Air Quality In China Research Articles

Estimation of carbon sequestration potential and air quality impacts of biochar production from straw in China

Aiming to optimize straw resource utilization and to reduce air pollutant and greenhouse gas emissions in China, the environmental benefits of biochar production using straw and utilization need to be assessed. Two biochar production scenarios were studied: centralized production scenario (CPS) utilizing an industrialized production method with advanced air pollution control devices, and decentralized production scenario (DPS) based on a distributed production method of biochar at the village level, compared to an open-burning scenario (OBS). The potential GHG emission reductions under DPS, including the benefit of soil biochar application, were evaluated as 680 Tg CO2-eq yr-1, which was lower than the reductions under CPS (780 Tg CO2-eq yr-1). Although the attentional centralized production method of biochar has more potential environmental benefits, at present the distributed production method is more practical in China due to its convenience, management ease, and lower costs. Modeling on air quality in China showed that in comparison with OBS, DPS could reduce the average monthly PM2.5 concentration of key regions by 19%, and about 190 Tg yr-1 biochar could be produced with 150 Tg C yr-1 sequestered in biochar. Our findings support widespread biochar use in China for improved air quality and climate neutrality.

Maximizing the net economic benefits of regulating indoor air quality in China

The WHO guideline levels for indoor air pollutants (IAPs) are based solely on health considerations. Attaining these levels may cost a disproportionate fraction of available public heath funds. To maximize the net economic benefit (NEB, = benefits - costs) of controlling IAPs, we develop a method based upon a new concept, optimal control concentration (OCC). For China, the estimated OCCs for indoor PM2.5 and formaldehyde in residences are 15 μg/m3 and 25 μg/m3, respectively. The estimated NEB achieved by controlling IAPs to their OCCs is almost 500 billion CNY a year, much greater than that of meeting the WHO guidelines (a negative NEB) and two Chinese standards (a negative NEB and about 200 billion CNY). Our method can be used by other countries to cost-effectively control IAPs.

Heterogeneity of population exposure to particulate matter pollution and its socioeconomic driving mechanism in Shaanxi Province, China

The rapid pace of economic and social development has led to a surge of particulate matter (PM) pollution incidents, which is detrimental to human health. Air quality in China has improved in recent years, but differences in PM exposure remain due to spatial heterogeneity in pollution and population. The identification of socioeconomic factors associated with PM pollution has attracted widespread attention. Current research predominantly targets cities, overlooking regional and county scale disparities. An analytical framework is established to evaluate the spatial heterogeneity in PM exposure and to identify the socioeconomic factors contributing to its pollution. The results revealed that: (1) the Theil index increased from 0.06 to 0.12, indicating a gradual increase in the inequality of PM exposure in Shaanxi Province. The differences within the Guanzhong Plain are obvious and the interregional differences substantially outweigh the intraregional variations. (2) Energy transition is pivotal in curbing air pollution in a region and economic growth consistently fuels particulate emissions. (3) For effective pollution mitigation, further emphasis on vegetation preservation and environmental inputs is imperative. The findings of this research provide decision support for optimizing air pollution control measures at the county scale.

Air Quality Benefits of Renewable Energy: Evidence from China’s Renewable Energy Heating Policy

This paper examines the impact of renewable energy heating on air quality in China, using the Qinling Mountains–Huaihe River line as a quasi-natural experiment to distinguish between regions with central heating and those without. Employing a difference-in-differences approach and analyzing panel data from 298 cities between 2014 and 2022, our findings indicate that the renewable energy heating policy has significantly improved air quality. Specifically, the policy led to substantial improvements in air quality, reducing concentrations of key pollutants: SO2 by 28.31%, CO by 7.57%, NO2 by 5.72%, and PM2.5 by 7.15%. The policy’s effects are most pronounced in regions with lower temperatures and in the eastern parts of the country. Further analysis emphasizes the critical role of energy transition, environmental regulations, and government investment in technology as key drivers of these air quality improvements.

Exploring the short-term effects of extreme temperatures on tuberculosis incidence in Shantou, China: a Coastal City perspective.

Coastal cities, due to their proximity to coastlines and unique climatic conditions, face growing challenges from extreme temperature events associated with climate change. Research on the impact of extreme temperatures on tuberculosis (TB) in these cities is limited, and findings from different regions lack consensus. This study focuses on Shantou, a coastal city in China, to investigate the influence of extreme temperatures on TB within this distinctive geographical context. Distributed Lag Non-Linear Models (DLNM) were employed to evaluate the effect of extreme temperatures on TB incidence risk in Shantou, a coastal city in China, spanning from 2014 to 2021. Daily TB case data were provided by the Shantou Tuberculosis Prevention and Control Institute. Daily meteorological information was sourced from the Reliable Prognosis website, while daily air pollutant data were obtained from the China Air Quality Online Monitoring and Analysis Platform. The study revealed a significant association between extreme temperatures and TB incidence, with the impact peaking at a lag of 27 days after exposure. Notably, extreme cold temperatures led to a temporary decrease in TB incidence with a lag of 1-2 days. Subgroup analysis indicated that males had a notably higher risk of TB under extreme temperature conditions compared to females. Additionally, individuals aged 65 years and above showed a significant cumulative effect in such conditions. This research enhances our comprehension of the effects of extreme temperatures on TB in coastal cities and carries substantial public health implications for TB prevention in China.

Rectifying local governments’ strategic environmental enforcement: Can refined air pollution monitoring enhance local air quality in China?

Insufficient local environmental enforcement has become a pivotal economic and political concern in China. In 2017, the Chinese central government introduced the Air Pollution Hot-Spot Grid (APHG) monitoring program. However, little is known about the consequences. This study investigates in detail how this monitoring program affects city-level air pollution by applying the difference-in-differences method. This program was responsible for a notable decrease in air pollution at the city level. This decrease was mostly the result of stronger local environmental governance, advances in green innovation, and an upgraded industrial structure. Additionally, an examination of heterogeneous treatment effects across different cities revealed that the most substantial effects were observed in large, non-resource-based, and eastern cities. Additional analysis reveals the presence of a spillover effect, whereby the adoption of this program in one city helps reduce air pollution in nearby cities. These results highlight the significance of refined air pollution monitoring for addressing imperfect local environmental enforcement.

Vehicle exhaust standards and urban air quality in China

This study quantifies the effects of increasing the share of low-emission passenger vehicles on urban air quality in China. We estimate a two-stage least squares model, using the phased implementation of National Vehicle Emission Standards VI in 2019 as an instrumental variable for fleet composition. Our findings indicate that a 1% increase in the share of vehicles compliant with the stricter vehicle exhaust standards leads to a 0.083% reduction in the average pollutant concentration across three measures of air pollution. Furthermore, our calculation suggests that the monetized health benefits from reductions in particulate matter outweigh the costs of adhering to stricter exhaust standards by a factor of two.

Detecting atmospheric oxidation in the PM2.5 and ozone multilayer complex network

Abstract Reducing the levels of Fine particulate matter (PM2.5) and ozone (O3) is essential for further improving air quality in China. The intricate and non-linear interactions between PM2.5 and O3 on a national scale over long-term records are not well understood. Here, we proposed a novel multi-layer network approach to bridge the gap. Our findings reveal that the variability of O3 precedes that of PM2.5 by one day. The degree, weighted degree, and edge distance follow a power-law decay distribution, suggesting that their relationship is not a random process. O3 concentration in the Yangtze River Delta (YRD) region and eastern Shandong Province significantly impacts the PM2.5 levels in surrounding areas. Conversely, PM2.5 concentrations in Shandong Province, Henan Province, YRD and Pearl River Delta (PRD) have a strong influence on O3 levels. Moreover, we quantified the seasonality of the interactions and elucidated the underlying reasons. The results revealed the interactions between PM2.5 and O3 are intricately tied to atmospheric oxidation processes. More specifically, in summer, the atmospheric oxidation has a strong impact on the interactions in key regions, such as the Beijing–Tianjin–Hebei,YRD region and Fenwei Plain. However, the PRD region experiences a more pronounced effect from atmospheric oxidation on this relationship in winter. These findings demonstrate that it is crucial to effectively regulate atmospheric oxidation to mitigate PM2.5 and O3. Our results also serve as a valuable methodological framework for understanding the characteristics of pollutants.

Digital finance policy and the challenge of air pollution in China

This study investigates the influence of digital finance tools on air quality in China from 1990 to 2020 using the cross-sectional augmented autoregressive distributed lag approach. The findings underscore the critical role of digital finance, especially internet banking, in reducing air pollution levels. The increased adoption of internet banking is linked to lower vehicular emissions and more efficient financial operations, aiding environmental preservation. Similarly, ATM banking is found to negatively correlate with air pollution, though to a lesser extent. In contrast, coal consumption, urban population growth, and inflation are positively associated with air pollution, highlighting the necessity for sustainable urban planning and energy transition policies. To combat air pollution, it is essential to utilize digital finance tools, broaden digitalization across various sectors, and employ AI and big data for precise interventions. Supporting green financial tools can help fund renewable energy projects, speeding up China’s shift to a low-carbon economy and mitigating the harmful effects of air pollution.

The spatial effects of innovation agglomeration on air quality in China: from the perspective of industrial development

ABSTRACT This study aims to explore the impact of innovation agglomeration on air pollution and industrial transformation within the context of China’s green development transition. We developed a general equilibrium model to theoretically explore these effects and employed an econometric analysis using panel data from 284 prefecture-level cities in China between 2005 and 2019 to empirically validate our findings. The main results are as follows: (1) Innovation agglomeration can significantly improve air quality, with a strong spatial spillover effect. (2) Innovation agglomeration can significantly promote transformation and upgrading of industrial structure, and it may also lead to the convergence of some industrial structures. Moreover, industrial structure transformation and upgrading partially mediates the relationship between innovation agglomeration and air pollution. (3) There is a nonlinear relationship between innovation agglomeration and air pollution. As industrial complementarity is developed, the effect of innovation agglomeration on air pollution enhances. These findings suggest that fostering innovation clusters and encouraging industrial diversification are key policy strategies for achieving sustainable urban development and improving environmental outcomes.

Spatial source, simulating improvement, and short-term health effect of high PM2.5 exposure during mutation event in the key urban agglomeration regions in China

Air quality in China has significantly improved owing to the effective implementation of pollution control measures. However, mutation events caused by short-term spikes in PM2.5 in urban agglomeration regions continue to occur frequently. Identifying the spatial sources and influencing factors, as well as improving the prediction accuracy of high PM2.5 during mutation events, are crucial for public health. In this study, we firstly introduced discrete wavelet transform (DWT) to identify the mutation events with high PM2.5 concentration in the four key urban agglomerations, and evaluated the spatial sources for the polluted scenario using Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model. Additionally, DWT was combined with a widely used artificial neural network (ANN) to improve the prediction accuracy of PM2.5 concentration seven days in advance (seven-day forecast). Results indicated that mutation events commonly occurred in the northern regions during winter time, which were under the control of both short-range transportation of dirty airmass as well as negative meteorology conditions. Compared with the ANN model alone, the average band errors decreased by 9% when using DWT-ANN model. The average correlation coefficient (R) and root mean square error (RMSE) obtained using the DWT-ANN improved by 10% and 12% compared to those obtained using the ANN, indicating the efficiency and accuracy of simulating PM2.5, by combining the DWT and ANN. The short-term mortality during mutation events was then calculated, with the total averted all-cause, cardiovascular, and respiratory deaths in the four regions, being 4751, 2554, and 582 persons, respectively. A declining trend in prevented deaths from 2018 to 2020 demonstrated that the pollution intensity during mutation events gradually decreased owing to the implementation of the Three-Year Action Plan to Win the Blue Sky Defense War. The method proposed in this study can be used by policymakers to take preventive measures in response to a sudden increase in PM2.5, thereby ensuring public health.

Sources and Specified Health Risks of 12 PM2.5-Bound Metals in a Typical Air-Polluted City in Northern China during the 13th Five-Year Plan.

The continuous monitoring of PM2.5 (including 12 metal elements) was conducted in Jinan, a city with poor air quality in China, during the 13th Five-Year Plan (2016-2020). Positive matrix factorization (PMF) was used to identify emission sources of PM2.5-bound metals, and the health risks of the metals and their emission sources were assessed. During the study period, the concentration of most metals showed a decreasing trend (except Al and Be), and a significant seasonal difference was found: winter > fall > spring > summer. The PMF analysis showed that there were four main sources of PM2.5-bound metals, and their contributions to the total metals (TMs) were dust emissions (54.3%), coal combustion and industrial emissions (22.3%), vehicle emissions (19.3%), and domestic emissions (4.1%). The results of the health risk assessment indicated that the carcinogenic risk of metals (Cr and As) exceeded the acceptable level (1 × 10-6), which was of concern. Under the influence of emission reduction measures, the contribution of emission sources to health risks changes dynamically, and the emission sources that contribute more to health risks were coal combustion and industrial emissions, as well as vehicle emissions. In addition, our findings suggest that a series of emission reduction measures effectively reduced the health risk from emission sources of PM2.5-bound metals.

Long-term change in winter aerosol composition and sources in Guiyang Southwest China (2003–2020)

This study presents a comprehensive analysis of air quality in China, Southwest China, over four winter seasons: 2003–2004, 2004–2005, 2017–2018 and 2019–2020. We initially collected Total Suspended Particles (TSP) samples during the earlier periods and PM2.5 samples during the later periods. Our goal was to illustrate the changes in sources of atmospheric pollutants over time. By focusing on the chemical composition of water-soluble inorganic ions (WSIIs), we highlighted significant long-term changes in air quality and pollution sources in Guiyang alongside the effectiveness of recent pollution treatment strategies. Historically affected by acid rain and acid pollution, Guiyang has shown notable improvements in air quality. Notably, sulfate pollution, primarily from coal combustion, has significantly decreased, with the sulfates concentration declining from an estimated 19.04 μg m−3 to 30.46 μg m−3 during the winter of 2003–2004, to just 7.37 μg m−3 in PM2.5 during the winter of 2019–2020. Additionally, the mean mass concentration of PM2.5 dropped by 18% between the 2017–2018 and 2019–2020 winters. An increasing ratio of nitrate to sulfate in the aerosols indicates a shift in pollution sources, with secondary nitrate pollution, largely from vehicle emissions, becoming increasingly prevalent. Positive Matrix Factorization (PMF) model analysis identified five major pollution sources, highlighting a transition from secondary sulfate to secondary nitrate as the primary contributors to air pollution in Guiyang, and secondary nitrate pollution mainly from vehicles emission was increasingly severe meanwhile the significance of ammonium should not be overlooked. The results stress the importance of local pollution sources and suggest a need for revised pollution control policies that address the evolving characteristics of aerosols and prioritize the major pollutants in Guiyang, especially during winter months.

Impact of Ultra-Low Emission Technology of Thermal Power Plants on Air Quality in China

Impact of Ultra-Low Emission Technology of Thermal Power Plants on Air Quality in China

:The Political Regulation Wave: A Case of How Local Incentives Systematically Shape Air Quality in China

:<i>The Political Regulation Wave: A Case of How Local Incentives Systematically Shape Air Quality in China</i>

Exploring spatiotemporal distribution characteristics of air quality and driving factors: empirical evidence of 288 cities in China.

Excellent air quality is important for China to achieve high quality economic development. The paper analyses the spatial and temporal distribution characteristics of the air quality index (AQI) in 288 Chinese cities, and further investigates the driving factors affecting air quality using the spatial Durbin model (SDM) based on the panel data of 288 Chinese cities from 2014 to 2021. The results of the study show that: (1) China's air quality level has improved in general, but there are large differences in air quality between regions; (2) China's AQI has significant spatial positive autocorrelation, and the Moran's scatter plot shows a high-high and low-low agglomeration; (3) The driving factors of air quality have different effects, and regional heterogeneity is obvious. Some developed regions in China have already crossed the inflexion point of the environmental Kuznets curve (EKC); promoting industrial upgrading and reducing pollutant emissions can significantly improve urban PM2.5 concentrations; and the "Three-Year Strategy for Conquering the Blue Sky War" policy has lowered the AQI in North China and improved PM2.5 concentrations nationwide. Based on the above findings, the paper puts forward corresponding policy recommendations.

Does ethanol-blended gasoline policy improve air quality in China?

Ethanol-blended gasoline has been increasingly adopted worldwide as a strategy to address pressing concerns related to energy security and air pollution. This study focuses on exploring how the pilot policy of promoting ethanol-blended gasoline for vehicles affects air quality. Using a panel dataset comprising daily air quality measurements spanning the period 2016–2020, we employ a staggered difference-in-difference (DID) approach to investigate the impact of this policy. The results reveal a significant improvement in air quality after the implementation of ethanol-blended gasoline policy. On average, the air quality index experiences a reduction of 9.71 units, accompanied by decreases in the concentrations of PM2.5, PM10, CO, and NO2 by 9.15 μg/m3, 10.28 μg/m3, 0.14 mg/m3, and 2.17 μg/m3, respectively. These findings remain consistent across a range of robustness checks. The heterogeneity analysis further indicates that cities with larger populations and more congested traffic observe a more pronounced improvement in air quality due to the implementation of ethanol-blended gasoline policy. Moreover, the cost-benefit analysis demonstrates that the estimated health benefits derived from the adoption of ethanol-blended gasoline, amounting to 12.73 billion yuan, outweigh the associated costs incurred by the policy implementation. The findings provide compelling evidence that supports the promising role of ethanol-blended gasoline policy in enhancing air quality and highlight the potential benefits of such a policy in addressing the challenges posed by air pollution.

Government-to-government peer pressure and air pollution: Causal evidence from an environmental ranking policy in China

This paper estimates the impact of peer governmental pressure on air quality using a regression discontinuity design inherent in China's air quality ranking system. Because air quality rankings are important for political evaluations, local officials who witnessed a decline in air quality ranking are motivated to enforce more stringent environmental standards compared to their counterparts with increased rankings. By exploiting this regulatory discontinuity with monthly air quality ranking data from 2012 to 2020 of 169 cities, we find that cities experiencing a lower air quality ranking in the current month compared to the previous month exhibit a subsequent improvement in air quality during the following month, as evidenced by decreased pollutant concentrations. Furthermore, our analysis reveals that in cities where pollutant rankings decline more sharply, officials are less likely to encounter fewer promotion opportunities. Importantly, we observe that the discontinuity in individual pollutant concentrations is not solely influenced by their respective rankings but is also impacted by the overall Air Quality Index (AQI) ranking. Linking the reduction in air pollutants concentration with the economic benefits, a back-of-the-envelope calculation indicates the decrease in premature deaths due to cardiovascular and respiratory diseases amounts to approximately 200 thousand, resulting in an associated economic saving of more than 600 billion Chinese yuan.

Observation and study of consecutive dust storms in the Taklimakan desert from March 16 to 27, 2022, using reanalysis models and lidar

A series of severe dust storms hit the Taklimakan desert between March 16 and 27, 2022, significantly deteriorating air quality throughout China. This study presents a comprehensive analysis of the vertical structure of aerosols during these dust storms, as well as their causes and impacts on China's regional and city-scale air quality, utilizing data from reanalysis models, coherent Doppler wind lidar, and air quality monitoring stations. During dust storms, intense wind layers increase dust emissions, resulting in reduced lidar detection ranges and signal strengths. In addition, lower temperatures prevail due to sunlight absorption and scattering. Moreover, high-speed winds at high altitudes increase dust particles that serve as cloud condensation nuclei, leading to increased humidity, decreased temperature, and precipitation. The Taklimakan desert's trough serves as a wind convergence zone, which promotes favorable conditions for the initiation of dust storms. Due to the steep pressure gradients, strong winds enter the Taklimakan desert through the gap between its mountains in the east, coming from northern Xinjiang and Inner Mongolia via the Hexi corridor, which facilitates the lifting and transport of dust aerosols. Dust is transported long distances from the Taklimakan desert to the eastern coasts, impacting numerous cities along the way. The emissions from these dust storms swept across most Chinese provinces. Even though each dust storm was over in the Taklimakan desert, its effects on China's air quality continued for several days. The coarse PM concentrations (PM10–2.5) in Hotan, Kashgar, Aksu, Korla, Hami, Xining, Yinchuan, Taiyuan, and Beijing spiked to levels around 14, 36, 11, 6, 7, 12, 11, 12, and 6 times higher than their 2022 averages, respectively. This study provides valuable insights into the causes and effects of the Taklimakan desert dust storms, helping authorities develop effective mitigation plans.

How do taxi drivers expose to fine particulate matter (PM2.5) in a Chinese megacity: a rapid assessment incorporating with satellite-derived information and urban mobility data

BackgroundTaxi drivers in a Chinese megacity are frequently exposed to traffic-related particulate matter (PM2.5) due to their job nature, busy road traffic, and urban density. A robust method to quantify dynamic population exposure to PM2.5 among taxi drivers is important for occupational risk prevention, however, it is limited by data availability.MethodsThis study proposed a rapid assessment of dynamic exposure to PM2.5 among drivers based on satellite-derived information, air quality data from monitoring stations, and GPS-based taxi trajectory data. An empirical study was conducted in Wuhan, China, to examine spatial and temporal variability of dynamic exposure and compare whether drivers’ exposure exceeded the World Health Organization (WHO) and China air quality guideline thresholds. Kernel density estimation was conducted to further explore the relationship between dynamic exposure and taxi drivers’ activities.ResultsThe taxi drivers’ weekday and weekend 24-h PM2.5 exposure was 83.60 μg/m3 and 55.62 μg/m3 respectively, 3.4 and 2.2 times than the WHO’s recommended level of 25 µg/m3. Specifically, drivers with high PM2.5 exposure had a higher average trip distance and smaller activity areas. Although major transportation interchanges/terminals were the common activity hotspots for both taxi drivers with high and low exposure, activity hotspots of drivers with high exposure were mainly located in busy riverside commercial areas within historic and central districts bounded by the “Inner Ring Road”, while hotspots of drivers with low exposure were new commercial areas in the extended urbanized area bounded by the “Third Ring Road”.ConclusionThese findings emphasized the need for air quality management and community planning to mitigate the potential health risks of taxi drivers.