Characteristics of public concern on haze in China and its relationship with air quality in urban areas

The impact of public eco-concern on urban eco-efficiency: A dual perspective analysis of net effect and configuration

Urban sustainable development is an important topic of concern across various sectors of society, and how to enhance urban eco-efficiency (UEE) is a critical question of our time. As an essential component of the institutional environment, the relationship between public eco-concern (PEC) and UEE requires a more nuanced exploration and validation. Based on the data collected from 279 Chinese cities from 2011 to 2020, this study employs a combination of spatiotemporal analysis, spatial Durbin model (SDM), and panel qualitative comparative analysis (QCA) to investigate the spatiotemporal distribution patterns of both the variables and their interrelations. The following conclusions were drawn. First, during the study period, the UEE values exhibited a fluctuating upward trend, whereas PEC showed a contrasting developmental direction. The spatial stratification of UEE was not prominent, with the overall equilibrium gradually improving; however, a polarization trend persisted, mainly characterized by a high-high clustering pattern in certain areas. Conversely, the equilibrium of PEC gradually declined, predominantly showing a high-low clustering pattern. Second, PEC significantly enhanced the UEE of the local and neighboring areas. Regionally, the western region aligned with the overall trend, whereas PEC in the eastern and central regions significantly affected the local UEE. Finally, through configurational analysis, the boundary scenarios of PEC were identified, which included two possibilities (PEC→∼CEE, ∼PEC→CEE) and five high-dimensional applicable scenarios. Results indicate important theoretical and practical insights into the utility mechanisms of PEC, contributing to the realization of urban sustainability development.

Public perceptions and practices on air quality and respiratory health: insights from a cross-sectional study in Saudi Arabia

This study aimed to assess public perceptions and practices regarding air quality and its impact on respiratory health in Saudi Arabia. A cross-sectional survey was conducted among 539 participants, selected through stratified random sampling across urban, semi-urban, and rural areas. Data were collected via an online questionnaire and analyzed using descriptive statistics, t-tests, and ANOVA. Findings indicated that 63.2% (n = 341) of participants occasionally checked air quality reports, with moderate confidence in interpreting them (52.5%, n = 283). Awareness of the health impacts of air pollution was higher in urban areas, while rural participants showed less concern and lower awareness (P < .0001). Younger participants (18-30 years) had the highest concern about air pollution (mean: 3.39), whereas older participants demonstrated lower awareness of associated health risks (P < .0001). The study found no significant gender differences in perceptions (P > .05). Despite moderate concern about air pollution, participants perceived a low impact on their quality of life (mean: 2.85). The study underscores the importance of localized public health strategies to address air quality concerns and mitigate respiratory health risks in Saudi Arabia.

Outdoor light at night, air pollution and risk of incident type 2 diabetes

BACKGROUND

Air pollution and outdoor light at night (LAN) have been reported to be related to type 2 diabetes (T2D). However, their interaction with risk of T2D remains uncertain. Therefore, our study aimed to explore the relationship between outdoor LAN, air pollution and incident T2D.

METHODS

Our study included a cohort of 24,147 subjects recruited from 2015 to 2018 in Ningbo, China. Land use regression models were used to evaluate particulate matter with a diameter ≤2.5 μm (PM2.5), ≤10 μm (PM10) and nitrogen dioxide (NO2). Satellite images data with a spatial resolution of 500m was used to estimate outdoor LAN levels. T2D new cases were identified by medical records based on health information system. Cox proportional hazards models were used to estimate Hazard ratios (HRs) and 95% confidence intervals (CIs). Moreover, we investigated the multiplicative and additive interactions between air pollution and outdoor LAN.

RESULTS

During 108,908 person-years of follow-up period, 1016 T2D incident cases were identified. The HRs (95% CIs) were 1.22 (1.15, 1.30) for outdoor LAN, 1.20 (1.00, 1.45) for PM2.5, 1.23 (1.11, 1.35) for PM10 and 1.19 (1.04, 1.37) for NO2 in every interquartile range increase, respectively. Furthermore, significant interactions were observed between outdoor LAN and NO2.

CONCLUSIONS

Our findings indicated that air pollution and outdoor LAN were positively associated with T2D. Moreover, we observed an interaction between outdoor LAN and NO2 suggesting that stronger associations for outdoor LAN and T2D in areas with higher levels of NO2, and for NO2 and T2D in areas with higher levels of outdoor LAN.

The tripartite evolutionary game of enterprises' green production strategy with government supervision and people participation

Government supervision and people participation play vital roles in enterprises' green production strategy, but few studies have considered the strategy choices behind government supervision and people's participation. This study contended that whether an enterprise adopts the green production strategy is influenced not only by its responsible attitude facing social responsibility but also by the following two factors, the intensity of government supervision and whether people choose to participate in supervision or not when facing the enterprise adopting the green production strategy or not. We constructed a tripartite evolutionary game model to explore the behavioral evolution rules and evolutionary stability strategies of government supervision, people participation, and enterprises' green production. Then we employed numerical simulation to analyze how various factors influence the strategy selection of the government, people, and enterprises. The results show that if the utility values of government supervision and people participation are greater than 0, the enterprises will adopt the green production strategy. The system stability is affected by a synergistic relationship between participation cost, reputation benefit, and government subsidies, and an incremental relationship between enterprises' green production benefit, government subsidies, people's reported bonus, and enterprises' green production cost. This study provides a new theoretical perspective for research on government supervision, people participation, and enterprises' green production strategy, and the results provide important references for improving the enterprises' green production and urban environmental management.

How public environmental appeals affect the collaborative governance in pollution and carbon reduction: Evidence from spatial effects across Chinese cities

China has always adhered to the strategy of sustainable development. It is prevalent the public want a good living environment, which requires local governments and businesses to enhance their environmental governance capabilities. Using the panel data from Chinese cities from 2012 to 2019 and econometrics models, we examine the impact mechanisms of public environmental appeals (PEA) on efficiency of collaborative governance in pollution reduction and carbon mitigation (GPC). Results indicate that there is a positive spatial clustering of GPC across cities, with high-high clustering is notably concentrated in the southern regions of China and low-low clustering is prevalent in the northern regions. Spatial econometrics model results reveal that the stronger PEA, the higher GPC. The result of mechanism analysis shows the mediation of environmentally friendly technological innovation is crucial. Subsequent inquiry uncovers that the digital economy positively moderates the impact of PEA on GPC. The Belt and Road policy region exhibits heightened sensitivity to PEA, thereby enhancing the positive impact of PEA on GPC.

Perception matters: How air pollution influences life satisfaction in China

Academic studies on environmental pollution have convincingly acknowledged the salient relevance of ambient pollutant emissions on individual life satisfaction. However, an understanding of how the different dimensions of air pollution influence public self-assessment of their living condition is required. This research investigates whether objective pollutant emissions and subjective evaluation influence individual life satisfaction. The findings were based on data from the China Environment Yearbook and China Social Survey in 2019. The multi-level linear regression model found that air pollutants emissions, including particulate matter (PM) and sulfur dioxide (SO2), failed to explain the variations in public life satisfaction because of the lag effect of public perception. A significant nexus between perceived air pollution and public life satisfaction was observed at a significance level of 0.01. Specially, as the perceived air pollution by the public increased by one-point, life satisfaction decreased by 0.22 on a scale of 1-10, on average. Heterogeneous analysis based on income further suggested the salient negative effect of PM emissions on life satisfaction only occurred in the high-income group. The findings were robust after various methodological analyses. This study has theoretical implications for understanding the effects of air pollution on public subjective perception and provides guidance for how the government can manage the relationship between environmental governance and life satisfaction.

How far can air pollution affect tourism in China? Evidence from panel unconditional quantile regressions

Previous studies provide empirical evidence for the connection between air pollution and tourism. However, many of them take the nexus as a linear one. It remains unexplored whether any thresholds are required for the nexus to materialize. This study systematically investigates whether PM2.5 concentrations-an essential indicator of air pollution-affect tourism in China at various tourism development levels. We analyze 284 Chinese cities from 2008 to 2018 using the Unconditional Quantile Regression method. Our statistical results reveal that air pollution positively influences tourism (regarding tourist visits and tourism revenue) in areas with low tourism development levels. However, a complex correlation between air pollution and tourism emerges when tourism development has reached a certain level. The correlation is initially negative, then positive, and finally disappears. But, the overall correlation remains negative. The effects of the interaction between air pollution and tourism resources on tourism are inverted U-shaped, implying that tourism resources can mitigate the negative effects of air pollution on tourism only when tourism development has reached a certain level. Based on the above findings, the associated policy implications are discussed.

The impact of public demands on local environmental governance performance: Evidence from civil environmental complaints placed on leaders at different government levels in China

The joint participation of multiple subjects is crucial for environmental governance. Using panel data for 273 Chinese cities during 2013-2019, this study investigates the impact and mechanism of public demands on environmental pollution. The results demonstrate that public demands measured by the number of environmental complaints placed on government leaders significantly reduce environmental pollution. Furthermore, increases in the rate and speed of government responses improve the effect of public demands on environmental governance. Public demands placed on provincial leaders reduce local environmental pollution to a greater extent than public demands placed on prefectural and county leaders. Province-level governments are more willing to consider public opinions and attach more importance to environmental governance; Prefecture-level governments prioritize province-level governments' attention to the environment when implementing environmental governance. Moreover, strong political ties between provincial and prefectural leaders and long tenures among prefectural leaders strengthen the pollution reduction effect of public demands placed on provincial leaders. The reduction effect of environmental complaints on pollution emission is more significant in cities with high level of Internet construction and environmental disclosure. Our results illustrate the role of public demands in environmental governance, offering a reference for developing effective environmental policies.

Prevention or ex-post forcing? The impact of dual environmental regulation on corporate environmental behavior

Corporate reactions to environmental regulation are the hottest topics in research on corporate environmental behavior. However, a few studies incorporate other environmental behavior into the same framework. By constructing a comprehensive indicator system of dual environmental regulation, this paper uses a comparative analysis to discuss Chinese A-listed corporations' environmental behavior from 2009 to 2017, which were influenced by dual environmental regulation. The study's results show that formal environmental regulation (FER) has a significant U-shaped effect on pre-emptive environmental behavior (PEB) but an insignificant impact on ex-post environmental behavior (NEB). After categorizing the various forms of FER, this study finds that market-incentive environmental regulation has a significant inverted U-shaped effect on NEB but an insignificant impact on PEB, voluntary-participation regulation have a significant U-shaped effect on PEB and an inverted U-shaped effect on their NEB, and command-control regulation has significant influence on neither PEB nor NEB. In addition, informal environmental regulation (IER) has a significantly positive and negative effect on PEB and NEB. This study shows that corporate perceptions of policies can have a positive impact on the interaction between the FER and PEB but a negative impact on the interaction between the IER and PEB, and no impact on the interaction between FER or IER and NEB. Moreover, the impact of FER and IER on corporate environmental behavior (CEB) varies depending on factors like ownership, industry characteristics, the market environment, and regional development. Therefore, governments should understand the choices related to corporate environmental behavior under the dual environmental regulation-formal and informal-and prioritize the synergistic impact of these dual environmental regulation, highlighting their enforceability, and take into account the heterogeneity of their targets and the market to stimulate PEB and decrease NEB to help enterprises align their short-term economic objectives with their long-term social goals.

How air pollution affects corporate total factor productivity?

To explore the relationship between air pollution and total factor productivity and new pathways, This paper examines the impact of air pollution on total factor productivity of A-share listed companies in Shanghai and Shenzhen between 2015 and 2019. It investigates this relationship by considering two pathways: investor sentiment and government attention. The findings indicate that air pollution suppresses total factor productivity of firms. However, air pollution stimulates investor sentiment, which in turn increases R&D investment and total factor productivity, reducing to some extent the dampening effect of air pollution on total factor productivity. There exists a notable positive correlation between air quality and government attention, acting as a mediating variable. This implies that air pollution has the potential to capture the attention of governmental entities, leading to the implementation of appropriate measures aimed at managing and mitigating the occurrence of air pollution caused by industrial enterprises.And the relevant governments should formulate a series of policies to meet the different needs of different enterprises. These two approaches have varying impacts depending on the type of enterprises, thus governments should develop laws to cater to the various demands of different types of enterprises.

Assessment of air pollution and air quality perception mismatch using mobility-based real-time exposure

Air pollution poses a threat to human health. Public perceptions of air pollution are important for individual self-protection and policy-making. Given the uncertainty faced by residence-based exposure (RB) measurements, this study measures individuals' real-time mobility-based (MB) exposures and perceptions of air pollution by considering people's daily movement. It explores how contextual uncertainties may influence the disparities in perceived air quality by taking into account RB and MB environmental factors. In addition, we explore factors that are related to the mismatch between people's perceived air quality and actual air pollution exposure. Using K-means clustering to divide the PM2.5 values into two groups, a mismatch happens when the perceived air quality is poor but the air pollution level is lower than 15.536μg/m3 and when the perceived air quality is good but the air pollution level is higher than 15.608μg/m3. The results show that there is a mismatch between air pollution exposure and perception of air pollution. People with low income are exposed to higher air pollution. Unemployed people and people with more serious mental health symptoms (e.g., depression) have a higher chance of accurately assessing air pollution (e.g., perceiving air quality as poor when air pollution levels are high). Older people and those with a higher MB open space density tend to underestimate air pollution. Students tend to perceive air quality as good. People who are surrounded by higher MB transportation land-use density and green space density tend to perceive air quality as poor. The results can help policymakers to increase public awareness of high air pollution areas, and consider the health effects of landscapes during planning.

Air pollution perception bias: Mismatch between air pollution exposure and perception of air quality in real-time contexts

Air pollution perception biases hinder the public's awareness of actual air quality. Past studies that examined the association and mismatch between actual and perceived air quality neglected individuals' dynamic exposure and their activity, travel, spatial, temporal, and social contexts. Using data collected with real-time air pollutant sensors and ecological momentary assessment (EMA), this study investigated the association and mismatch between momentary air pollution exposure and perceived air quality. It also examined how activity type, travel mode, spatial and temporal contexts, and social factors contribute to this disparity. The results show that exposure to air pollution is significantly higher in residential areas (1.777 μg/m3) and transportation land-use areas (2.863 μg/m3) compared to commercial areas. Exposure in the evening is 1.308 μg/m3 higher than in the afternoon. Working or studying activities are associated with 2.863 μg/m3 lower exposure, and individuals perceive air quality as good when working or studying and in residential areas. Conversely, individuals assess air quality as poor in railway travel contexts and being accompanied by friends. This study also reveals the nonstationary association between air pollution exposure and perceived air quality. The odds of underestimating air pollution are 1.8-2.7 times as high as that in residential areas and 2.1 to 2.6 times that in transportation land-use areas when compared to commercial areas. Implementing targeted mitigation measures in these contexts can enhance public awareness of air pollution.

Particulate matter concentration effects on attention to environmental issues: a cross-sectional study among residents in Korea's Pohang Industrial Complex

Background

With modernization, air pollution has become increasingly serious, and its effects on health have been revealed. As a result, public interest in environmental pollution has become critical for regulating air pollution. In our study, we aim to evaluate the impact of air pollution levels on public attention to environmental issues and examine whether awareness of the residential environment's impact on health acts as a mediator in this relationship.

Methods

We conducted an analysis on 400 individuals surveyed in the preliminary feasibility study on adverse health effects in the Pohang Industrial Complex, to examine the relationship between particulate matter 2.5 (PM2.5) and attention to environmental issues. Logistic regression analysis was performed, and mediation analysis was used to determine whether awareness of the residential environment's impact on health mediated the relationship.

Results

The logistic regression analysis results showed that PM2.5 levels were associated with attention to environmental issues (adjusted odds ratio [AOR]: 2.1; 95% confidence interval [CI]: 1.3-3.5; p = 0.003) and awareness of health impacts (AOR: 3.4; 95% CI: 1.6-7.1; p = 0.001). The PM2.5 levels showed 9.9% (95% CI: 5.4-14.0) increase in the prevalence of high attention to environmental issues, of which, only 1.0% (95% CI: 0.2-2.3) were mediated by health impact awareness. In the overall analysis, 10% of the total effect of PM2.5 on attention to environmental issues was mediated by health impact awareness.

Conclusions

According to this study's results, there was a correlation between air pollution levels and attention to environmental issues. Awareness of the health impacts of air pollution partially mediated the effect of air pollution levels on attention to environmental issues. In future studies, it is recommended to identify other mediators to further understand this structure.

Air Quality, Pollution Perception, and Residents' Health: Evidence from China

Environmental and resident health issues associated with air pollution are an area of growing concern for both policy officials and the general public. In recent years, China has been accelerating the construction of a Beautiful China and a Healthy China, with the aim of protecting and improving the environment and ensuring public health. In this study, we aimed to explore the impact of air quality and air pollution perception on residents' health. This study used the 2017 Chinese General Social Survey data to measure self-rated health, mental health, and air pollution perception. Using matched socioeconomic indicators and air pollution data, we analyzed the relationship between subjective perception of air pollution, objective air pollution data, and residents' health. The results showed the following: (1) Air pollution perception has a significant negative impact on self-rated health and mental health. Thus, it needs more consideration to reduce environmental health risks. (2) Objective air pollution has a significant negative impact on mental health. At the same time, its effect on self-rated health was insignificant. These results provide empirical evidence supporting the Chinese government's decision to invest more in combating air pollution and ensuring the health of Chinese residents.

The long-term impacts of air quality on fine-grained online emotional responses to haze pollution in 160 Chinese cities

Air pollution poses a great threat to public health and social stability by influencing multiple emotions. In particular, the air quality in developing countries is deteriorating along with rapid industrialization and urbanization, and multiple emotions may change along with regulation updates and air quality trending. Monitoring changes in public emotion is crucial for environmental governance. However, limited evidence exists for long-term effects of air quality on fine-grained emotions. Traditional surveys have the drawbacks of spatial limitations and high costs of time and money. Here, we use deep learning models to identify multiple emotions of over 10 million haze-related tweets and evaluate the effect of air quality on emotional predispositions for 160 cities from 2014 to 2019 in China. We find that sadness and joy are persistently associated with air quality, while anger and disgust are not. Surprisingly, the effects on fear vanished in the last three years. Moreover, air pollution initially had a greater impact on expressed fear in cities with higher income, poorer air quality and a greater percentage of women. Through popularity ranking and dynamic topic model, we interpretively revealed that people are no longer overly panicked and their attention is shifting toward policies and sources of haze. Our findings highlight the temporal evolution in the public's emotional response and provide significant implications for equitable public policies.

Realizing direct and indirect impact of environmental regulations on pollution: A path analysis approach to explore the mediating role of green innovation in G7 economies

The alarming impact of climate change and environmental pollutants has increased the focus of policymakers and think tanks' focus on formulating environmental regulations. Environmental regulations may reduce emissions directly and indirectly, as postulated by the famous Porter Hypothesis. It shows that environmental regulation may enhance pollution-reducing innovation by reducing agency costs while at the same time increasing firms' private benefit. The study is designed to investigate environmental regulations' direct and indirect impact on CO2 and GHG emissions using innovations as mediation factors. The study employs a structural equation method using data on G7 economies from 1990 to 2020 to test the relationship between regulations, innovations, and pollution. The study findings confirm that environmental regulations help reduce emissions directly. Our findings also confirm the Porter hypothesis whereby regulations encourage innovations and result in reduced emissions through this indirect channel. The study findings have significant implications for controlling pollution through placing environmental regulations and encouraging innovations.

Public Concern about Haze and Ozone in the Era of Their Coordinated Control in China

In China, due to the implementation of the Action Plan for Prevention and Control of Air Pollution (APPCAP), the concentrations of PM_2.5 (fine particulate matter) and severe haze in most cities have decreased significantly. However, at present, haze pollution in China has not been completely mitigated, and the problem of O₃ (ozone) has become prominent. Therefore, the prevention and control of haze and O₃ pollution have become important and noticeable issues in the field of atmospheric management. We used the Baidu search indices of "haze" and "ozone" to reflect public concerns about air quality and uncover different correlations between level of concern and level of pollution, and then we identified regions in China that require public attention. The results showed that (1) over the last decade, the search index of haze had a rapid trend of variation in line with changes in haze pollution, but that of O₃ had a relatively slowly increasing trend; (2) the lag days between the peaks of public concern and the peaks of air pollution became increasingly shorter according to daily data analysis; and (3) 96 polluted cities did not receive sufficient public attention. Although periods of heavily haze-polluted weather, which affects visibility, have generated much public concern, periods of slight pollution have not received enough public attention. Public health protection and environmental participation regarding these periods of slight pollution in China deserve appropriate levels of attention.

The effect of air pollution on Chinese green bond market: The mediation role of public concern

Green bonds are becoming increasingly important in sustainable investments since their environmental protection attributes allow them to benefit from environmental degradation. However, the mechanism of environmental degradation on green bonds has not yet been studied. This study proposes a mediation model to analyze air pollution's influence on green bonds. Theoretically, air pollution leads to increased public concern through public environmental awareness and perceptions of physical health risks. Enhanced public concern drives investors' green preference and environmental responsibility, thus expanding green bond demand, in which public concern plays an important mediation role. To verify the mediating effect, causal stepwise regression and bootstrap methods are used. The empirical results confirm this theoretical mechanism. Air pollution is significantly positively related to public concern. Public concern is positively linked with green bond investment willingness, resulting in increased volatility. The total positive effect of air pollution on green bonds is partly absorbed by the mediating effect of public concern that is significantly positive and reaches 30.21% of the total effect. In addition, major crisis events (e.g., COVID-19) may hinder the positive mediation process by generating a negative trend and distracting the public. This means that the government could propose appropriate measures to minimize the negative aspects in order to promote green finance. The mediation model is also useful for investors wishing to increase green assets in their portfolios and provides an incentive for businesses to promote green finance.

High Resolution On-Road Air Pollution Using a Large Taxi-Based Mobile Sensor Network

Traffic-related air pollution (TRAP) was monitored using a mobile sensor network on 125 urban taxis in Shanghai (November 2019/December 2020), which provide real-time patterns of air pollution at high spatial resolution. Each device determined concentrations of carbon monoxide (CO), nitrogen dioxide (NO2), and PM2.5, which characterised spatial and temporal patterns of on-road pollutants. A total of 80% road coverage (motorways, trunk, primary, and secondary roads) required 80-100 taxis, but only 25 on trunk roads. Higher CO concentrations were observed in the urban centre, NO2 higher in motorway concentrations, and PM2.5 lower in the west away from the city centre. During the COVID-19 lockdown, concentrations of CO, NO2, and PM2.5 in Shanghai decreased by 32, 31 and 41%, compared with the previous period. Local contribution related to traffic emissions changed slightly before and after COVID-19 restrictions, while changing background contributions relate to seasonal variation. Mobile networks are a real-time tool for air quality monitoring, with high spatial resolution (~200 m) and robust against the loss of individual devices.

The energy consumption-environmental quality nexus in BRICS countries: the role of outward foreign direct investment

This paper examines the role of outward foreign direct investment on energy consumption and environmental quality in BRICS from 1990 to 2019. Most of the previous research considered foreign direct investment mainly focused on the environmental impact on the host country effect and ignored the home country effect. Therefore, the current study examines the home country effect of environmental pollution. We use various methodologies like cross-sectional dependence and the Pesaran-Yamagata slope homogeneity for the diagnostic test. After confirming the diagnosis test, we employ second-generation panel unit root tests, which confirms that all elements are stationary at first difference. The pooled mean group (PMG), Westerlund cointegration, two-step generalised method of moments (GMM), panel fully modified ordinary least square (FMOLS), and dynamic ordinary least square (DOLS) model have been used to determine the short-term and long-term association among the variables. The cointegration and PMG results confirm that the short-run and long-run association exists among the considered variables. The results reveal that developing countries produced environmental pollution at the early stage of development and checked in the long run. The study used the STIRPAT model to build an extended carbon dioxide emissions model by incorporating outward FDI, GDP per capita, and technology to achieve our objectives. The empirical results hold up the environmental Kuznets curve hypothesis, implying that outward FDI and energy consumption help expand greener technology to host countries' environmental improvement in the long run and confirm that an inverted U-shaped linkage exists. Hence, the study suggests that developing countries should pay more attention to sustainable development and technological development that encourages more eco-friendly and environment-friendly technology.

Exploring the Spatiotemporal Evolution and Sustainable Driving Factors of Information Flow Network: A Public Search Attention Perspective

The promotion of information flow reinforces the interactive cooperation and evolutionary process among cities. In the information age, public online search is a typical behavior of Internet society, which is the key to information flow generation and agglomeration. In this study, we attempt to explore the evolutionary characteristics of intercity networks driven by public online social behavior in the information age and construct an information flow network (IFN) from the perspective of public search attention. We also explore the evolution of the IFN in terms of the whole network, node hierarchy, and subgroup aggregation. Meanwhile, we also discuss the impact of the sustainable driving factors on the IFN. Finally, an empirical study was conducted in Guanzhong Plain Urban Agglomeration (GPUA). Our results show that: (1) the information flow in GPUA fluctuating upward in the early study period and gradually decreasing in the later study period. However, the agglomeration degree of information flow in the urban agglomeration continues to increase. (2) The hierarchical structure of urban nodes in GPUA presents a trend of “high in the middle and low on both sides”, and the formation of subgroups is closely related to geographic location. (3) The driving factors all impacting the IFN include public ecology, resource investment, information infrastructure, and economic foundation. This study provides theoretical and practical support for exploring the intercity network and promotes the sustainable urban development.

Retrospect and Outlook of Research on Regional Haze Pollution in China: A Systematic Literature Review

Regional haze pollution, a severe atmospheric environmental problem, has profoundly harmful effects on the ecological environment, public health and the quality of economic development, and has accordingly attracted considerable attention from policymakers, researchers and the public. This article comprises a systematic literature review of the existing research on the theoretical mechanism, empirical analysis and institutional arrangement of regional haze pollution. As a result, it is found that various studies from multiple disciplines have touched upon the relevance of haze issues, including theoretical and experimental research on its formation, evolution and mechanisms from the perspective of the natural sciences, as well as empirical analysis and policy research on governance strategies, effects and mechanisms from the perspective of the social sciences, yet a systematic review and critical assessment synthesizing the above research is urgently needed. Future directions and research prospects are highlighted, showing that it is necessary to supplement and improve the theory and practice concerning the identification, measurement and assessment of haze pollution, as well as regional controlling strategies and policy implementation assessments. In short, in this review, we have aimed to help integrate the theoretical and empirical consensus in multidisciplinary fields, thereby promoting the accurate analysis, fine management and the development of precise policies in regards to regional haze pollution.

Does Environmental Information Disclosure Affect the Sustainable Development of Enterprises: The Role of Green Innovation

Along with command-and-control and market-incentive environmental regulation policies, environmental information disclosure (EID) is an important measure used by the Chinese government to implement environmental governance. In the context of advocating for corporate sustainable development and green governance, this study uses data from China’s Shanghai and Shenzhen A-share listed companies in heavily polluting industries spanning 2008–2019 to empirically explore the relationship between corporate EID and green innovation (GI). The results reveal the following: (1) high-quality EID significantly promotes the absolute GI level and the relative GI level of enterprises. (2) An intermediary model found that the internal mechanism of corporate EID used to promote GI mainly comes from the government’s energy-saving innovation subsidy effect and the social media attention effect. (3) Corporate EID has a more evident promotional effect on green patents for energy conservation and green patents for inventions. (4) The EID of state-owned enterprises is more conducive to GI than to the activities of private enterprises. (5) The EID of enterprises in high-level administrative cities has no significant impact on GI. However, it has a significant promoting effect in low-level administrative cities. The research not only provides an empirical basis for China to improve the environmental information disclosure system of listed companies but also to offer guidance for companies to pursue green and sustainable development.

Strong Acids or Bases Displaced by Weak Acids or Bases in Aerosols: Reactions Driven by the Continuous Partitioning of Volatile Products into the Gas Phase

Aerosols are ubiquitous in the atmosphere and profoundly affect climate systems and human health. To gain more insights on their broad impacts, we need to comprehensively understand the fundamental properties of atmospheric aerosols. Since aerosols are multiphase, a dispersion of condensed matter (solid particles or liquid droplets, hereafter particles) in gas, partitioning of volatile matter between the condensed and the gas phases is one defining characteristic of aerosols. For example, water content partitioning under different relative humidity conditions, known as aerosol hygroscopicity, has been extensively investigated in the past decades. Meanwhile, partitioning of volatile organic or inorganic components, which is referred to as aerosol volatility, remains understudied. Commonly, a bulk solution system is treated as a single phase, with volatility mainly determined by the nature of its components, and the composition partitioning between solution and gas phase is limited. Aerosols, however, comprise an extensive gas phase, and their volatility can also be induced by component reactions. These reactions occurring within aerosols are driven by the formation of volatile products and their continuous partitioning into the gas phase. As a consequence, the overall aerosol systems exhibit prominent volatility. Noteworthily, such volatility induced by reactions is a phenomenon exclusively observed in the multiphase aerosol systems, and it is trivial in bulk solutions due to the limited extent of liquid-gas partitioning. Take the chloride depletion in sea salt particles as an example. Recent findings have revealed that chloride depletion can be caused by reactions between NaCl and weak organic acids, which release HCl into the gas phase. Such a reaction can be described as a strong acid displaced by a weak acid, which is hardly observed in bulk phase. Generally, this unique partitioning behavior of aerosol systems and its potential to alter aerosol composition, size, reactivity, and other physicochemical properties merits more attention by atmospheric community.This Account focuses on the recent advancements in the research of component reactions that induce aerosol volatility. These reactions can be categorized into four types: chloride depletion, nitrate depletion, ammonium depletion, and salt hydrolysis. The depletion of chloride or nitrate can be regarded as a displacement reaction, in which a strong acid is displaced by a weak acid. Such a reaction releases highly volatile HCl or HNO₃ into the gas phase and leads to a loss of chloride or nitrate within the particles. Likewise, ammonium depletion is a displacement reaction in which a strong base is displaced by a weak base, resulting in release of ammonia and substantial changes in aerosol hygroscopicity. In addition, aerosol volatility can also be induced by salt hydrolysis in a specific case, which is sustained by the coexistence of proton acceptor and hydroxide ion acceptor within particles. Furthermore, we quantitatively discuss these displacement reactions from both thermodynamic and kinetic perspectives, by using the extended aerosol inorganic model (E-AIM) and Maxwell steady-state diffusive mass transfer equation, respectively. Given the ubiquity of component partitioning in aerosol systems, our discussion may provide a new perspective on the underlying mechanisms of aerosol aging and relevant climate effects.

The Adverse Impact of Air Pollution on China’s Economic Growth

This study empirically evaluates the impact of air pollution on China’s economic growth, based on a province-level sample for the period 2002–2017. Air pollution is measured by the concentration of fine particulate matter (PM2.5), and economic growth is measured by the annual growth rate of gross domestic product (GDP) per capita. A panel data fixed-effects regression model is built, and the instrumental variables estimation method is utilized for quantitative analyses. The study reports a significant negative impact of air pollution on the macroeconomic growth of China. According to our instrumental variables estimation, holding other factors constant, if the concentration of PM2.5 increases by 1%, then the GDP per capita growth rate will decline by 0.05818 percentage points. In addition, it is found that the adverse effect of atmospheric pollution is heterogeneous across different regions. The effect is stronger in the eastern region and in provinces with smaller state-owned enterprise shares, fewer governmental expenditures for public health services, and fewer medical resources. The study results reveal that air pollution poses a substantial threat to the sustainable economic growth of China. Taking actions to abate air pollution will generate great economic benefits, especially for those regions which are heavily damaged by pollution.

A complete atmospheric emission inventory of F, As, Se, Cd, Sb, Hg, Pb, and U from coal-fired power plants in Anhui Province, eastern China

Anhui Province is the most important energy production base for eastern China. Many large pithead coal-fired power plants are being operated in the coal-rich Huainan and Huaibei coalfields in northern Anhui. To assess the environmental risks of local coal-fired power plants, a complete atmospheric emission inventory of F, As, Se, Cd, Sb, Hg, Pb, and U from coal-fired power plants in Anhui was compiled by a simple mass-balance-based method. The results indicated that the atmospheric emissions of F, As, Se, Cd, Sb, Hg, Pb, and U in 2017 from the Anhui coal-fired power plants were 578 t, 2.01 t, 15.3 t, 0.57 t, 0.18 t, 2.80 t, 23.7 t, and 0.099 t, respectively. The emission factor is the major contributor to the uncertainties in this inventory. With increasing energy demand by the more developed eastern China region, the atmospheric emissions of volatile hazardous elements will continue to increase in the near future.

A hybrid model based on PROMETHEE and PLTSs for the assessment of public participation in community meteorological disaster prevention and mitigation

Communities are the fundamental units of society, and community-based disaster management is the foundation of societal disaster management systems. It is important to implement disaster prevention and mobilize all residents in the community to participate in preparedness activities. However, people’s attitudes and understanding of these issues are often ambiguous because meteorological disaster prevention and mitigation (MDPM) is complex. A hybrid model based on probabilistic term sets (PLTSs) and PROMETHEE method is put forward to solve this problem. To solve the problem from the view of big data, the experimental data are from Baidu’s disaster prevention and mitigation questionnaires. The data of these questionnaires are aggregated through PLTSs. Then, the PROMETHEE method is used to learn about the public’s understanding of community meteorological disaster prevention and mitigation (CMDPM) information and their willingness to participate in activities. The results indicate that communities in East, Northwest, Southwest, and North China have a higher willingness to join volunteer services. The proposed model makes it more convenient for decision-makers (DMs) to describe problems by PLTSs and is more appropriate for individuals’ understanding and communication.

Using Internet Search Queries to Assess Public Awareness of the Healthy Cities Approach: A Case Study in Shenzhen, China

Cities around the globe are embracing the Healthy Cities approach to address urban health challenges. Public awareness is vital for successfully deploying this approach but is rarely assessed. In this study, we used internet search queries to evaluate the public awareness of the Healthy Cities approach applied in Shenzhen, China. The overall situation at the city level and the intercity variations were both analyzed. Additionally, we explored the factors that might affect the internet search queries of the Healthy Cities approach. Our results showed that the public awareness of the approach in Shenzhen was low. There was a high intercity heterogeneity in terms of interest in the various components of the Healthy Cities approach. However, we did not find a significant effect of the selected demographic, environmental, and health factors on the search queries. Based on our findings, we recommend that the city raise public awareness of healthy cities and take actions tailored to health concerns in different city zones. Our study showed that internet search queries can be a valuable data source for assessing the public awareness of the Healthy Cities approach.

Does public concern over haze pollution matter? Evidence from Beijing-Tianjin-Hebei region, China

Chinese residents are becoming more and more concerned about the living environment especially under the situation of environmental degradation caused by the unbalanced and inadequate economic development. The widespread of internet use provide a new way for public to express the dissatisfaction on environmental pollution. Although the public is the main body of society, the public concern over environmental issues are rarely studied. In this paper, the impact of public concern over haze on haze pollution is quantitatively examined by the utilization of econometric model. Specifically, the Baidu search index (BSI) is utilized as indicators for public concern. Using the panel data consisting of 13 cities in Beijing-Tianjin-Hebei region from the period from January 2014 to December 2019, estimation results showed a significant improvement effect of public concern on haze pollution. In general, the public concern can improve the air quality in a short turn. However, this improvement effect varies with different economic development levels. These findings can help policy makers to better understand the role of public in social governance and improve the air quality in China with the inclusion of public participation.

Assessing NO2-related health effects by non-linear and linear methods on a national level

Exposure to NO₂ pollution has a significant adverse effect on residents' health. However, few studies have assessed the health effects associated with NO₂ pollution. Compared with PM_2.5 pollution, the harmfulness of NO₂ pollution has not been quantitatively studied or clearly identified. In this study, we assessed the NO₂ exposure-related health effects by non-linear and linear methods, taking advantage of online monitoring and survey data. We also assessed the economic cost of NO₂ pollution in 338 cities in China. Our results showed that the average annual concentration of NO₂ in the top fifteen cities with more than ten million permanent residents (except for Shenzhen, in the Guangdong province) exceeded the annual Grade II standards (40 μg/m³). The estimated national NO₂-related all-cause mortality for non-linear and linear methods were 388.5 × 10³ (95% CI: 198.1 × 10³-748.2 × 10³) and 374.1 × 10³ (95% CI: 194.3 × 10³-695.9 × 10³), respectively. The total calculated national economic cost was about 28.8 billion US$ (95% CI: 14.7-55.4) in 2016. In addition, the comparison results showed that the harm caused by PM_2.5 pollution was about four times that of NO₂ pollution. Our statistics contribute to the limited research on NO₂ pollution's effects on health and the economy in China.

Asymmetric and Spatial Non-Stationary Effects of Particulate Air Pollution on Urban Housing Prices in Chinese Cities

Fine particulate matter(PM2.5) pollution will affect people’s well-being and cause economic losses. It is of great value to study the impact of PM2.5 on the real estate market. While previous studies have examined the effects of PM2.5 pollution on urban housing prices, there has been little in-depth research on these effects, which are spatially heterogeneous at different conditional quantiles. To address this issue, this study employs quantile regression (QR) and geographically weighted quantile regression (GWQR) models to obtain a full account of asymmetric and spatial non-stationary effects of PM2.5 pollution on urban housing prices through 286 Chinese prefecture-level cities for 2005–2013. Considerable differences in the data distributions and spatial characteristics of PM2.5 pollution and urban housing prices are found, indicating the presence of asymmetric and spatial non-stationary effects. The quantile regression results show that the negative influences of PM2.5 pollution on urban housing prices are stronger at higher quantiles and become more pronounced with time. Furthermore, the spatial relationship between PM2.5 pollution and urban housing prices is spatial non-stationary at most quantiles for the study period. A negative correlation gradually dominates in most of the study areas. At higher quantiles, PM2.5 pollution is always negatively correlated with urban housing prices in eastern coastal areas and is stable over time. Based on these findings, we call for more targeted approaches to regional real estate development and environmental protection policies.

Risk Perception of Air Pollution: A Systematic Review Focused on Particulate Matter Exposure

The adverse health effects of exposure to air pollutants, notably to particulate matter (PM), are well-known, as well as the association with measured or estimated concentration levels. The role of perception can be relevant in exploring effects and pollution control actions. The purpose of this study was to explore studies that analyse people's perception, together with the measurement of air pollution, in order to elucidate the relationship between them. We conducted a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. In March 2020, PubMed, EMBASE, and Scopus databases were explored in an attempt to search for studies published from 2000 to 2020. The review included 38 studies, most of which were conducted in China (n = 13) and the United States (n = 11) and published over the last four years (n = 26). Three studies were multicenter investigations, while five articles were based on a national-level survey. The air quality (AQ) was assessed by monitoring stations (n = 24) or dispersion models (n = 7). Many studies were population questionnaire-based, air monitoring and time-series studies, and web-based investigations. A direct association between exposure and perception emerged in 20 studies. This systematic review has shown that most of the studies establish a relationship between risk perception measurement. A broad spectrum of concepts and notions related to perception also emerged, which is undoubtedly an indicator of the wealth of available knowledge and is promising for future research.

Does environmental information disclosure contribute to improve firm financial performance? An examination of the underlying mechanism

Given the widespread impacts of firm activities on the environment, firms are increasingly required to disclose environmental information. However, the relation between environmental information disclosure and firm financial performance is controversial and the mechanism through which environmental information disclosure affects financial performance is insufficiently investigated. This research examined the effect of environmental information disclosure on financial performance and explored the mediating effects of visibility (e.g., analyst coverage and institutional ownership) and liquidity. Panel data from 289 Chinese listed firms were analyzed with the assistance of STATA Software. The results revealed that environmental information disclosure positively (directly) affects financial performance. Further, environmental information disclosure also indirectly affects financial performance via analyst coverage (e.g., number of analysts and number of reports) and liquidity. Analyst coverage and liquidity mediate the relationship between environmental information disclosure and financial performance while institutional ownership has no mediating effect. According to the results, practical implications were discussed and future research directions were noted.

Asymmetrically Spatial Effects of Urban Scale and Agglomeration on Haze Pollution in China

Rapid urbanization in China not only promotes the rapid expansion of urban population and economic agglomeration, but also causes the aggravation of haze pollution. In order to better clarify the asymmetric and nonlinear effects of urban scale and agglomeration on haze pollution, this paper quantitatively evaluates the spatial spillover effects of population size and economic agglomeration on haze pollution in 342 Chinese cities from 2001 to 2016 by using exploratory spatial data analysis (ESDA) and spatial econometric model. The results show the following: (1) During the research period, the distribution of urban scale, agglomeration, and haze pollution in China presented complex asymmetrical features, with the former two presenting a “core–periphery” distribution mode, while the latter having a tendency to spread around. In addition, under the influence of urban population size and economic agglomeration, haze pollution in Chinese cities presents significant spatial autocorrelation, with the agglomeration degrees showing a fluctuating upward trend during the study period. (2) Both urban scale and urban agglomeration have positive global spatiotemporal correlation with haze pollution. Local spatial correlation features are more obvious in China’s emerging urban agglomerations like Beijing–Tianjin–Hebei and Yangtze River Delta. (3) The spatial effects of haze pollution are better evaluated by spatial Durbin model (SDM) with spatial fixed effects, obtaining a coefficient of 0.416, indicating haze in neighboring cities affected each other and had significant spillover. By decomposing the effect of urban scale and agglomeration on haze as direct and indirect effects, the direct effect of urban population size and the indirect effect of urban economic agglomeration are found to be more prominent, reflecting that significant asymmetrical characteristics exist in the spatial effects of urban size and agglomeration on urban haze. (4) Among the control variables that affect China’s rapid urbanization, the level of urban economic development has a positive effect on haze pollution, while the high-level industrial structure and improved technical level can effectively reduce haze pollution. Continuous decline of haze concentration of Chinese cities in recent years has been indicating the spatial relationships between haze and urban size and agglomeration have a decoupling trend. The findings contribute to theory by emphasizing the spillover effect and spatial heterogeneities of geographical factors, and have implications for policy makers to deal with haze pollution reasonably and effectively.

Response of dust particle pollution and construction of a leaf dust deposition prediction model based on leaf reflection spectrum characteristics

Urban plants can improve several environmental pollution problems in cities, especially dust prevention, noise reduction, purification of the atmosphere, etc. To explore the influence of dust deposition on the spectral characteristics of the leaf, a foliar dust deposition prediction model based on high-spectrum data was established. Taking Euonymus japonicus L., the common greening tree species in Beijing, as the research object, high (T1), medium (T2), and low (T3) dust pollution gradients were set and hyperspectral data were collected. Results showed that: (1) in the dust-contaminated environment with different concentrations, the trend of the reflectance curve of the leaves of Euonymus japonicus L. was generally consistent. The spectral reflectance of the leaf surface was positively correlated with the amount of leaf dust. (2) There were five obvious reflection peaks and five main absorption valleys with the same positions and ranges in the 350-2500 nm range. (3) The spectral reflectance of leaf flour dust particles of Euonymus japonicus L. was significantly different before and after dusting, and its size was generally clean leaves > dust-depositing leaves. The sensitive range of its spectral response was 695-1400 nm. (4) The overall trend of the first derivative spectrum was basically the same. The red edge slope and the blue edge slope appeared as T3 > T2 > T1, the red edge position and the blue edge position appeared as T1 < T2 < T3. The red edge position of the leaf surface after dust deposition had an obvious "blueshift", and the moving distance increases with the increase of dust retention on leaf surface. (5) The leaf water index (y = - 1.18x² + 0.5424x + 0.9917, R² = 0.8030, RMSE = 0.187) had the highest accuracy in the regression model of leaf surface dust deposition using spectral parameters. The test showed that the R² reached 0.9019, which indicated that the model has a good fitting effect. This prediction model can effectively estimate the dust deposition of the leaf surface of Euonymus japonicus L.

The Relationship Between the Actual Level of Air Pollution and Residents' Concern about Air Pollution: Evidence from Shanghai, China

This study explored the relationship between the actual level of air pollution and residents’ concern about air pollution. The actual air pollution level was measured by the air quality index (AQI) reported by environmental monitoring stations, while residents’ concern about air pollution was reflected by the Baidu index using the Internet search engine keywords “Shanghai air quality”. On the basis of the daily data of 2068 days for the city of Shanghai in China over the period between 2 December 2013 and 31 July 2019, a vector autoregression (VAR) model was built for empirical analysis. Estimation results provided three interesting findings. (1) Local residents perceived the deprivation of air quality and expressed their concern on air pollution quickly, within the day on which the air quality index rose. (2) A decline in air quality in another major city, such as Beijing, also raised the concern of Shanghai residents about local air quality. (3) A rise in Shanghai residents’ concern had a beneficial impact on air quality improvement. This study implied that people really cared much about local air quality, and it was beneficial to inform more residents about the situation of local air quality and the risks associated with air pollution.

Escape or stay? Effects of haze pollution on domestic travel: Comparative analysis of different regions in China

Haze pollution has significant impacts on tourist perception and behaviour, including a sharp increase in risk perception and a decline in tourism experience quality. However, given the intervention of multiple factors, whether these impacts necessarily have a negative effect on the overall scale of regional tourism remains unknown. Hence, this paper explored the overall effect of haze pollution on domestic travel. Using 28 major cities in China as examples, we employed a two-way fixed effect panel model to investigate this issue. Combined with the comparisons between the results of different subgroups, including high cities, medium cities, low cities, outbreak cities and non-outbreak cities, this study found that there was no significant effect of haze concentration on domestic travel, but public awareness of haze pollution had a significant positive effect on that. Meanwhile, public awareness exerted a negative moderating effect of haze concentration and domestic travel. The findings are beneficial for understanding the new situation faced by the tourism industry, and several suggestions are provided for policy makers and travel agencies.

Assessing customers' perceived value of the anti-haze cosmetics under haze pollution

Air pollution caused by haze may damage residents' skin, which affects their willingness to buy anti-haze cosmetics. Thus, this paper pays attention to residents' willingness to buy anti-haze cosmetics through customer perceived value theory. In this study, it is assumed that all consumers are rational economic people and that anti-haze cosmetics on the market can effectively cleanse, isolate and repair haze damage. Based on customer perceived value theory and the characteristic of anti-haze cosmetics, four main drivers and had been selected out, that is, monetary value, social value, brand value and perceived haze awareness. Then, based on 314 valid questionnaires, the structural equation analysis method had been used to analyze the impact of the four dimensions of customer perceived value theory on perceived value and consumers' purchase intention of anti-haze cosmetics. The empirical results showed that monetary value, social value, and perceived haze awareness had positive impact on perceived value and purchase intention of anti-haze cosmetics, while brand value only affects perceived value. Perceived value was a partial mediator between the relations of monetary value, social value, perceived haze awareness and purchase intention, while played a completely mediating role between brand value and purchase intention. Then, we also found that price sensitivity played a significant down-modulatory role in perceived value and purchase intention. Furthermore, the perceived haze awareness is the term that we first proposed in this realm, which extends and optimizes Customer Perceived Value. Finally, according to the survey results, consumers would be willing to pay an additional 56.1 yuan per month for the anti-haze effect of cosmetics.

A Novel Linear Time-Varying GM(1,N) Model for Forecasting Haze: A Case Study of Beijing, China

Haze is the greatest challenge facing China’s sustainable development, and it seriously affects China’s economy, society, ecology and human health. Based on the uncertainty and suddenness of haze, this paper proposes a novel linear time-varying grey model (GM)(1,N) based on interval grey number sequences. Because the original GM(1,N) model based on interval grey number sequences has constant parameters, it neglects the dynamic change characteristics of parameters over time. Therefore, this novel linear time-varying GM(1,N) model, based on interval grey number sequences, is established on the basis of the original GM(1,N) model by introducing a linear time polynomial. To verify the validity and practicability of this model, this paper selects the data of PM10, SO2 and NO2 concentrations in Beijing, China, from 2008 to 2018, to establish a linear time-varying GM(1,3) model based on interval grey number sequences, and the prediction results are compared with the original GM(1,3) model. The result indicates that the prediction effect of the novel model is better than that of the original model. Finally, this model is applied to forecast PM10 concentration for 2019 to 2021 in Beijing, and the forecast is made to provide a reference for the government to carry out haze control.

The aggravation of urban air quality deterioration due to urbanization, transportation and economic development - Panel models with marginal effect analyses across China

In this paper, panel data models are established to examine the impacts of urban construction, transport facilities, and economic development on the urban air quality. Combined with data from different tiers of Chinese cities for two time series, 2010 and 2015, the variable-intercept model (VIM) is used to determine the parameters and significance of each independent variable. The marginal effects of different categories of independent variables (urbanization, transportation and economy) on the urban air quality are also studied with regard to the results of different VIMs. The results show that transportation factors (such as annual passenger trips, bus numbers and taxi numbers) have the most significant effects on the air quality for all the Chinese cities. Moreover, urbanized area and annual gross value of industrial output also have prominent impacts on the air quality across China. In addition, the marginal effects of the air quality index obtained via VIMs with classified local variables reflect that the influences of urbanization, transportation and economy on urban air quality are substantially different among different tiers of cities. Therefore, based on the findings, we propose measures to improve air quality for different tiers of cities, such as rational use of space resources, optimizing transport modes, and encouraging carpooling.

The end effect in air pollution: The role of perceived difference

As the common saying goes: All's well that ends well. This research was the first to explore whether the end effect could be observed in the perception of air pollution and further examined the effect of perceived difference on the end effect. In Experiment 1, participants went through a short trial of 30 severe air pollution pictures and a long trial of 45 pollution pictures containing 15 extra moderate pollution pictures at the end. The results showed preference for the long trial as well as more willingness to experience it again, which verified the end effect. In Experiment 2, the long trial was adjusted to 45 severe air pollution pictures, which caused the end effect to disappear. In Experiment 3, it was confirmed that perceived difference had an impact on the end effect, as the end effect worked when subjects cognitively focused on the variated pollution extent but disappeared when they focused on the air pollution quality. These results advance our understanding by directly demonstrating the influence of perceived difference on the end effect as well as providing a useful view to intervene in people's perception of air pollution. Further theoretical and practical implications are discussed.

Air pollution lowers Chinese urbanites' expressed happiness on social media

High levels of air pollution in China may contribute to the urban population's reported low level of happiness^1-3. To test this claim, we have constructed a daily city-level expressed happiness metric based on the sentiment in the contents of 210 million geotagged tweets on the Chinese largest microblog platform Sina Weibo^4-6, and studied its dynamics relative to daily local air quality index and PM_2.5 concentrations (fine particulate matter with diameters equal or smaller than 2.5 μm, the most prominent air pollutant in Chinese cities). Using daily data for 144 Chinese cities in 2014, we document that, on average, a one standard deviation increase in the PM_2.5 concentration (or Air Quality Index) is associated with a 0.043 (or 0.046) standard deviation decrease in the happiness index. People suffer more on weekends, holidays and days with extreme weather conditions. The expressed happiness of women and the residents of both the cleanest and dirtiest cities are more sensitive to air pollution. Social media data provides real-time feedback for China's government about rising quality of life concerns.

Evaluation of Landsat-8 and Sentinel-2A aerosol optical depth retrievals across Chinese cities and implications for medium spatial resolution urban aerosol monitoring

In urban environments, aerosol distributions may change rapidly due to building and transport infrastructure and human population density variations. The recent availability of medium resolution Landsat-8 and Sentinel-2 satellite data provide the opportunity for aerosol optical depth (AOD) estimation at higher spatial resolution than provided by other satellites. A year of 30 m Landsat-8 and 10 m Sentinel-2A AOD data retrieved using the Land Surface Reflectance Code (LaSRC) were compared with coincident ground-based Aerosol Robotic Network (AERONET) Version 3 AOD data for 20 Chinese cities. Stringent selection criteria were used to select contemporaneous data - only satellite and AERONET data acquired within 10 minutes were considered. The average satellite retrieved AOD over a 1470 m × 1470 m window centered on each AERONET site was derived to capture fine scale urban AOD variations. AERONET Level 1.5 (cloud-screened) and Level 2.0 (cloud-screened and also quality assured) data were considered. For the 20 urban AERONET sites in 2016 there were 106 (Level 1.5) and 67 (Level 2.0) Landsat-8 AERONET AOD contemporaneous data pairs, and 118 (Level 1.5) and 89 (Level 2.0) Sentinel-2A AOD data pairs. The greatest AOD values (>1.5) occurred in Beijing, suggesting that the Chinese capital was one of the most polluted cities in China in 2016. The LaSRC Landsat-8 and Sentinel-2A AOD retrievals agreed well with the AERONET AOD data (linear regression slopes > 0.96; coefficient of determination r2 > 0.90; root mean square deviation < 0.175) and demonstrate that the LaSRC is an effective and applicable medium resolution AOD retrieval algorithm over urban environments. The Sentinel-2A AOD retrievals had better accuracy than the Landsat-8 AOD retrievals, which is consistent with previously published research. The implications of the research and the potential for urban aerosol monitoring by combining the freely available Landsat-8 and Sentinel-2 satellite data are discussed.

How Far Has China’s Urbanization Gone?

China’s rapid urbanization has attracted wide international attention. However, it may not be sustainable. In order to assess it objectively and put forward recommendations for future development, this paper first develops a four-dimensional Urbanization Quality Index using weights calculated by the Deviation Maximization Method for a comprehensive assessment and then reveals the spatial association of China’s urbanization by Exploratory Spatial Data Analysis. The study leads to three major findings. First, the urbanization quality in China has gradually increased over time, but there have been significant differences between regions. Second, the four aspects of urbanization quality have shown the following trends: (i) the quality of urban development has steadily increased; (ii) the sustainability of urban development has shown a downward trend in recent years; (iii) the efficiency of urbanization improved before 2006 but then declined slightly due to capital, land use, and resource efficiency constraints; (IV) the urban–rural integration deteriorated in the early years but then improved over time. Third, although the urbanization quality has a significantly positive global spatial autocorrelation, the local spatial autocorrelation varies between eastern and western regions. Based on these findings, this paper concludes with policy recommendations for improving urbanization quality and its sustainability in China.