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The interaction between green finance and other factors, such as ecological environment, has been a research hotspot nowadays. Especially, the reasonable guiding of capital into energy conservation and environmental protection industries would greatly affect those factors, so as to the relation between them. This paper aimed to analyze the relationships between green finance, technological progress, and ecological performance quantitatively. The entropy method was used to respectively construct the system of index for green finance and technological progress, and index for ecological performance was measured by the super-SBM model. The panel vector autoregressive (PVAR) model was selected to empirically analyze dynamic relationships based on datasets from 30 provinces in China during 2008-2019 period. The results told that (1) from 2008 to 2019, China's overall level of green finance, technological progress and ecological performance increased to varying degrees. Spatially, the areas with high-developed green finance greatly coincided with those such as large cities or the eastern coast that had good financial development. The distribution of technological progress index were similar, except some underdeveloped areas with relatively advanced scientific research institutes. The ecological performance, however, was high in the South and low in the north. (2) In the lag for 3 years, the influence of green finance on ecological performance in different regions was all positive for that all the coefficient symbols that passed the significance test were above 0, while that on technological progress was negative first and then positive. And the effects of technological progress on ecological performance were positive in ecological regions and negative in low ecological regions (0.0893 and -0.1211 in the case of three-stage lag respectively). (3) The contribution of green finance to ecological performance was high according to the results of variance decomposition, maintained at about 30%, and that of technological progress increased year by year (from 0.000 to 0.039). Therefore, we proposed to strengthen the development of green finance in underdeveloped regions. The emphasis should be laid on the researches and applications of green technology, the formulation of financing policies in innovation compensation and the establishment of a dynamic monitoring system for the ecological environment., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Environmental protection and innovation performance are key issues that affect the sustainable development and value growth of cities. Using data of 272 prefecture-level cities during 2002-2016 and 2,169 listed companies, and the air ventilation coefficient and government environmental regulations, as the instrumental variables for PM 2.5 concentrations, this paper applies two-stage OLS (2SLS) to investigate how air pollution affects China's technological innovation and its realization mechanism. The results indicate that the rise in air pollution significantly inhibits the technological innovation level of regions as a whole as well as individual enterprises. When considering the spatial effect of the spread of PM 2.5 concentrations, due to positive spillover effects on innovation activities, the spread of air pollution has negative impacts on technological innovation activities in surrounding cities. Human capital and labour costs are important channels through which air pollution influences China's technological innovation. The implementation of pilot carbon trading policies can effectively reduce air pollution and then contribute to the achievement of the goals of the green growth strategy., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Free-trade zones are highlands of regional development that have a radiating effect on surrounding cities. This paper uses Yangtze River Delta Urban Agglomeration (YRDUA) data from 2003 to 2018, to examine the impact of the China (Shanghai) pilot free-trade zone (SPFTZ) on green total factor productivity (GTFP) in the YRDUA. It uses the regression discontinuity (RD) method and analyzes the influence mechanism with the help of the mediating effect model. The paper presents the following major findings. The establishment of the SPFTZ significantly promoted GTFP in the YRDUA, with technological progress being the main driving force. An analysis using the mediating effect model found that financial efficiency and industrial structure upgrading play a complete mediating role in GTFP growth in the YRDUA. Therefore, the SPFTZ should make use of its policy advantages, take full advantage of the effect of the green growth pole, and promote green mutual development with the YRDUA., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Very few studies exist in rationalizing comprehensively the relationship between market integration and green economic growth in China. This paper tries to answer the question whether and how market integration influences regional green economic growth in China. Based on the panel data of 285 city-level regions from year 2004 to 2018 in China, this paper develops explanatory mechanism and discusses the influence theoretically and empirically. To advance the analysis, we construct market integration indicator through relative price variance method based on commodity retail price index and employ the Malmquist-Luenberger (ML) productivity index and DEA-SBM (data envelopment analysis-slacks-based measure) model to evaluate green total factor productivity (GTFP) as indicator for green economic growth. Our empirical findings are: (1) Apparent regional imbalance exists in both the development of market integration and green growth and gaps are expanding from year 2004 to 2018. (2) Market integration promotes regional green growth significantly. (3) Mechanism analysis illustrates that market integration fosters green growth through economies of scale effect, composition effect and spillover effect, respectively. (4) Heterogeneous analysis suggests that the influence from market integration on green growth varies depending on region's difference in traffic situation and in overall development level., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Campaign-style environmental implementation (CEI) is widely exerted in environmental protection, while its benefits and costs are controversial. We take advantage of the Central Environmental Protection Inspection (CEPI) System-a latest and distinguished form of CEI launched by China in 2016, as a quasi-natural experiment, to compare the benefits and costs of CEI based on water pollution effect estimates. Our results based on the annual panel data from 500 cities during 2009-2018 show that CEPI significantly reduced water pollution by an average of 20.7%. Further cost-benefit analysis based on the estimates of water pollution reduction shows that the potential health benefits of mortality and morbidity reduction resulting from CEPI are at least $12.26 billion, without bearing additional economic costs. We also explore why CEPI is cost-effective and find that CEPI reduces water pollution and becomes cost-effective mainly through deterring local officials, punishing polluting enterprises, and increasing public participation in environmental governance., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Labor agglomeration with heterogeneous skills has different effects on urban air pollution. Based on the panel data of 263 prefecture level cities in China from 2006 to 2019, this paper constructs a Spatial Durbin Model to explore the impact of skill heterogeneous labor agglomeration and the interaction between skill heterogeneous labor agglomeration on urban air pollution. The results show that there is a positive U-shaped relationship between high-skilled labor agglomeration, low-skilled labor agglomeration, and urban air pollution. From the perspective of restraining urban air pollution, high-skilled labor agglomeration is stronger than low-skilled labor agglomeration. Under the influence of high skilled labor agglomeration, the inhibitory effect of low-skilled labor agglomeration on urban air pollution is enhanced. High-skilled labor agglomeration and low-skilled labor agglomeration reduce the degree of urban air pollution by promoting the improvement of urban innovation level. Based on this, this paper puts forward some policy suggestions, such as further promoting urban labor agglomeration, formulating reasonable urban population management policies, strengthening labor exchange and learning, and carrying out labor knowledge and skills training., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Whether high-speed rail (HSR) can promote the coordination between the economy and environment is a critical issue that needs to be investigated. We used balanced panel data of 281 prefecture-level or above cities in China from 2005 to 2017 to consider the opening of HSR as a quasi-natural experiment. We integrated the difference-in-differences (DID) model, the spatial difference-in-differences (SDID) model, and social network analysis (SNA) to empirically investigate the impact of HSR on urban environmental efficiency (UEE). The results showed that HSR significantly improved UEE by 4.6% annually during the study period, although the effect of HSR on UEE exhibited a time lag and varied dramatically in different cities. An analysis of the mechanism showed that the effect of technological innovation and the structural effect brought by the opening of HSR were the main contributors to the improved UEE. Further analysis showed that HSR service centrality also significantly improved UEE and HSR opening and HSR service centrality both had positive spatial spillover effects on the UEE of neighboring cities. Several policy implications are proposed accordingly to make full use of the advantages of HSR to improve UEE for China., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Regional density is a useful tool for analyzing regional spatial structure as well as a good starting point for analyzing regional CO2 emissions per capita. This paper empirically analyzes the relationship between regional density and per capita CO 2 emissions in China's prefecture-level administrative regions. We improve the CO 2 emission measurement method for prefecture-level administrative regions and estimate the per capita CO 2 emissions of 252 prefectural-level cities in China from 2003 to 2013. Using panel fixed effect model regression, and taking the terrain roughness index as an instrumental variable to solve endogeneity, we find that the relationship between regional density and per capita CO 2 emissions presents in an inverted U-shape, per capita CO 2 emissions first increase with the increase of regional density, and after reaching the turning point, it decreases with regional density. In a mechanism test, analyzing the interaction terms between regional density and industrial structure, and regional density and urbanization level respectively. We found that industrial structure and urbanization are important mechanisms for regional density to affect CO 2 emissions. In order to reduce per capita CO 2 emissions, we propose corresponding policy implications for the regions in different positions of the "U" curve., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Management of economic growth targets is a universal measure employed by worldwide governments for macroeconomic regulation. This paper aims to empirically investigate the impact of economic growth targets set by governments of prefecture-level cities on the environmental regulation intensity. We extracted panel data on annual economic growth targets and environmental regulation indicators from the government work reports (2009-2016) of 284 China's prefecture-level cities. The study concludes that an increase in economic growth target significantly weakens the intensity of environmental regulation. The conclusion still holds true after robustness tests, including changing measurement variables, regression samples, and conducting endogenous tests. The underlying reason for the inhibitory effect may be that in order to achieve economic growth targets, local governments prefer less stringent environmental regulations. They subsequently expand outputs in the short term by increasing the proportion of secondary industry in GDP, land transfer area, and fixed asset investment. Further research in this paper also finds that only cities with low economic development levels and low openness to the outside world experience the negative effect of a local government's annual economic growth target on environmental regulation intensity., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The ecological environment and economic development are double-edged swords. Nevertheless, we can still achieve green and coordinated development through environmental regulations and industrial agglomeration. Based on the panel data from 269 cities in China from 2008 to 2017, using the SBM-DEA model, the Malmquist-Luenberger (ML) index, and the spatial Durbin model (SDM) under different weight matrices, this paper explored the spatial pattern of ecological efficiency, the internal evolution mechanism, and the spillover effects of industrial agglomeration and environmental regulation on ecological efficiency. The results demonstrated that China's urban ecological efficiency had an obvious spatial pattern of "high in the east and low in the west." Due to the different life cycles of cities, the internal evolution mechanism of urban ecological efficiency had significant differences. Pure technological efficiency (PEFFCH), technological progress (TECH), and scale efficiency (SECH) have contributed the most to the ecological efficiency of the eastern, central, and western regions, respectively. Furthermore, a significant U-shaped relationship existed between industrial agglomeration and ecological efficiency. In particular, urban ecological efficiency will be improved when the industrial agglomeration level exceeds a certain scale. However, the spillover effects of industrial agglomeration were more sensitive to distance factors, leading to failure of the significance test under the economic distance and asymmetric economic distance matrix. The "innovation compensation effect" of environmental regulation was greater than the "compliance cost," which verified the applicability of the "Porter Hypothesis" in urban ecological efficiency to a certain extent. Finally, the geographical detector showed that each variable had a certain impact on the urban ecological efficiency, and the impact of the interaction term was greater than that of a single variable., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This paper examines a causal relationship between the opening of a city's subway system and its air quality by exploiting daily data on prefecture-level cities in China from 2000 to 2012. Using multi-period difference in differences (DID) method, we find that air quality can be significantly improved following a subway system opening. Robustness tests support the fundamental empirical results. Heterogeneity analysis shows that cities in the eastern and western regions and cities with higher GDP or cities with larger population experience greater and more significant reduction in pollution. We further find that the air pollution continues to decrease with the extension and prolonged operating period of a subway system. Mechanism analysis shows that the resulted air pollution index (API) reduction is due to the substitution effect of taxi., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The driving pattern of three-wheeled auto-rickshaws is governed by commuter's demands on certain fixed roads that offer flexible mobility solutions in a mid-size city. This flexibility creates unique driving patterns, frequent stop-and-go conditions, frequent acceleration, braking, and excessive idling, which affect emission rates. Existing emission testing regulation based on the driving cycle does not represent real-world conditions. In this paper, the real-world driving cycle of three-wheeled auto-rickshaw has been developed to provide realistic CO, HC, and NO X pollutants and see the effect of introducing modal shift of electric auto-rickshaw to reduce emission for India. Two policy scenarios were evaluated (1) with a 5% modal shift to electric auto-rickshaw, and (2) without modal shift. The results indicate that with a 5% shift to electric auto-rickshaw, by 2030, emissions will decrease by 6.30% compared to the baseline scenario. Further, by 2030, the projected CO emission would be 1,696,670 ton/year, and HC and NO X emissions would be 2,067,371 ton/year. Results can be useful for policy interventions towards cleaner fuel and the aggressive adoption for reducing pollution from auto-rickshaw., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

To explore the relations between the number of accident deaths (NCD) and various factors in construction safety, a multiple linear regression model was established, based on the panel data of economy, construction labor, and the number of accident deaths in 31 provinces (regions) of China from 2009 to 2018. The results show that the average total profits and taxes (TPAT), and the death rate of ten thousand people (DR) are positively correlated with NCD, while the labor productivity (LP) is negatively correlated with it. Under the condition that other factors remain unchanged, NCD increases by 0.02 per a hundred million CNY. However, if DR increases by one ten thousand, NCD will increase by 8.66 on average. On the contrary, when LP increases by a hundred million CNY per ten thousand people, NCD decreases by 0.19. The model also predicts NCD in different provinces and cities from 2019 to 2020 with the method of quadratic exponential smoothing. As well, practice results show that the model is effective and practical., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Urban governance is an important cornerstone in the modernization of a national governance system. The establishment of smart cities driven by digitalization will be a vital way to promote economic green and sustainable growth. By using the data of 274 prefecture-level cities in China from 2004 to 2017, we study the impact of smart city policy on economic green growth and the underlying mechanism of the impact. It is shown that the establishment of smart cities has significantly promoted the green growth of China's economy. This conclusion is further confirmed by using exogenous geographic data as instrumental variables and robustness tests, such as the quasi-experimental method of Difference in Difference with Propensity Score Matching (PAM-DID). The mechanism test shows that promoting economic growth, reducing per unit GDP energy consumption, and lowering waste emissions represent three ways for smart cities to promote green economic growth. The heterogeneity test shows that smart city policy has an obvious promotional effect on the economic green growth of both large cities and non-resource-based cities. This paper is expected to provide a reference for the urban development and economic transformation of emerging economies., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In China, the local government's "land for development" strategy has led to a large number of urban construction land allocated to the industrial field, which has promoted the rapid development of industry and economy in the short term but also brought serious environmental quality losses. This paper systematically sets out how land misallocation works on urban air quality and employs the spatial Durbin model (SDM) to conduct an empirical analysis on the panel data of 283 China cities at or above the prefecture level. The result shows that, stimulated by financial maximization and political promotion, in order to obtain more fiscal revenue and growth performance, local governments prefer to allocate a large number of urban construction land to industry and related fields, which leads to the underestimation of industrial land price and the misallocation of land resources. Land misallocation has exerted significant inhibiting effects on the air quality of local and their surrounding cities through inhibiting the upgrading of industrial structure. Further analysis reveals that the bigger the city, the lesser the inhibition effects of land misallocation on upgrading of industrial structure and urban air quality and vice versa. The conclusions of this paper can provide a useful reference for local governments to optimize land allocation, promote economic restructuring, and environmental quality upgrading., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

This paper analyzes the theoretical mechanism and transmission channel for the impact of air pollution on firms' domestic value-added ratio (DVAR) in exports. Based on the matched Chinese Industrial Enterprises Database and China Customs Enterprise Database, the DVAR in exports is measured, and this mechanism is empirically tested with standard measurement methods. The study concludes that air pollution is not conducive to raising the DVAR during the sample period. This conclusion remains robust to many issues, such as endogeneity, measurement error, extension of the sample interval, substitution of the air pollution index, and policy changes. The impact of air pollution on the DVAR varies by the type of firm ownership, size, and age, as well as the size and location of the city. In addition, the negative impact of air pollution on the DVAR grows with increases in the PM2.5 concentration. The growing factor prices of domestic intermediate goods and the falling productivity due to air pollution are important transmission channels for the negative impact of air pollution on the DVAR. In order for firms to open up on all fronts through quality trade development, we recommend the prevention and control of air pollution, fueling internal driving forces for firms' independent innovation, and encouraging firms to target the medium- and high-end markets., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The increased use of renewable energy in electricity generation has not been sufficient to reduce the associated emissions. Therefore, a better understanding of the evolution of electricity consumption may be advisable to undertake suitable energy policies. This paper contributes to this understanding by analyzing the non-linear income and temperature effects on electricity demand in the residential sector in Andalusia (Spain). To this end, panel data OLS, PCSE, and quantile regression analysis methods have been performed to provide a complete picture of the relationship between the studied variables. The results show evidence to support an inverted N-shaped relationship, with respect to income, without reaching the upper threshold point. The results also show that electricity elasticity, with respect to income, tends to increase with residential electricity consumption. It is also observed that temperature values, increasing above 22°C and temperatures decreasing below 15°C progressively, increase residential electricity consumption, the elasticity with respect to temperatures being higher for municipalities with lower residential electricity consumption. Reinforcing energy efficiency measures in the municipalities with the highest electricity consumption is recommended., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The inefficient enforcement of environmental policies cannot address global environmental challenges. As a result, China's government has implemented the Central Environmental Protection Inspection (CEPI) to overcome the policy-implementation gap between higher and lower levels of government. The existing literature has examined the positive effects of CEPI on environmental pollution, but has not explained the mechanisms for its success. To examine these mechanisms, this article uses a series of regression analyses on an empirical data set of 282 prefecture-level cities from 2010 to 2018. The results identify the mechanism for the effective implementation of CEPI, from the perspective of the campaign-style governance of local officials at local levels. This study also shows the heterogeneity of the campaign-style governance behavior of local officials, including position types and professional and cultural backgrounds. And finally, this study demonstrates that the campaign-style governance behavior of local officials has a moderating effect on the relationship between environmental pollution and local officials' promotion. Ultimately the article proposes that higher government levels should adopt the effective incentives policy to address gaps between environmental policy and implementation., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

The utilization of economic capabilities to raise production in the economy enhances the industrial activities and use of transportation. These activities deteriorate the quality of the environment and raise the level of particulate matter (PM 2.5 ). The objective of this study is to investigate the impact of economic capabilities and population agglomeration on PM 2.5 emissions for the sample of 23 sub-Saharan African countries-a highly polluted region of the world. The study used panel regression from 2007 to 2015 and found that production capabilities are highly significant and directly effecting PM 2.5 emissions. The Kuznets hypothesis does not hold in this region, and the concentration of population in urban areas is also significant. To avoid the problem of possible endogeneity in the empirical model and for robustness check, the study also utilized system GMM and found consistent results. The findings of the study are highly valuable to reduce PM 2.5 and propose that the policymakers in Sub-Saharan African countries should opt for industrial specialization rather than economic complexity and ensure that the proper measures are taken to control PM 2.5 . Moreover, population concentrations should not be taken place in a few main urban cities., (© 2020. Springer-Verlag GmbH Germany, part of Springer Nature.)

This paper examines urban environmental performance using a unique database of 286 Chinese cities for the period 2002-2014. Both the dynamics of urban total factor environmental efficiency and total factor environmental productivity are explored employing slack-based measures. The findings reveal a U-shaped trend of urban environmental performance over time during the sample period. Energy conservation and pollutant reduction were the key drivers of this transformation, while the deterioration in capital efficiency slowed down this transformation. In terms of regional and city-size heterogeneities, the eastern and large cities showed better environmental performance. In addition, environmental Kuznets relationship existed for waste water and SO 2 emissions, but not for CO 2 emissions.

Based on the Government Work Report of 265 prefecture-level cities in China from 2004 to 2015, this article combines economic growth expectations data and keyword capture to explore the relationship between government economic growth expectations and air pollution. The main results are as follows: (1) The economic growth expectations of local governments, and the "increment" between prefecture-level and provincial governments' growth expectations for economic growth have significantly increased air pollution. The certainty and completion degree of economic growth expectations have different effects on air pollution, and the impact of the expected rigid constraint and overfulfilled degree on air pollution are prominent. When the city's real economic growth exceeds 1%, 2%, 3%, and 4% of growth expectations, respectively, SO 2 emissions will increase by 10.577%, 10.671%, 11.825%, and 16.296%, and PM 2.5 concentration will increase by 2.115%, 2.503%, 3.592%, and 4.421%. (2) The government's annual economic growth expectations have different effects on different types of technological innovation. For every 1% increase in the government's economic growth expectations, the green technology will be reduced by 0.956% which exacerbates regional air pollution. Furthermore, the green technology can explain 6.5% of air pollution induced by government economic growth expectations.

Based on the development concepts of "innovation, coordination, green, opening and sharing," a high-quality economic evaluation index system is constructed using city-level data in Yangtze River Economic Belt (YREB), China. Further, the spatial lag model is used to empirically study the effects of environmental regulation, foreign direct investment, and its interaction term on the high-quality economic development. The results show that environmental regulation is conducive to promoting high-quality economic development, which provides a certain empirical basis for the Porter Hypothesis. In addition, foreign direct investment also plays a significant positive role. Specifically, environmental regulation has positive impacts on the relationship between foreign direct investment and the high-quality economic development. Finally, this paper puts forward some countermeasures and suggestions, such as improving environmental regulation policy and actively introducing high-quality foreign direct investment.

Solar photovoltaic panels are increasingly being used throughout the world, particularly in Egypt, where a station has been constructed in the city of Aswan with a capacity of 1480 MW, and is classified as one of the largest photovoltaic plants in the Middle East country, where photovoltaic systems are characterized as environmentally friendly and do not produce any pollutants, and photovoltaic systems have the ability to operate with diffuse radiation. It is therefore very important to understand how photovoltaic panels respond to changing weather conditions and how climate conditions affect the performance of photovoltaic cells, as only 15-20% of solar radiation can be converted to electricity, while the rest is wasted as thermal heat. There are two very important factors influencing the efficiency of the photovoltaic cells: the cell temperature and the solar radiation intensity on the photovoltaic cells. Cooling of the optical surfaces is one of the main factors that must be considered in order to achieve the highest efficiency when operating the solar PV systems. By using the appropriate cooling technology for the photovoltaic cells, the electrical efficiency is improved, and the cell degradation rate is decreased over time, which increases the life span of the PV panels. In some applications, such as industrial and domestic applications, excess energy removed with cooling technology could be used. The cooling mediums used to cool the PV panels are water, air, PCM, and nanofluid. Also, the spectral splitting utilization represents a good solution for hybrid solar photovoltaic-thermal applications to obtain higher performance of the photovoltaic. This paper gives a brief analysis of technologies used to improve PV systems efficiency in terms of the nature of cooling media, spectral splitting, and reflectors. Moreover, the economic study of these techniques is presented to demonstrate their economic feasibility. The aims of the present review paper are to provide good knowledge and understanding of all technologies used to improve the performance of PV systems and demonstrate the economic feasibility of these technologies.

This study examines the impact of economic and financial activities on air pollution in China using prefecture-level panel data from 2004 to 2015. Recruiting the air quality index (AQI) as a measure of overall air quality in Chinese cities, we find that industrial production, financial development, and economic integration lead to higher overall air pollution. Nevertheless, efficiency in urban planning through public transportation and population density alleviates this environmental degradation. A closer look into the two main air pollutants in China, sulphur dioxide and dust, further highlights the complexity of the issue. We find that trade openness reduces both sulphur dioxide and dust emissions, whereas financial development reduces sulphur dioxide emissions but increases dust in Chinese cities. Our findings are of particular interest to policymakers when devising environmental policies in support of sustainable economic development.

We attempt to understand the pollution characteristics and carcinogenic risk of toxic elements around Hutou Village, Xuanwei City, Yunnan Province, China. For this propose, 48 road dust samples were collected systematically, and the concentrations of Cr, Ni, Cu, Zn, As, Cd, Pb, Co, and Cr(IV) were analyzed and compared; the spatial distribution was obtained. The I geo and EF indices and multivariate statistical analysis (CA, PCA, HACA) were carried out for source investigation, and human health risk assessment was also adopted to evaluate local non-carcinogenic and carcinogenic risks. The result showed that Cr, Ni, Cu, Cd and Co contaminations were quite serious; Zn, As, Cd, and Pb had similar distribution pattern, and Cr and Ni also shared similar distribution characteristics; Cd, Pb, Zn, and As ascribed to anthropogenic sources, while Cr and Ni originated from either anthropogenic activity or natural sources; Co and Cu originated from natural sources; the non-carcinogenic risk of Co cannot be ignored. The carcinogenic risk of Ni was considered unacceptable. Finally, an indoor coal-burning pattern was established that the high Cd and Ni inhalation and ingestion model was associated with lung cancer.

Environmental regulations affect employment through productivity output and factor substitution. This paper employs a difference-in-differences (DID) method to investigate the effect of China's Two Control Zones (TCZ) policy on the urban employment in 287 cities from 1994 to 2009. We apply the DID method to two time points: 1998 for policy issuance and 2000 for the policy implementation. From the results of analyses on full-sample cities, the TCZ policy did not contribute to increasing total urban employment. Moreover, a negative impact on employment resulted from sulfur dioxide and acid rain controls in secondary and tertiary industries, respectively. In the acid rain control zone, the TCZ policy increased the average wage of urban workers. Negative effects on employment were observed in larger cities. The policy triggered labor migration from larger to smaller cities, resulting in significant increases in primary and tertiary industry employment in smaller cities, although the effects on mid-size cities were insignificant. This study provides important empirical evidence and insight into the impact of the TCZ policy on urban employment.

Dhaka is one of the highly populated cities in the world. Increased urbanization and population growth in Dhaka are mostly dependent on groundwater, with 78% of the supply water coming from the Plio-Pleistocene Dupi Tila aquifer. This research was conducted with the objectives of identifying ion chemistry, hydrochemical processes and their relationship to groundwater quality and finding out the impact of over-exploitation on Dupi Tila aquifer. Three consecutive semi-confined aquifers have been delineated up to the explored depth: the Upper Dupi Tila aquifer (UDA), Middle Dupi Tila aquifer (MDA) and Lower Dupi Tila aquifer (LDA). Hydrogeochemical processes and water quality have been inferred from bivariate plots, correlation of major ions, piper plot and stable isotopes analysis. The total dissolved solids show an increasing downwards trend from an average of 267 mg/l in UDA to an average of 284 mg/l in LDA. Waters in all three aquifers as well as surface water (SW) are mainly of Ca/Mg-HCO 3 type. The weathering of aluminosilicates controls the concentration of the major ions. Even though there is a significant decline in piezometric level both in UDA (> -85 m Public Works Department reference datum (PWD)) and MDA (> -65 m PWD), there is no evidence of groundwater recharge through direct infiltration from the river. The stable isotopes indicate most of the UDA, MDA and LDA waters are mainly from local precipitation. Increasingly enriched mean values for stable isotopes for the subsequent aquifers UDA, MDA and LDA, as well as increasing P CO2 for UDA < MDA < LDA, indicate increasingly warmer recharge conditions. The overall groundwater quality in the aquifers is good. At present, we have no indication that groundwater exploitation has altered groundwater quality of the Dupi Tila aquifer. Therefore, it is of vital importance to regularly monitor water quality for the purposes in order to timely detect any potential water quality alteration that could be aggravated by the vast decline in piezometric level, in view of the long-term sustainable development of the groundwater resources of this city., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Land transformation monitoring is essential for controlling the anthropogenic activities that could cause the degradation of natural environment. This study investigated the urban heat island (UHI) effect at the Asansol and Kulti blocks of Paschim Bardhaman district, India. The increasing land surface temperature (LST) can cause the UHI effect and affect the environmental conditions in the urban area. The vulnerability of the UHI effect was measured quantitatively and qualitatively by using the urban thermal field variation index (UTFVI). The land use and land cover (LULC) dynamics are identified by utilizing the remote sensing and maximum likelihood supervised classification techniques for the years 1990, 2000, 2010, and 2020, respectively. The results indicated a decrease around 19.05 km 2 , 15.47 km 2 , and 9.86 km 2 for vegetation, agricultural land, and grassland, respectively. Meanwhile, there is an increase of 35.69 km 2 of the built-up area from the year 1990 to 2020. The highest LST has increased by 11.55 °C, while the lowest LST increased by 8.35 °C from 1990 to 2020. The correlation analyses showed negative relationship between LST and vegetation index, while positive correlation was observed for built-up index. Hotspot maps have identified the spatio-temporal thermal variations in Mohanpur, Lohat, Ramnagar, Madhabpur, and Hansdiha where these cities are mostly affected by the urban expansion and industrialization developments. This study will be helpful to urban planners, stakeholders, and administrators for monitoring the anthropological activities and thus ensuring a sustainable urban development., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Vietnam is highly vulnerable to climate change-related extreme weather events such as heatwaves. This study assesses the association between heatwaves and hospitalizations due to mental and behavioral disorders (MBDs) in Ho Chi Minh City (HCMC). We collected daily MBD hospital admissions data at the HCMC Mental Health Hospital from 2017 to 2019. Heatwaves effects were characterized into the main effect (i.e., the intensity of temperature during heatwaves) and the added effect (i.e., the duration of heatwaves). Time series Poisson regression coupled with a distributed lag linear model (DLM) was used to quantify the 14-day lags effect of heatwaves. Confounders including long-term trend, seasonality, days of the week, holidays, and relative humidity were included in the model. Heatwaves increased all-cause MBD hospitalization by 62% (95%Cl, 36-93%) for the main effect and by 8% (95% Cl, - 3% to 19%) for the added effect. Noticeably, the group aged 18-60 years old was affected by the main effect of the heatwave, while the group aged 61 years and older was affected by the added effect of the heatwave. The effects of heatwaves differed among groups of MBD hospitalizations. The mental and behavioral disorder group due to psychoactive substance use was significantly affected by the main effect of heatwaves (RR:2.21; 95%Cl:1.55-3.15). The group of schizophrenia, schizotypal and delusional disorders were highly vulnerable towards both the main and the added effect of heatwaves with RR = 1.50 (95%CI, 1.20-1.86) and RR = 1.14 (95%CI, 1.01-1.30), respectively., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Collaborative innovation can promote scientific productivity and the development of clean technology and thus has a great potential in constraining the ecological footprint. However, current studies on the impact of collaborative innovation on ecological footprint are insufficient, and results remain controversial. To better understand these impacts, this paper took Guangdong-Hong Kong-Macao Greater Bay Area of China as a case, estimated the ecological footprint at the municipal level from 2008 to 2018, measured collaborative innovation both from four dimensions and from a composite approach, then applied threshold regression models to compare the impact of collaborative innovation on the ecological footprint across different economic intervals. The findings showed that: the ecological footprint of the Greater Bay Area displayed an overall upward trend with prominent spatial heterogeneity. The impact of collaborative innovation on the ecological footprint presented a double-threshold effect when examined with different indicators. Among which, the flow of scientific personnel and capital boosted the ecological footprint, which intensified with economic development, while collaboration in technology exerted significant inhibitory effects on ecological footprint, and the influence of inter-city knowledge collaboration was limited. Overall, collaborative innovation inhibited ecological footprint when measured by a composite index. This might inspire policymakers to adopt sustainable strategies depending on the type of collaborative innovation and the economic status of the city to constrain growth of the ecological footprint, thus minimizing the pressures of human activities on the environment and moving towards a more carbon neutral society., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The increasing drift of urbanization and its impact on urban human settlements are of major concern for China cities. Therefore, demystifying the spatial-temporal patterns, regional types, and affecting factors of urban livability in China is beneficial to urban planning and policy making regarding the construction of livable cities. In accordance with its connotation and denotation, this study develops a systematic evaluation and analysis framework for urban livability. Drawing on the panel data of 40 major cities in China from 2005 to 2019, an empirical research was further conducted. The results show that urban livability in China has exhibited a rising trend during the period, but this differs across dimensions. The levels of urban security and environmental health are lower than those of the three other dimensions. Spatially, cities with higher livability are mainly distributed in the first quadrant divided by the Hu Line and Bole-Taipei Line. Cities in the third quadrant are equipped with the lowest livability. In addition, the 40 major cities can be divided into five categories, and obvious differences exist in terms of the geographical distribution, overall livability level, and sub-dimensional characteristics of the different types. Furthermore, the results of the System GMM estimator indicate that the overall economic development exerts an inhibiting effect on the improvement of urban livability in present-day China, but this logical effect exhibits obvious heterogeneity in different time periods and diverse city scales. Finally, there are also differences in the influencing direction and degree of specific economic determinants., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

To address climate change, one of the toughest contemporary environmental issues, growing importance is attached to the role of the digital economy in combating environmental degradation. Using panel data from 237 Chinese cities during the period 2011-2018, this paper attempts to provide a more systematic view of the relationship between the digital economy and urban low-carbon sustainable development to make up for the existing empirical inconclusiveness. Based on the fixed-effect model, results show that boosting the digital economy can effectively promote urban low-carbon sustainable development, and the conclusion remains robust across a series of robustness checks. Furthermore, innovation factor mobility is the critical transmission channel through which the digital economy affects urban low-carbon sustainable development. Spatiotemporal heterogeneity analysis reveals that the promoting effect of the digital economy on urban low-carbon sustainable development decreases from the northeast to the southeast of China, whereas the impact of innovation factor mobility on urban low-carbon sustainable development decreases from the southeast to the northeast with the Pearl River Delta as the core. Panel threshold regression analysis shows that the impact of the digital economy on urban low-carbon sustainable development is getting stronger with the increase of economic development level charactered with nighttime lights., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Recent environmental research has found that people with higher incomes and in more developed countries are more willing to pay (WTP) to protect their environment than people in developing countries. Based on this assumption, the study investigated Pakistani citizens' attitudes toward environmental protection, precisely their willingness to pay higher prices and taxes to preserve the natural environment. The research was carried out in three Punjab cities (Hasan Abdal, Wah, and Taxila) and four KPK cities (Abbottabad, Havelian, Mansehra, and Haripur). The selected cities are home to knowledgeable people who work in various universities, schools, hospitals, medical colleges, and nearby industrial estates and have a sense of environmental protection and can understand the healthcare issues related to environmental damages. The survey was divided into two sections: one about the participants' socio-demographic information and the other about people's willingness to pay higher prices and taxes to protect the environment. Four hundred and sixty-two people took part in the survey, and the data were analyzed using the bootstrap regression approach. The results show that gender has a detrimental impact, although population density and education positively impact a country's willingness to pay for environmental protection (WTPEP). Women are more likely to engage in pro-environmental behavior than men, resulting in disparities in their perceptions of male and female respondents in the study. People who live in crowded places tend to pay for environmental protection because of population density, healthcare difficulties, and air pollution. The respondents are well-versed in the externalities of environmental pollution; they are hopeful about paying for a better healthcare environment. Other criteria, such as the respondent's income, health status, total pollution level in the country, and per capita income, enable respondents to pay for environmental preservation to achieve long-term sustainable growth. The government must embrace air quality regulations and empower its citizens by offering better healthcare services since they are enthusiastic about paying higher taxes and fees to protect the environment., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Inclusive green growth (IGG) offers an effective alternative to pursue sustainable development. The core of the IGG system lies in the coordination of inclusive, green, and growth subsystems. However, there is little quantitative assessment on IGG based on subsystem collaboration. This study proposes a holistic scheme of inclusive-green-growth nexus in Anhui province from 2009 to 2018 by using an integrated approach, namely, the entropy weight approach (EWA), coupling coordination degree model (CCDM), grey prediction model (GPM), and obstacle factor diagnostic model (OFDM). The results show that: (1) The proposed integrated approach could be viable to measure the synergistic interactions among internal IGG subsystems; (2) At the provincial level, a relatively high IGG performance but a low coupling coordination degree (CCD) of the IGG nexus are seen. Although the predicted value of CCD will show an upward trend, it will not be able to cross the start stage. The obstacle factors on the coordinated development of IGG can be divided into two stages: (3) At the prefectural level, the cities in which CCD is rising outnumber those it is falling. However, the CCD is also low, and the gap between cities is getting wider. The obstacles that affect the CCD of cities see a dynamic evolution trend from "inclusive obstacle type" to "inclusive and growth obstacle type" then to "green obstacle type" over the decade., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Industrial structure change is an important cause of air pollution in China. Regarding the "Triple Play" reform (TPR) led by the Chinese government as a quasi-natural experiment of industrial convergence, this study constructs an analysis framework for the impact of industrial convergence on air pollution. Based on panel data at the Chinese city level from 2004 to 2016, this paper empirically examines the impact of industrial convergence on air pollution by using a difference-in-difference model, the propensity score matching method, and a mediation model. The results show that (1) the TPR significantly alleviates air pollution of cities; (2) the TPR reduces air pollution by improving green technological innovation and industrial structural upgrading; (3) the TPR significantly reduces air pollutants in the southern, coastal, non-resource-based cities and cities with higher technological absorption capacity, but its impact in the northern, inland, resource-based cities and cities with lower technological absorption capacity is not remarkable. This research provides feasible suggestions for the government to promote industrial convergence through deregulation policies and then reduce air pollution., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Urban heat island (UHI) has a great influence on human wellbeing in urban areas. Previous studies have investigated impact on environment, ecosystem, and human health of UHI. To investigate economic impact of UHI is a lack of research. In this study, spatial-econometric hedonic housing price models are developed for estimating the marginal value of summer UHI in Beijing, China. The results showed that UHI effects in Beijing became severe from 2015 to 2017. The heat islands showed a mix of high and sub-high land surface temperature (LST). The spatial Durbin model estimates that one-unit increase of UHI intensity (UHII) would lower the housing value by 3.91%. Regarding the different districts, households had different attitudes to the UHI effect. Specifically, households regarded UHI effect as amenity in the four suburban districts with hills and relatively low LSTs; however, in most urban districts and their surroundings, households were willing to pay to avoid UHI effects with 13.0 dollars to 826.3 dollars for one-degree UHII decrease. This study highlights the urgent need for planners and decision-makers to consider urban expansion, UHI effect, and their economic impact in future urban planning., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Does the growth of non-polluting exports lead to better environmental performance? The answer depends on how these exports rest on local comparative advantages. The more exports rely on polluting inputs, the worse their environmental performance would be. In practice, it is difficult to directly measure the polluting inputs for exporting products at the local level. This study proposes an approach to measure the reliance of exports on local polluting inputs, based on the product relatedness theories and the resource-based view of firms. This approach applies the locational quotient to indicate local resource advantages. Then, it uses the co-occurrence probability to measure the product relatedness of one export to local resource advantages. Finally, it distinguishes the product relatedness to polluting resource advantages from non-polluting ones. A higher level of polluting product relatedness is expected to depress the environmental performance of exports. Using 30 sectors in 281 Chinese cities as a case, this study applies the fixed effect model and the threshold regression model to examine the effects of product relatedness on environmental performance. Empirical results support the efficiency of using product relatedness to predict the environmental performance of exports. A higher level of polluting product relatedness leads to poorer environmental performance and more adverse effects of export growth on the environment., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Road dust, which reflects ambient air quality, receives various pollutants including toxic metal(oid)s from several natural and/or anthropogenic sources. This manuscript reports a comprehensive evaluation of the levels of seventeen metal(oid)s in road dust of a megacity (Dhaka, Bangladesh). Different evaluation approaches were implemented including statistical analysis and GIS mapping, besides environmental, ecological, and human health risk indices. From 30 sampling sites, representative samples were collected, which were analyzed by neutron activation analysis. The average concentrations (± SD) of Na, Mg, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Zn, As, Rb, Sb, Cs, Ba, and W were 11,738 ± 560 µg g -1 , 12,410 ± 1249 µg g -1 , 62,127 ± 5937 µg g -1 , 8.89 ± 0.47 µg g -1 , 5224 ± 1244 µg g -1 , 66 ± 8 µg g -1 , 66.7 ± 6.9 µg g -1 , 547 ± 110 µg g -1 , 25,150 ± 1723 µg g -1 , 8.39 ± 0.65 µg g -1 , 125 ± 17 µg g -1 , 3.63 ± 0.56 µg g -1 , 87 ± 9 µg g -1 , 0.75 ± 0.28 µg g -1 , 4.40 ± 0.48 µg g -1 , 397 ± 87 µg g -1 , and 3.82 ± 1.77 µg g -1 , respectively. The distance-based redundancy analysis showed that the northern region was enriched with Na, Mn, Al, Fe, Zn, and Rb, while the southern region was enriched with Fe, Al, Ti, Cr, and Mg. The GIS mapping shows hot spots of Sc, Cr, Zn, and Cs were observed mostly in heavy traffic areas. Significant positive correlations of Fe-Sc, Al-Mg, V-Mg, V-Al, Cs-Rb, Cs-Sc, Rb-Sc, As-Na, and Cs-Rb invoked their inter-dependency and persistence in road dust. Depending on a set of environmental and ecological index-based calculation, the degree of metal(oid) pollution followed the descending order as W > Sb > Zn > Cr > As > Ti > Sc > V, while no pollution was recorded by Mn, Fe, Al, Rb, Cs, Co, and Ba. Importantly, the total hazard index values for adults and children were higher than unity, indicating potential non-carcinogenic health risks from exposure of road dust. Furthermore, the total carcinogenic risks from Cr and As through ingestion and dermal contact exceeded the standard guideline values. The implementation of different evaluation approaches strengthens the findings of metal(oid) source apportionment., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

As the main driving force for the economic development of East China, the economic development of Anhui has been in good state in recent years. In 2019, the GDP of Anhui Province has reached 3711.4 billion yuan with an increase of 7.5% over the previous year. With the rapid economic development, many environmental problems such as resource depletion, vegetation degradation, and air quality decline have gradually increased. The ecological environment is an important foundation for social and economic development. To examine the status of regional ecological security, this study builds a comprehensive evaluation index system based on the "pressure-state-response" (PSR) framework and uses the entropy weight method to determine the index weight. Then the normal cloud model is introduced to dynamically calculate the ecological security status of Anhui Province from 2010 to 2019. The results show that (1) the ecological security status of Anhui has improved significantly and reached a safe status in 2019. (2) The ecological security status of 16 prefecture-level cities has also been improved, and the ecological security status of these cities is at level III and above except Huainan. There are significant differences in internal development, and the ecological security status of the southern region is ahead of the northern and central region. (3) From the perspective of the criterion level, the pressure and response subsystems develop faster, and the state subsystem develops more slowly. Therefore, it is necessary to pay more attention to the impact of the state subsystem on the overall development of ecological security in the future., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Greater Cairo, Egypt, which lies in the apex of the Nile Delta, is one of the most populated regions in the world. Air pollution is a profound environmental issue prevailing in the urban/rural landscapes of this crowded megacity. The objectives of the present study were to utilize remotely sensed data in order to address the seasonal variations of the nocturnal surface urban heat island intensity (SUHII) as extracted from the American Moderate Resolution Imaging Spectroradiometer (MODIS) satellite and the related seasonal distribution of selected air pollutants, including nitrogen dioxide (NO 2 ), sulphur dioxide (SO 2 ), and carbon monoxide (CO) as extracted from the European TROPOspheric Monitoring Instrument (TROPOMI) for the period from 2018 to 2021. It is observed that there is clear nocturnal urban heat island over Greater Cairo, particularly at the administrative districts dominated by urban land use with high density of population and at the industrial and power generation locations. The highest SUHII is observed during winter. On the other hand, the selected pollutants also represent an urban pollution island (UPI) capping the regions of high SUHII. At the seasonal level, the highest NO 2 correlation with the SUHII occurs during spring (R 2 = 0.59), while the CO correlates maximum during winter (R 2 = 0.51). Nonetheless, the seasonal SO 2 distribution is poorly related to the SUHII as this specific pollutant is significantly associated with the industrial land use. Climatic and topographic factors could intensify the distribution of air pollution in the study area. Results of this study demonstrate the significance of geospatial technology tools in the subtle analysis and addressing regional air pollution. The outputs are also of a paramount implication on the management of urban environment and the adaptation of urban air quality., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Traffic emission is one of the main sources of haze pollution, but few studies have evaluated the dynamic impact and mechanism of transportation infrastructure on haze pollution based on a spatial perspective. This study selects the annual data of 30 provinces in China from 2000 to 2017 and uses a dynamic spatial Durbin model to study the dynamic impact of transportation infrastructure on haze pollution. The results show that transportation infrastructure has a significant spatial spillover effect on haze pollution, and the spatial spillover effect has regional heterogeneity. Specifically, whether long term or short term, highway traffic has a boosting effect on haze pollution, while railway traffic has an inhibitory effect on haze pollution. In addition, transportation infrastructure can affect haze pollution through three paths: expanding economic scale, promoting transformation of industrial structure, and promoting technological progress. At the regional level, the improvement of highway traffic density in eastern, central, and western regions will significantly increase haze pollution. The enhancement of railway traffic density has a significant inhibitory and boosting effect on haze pollution in central and western regions, respectively. For the eastern region, railway traffic construction can only restrain local haze pollution, but cannot exert the spatial spillover effect of railway traffic to reduce haze. The conclusions of this paper provide policy inspirations for giving full play to the haze reduction effect of transportation infrastructure and the development of green transportation., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Under the goal of carbon neutralization, the prevention and control of pollution emissions are very meaningful. Different levels of urban economic development correspond to different pollutant discharges. An assessment of pollution inequality among cities can quantitatively explain regional differences in pollution treatment. This paper proposes a new paradigm to measure pollution inequality within the Yangtze River Delta Economic Zone of China and aims to compare the inequality of pollutant discharge of urban agglomerations and nonurban agglomerations from 2001 to 2017. The findings reveal that the overall pollutant discharge shows a slight upward trend and gradually changes from a "two polarization" distribution in 2001 to a "centralized" distribution in 2017. However, the inequality of pollutant discharge declines during this period, whereby the pattern of the within-group inequality component is similar to the overall inequality, while the inequality of nonurban agglomeration pollution is more severe than that of urban agglomeration pollution. Further decomposition indicates that the difference in pollution intensity is the most critical factor leading to the inequality of pollution discharge, and reducing the gap in energy intensity is the most rapid way to reduce the inequality of pollution discharge. To measure the total driving force that leads to their inequality and to predict the degree of inequality of pollutant discharge, we use a new Theil-DEA model. Based on the empirical results, we anticipate that the imbalance of pollutant discharge will either temporarily maintain the status quo or worsen. Finally, we briefly discuss policy recommendations and special issues., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Based on panel data on 248 prefecture-level cities in China from 2003 to 2018, this study first estimates the treatment effect of the Shanxi Comprehensive Reform Area policy on PM 2.5 concentrations using a PSM-DID method within the counterfactual framework. The average treatment effect shows that contrary to the naive before-after analysis, on average, the Shanxi Comprehensive Reform Area policy significantly increased the PM 2.5 concentrations of prefecture-level cities in Shanxi Province by 0.211% annually, and the place-based placebo test shows that the treatment effect obtained above is robust. Second, the dynamic treatment effects show a continuous decrease in incremental effects during 2011-2018, gradually decreasing from a significant positive increment during 2011-2015 to a zero or even a negative increment during 2016-2018, indicating that the Shanxi Comprehensive Reform Area policy gradually increased in environmental friendliness. Third, the mediating effects estimated by the causal steps procedure show that the Shanxi Comprehensive Reform Area policy influenced PM 2.5 concentrations by increasing the intensity of resource exploitation and decreasing the intensity of environmental regulations, but the capacity of scientific and technological innovations had no mediating effect on the relationship between the policy and PM 2.5 concentrations. Therefore, the government should further reduce the intensity of resource exploitation, strengthen the intensity of environmental regulations, and promote environmentally focused scientific and technological innovations to reduce PM 2.5 concentrations in Shanxi Province., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

China has become one of the countries with the most severe smog pollution, especially in winter. Many local governments had to take various measures to combat the smog. The driving restriction is one of the policies being widely implemented throughout the country, but the actual effect has been controversial. Over 30 cities in China adopted the driving restriction policy in winter specifically in recent years. In this study, regression discontinuity (RD) method is applied to 16 cities to study whether the policy was effective or not and to find out the reason behind. It is found that (1) the effect has shown differences in different cities, in Cangzhou, Linfen and Shijiazhuang, the policy was effective on winter smog control, while it was ineffective in Luoyang, Tangshan, Xinyang and Zhoukou. (2) High proportion of secondary industry in GDP and inconvenient public transport system has inhibitory effect on the effectiveness of the driving policy. (3) Population density, GDP, the proportion of urban green area and driving restriction intensity have no significant impact on the effectiveness of the driving restriction policy. (4) In terms of meteorological factors, average temperature, rainfall, wind speed and air pressure have a negative impact on PM2.5, while humidity has a positive impact on PM2.5., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Government information transparency is taken as a prominent instrument of environmental regulation in Chinese cities, especially in the current digital age. However, polluters' strategic emission and production behaviors across cities, confronted with changing information disclosure level, might make the policy's effect unexpected in practice. While many existing studies have explored the impact of institutions on pollution, government information disclosure only attracted little attention from empirical studies. Using the method framework of the spatial Durbin model, this study empirically investigates the impact of government information transparency on sulfur dioxide emissions with samples of 264 Chinese cities from 2005 to 2012. We find that a city's government information transparency negatively relates to its local emission level of sulfur dioxide. Moreover, a city's sulfur dioxide emissions positively relate to its neighboring cities' government information transparency levels. The further calculations of marginal effects show that the average of such a direct and local impact of government information transparency outweighs the average indirect effect a city receives from its neighboring cities, making government information transparency benefits to pollution abatement in total., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

One of the significant challenges in urbanization is the air pollution. This highlights the need of the green city concept with reconsideration of houses, factories, and traffic in a green viewpoint. The literature review confirms that this reconsideration for green space has a positive effect on the air quality of large cities and to reduce the air pollution. The purpose of this study is to evaluate the annual vegetation changes in the green space of Mashhad, Iran as a very populated city in the middle east to study the air pollution. To investigate the relationship between the air pollution and vegetation, the Landsat 8 satellite images for summer seasons of 2013-2019 were used to extract changes in vegetation by calculating the normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), and the optimized soil adjusted vegetation index (OSAVI). The main contribution in comparison with the relevant studies is to study the relationship between clean, healthy, and unhealthy days with the green space area for the first time in Mashhad, Iran. The results show that the implementation of green city concept in Mashhad, Iran, has been increased by 64, 81, and 53% by NDVI, EVI, and OSAVI, respectively, during the study period. The vegetation area of this city is positively correlated to clean and healthy days and has a negative correlation to unhealthy days, in which the greatest values for NDVI, EVI and OSAVI are 0.33, 0.52, and -0.53, respectively., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Cities are faced with various kinds of pollution issues in the process of economic development, among which industrial pollution has become the most terrifying environmental issue in recent years, so that industrial pollution control should be emphasized. Finding out the key factors influencing industrial pollutant emissions is the basis of taking corresponding measures. Previous studies only focused on one pollutant without a comparative analysis of the contribution of influencing factors to multiple pollutants. Therefore, this study aims to identify the key influencing factors of industrial pollutants in Nanjing, Suzhou, Xuzhou, and Taizhou in Jiangsu Province during the years 2008-2018 by using the logarithmic mean Divisia index (LMDI) method. The results from decomposition indicate the following. (1) Emission intensity (EI) and energy efficiency (EE) are negative factors for decreasing industrial pollutant emissions, while the economic output (EO) and population (P) are positive factors for increasing industrial pollutant emissions. (2) Emission intensity has the most significant influence to industrial wastewater in decreasing emissions; energy efficiency makes the biggest contribution to industrial solid waste in decreasing emissions, economic output and population contribute the most to industrial solid waste in increasing emissions. (3) Nanjing has the highest contribution rate of emission intensity and population, and the contribution rate of energy efficiency and economic output to Taizhou is the highest. Identifying the key driving factors of different pollutants can serve as evidence and guidance for urban environmental governance, therefore reducing emissions ulteriorly, and achieving sustainable development., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

An increasing trend of urban floods in India from past several years causes major damages on Indian cities. By 2050, more than half of the population in the developing countries like India are expected to migrate to urban regions. Urbanization is triggered in developing countries as people migrate to cities in search of employment opportunities resulting in formation of new slums. With high density of population concentration in cities, urban floods are triggered leading to a significant impact of human life and economy of the country. The review focuses on addressing the urban flood occurrence in India and its relationship with population growth climate change. The study also describes the impact of urban floods to the environment and integrated methodologies adopted over decades for the prediction and effective mitigation and management during a disaster event., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

A yearlong study of odor-active VOCs was carried out in the northwestern district of the city of Thessaloniki, Greece, which is in close vicinity to a large-scale petroleum refining and petrochemical process complex, as well as other activities such as power generation from natural gas burning and liquefied petroleum gas (LPG) shipping. Odor nuisance has been a major concern in the district often rising complaints from local residents. A total of 312 samples of VOCs were collected at three sites during a 12-month period (May 2018-May 2019) on thermal desorption cartridges and analyzed by thermal desorption gas chromatography interfaced with mass selective detector (TD-CG/MS). Fifty-five odorous compounds including 8 mercaptans, 5 thiophenes, 7 sulfides, 22 aromatics, and 13 aldehydes were measured, and their spatial and temporal variations were assessed. Concentrations found were compared with those measured at other sites within the urban agglomeration Thessaloniki. Correlations with meteorological conditions (ambient temperature, relative humidity, wind direction/speed, and frequency/depth of temperature inversions) were investigated. Bivariate polar plots of the concentrations of Σ 8 Mercaptans, Σ 5 Thiophenes, Σ 7 Sulfides, Σ 22 Aromatics, and Σ 13 Aldehydes as a function of wind speed and wind direction were constructed for source localization., (© 2020. Springer-Verlag GmbH Germany, part of Springer Nature.)

Elevated noise level is an emerging global problem. Therefore, the present work is conducted that can improve, increase, and integrate the already known issue in literature with new information coming from an emerging country such as Pakistan. The objectives of this study were (i) to assess the urban noise levels and traffic density of Chiniot and Jhang and (ii) to determine nonauditory health effects of noise levels on the residents of both cities. Noise levels were examined from 181 locations (103 from Jhang and 78 from Chiniot) and categorized into hospitals, educational, religious and recreational, residential, industrial areas, and traffic intersections. A-weighted noise level measurements were taken using an integrated sound level meter which recorded short-term road traffic noise continuously for 15 min at each location (LA eq15 ). The urban noise data showed 82% of the sites in Jhang (LA max = 103 dB) and 95% in Chiniot (LA max = 120 dB) exceeded the noise limits set by the National Environment Quality Standard of Pakistan (NEQS-Pak) and World Health Organization (WHO). Moreover, higher intensity of noise levels (LA eq15 ≥ 100 dB) was recorded in Chiniot (17 sites) than in Jhang (1 site). Regression analysis showed a relatively strong relationship of traffic density with noise at Chiniot (R 2 = 0.48) compared to Jhang (R 2 = 0.31). However, spatial variability of noise with traffic density was observed in both cities. Survey study revealed that all the respondents in Jhang and Chiniot suffered from many noise-related health problems such as annoyance (53 and 51%), depression (45 and 47%), dizziness (61 and 65%), headache (67 and 64%), hypertension (71 and 56%), hearing loss (53 and 56%), physiological stress (65 and 65%), sleeplessness (81 and 84%), and tinnitus (70 and 62%) due to noise, respectively. We conclude that noise levels are higher in Chiniot primarily due to high road traffic and secondarily due to high population density. It is recommended that vehicle maintenance and family and urban planning could be effective measures to reduce urban noise levels., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)