Regional Pollution Research Articles

The heterogeneous effects of Chinese industrial parks on environmental pollution

As a form of regional agglomeration, industrial parks create huge benefits for China's economic development, but they also generate considerable environmental externalities and are expected to become the breakthrough to achieve green transformation. This study builds a panel data set by combining a variety of data on the environmental and economic characteristics of firms, industrial parks, and regions, and empirically investigates the effects of establishing industrial parks on emissions of COD, NH3, SO2, and dust. We find such effects are heterogeneous across scales of investigation and types of industrial parks. After entering the industrial parks, firms can reduce their environmental pollution, and the emissions of COD, SO2 and dust have decreased by 9.3 %, 13.4 % and 4.6 %, respectively. However, the study at the regional level finds that, after the establishment of industrial parks, the overall emissions of COD, NH3, SO2, and dust have increased by 37.9 %, 365 %, 45.5 % and 34.9 %, respectively. The expansion of production scale and the increase of pollution-intensive industries are the main factors that cause more serious regional pollution. Meanwhile, the improvement of pollution treatment is very limited. After the establishment of a new park, the emission intensities of newly entered firms are higher than those of pre-existing firms, indicating industrial parks may lower environmental requirements in exchange for economic growth. Parks with clean dominant industries, high levels of water reuse and technical innovation tend to emit less pollutants. Based on the results, this study gives four suggestions for establishing environment-friendly industrial parks, that is, to plan the industrial layout rationally, to speed up the construction of pollution treatment facilities, to increase the environmental threshold for entrance, and to promote technical innovation.

Dissent in the sediment? Lake sediments as archives of short- and long-range impact of anthropogenic activities in northeastern Germany

The suitability of lake sediment cores to reconstruct past inputs, regional pollution, and usage patterns of pesticides has been shown previously. Until now, no such data exist for lakes in eastern Germany. Therefore, 10 sediment cores (length 1 m) of 10 lakes in eastern Germany, the territory of the former German Democratic Republic (GDR), were collected and cut into 5–10-mm layers. In each layer, concentrations of trace elements (TEs) As, Cd, Cr, Cu, Ni, Pb, S, and Zn, as well as of organochlorine pesticides (OCPs), i.e., dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH), were analyzed. A miniaturized solid–liquid extraction technique in conjunction with headspace solid-phase microextraction (HS-SPME) and gas chromatography–mass spectrometry (GC–MS) was used for the latter. The progression of TE concentrations over time is uniform. It follows a trans-regional pattern and is indicative of activity and policy making in West Germany before 1990 instead of those in the GDR. Of OCPs, only transformation products of DDT were found. Congener ratios indicate a mainly aerial input. In the lakes’ profiles, several regional features and responses to national policies and measures are visible. Dichlorodiphenyldichloroethane (DDD) concentrations reflect the history of DDT use in the GDR. Lake sediments proved to be suitable to archive short- and long-range impacts of anthropogenic activity. Our data can be used to complement and validate other forms of environmental pollution long-term monitoring and to check for the efficiency of pollution countermeasures in the past.

The Study of the state of soil cover of the coastal zones of the Caspian Sea, subject to the influence of climatic and anthropogenic factors

This article is dedicated to research of climate impact change and human activity on ecosystems. It is expressed as metals which is called heavy pollution. It covers the coastal territory of northwestern regions of Apsheron. Pollution in the coastal regions of the Caspian Sea with toxic substances, is of great concern, periodic studies of these zones for the presence of heavy metals are necessary. For the first time, a comparative analysis of the content of heavy metals in the territories of the northwestern part of the Absheron was carried out and the hypothetical reasons for their accumulation were presented. The studied soils in the northwestern part of the peninsula were grouped the degree of the density of heavy metals. Zinc (78.62 mg/kg, at a depth of 0–20 sm) copper and cadmium (23.65 mg/kg and 0.92 mg/kg at a depth of 0–20 sm). The concentration of zinc and copper in the northwestern direction of Apsheron by 1.18 and 1.57 times, compared with the allowable norms for clarks. Under the impact of flooding of coastal zones by the waters of the Caspian Sea, the average content of heavy metals, Ni, Cd, Pb in flooded soils at a depth of 0-100 sm increased by 1.7 times.

Unveiling Air Pollution in Crimean Mountain Rivers: Analysis of Sentinel-5 Satellite Images Using Google Earth Engine (GEE)

This article presents an assessment of atmospheric pollutant concentrations based on state-of-the-art geoinformation research methods that utilize Sentinel-5 satellite imagery, the cloud computing platform Google Earth Engine (GEE), and ArcGIS 10.8 software. The spatial distributions of some pollutants (nitrogen dioxide, sulfur dioxide, formaldehyde, carbon monoxide, methane) in the atmosphere are analyzed on the example of the basins of the Zapadnyy Bulganak, Alma, Kacha, Belbek, and Chernaya rivers on the north-western slope of the Crimean Mountains. The concentrations of the average annual and average monthly values of pollutants for each catchment area are compared. The GEE (Google Earth Engine) platform is used for extracting annual and monthly average rasters of pollutant substances, while ArcGIS is utilized for enhanced data visualization and in-depth analytical processing. Background concentrations of pollutants within protected natural areas are calculated. By comparing the spatial and temporal distribution of pollutant values with the background concentrations within these protected areas, a complex index of atmospheric pollution is constructed. The spatial and temporal variability of nitrogen dioxide (NO2) concentrations has been thoroughly examined. Based on the regression analysis (R > 0.85), the field of values of the total amount of emissions (which are analyzed for only six points in the study area and in the surrounding areas) was restored on the basis of the spatial and temporal heterogeneity of the field of distribution of nitrogen dioxide values (NO2). Since air pollution can have negative consequences, both for human health and for the ecosystem as a whole, this study is of great importance for assessing the ecological situation within the river basins of the north-western slope of the Crimean Mountains. This work also contributes to a general understanding of the problem of gas emissions, whose study is becoming increasingly relevant. The aim of this research is to assess the potential application of Sentinel-5 satellite imagery for air quality assessment and pollution analysis within the river basins of the north-western slopes of the Crimean Mountains. The significance of this study lies in the innovative use of Sentinel-5 satellite imagery to investigate air pollution in extensive regions where a regular network of observation points is lacking.

Analysis of water pollution in Chinese port regions to inform green port development

<p>Water transport has emerged as one of the most significant modes of transportation globally, owing to its high carrying capacity, low transport costs, and minimal energy consumption. As a critical hub for land-water transfer, ports experience frequent interactions between ships and land, leading to substantial discharges of domestic sewage and oily wastewater, as well as suspended pollutants from construction activities. Consequently, water pollution in port areas has become increasingly severe. To implement sustainable development strategies and promote green port initiatives, it is essential to research and address water pollution in these areas. This paper first summarizes the sources and impacts of the main water pollutants associated with port construction and operations. It then discusses the spatial and temporal distribution patterns of these pollutants. Finally, based on a literature review, the author highlights the current state of water pollution in port areas, advocates for the introduction of ecological engineering solutions for wastewater treatment, compares the differences in water pollution prevention plans between domestic and international ports, and identifies the shortcomings and gaps in existing research and prevention efforts related to water pollution in port areas.</p>

Molecular compositions and stable carbon isotopes (δ13C) of PAHs in wintertime PM2.5 in urban Xi'an, China: Implications for source distribution and atmospheric oxidation

Atmospheric polycyclic aromatic hydrocarbons (PAHs) are potentially carcinogenic and mutagenic to human beings, and thus have attracted significant attention in recent decades. Compound-specific stable carbon isotopes (δ13C) of PAHs are indicative for source identification, but have not been extensively applied in tracing atmospheric oxidation processes. In this study, we examined the molecular compositions and δ13C values of PAHs in wintertime PM2.5 in a highly polluted urban region in Norwest China. The average concentrations of total parent-PAHs (pPAHs) and oxygenated-PAHs (OPAHs) were measured as 70 ± 29 and 36 ± 17 ng m−3, respectively. The results obtained from the incremental lifetime cancer risk (ILCR) model suggested a high potential cancer risk of PAHs in the urban region. The temperoal variations of PAHs and carbonaceous fractions implied that the contribution of secondary organic compounds was limited during the severe pollution period (PM2.5 > 115 μg m−3). Both molecular diagnostic ratios and δ13C values indicated that the major emission sources of the pPAHs were coal and/or biomass burning. The δ13C value of fluorene became heavier as the OPAHs concentration increased, while the concentrations of fluorene was negatively correlated with OPAHs, indicating the secondary formation of OPAHs from fluorene oxidation in the cold season. Our results also confirmed that δ13C values of pPAHs are indeed indicative of atmospheric oxidation processes.

Unveiling the Power of Stochastic Methods: Advancements in Air Pollution Sensitivity Analysis of the Digital Twin

Thorough examination of various aspects related to the distribution of air pollutants in a specific region and the factors contributing to high concentrations is essential, as these elevated levels can be detrimental. To accomplish this, the development and improvement of a digital twin that encompasses all relevant physical processes in the atmosphere is necessary. This tool, known as DIGITAL AIR, has been created, and it is now necessary to extend it with precise sensitivity analysis. DIGITAL AIR is gaining popularity due to its effectiveness in addressing complex problems that arise in intricate environments; this motivates our further investigations. In this paper, we focus on the preparation and further investigation of DIGITAL AIR through sensitivity analysis with improved stochastic approaches for investigating high-level air pollutants. We discuss and test the utilization of this digital tool in tackling the issue. The unified Danish Eulerian model (UNI-DEM) plays a crucial role within DIGITAL AIR. This mathematical model, UNI-DEM, is highly versatile and can be applied to various studies concerning the adverse effects caused by elevated air pollution levels.

Automated Drone-Delivery Solar-Driven Onsite Wastewater Smart Monitoring and Treatment System.

Treating potential polluted water sources is urgent and challenging, especially for natural water sources. Numerous research groups focus on either smart water monitoring or new adsorbent. However, either aspect alone is insufficient for complex nature water source treatment. Here, integrating the state-of-art machine learning technique, a sustainable silk-based bioadsorbent, and wireless Internet of Things, an integrated automated drone-delivery solar driven onsite water monitoring & treatment system (WMTS) for the contaminated nature water sources is developed. In short, the embedded sensors and microprogrammed control unit capture and upload the real-time monitoring data to the cloud server for data analysis and optimized treatment strategy. Meanwhile, a grid map system based on the satellite remote sensing images directs the minimum number of WMTS units to cover the entire polluted region. Finally, unmanned aerial vehicles provide autonomous dispatch, operation, and maintenance, especially in hard-to-reach sites. Overall, this work offers a general, sustainable, energy-efficient, and closed-loop solution toward efficiently alerting and on-site treating nature water source contamination.

Discussion on the design of compensation standards for regional environmental pollution from the perspective of new structural economics

How to effectively protect the ecological environment while socio-economic development, to achieve the harmonious and sustainable development of human society and the natural ecological environment, has been paid more and more attention by governments and academic circles around the world. Therefore, the design of compensation standards for regional environmental pollution is proposed from the perspective of new structural economics. Based on the perspective of new structural economics, this paper provides a new explanation of the impact of fiscal decentralization on environmental pollution, according to the economic and technical indicators related to ecological environmental pollution, with the help of the subjective and objective empowerment method combined with the analysis of hierarchy method and entropy method, the weight of each ecological environment pollution evaluation index in the evaluation and division of ecological environmental pollution level is studied, and the comprehensive evaluation method is used to construct the ecological environment pollution technology rating evaluation model, and the compensation value of regional environmental pollution is finally obtained by combining the panel regression model. The method of this paper has wide applicability and significant advantages. The experimental results show that the COD emission of the North Water Source Area (QZ) of the Qingzhang River is 208t/a, and the upstream of the drinking water source area needs to compensate 3.88 million yuan downstream for water quality and water ecological restoration.

Temporal and Spatial Distribution of Ozone and Its Influencing Factors in China

Tropospheric ozone (O3) pollution has emerged as a significant concern, as it can adversely influence human health, daily activities, and the surrounding environment(The following tropospheric O3 is referred to as O3). Research on the societal contribution to O3 primarily concentrates on the generation mechanisms and chemical processes, with limited studies examining the influence of social and economic activities on O3 at a national scale. In this investigation, spatial econometric models, random forest models, and geographically weighted regression (GWR) were adopted for assessing the effects of meteorological, natural, and socioeconomic factors on O3 concentration throughout the country. The spatial error model (SEM) revealed that precipitation, temperature, wind direction, per capita GDP, RD project funding, and SO2 were the primary factors influencing O3 concentration in China, among which precipitation had the strongest effect on O3, followed by temperature and SO2. Subsequently, the GWR model was utilized to demonstrate the regional differences in the impacts of precipitation, NOx, secondary industry proportion, and electricity consumption. In central and western regions, such as Jiangxi, Guangxi, and Guizhou, precipitation, NOx, and power consumption were the leading factors contributing to severe O3 pollution. The secondary industry proportion substantially affected O3 pollution in the Beijing-Tianjin-Hebei region, indicating that this sector played a crucial role in the region’s economic growth and contributed to elevated O3 concentrations. Meteorological, natural, and socioeconomic factors exhibited a lesser influence on O3 pollution in most eastern regions compared to central and western regions. This study’s findings identified the primary contributors to O3 pollution and provided a scientific basis for developing strategies to mitigate its impact.

Formation mechanism, precursor sensitivity and control strategies of summertime ozone on the Fenwei Plain, China

As one of the most polluted regions in China, the Fenwei Plain has suffered severe summertime ozone (O3) pollution in recent years. However, related studies in this region are still scarce. In this study, a comprehensive observation campaign was conducted in a typical city on the Fenwei Plain. An observation-based model (OBM) was used to investigate the summer O3 formation mechanism, precursor sensitivity and control strategies during O3-polluted and clean periods. Our results showed that O3 pollution was accompanied by increased O3 precursor concentrations (∼15% higher) and unfavorable meteorological conditions. In situ O3 production played a dominant role in the daytime O3 concentration increment in both polluted (+6.0 ppbv/h) and clean (+3.5 ppbv/h) periods. HO2 + NO (65.9%–66.7%) was the most dominant pathway of daytime O3 formation, and OH + NO2 (41.3%–63.1%) was the most dominant pathway of O3 destruction. Regional transport has a certain contribution to the occurrence of polluted days, as well as a diluting effect on clean days. Regional transport had a certain contribution effect on polluted days and a dilution effect on clean days. The southeastern regions were potential source regions of high O3, and the northwestern regions were potential source regions of low O3. When pollution occurred, the O3 formation control regimes transformed from a volatile organic compound (VOC)-limited regime to a transition regime, corresponding to an increase in precursor concentrations and stronger local O3 production. A 30% reduction in VOCs and a 20% reduction in NOx (VOCs/NOx ≈ 1.5) were determined to be the optimal control strategies to achieve the O3 control target (82 ppbv) in summer. VOC reductions should target reactive and O3-sensitive species (Oxygened VOCs, alkenes, aromatics) to effectively alleviate O3 pollution. This study could provide scientific support for local O3 pollution control on the Fenwei Plain.

Pathways toward PM2.5 air quality attainment and its CO2 mitigation co-benefits in China's northern cities by 2030

Rapid economic development and urbanization have left millions of people in urban areas vulnerable to the adverse effects of air pollution. Reducing serious PM2.5 pollution remains a major policy challenge for Chinese cities, such as the “2 + 26” Cities in the most polluted region of China, despite adopting various air pollution-control measures since 2017. In this study, we use a Greenhouse Gas and Air Pollution Interactions and Synergies model for the “2 + 26” Cities to explore feasible pathways for achieving the PM2.5 air quality annual standard (35 μg/m3) until 2030 by developing four future scenarios based on a 2017 emission inventory. The results show that by continuing the control policies from before 2020, including the Air Pollution Prevention and Control Action Plan from 2013 and the Three-Year Action Plan for Wining the Blue Sky Defense Battle from 2018, and implementing the policies likely to be proposed after 2020, the “2 + 26” Cities will not succeed in achieving the standard by 2030; furthermore, the amount of the population living below 35 μg/m3 will not exceed 12%. Nevertheless, by combining the best available technologies, the regional average PM2.5 concentration in the “2 + 26” Cities is 34 μg/m3 by 2030, attaining the target; moreover, more than half of the population will experience air quality that conforms to the standard. Under this scenario, emissions of primary PM2.5, SO2, NOx, NH3 and NMVOCs are estimated to decrease by 75%, 69%, 76%, 32% and 52%, respectively, in 2017–2030. The emission reductions under alternative scenarios vary widely across cities, indicating the need for differentiated control strategies among cities. Considering the predominant contributions to emissions and the lack of effective control measures, fuel conversion, off-road, agricultural and solvent use sectors should be paid more attention to enable further emission reductions in future. In addition, CO2 emission reduction co-benefits of implemented clean air action measures have been identified; however, the negative reduction effects of these measures should be given more attention (e.g., increased carbon emissions in the power sector from electrification of end-users).

Regional aerosol forecasts based on deep learning and numerical weather prediction

Atmospheric chemistry transport models have been extensively applied in aerosol forecasts over recent decades, whereas they are facing challenges from uncertainties in emission rates, meteorological data, and over-simplified chemical parameterizations. Here, we developed a spatial-temporal deep learning framework, named PPN (Pollution-Predicting Net for PM2.5), to accurately and efficiently predict regional PM2.5 concentrations. It has an encoder-decoder architecture and combines the preceding PM2.5 observations and numerical weather prediction. Besides, the model proposes a weighted loss function to promote the forecasting performance in extreme events. We applied the proposed model to forecast 3-day PM2.5 concentrations over the Beijing-Tianjin-Hebei region in China on a three-hour-by-three-hour basis. Overall, the model showed good performance with R2 and RMSE values of 0.7 and 17.7 μg m−3, respectively. It could capture the high PM2.5 concentration in the south and relatively low concentration in the north and exhibit better performance within the next 24 h. The use of the weighted loss function decreased the level of “high values underestimation, low values overestimation”, while incorporating the preceding PM2.5 observations into the encoder phase improved the predictive accuracy within 24 h. We also compared the model result with that from a state-of-the-art numerical model (WRF-Chem with pollutant data assimilation). The temporal R2 and RMSE from the WRF-Chem were 0.30−0.77 and 19−45 μg m−3 while those from the PPN model were 0.42−0.84 and 15−42 μg m−3. The proposed model shows powerful capacity in aerosol forecasts and provides an efficient and accurate tool for early warning and management of regional pollution events.

The evaluation analysis on the airborne dust regional pollution of the anchor drilling operation in the tunnel.

The anchor drilling operations generate massive airborne dust particles in the tunnel heading face that raises the pneumoconiosis morbidity and explosion risk. In this paper, a full-scale tunnel physical model is constructed to study the effect of the wind velocity and drilling site position on the airborne dust regional pollution scope based on the actual anchor drilling craft. The research indicates that the four extensive vortex areas keep the dust suspension at 14m from the heading face and make the deposition dust particle refloat. The average respirable dust rate reaches the maximum value at section 5m and presents a gradual decline as the dust particle migrates along the outlet direction. Raising the wind velocity contributes to alleviating the airborne dust pollution in the anchor drilling operation. As the wind velocity increases from 3 to 24m/s, the high dust concentration area and number higher than 200mg/m3 pose overall decrease trends, and the average dust concentration displays a linear decrease until 26.14-58.65mg/m3 around the anchor worker head. Moving the drilling site positions closer to the exhaust air duct aggravates the airborne dust pollution in the front breathing zone. As the anchor drilling operation switches from the return air side to the supply air side, the dust concentration area ascends by 59.4-84.4% in the personnel respiratory space.

Four-party evolutionary game analysis of third-party recycling treatment of livestock and poultry breeding waste

In response to the problem of governmental failure to control livestock and poultry breeding pollution (LPBP) in countries or regions with a large number of small and medium-scale livestock and poultry farmers (SM-LPF), this paper proposes the theory of recycling treatment through the third-party companies (TPC). Firstly, based on the evolutionary game theory, this paper constructs an evolutionary game model with four parties, including SM-LPF, TPC, the consuming party (TCP) and the local government (TLG) into the same analysis framework. And then systematically derives the stability of strategies and possible different combinations of strategies of four parties based on expected utility theory and Lyapunov's first law. Finally, the theoretical derivation results are verified and sensitivity analysis of key parameters is carried out by combining the system dynamics method. The results show that: (1) There is a significant correlation between the four-party game players, and the strategy choice of each game player is influenced by other game players. TLG can promote the benign interaction of the four game players to achieve the desired evolutionary results of Scenario 3 (cooperation, investment, purchase, promotion) through the formulation of reasonable subsidy and reward and punishment mechanisms. (2) The main factors affecting the third-party recycling treatment include government regulation, internal factors, market demand for environmental protection services, and market demand for organic fertilizers. (3) TLG subsidies to SM-LPF have the greatest impact on the evolution of the system, and subsidies to other game players have less impact on the evolutionary results of the system, while it is found that there is an optimal interval for the proportion of local government subsidies to farmers, beyond which the system will be unstable. This study provides practical guidance and policy reference for promoting the participation of TPC in LPBP management and has theoretical and practical value for establishing mechanism of livestock and poultry breeding waste recycling. It also enriches and develops the theory of third-party governance.

Water quality pollution assessment and source apportionment of lake wetlands: A case study of Xianghai Lake in the Northeast China Plain

Surface water pollution has always posed a serious challenge to water quality management. Improving water quality management requires figuring out how to comprehend water quality conditions scientifically and effectively as well as quantitatively identify regional pollution sources. In this study, Xianghai Lake, a typical lake-type wetland on the Northeast China Plain, was taken as the research area. Based on a geographic information system (GIS) method and 11 water quality parameters, the single-factor evaluation and comprehensive water quality index (WQI) methods were used to comprehensively evaluate the water quality of the lake-type wetland in the level period. Four key water quality parameters were determined by the principal component analysis (PCA) method, and more convenient comprehensive water quality evaluation models, the minimum WQI considering weights (WQImin-w) and the minimum WQI without considering weights (WQImin-nw) were established. The multiple statistical method and the absolute principal component score-multiple liner regression (APCS-MLR) model were combined to analyse the lake pollution sources based on the spatial changes in pollutants. The findings demonstrated that the WQImin-nw model’s water quality evaluation outcome was more accurate when weights were not taken into account. The WQImin-nw model can be used as a simple and convenient way to comprehend the variations in water quality in wetlands of lakes and reservoirs. It was concluded that the comprehensive water quality in the study area was at a “medium” level, and CODMn was the main limiting factor. Nonpoint source pollution (such as agricultural planting and livestock breeding) was the most important factor affecting the water quality of Xianghai Lake (with a comprehensive contribution rate of 31.65%). The comprehensive contribution rates of sediment endogenous and geological sources, phytoplankton and other plants, and water diversion and other hydrodynamic impacts accounted for 25.12%, 19.65%, and 23.58% of the total impact, respectively. This study can provide a scientific method for water quality assessment and management of lake wetlands, and an effective support for migration of migratory birds, habitat protection and grain production security.

Interaction mechanism and spatial effect of cross-regional haze pollution based on a multisectoral economy-energy-environment (3E) model and the evidence from China.

The transboundary characteristics and multisectoral factor interaction mechanism of haze pollution have aroused widespread attention but remain understudied. This article proposes a comprehensive conceptual model that clarifies regional haze pollution, further establishes a theoretical framework on a cross-regional, multisectoral economy-energy-environment (3E) system, and attempts to empirically investigate the spatial effect and interaction mechanism employing a spatial-econometrics model based on China's province-level regions. The results demonstrate that (1) regional haze pollution is a transboundary atmospheric state formed by the accumulation and agglomeration of various emission pollutants; moreover, there is a "snowball" effect and a spatial spillover effect. (2) The formation and evolution of haze pollution are driven by the multisectoral factors of 3E system interaction, and the findings still hold after theoretical and empirical analysis and robustness tests. (3) Significant spatial autocorrelation exists for the 3E factors, presenting different clustering modes with a dynamic spatiotemporal evolution, particularly in the high-high (H-H) mode and low-low (L-L) mode. (4) Significant heterogeneous impacts of economic and energy factors on haze pollution are identified, namely, an inverted "U-shaped" relationship and a positive linear association, respectively. Further spatial analysis demonstrates a strong spatial spillover and obvious path dependence among local and neighboring regions. Policymakers are advised to consider multisectoral 3E system interaction and cross-regional collaboration. Integr Environ Assess Manag 2023;00:1-19. © 2023 SETAC.

Economic growth and environmental pollution in China: New evidence from government work reports

In China, economic growth targets significantly affect the economic behavior of local governments. This paper analyzes a dataset of the economic growth targets from 230 city government work reports from 2004 to 2019 to reveal how economic growth targets affect local environmental pollution. The empirical results show that the economic growth targets are “overweight” from the higher-level governments to the lower-level governments, which significantly aggravates regional environmental pollution because of environmental regulation relaxation, blocked industrial structure upgrades and technological innovation inhibition. Furthermore, to exceed the economic growth targets, local governments usually adopt the “riding a seesaw” strategy for the treatment of different pollutants. If the economic growth target statements are ambiguous or attainable, then environmental pollution is reduced. Interestingly, the “preemptive” city government, which sets economic growth goals before its province, is more inclined to maintain growth at the expense of the environment. This study provides important evidence for the literature on the impacts of government behavior on environmental pollution.

Reduction pathways identification of agricultural water pollution in Hubei Province, China

The differentiated management of agricultural water pollution plays a significant role in alleviating water quality crisis, which is an important factor to guarantee sustainable water use and agriculture. The key is to accurately identify the differentiated pathways to reduce water pollution due to agricultural activities. Taking Hubei Province as a case study, this study comprehensively explored the actual spatial–temporal characteristics and main influencing factors of agricultural grey water footprint (AGWF) for the time period from 2010 to 2019 at the provincial and municipal levels by creatively combining the Dagum Gini coefficient, Moran’s I index and Generalized Divisia Index Method (GDIM). On the basis, the Tapio decoupling model was used to examine the status quo of AGWF reduction in the context of economic development and to classify the two-dimensional decoupling state between AGWF and agricultural GDP (AGDP), aiming at guiding the implementation of zoning management. The analysis yield four significant results: (1) Compared with 2010, the AGWF of Hubei Province in 2019 has achieved negative growth both at the provincial and municipal levels. The AGWF of Hubei Province and its 17 prefecture-level cities presented a trend of first rising and then declining. On the whole, AGWF was positively correlated with AGDP at the municipal level. (2) During the whole study period, the difference in AGWFs of 17 subregions in Hubei Province basically remained in a “relatively unbalanced” state. There was no significant spatial dependence among the subregions on the whole. (3) AGDP and permanent resident population were the main promoting factors of AGWF increase, while AGWF intensity, AGDP per capita and agricultural water use (AWU) intensity were the main inhibiting factors. Among them, AGDP and AGWF intensity respectively played the largest promoting and inhibiting effects on the increase of AGWF. (4) AGWF and AGDP of 17 prefecture-level cities in Hubei Province have all achieved strong decoupling, indicating that AGWFs in these regions have achieved both quantity and efficiency control. These cities were divided into different categories and given differentiated zoning management measures. This study puts forward a complete analytical framework for differentiated zoning management of regional agricultural water pollution. The research findings of this paper can provide important policy implications for other cases as well.

Cities of Central Asia: New hotspots of air pollution in the world

Central Asian cities are one of the hotspots for air pollution worldwide. There are limited studies and knowledge regarding air quality variation in this region. This study investigated PM2.5 temporal variations and the influence of meteorological parameters on PM2.5 concentrations for six major cities in Central Asia: Almaty and Astana (Kazakhstan), Ashgabat (Turkmenistan), Bishkek (Kyrgyzstan), Dushanbe (Tajikistan), and Tashkent (Uzbekistan). The results show severe air quality deterioration in the cities with annual PM2.5 concentrations up to ten-fold higher than the limits. A clear seasonal pattern with winter peaks was observed in Almaty, Bishkek, and Astana, whereas winter and summer were highly polluted in Tashkent and Dushanbe. Based on the pollution profiles, cities were classified into several clusters. Episodes with high PM2.5 concentrations were evaluated for regional pollutant transportation using the HYSPLIT model. The results of this investigation highlight a significant discrepancy in official emissions inventory studies. While previous studies have suggested that transportation is the primary source of air pollution, the approach to estimate the share of emission sources was based on an outdated methodology that obscures information on the most hazardous pollutants, including PM2.5. This study shows that coal combustion is the primary source of PM2.5 pollution in most cities, offering policymakers critical insights into the sources of air pollution in the region. These findings demonstrate the need for policymakers to take swift action to address coal use and adopt effective measures to mitigate PM2.5 pollution, thereby improving the health and well-being of the population.