Assessment of Meteorological Variables and Air Pollution Affecting COVID-19 Cases in Urban Agglomerations: Evidence from China

The 2019 novel coronavirus disease (COVID-19) has become a severe public health and social problem worldwide. A limitation of the existing literature is that multiple environmental variables have not been frequently elaborated, which is why the overall effect of the environment on COVID-19 has not been conclusive. In this study, we used generalized additive model (GAM) to detect the relationship between meteorological and air pollution variables and COVID-19 in four urban agglomerations in China and made comparisons among the urban agglomerations. The four urban agglomerations are Beijing-Tianjin-Hebei (BTH), middle reaches of the Yangtze River (MYR), Yangtze River Delta (YRD), and the Pearl River Delta (PRD). The daily rates of average precipitation, temperature, relative humidity, sunshine duration, and atmospheric pressure were selected as meteorological variables. The PM2.5, PM10, sulfur dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), and carbon monoxide (CO) contents were selected as air pollution variables. The results indicated that meteorological and air pollution variables tended to be significantly correlated. Moreover, the nature of the relationship between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and meteorological and air pollution variables (i.e., linear or nonlinear) varied with urban agglomerations. Among the variance explained by GAMs, BTH had the highest value (75.4%), while MYR had the lowest value (35.2%). The values of the YRD and PRD were between the above two, namely 45.6% and 62.2%, respectively. The findings showed that the association between SARS-CoV-2 and meteorological and air pollution variables varied in regions, making it difficult to obtain a relationship that is applicable to every region. Moreover, this study enriches our understanding of SARS-CoV-2. It is required to create awareness within the government that anti-COVID-19 measures should be adapted to the local meteorological and air pollution conditions.

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Integrating Sustainability Assessment into Decoupling Analysis: A Focus on the Yangtze River Delta Urban Agglomerations

Sustainability ◽

10.3390/su12197872 ◽

2020 ◽

Vol 12 (19) ◽

pp. 7872

Author(s):

Yijia Huang ◽

Jiaqi Zhang ◽

Jinqun Wu

Keyword(s):

Environmental Sustainability ◽

Yangtze River ◽

Sustainability Assessment ◽

Yangtze River Delta ◽

River Delta ◽

The Yangtze River ◽

Urban Agglomerations ◽

Decoupling Analysis ◽

The Yrd ◽

The Yangtze River Delta

Rapid urbanization has led to a growing number of environmental challenges in large parts of China, where the Yangtze River Delta (YRD) urban agglomerations serve as a typical example. To evaluate the relationship between environmental sustainability gaps and urbanization in 26 cities of the YRD, this study revisited the environmental sustainability assessment (ESA) by combining the metrics of environmental footprints and planetary boundaries at the city level, and then integrated the footprint-boundary ESA framework into decoupling analysis. The results demonstrated considerable spatiotemporal heterogeneity in the environmental sustainability of water use, land use, carbon emissions, nitrogen emissions, phosphorus emissions and PM2.5 emissions across the YRD cities during the study period 2007–2017. Decoupling analysis revealed a positive sign that more than half of the 26 cities had achieved the decoupling of each category of environmental sustainability gaps from urbanization since 2014, especially for nitrogen and phosphorus emissions. On the basis of ESA and decoupling analysis, all the cities were categorized into six patterns, for which the optimal pathways towards sustainable development were discussed in depth. Our study will assist policy makers in formulating more tangible and differentiated policies to achieve decoupling between environmental sustainability gaps and urbanization.

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Ozone and fine particle in the western Yangtze River Delta: an overview of 1 yr data at the SORPES station

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-5813-2013 ◽

2013 ◽

Vol 13 (11) ◽

pp. 5813-5830 ◽

Cited By ~ 198

Author(s):

A. J. Ding ◽

C. B. Fu ◽

X. Q. Yang ◽

J. N. Sun ◽

L. F. Zheng ◽

...

Keyword(s):

Air Pollution ◽

Air Quality ◽

Yangtze River ◽

Eastern China ◽

Ambient Air ◽

Yangtze River Delta ◽

River Delta ◽

Control Measures ◽

Transport Pathway ◽

The Yrd

Abstract. This work presents an overview of 1 yr measurements of ozone (O3) and fine particular matter (PM2.5) and related trace gases at a recently developed regional background site, the Station for Observing Regional Processes of the Earth System (SORPES), in the western part of the Yangtze River Delta (YRD) in eastern China. Ozone and PM2.5 showed strong seasonal cycles but with contrast patterns: O3 reached a maximum in warm seasons but PM2.5 in cold seasons. Correlation analysis suggests a VOC-sensitive regime for O3 chemistry and a formation of secondary aerosols under conditions of high O3 in summer. Compared with the National Ambient Air Quality Standards in China, our measurements report 15 days of O3 exceedance and 148 days of PM2.5 exceedance during the 1 yr period, suggesting a severe air pollution situation in this region. Case studies for typical O3 and PM2.5 episodes demonstrated that these episodes were generally associated with an air mass transport pathway over the mid-YRD, i.e., along the Nanjing–Shanghai axis with its city clusters, and showed that synoptic weather played an important role in air pollution, especially for O3. Agricultural burning activities caused high PM2.5 and O3 pollution during harvest seasons, especially in June. A calculation of potential source contributions based on Lagrangian dispersion simulations suggests that emissions from the YRD contributed to over 70% of the O3 precursor CO, with a majority from the mid-YRD. North-YRD and the North China Plain are the main contributors to PM2.5 pollution in this region. This work shows an important environmental impact from industrialization and urbanization in the YRD region, and suggests an urgent need for improving air quality in these areas through collaborative control measures among different administrative regions.

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Ambient PM2.5 Estimates and Variations during COVID-19 Pandemic in the Yangtze River Delta Using Machine Learning and Big Data

Remote Sensing ◽

10.3390/rs13081423 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1423

Author(s):

Debin Lu ◽

Wanliu Mao ◽

Lilin Zheng ◽

Wu Xiao ◽

Liang Zhang ◽

...

Keyword(s):

Machine Learning ◽

Air Pollution ◽

Big Data ◽

Yangtze River ◽

Regression Models ◽

Yangtze River Delta ◽

River Delta ◽

The Yangtze River ◽

The Yrd ◽

The Yangtze River Delta

The lockdown of cities in the Yangtze River Delta (YRD) during COVID-19 has provided many natural and typical test sites for estimating the potential of air pollution control and reduction. To evaluate the reduction of PM2.5 concentration in the YRD region by the epidemic lockdown policy, this study employs big data, including PM2.5 observations and 29 independent variables regarding Aerosol Optical Depth (AOD), climate, terrain, population, road density, and Gaode map Point of interesting (POI) data, to build regression models and retrieve spatially continuous distributions of PM2.5 during COVID-19. Simulation accuracy of multiple machine learning regression models, i.e., random forest (RF), support vector regression (SVR), and artificial neural network (ANN) were compared. The results showed that the RF model outperformed the SVR and ANN models in the inversion of PM2.5 in the YRD region, with the model-fitting and cross-validation coefficients of determination R2 reached 0.917 and 0.691, mean absolute error (MAE) values were 1.026 μg m−3 and 2.353 μg m−3, and root mean square error (RMSE) values were 1.413 μg m−3, and 3.144 μg m−3, respectively. PM2.5 concentrations during COVID-19 in 2020 have decreased by 3.61 μg m−3 compared to that during the same period of 2019 in the YRD region. The results of this study provide a cost-effective method of air pollution exposure assessment and help provide insight into the atmospheric changes under strong government controlling strategies.

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Air quality and emissions in the Yangtze River Delta, China

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-10-23657-2010 ◽

2010 ◽

Vol 10 (10) ◽

pp. 23657-23703

Author(s):

L. Li ◽

C. H. Chen ◽

C. Huang ◽

Y. J. Wang ◽

H. Y. Huang ◽

...

Keyword(s):

Air Pollution ◽

Air Quality ◽

Yangtze River ◽

Yangtze River Delta ◽

River Delta ◽

Pollution Monitoring ◽

The Yangtze River ◽

Monthly Average ◽

The Yrd ◽

The Yangtze River Delta

Abstract. Regional trans-boundary air pollution has become an important issue in the field of air pollution modeling. This paper presents the results of the implementation of the MM5-CMAQ modeling system in the Yangtze River Delta (YRD) for the months of January and July of 2004. The meteorological parameters are obtained by using the MM5 model. A new regional emission inventory with spatial and temporal allocations based on local statistical data has been developed to provide input emissions data to the MM5-CMAQ modeling system. The pollutant concentrations obtained from the MM5-CMAQ modeling system have been compared with observational data from the national air pollution monitoring network. It is found that air quality in winter in the YRD is generally worse than in summer, due mainly to unfavorable meteorological dispersion conditions. In winter the pollution transport from Northern China to the YRD reinforces the pollution caused by large local emissions. The monthly average concentration of SO2 in the YRD is 0.026 ± 0.011 mg m−3 in January and 0.017 ± 0.009 mg m−3 in July. Monthly average concentrations of NO2 in the YRD in January and July are 0.021 ± 0.009 mg m−3, and 0.014 ± 0.008 mg m−3 respectively. Visibility is also a problem, with average deciview values of 26.4 ± 2.95 dcv in winter and 17.6 ± 3.3 dcv in summer. The ozone concentration in the downtown area of a city like Zhoushan can be very high, with the highest simulated value reaching 107 ppb. Our results show that ozone and haze have become extremely important issues in the regional air quality. Thus, regional air pollution control is urgently needed to improve air quality in the YRD.

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The Moderating Effect of Innovation on the Relationship between Urbanization and CO2 Emissions: Evidence from Three Major Urban Agglomerations in China

Sustainability ◽

10.3390/su11061633 ◽

2019 ◽

Vol 11 (6) ◽

pp. 1633 ◽

Cited By ~ 6

Author(s):

Yanwen Sheng ◽

Yi Miao ◽

Jinping Song ◽

Hongyan Shen

Keyword(s):

Co2 Emissions ◽

Spillover Effect ◽

Yangtze River Delta ◽

River Delta ◽

Policy Implications ◽

Spatial Spillover ◽

Urban Agglomerations ◽

The Yrd ◽

The Relationship ◽

Spatial Spillover Effect

This study investigates the relationship between urbanization, innovation, and CO2 emissions, with particular attention paid to the issue of how innovation influences the effect of urbanization on CO2 emissions in urban agglomerations, considering the spatial spillover effect between cities. Therefore, based on panel data on 48 cities in the three major urban agglomerations in China from 2001–2015, a spatial econometric model is used to estimate the effect of urbanization and innovation on CO2 emissions. The empirical results indicate that the relationship between urbanization and CO2 emissions follows a U-shaped curve in the Beijing-Tianjin-Hebei (BTH), an N-shaped curve in the Yangtze River Delta (YRD) and an inverted N-shaped pattern in the Pearl River Delta (PRD). Additionally, innovation shows a significantly positive effect on reducing CO2 emissions in the YRD, but does not exert a significantly direct effect on CO2 emissions in the BTH and the PRD. More importantly, innovation played an important moderating role between urbanization and CO2 emissions in the YRD and PRD, suggesting that reducing the positive impacts of urbanization on CO2 emissions depends on innovative development. In addition, urban CO2 emissions presented a clearly negative spatial spillover effect among the cities in the three urban agglomerations. These findings and the following policy implications will contribute to reducing CO2 emissions.

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The Modeling Study about Impacts of Emission Control Policies for Chinese 14th Five-Year Plan on PM2.5 and O3 in Yangtze River Delta, China

Atmosphere ◽

10.3390/atmos13010026 ◽

2021 ◽

Vol 13 (1) ◽

pp. 26

Author(s):

Zhen Li ◽

Shaocai Yu ◽

Mengying Li ◽

Xue Chen ◽

Yibo Zhang ◽

...

Keyword(s):

Air Pollution ◽

Yangtze River ◽

Model Simulation ◽

Emission Control ◽

Yangtze River Delta ◽

River Delta ◽

Chinese Government ◽

Control Policies ◽

Simulation Results ◽

The Yrd

The Chinese government has made great efforts to combat air pollution through the reductions in SO2, NOx and VOCs emissions, as part of its socioeconomic Five-Year Plans (FYPs). China aims to further reduce the emissions of VOCs and NOx by 10% in its upcoming 14th FYP (2021–2025). Here, we used a regional chemical transport model (e.g., WRF/CMAQ) to examine the responses of PM2.5 and O3 to emission control policies of the 14th FYP in the Yangtze River Delta (YRD) region. The simulation results under the 4 emission control scenarios in the 2 winter months in 2025 indicate that the average concentrations of city mean PM2.5 in 41 cities in the YRD were predicted to only decrease by 10% under both S1 and S1_E scenarios, whereas the enhanced emission control scenarios (i.e., S2_E and S3_E) could reduce PM2.5 in each city by more than 20%. The model simulation results for O3 in the 3 summer months in 2025 show that the O3 responses to the emission controls under the S1 and S1_E scenarios show different control effects on O3 concentrations in the YRD with the increase and decrease effects, respectively. The study found that both enhanced emission control scenarios (S2_E and S3_E) could decrease O3 in each city by more than 20% with more reductions in O3 under the S3_E emission control scenario because of its higher control strengths for both NOx and VOCs emissions. It was found that emission reduction policies for controlling high emission sectors of NOx and VOCs such as S2_E and S3_E were more effective for decreasing both PM2.5 and O3 in the YRD. This study shows that O3 controls will benefit from well-designed air pollution control strategies for reasonable control ratios of NOx and VOCs emissions.

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Ozone and fine particle in the western Yangtze River Delta: an overview of 1-yr data at the SORPES station

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-13-2835-2013 ◽

2013 ◽

Vol 13 (1) ◽

pp. 2835-2876 ◽

Cited By ~ 2

Author(s):

A. J. Ding ◽

C. B. Fu ◽

X. Q. Yang ◽

J. N. Sun ◽

L. F. Zheng ◽

...

Keyword(s):

Air Pollution ◽

Air Quality ◽

Yangtze River ◽

Ambient Air ◽

Yangtze River Delta ◽

River Delta ◽

Control Measures ◽

Transport Pathway ◽

The North ◽

The Yrd

Abstract. This work presents an overview of 1-yr measurements of ozone (O3) and fine particular matter (PM2.5) and related trace gases at a recently developed regional background site, the Station for Observing Regional Processes of the Earth System (SORPES), in the western part of the Yangtze River Delta (YRD) in East China. O3 and PM2.5 showed distinguished seasonal cycles but with contrast patterns: O3 reached a maximum in warm seasons but PM2.5 in cold seasons. Correlation analysis suggests a VOC-sensitive regime for O3 chemistry and also indicates a substantial formation of secondary aerosols under conditions of high O3 in summer. Compared with the National Ambient Air Quality Standards in China, our measurements report 15 days of O3 exceedance and 148 days of PM2.5 exceedance during the 1-yr period, suggesting a severe air pollution situation in this region. Case studies for typical O3 and PM2.5 episodes demonstrated that these episodes were generally associated with an air mass transport pathway over the mid-YRD, i.e. along the Nanjing-Shanghai axis with its city clusters, and showed that synoptic weather played an important role in air pollution, especially for O3. Agricultural burning activities caused high PM2.5 and O3 pollution during harvest seasons, especially in June. A calculation of potential source contributions based on Lagrangian dispersion simulations suggests that emissions from the YRD contributed to over 70% of the O3 precursor CO, with a majority from the middle-YRD. North-YRD and the North China Plain are the main contributors to PM2.5 pollution in this region, especially for the burning episode days. This work shows an important environmental impact from industrialization and urbanization in the YRD region, and suggests an urgent need for improving air quality in these areas through collaborative control measures among different administrative regions.

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Air quality and emissions in the Yangtze River Delta, China

Atmospheric Chemistry and Physics ◽

10.5194/acp-11-1621-2011 ◽

2011 ◽

Vol 11 (4) ◽

pp. 1621-1639 ◽

Cited By ~ 107

Author(s):

L. Li ◽

C. H. Chen ◽

J. S. Fu ◽

C. Huang ◽

D. G. Streets ◽

...

Keyword(s):

Air Pollution ◽

Air Quality ◽

Yangtze River ◽

Yangtze River Delta ◽

Average Concentration ◽

River Delta ◽

The Yangtze River ◽

Monthly Average ◽

The Yrd ◽

The Yangtze River Delta

Abstract. Regional trans-boundary air pollution has become an important issue in the field of air pollution modeling. This paper presents the results of the implementation of the MM5-CMAQ modeling system in the Yangtze River Delta (YRD) for the months of January and July of 2004. The meteorological parameters are obtained by using the MM5 model. A new regional emission inventory with spatial and temporal allocations based on local statistical data has been developed to provide input emissions data to the MM5-CMAQ modeling system. The pollutant concentrations obtained from the MM5-CMAQ modeling system have been compared with observational data from the national air pollution monitoring network. It is found that air quality in winter in the YRD is generally worse than in summer, due mainly to unfavorable meteorological dispersion conditions. In winter, the pollution transport from Northern China to the YRD reinforces the pollution caused by large local emissions. The monthly average concentration of SO2 in the YRD is 0.026 ± 0.011 mg m−3 in January and 0.017 ± 0.009 mg m−3 in July. Monthly average concentrations of NO2 in the YRD in January and July are 0.021 ± 0.009 mg m−3, and 0.014 ± 0.008 mg m−3, respectively. The monthly average concentration of PM10 in the YRD is 0.080 ± 0.028 mg m−3 in January and 0.025 ± 0.015 mg m−3 in July. Visibility is also a problem, with average deciview values of 26.4 ± 2.95 dcv in winter and 17.6 ± 3.3 dcv in summer. The ozone concentration in the downtown area of a city like Zhoushan can be very high, with the highest simulated value reaching 0.24 mg m−3. In January, the monthly average concentration of O3 in the YRD is 0.052 ± 0.011 mg m−3, and 0.054 ± 0.008 mg m−3 in July. Our results show that ozone and haze have become extremely important issues in the regional air quality. Thus, regional air pollution control is urgently needed to improve air quality in the YRD.

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Decoupling Analysis between Economic Growth and Air Pollution in Key Regions of Air Pollution Control in China

Sustainability ◽

10.3390/su13126600 ◽

2021 ◽

Vol 13 (12) ◽

pp. 6600

Author(s):

Jing Li ◽

Lipeng Hou ◽

Lin Wang ◽

Lina Tang

Keyword(s):

Economic Growth ◽

Air Pollution ◽

Economic Development ◽

Pollution Control ◽

Environmental Policies ◽

River Delta ◽

Chinese Government ◽

Air Pollution Control ◽

The Relationship ◽

No2 Pollution

The Chinese government has implemented a number of environmental policies to promote the continuous improvement of air quality while considering economic development. Scientific assessment of the impact of environmental policies on the relationship between air pollution and economic growth can provide a scientific basis for promoting the coordinated development of these two factors. This paper uses the Tapio decoupling theory to analyze the relationship between regional economic growth and air pollution in key regions of air pollution control in China—namely, the Beijing–Tianjin–Hebei region and surrounding areas (BTHS), the Yangtze River Delta (YRD), and the Pearl River Delta (PRD)—based on data of GDP and the concentrations of SO2, PM10, and NO2 for 31 provinces in China from 2000 to 2019. The results show that the SO2, PM10, and NO2 pollution in the key regions show strong and weak decoupling. The findings additionally indicate that government policies have played a significant role in improving the decoupling between air pollution and economic development. The decoupling between economic growth and SO2 and PM10 pollution in the BTHS, YRD, and PRD is better than that in other regions, while the decoupling between economic growth and NO2 pollution has not improved significantly in these regions. To improve the relationship between economic growth and air pollution, we suggest that the governments of China and other developing countries should further optimize and adjust the structure of industry, energy, and transportation; apply more stringent targets and measures in areas of serious air pollution; and strengthen mobile vehicle pollution control.

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