economic development has the potential to increase significantly the emissions of nitrogen oxides in parts of Asia. Here we present the tropospheric column amounts of nitrogen dioxide retrieved from two satellite instruments GOME and SCIAMACHY over the years 1996-2004. We find substantial reductions in nitrogen dioxide concentrations over some areas of Europe and the USA, but a highly significant increase of about 50 per cent-with an accelerating trend in annual growth rate-over the industrial areas of China, more than recent bottom-up inventories suggest.

Accuracy and repeatability of commercial geocoding.

The authors estimated accuracy and repeatability of commercial geocoding to guide vendor selection in the Life Course Socioeconomic Status, Social Context and Cardiovascular Disease study (2001-2002). They submitted 1,032 participant addresses (97% in Maryland, Minnesota, Mississippi, or North Carolina) to vendor A twice over 9 months and measured repeatability as agreement between levels of address matching, discordance (%) between statistical tabulation areas, and median distance (d, in meters) and bearing (theta;, in degrees) between coordinates assigned on each occasion (H(o):Sigma(i)( = 1 -->) (n) [theta;(i) /n] = 180 degrees ). They also submitted 75 addresses of nearby air pollution monitors (77% urban/suburban; 69% residential/commercial) to vendors A and B and then measured accuracy by comparing vendor- and US Environmental Protection Agency (EPA)-assigned geocodes using the above measures. Repeatability of geocodes assigned by vendor A was high (kappa = 0.90; census block group discordance = 5%; d < 1 m; theta; = 177 degrees ). The match rate for EPA monitor addresses was higher for vendor B versus A (88% vs. 76%), but discordance at census block group, tract, and county levels also was, respectively, 1.4-, 1.9-, and 5.0-fold higher for vendor B. Moreover, coordinates assigned by vendor B were further from those assigned by the EPA (d = 212 m vs. 149 m; theta; = 131 degrees vs. 171 degrees ). These findings suggest that match rates, repeatability, and accuracy should be used to guide vendor selection.