Environmental regulation is considered an important means to solve PM₂.₅ pollution. Based on panel data of 280 cities in China from 2003 to 2016, this paper analyzes the dual effects of environmental regulation on PM₂.₅ pollution, namely, the direct effect and the indirect effect by three transmission channels of the technological innovation, industrial structure, and foreign direct investment (FDI). The impact of urban heterogeneity on the effects of environmental regulation is then examined. The study found that environmental regulation has a significant negative impact on PM₂.₅ pollution. In addition, environmental regulation can indirectly reduce PM₂.₅ pollution through technological innovation and industrial structure adjustment. However, it also restrains the environmental spillover effect of FDI, in this way exacerbating PM₂.₅ pollution. Urban heterogeneity factors such as geographical location, city size, and resource endowment have an impact on pollution control and the haze reduction effect of environmental regulation. Finally, based on the research conclusion, some suggestions are proposed for strengthening environmental regulation and reducing PM₂.₅ pollution.

The global problem of domestic waste management increases with rapid population growth and with economic and urban development. In developing countries, treatment of rural domestic waste (RDW) is distinguished from urban waste. Quantitative assessment of greenhouse gas emissions from RDW disposal treatment is needed to achieve carbon neutrality. Reliable global warming potential (GWP) assessments of RDW are not differentiated in the widely accepted “urban–rural integration” centralized disposal model. We considered five different scenarios for RDW management. Scenario 1 (S1), unsanitary landfill (open-air dump); scenario 2 (S2), sanitary landfill; scenario 3 (S3), incineration; scenario 4 (S4), biological + incineration; and scenario 5 (S5), classification + composting + sanitary landfill + recycling. Life cycle assessment was used for GWP, and sensitivity analysis was calculated to point out the sensitive parameter. We found that the mean GWP ranged from 5.14 × 10⁴ to 2.31 × 10⁵ kg CO₂-equivalents. Pollution from untreated RDW with landfill gas emissions led to large contributions under all scenarios. The collection and transportation ratio was sensitive to all scenarios, and we found that, if the recyclable materials separated at source were not used efficiently, the impact on GWP would be greater than under the unclassified waste scenarios. A “new urban–rural integration” mode (S5) that included household classification, village collection, town transfer, and county and urban disposal was introduced for RDW management. These quantitative results have a great potential for promoting effective RDW management in China and other developing countries.

Ice masses and snow of Hunza River Basin (HRB) are an important primary source of fresh water and lifeline for downstream inhabitants. Changing climatic conditions seriously put an impact on these available ice and snow masses. These glaciers may affect downstream population by glacial lake outburst floods (GLOF) and surge events due to climatic variation. So, monitoring of these glaciers and available ice masses is important. This research delivers an approach for dynamics of major glaciers of the Hunza River Basin. We delineated 27 major glaciers of HRB and examined their status by using Landsat (OLI, ETM+, ETM, TM), digital elevation model (DEM) over the period of 1990–2018. In 1990, the total area covered by these glaciers is about 2589.75 ± 86 km² and about 2565.12 ± 68km² in 2018. Our results revealed that from 2009 to 2015, glacier coverage of HRB advanced with a mean annual advance rate of 2.22 ± 0.1 km² a⁻¹. Conversely, from 1994 to 1999, the strongest reduction in glacier area with a mean rate of − 3.126 ± 0.3 km² a⁻¹ is recorded. The glaciers of HRB are relatively stable compared to Hindukush, Himalayan, and Tibetan Plateau region of the world. The steep slope glacier’s retreat rate is more than that of gentle slope glaciers, and the glaciers below an elevation of 5000 m above sea level change significantly. Based on climate data from 1995 to 2018, HRB shows a decreasing trend in temperature and increasing precipitation. The glacier area’s overall retreat is due to an increase in summer temperature while the glacier advancement is induced possibly by winter and autumn precipitation.

The increasing issue of global warming has received tremendous attention from researchers around the world as researchers are actively publishing their findings related to environmental issues such as greenhouse gas emissions, carbon footprint, and air quality. In this bibliometric review, Scopus database was accessed to retrieve publications from 1971 to 2021, related to carbon footprint of buildings which is significantly associated with global warming and air quality. The results suggested that 41% of publications were published in close access journals requiring nominal subscription fee and/or institutional permissions for access to articles. Only 1% of publications were in press for publication, while 99% of them were online available. The trend of publications on carbon footprint has increased after 2002 and is also increasing in recent years as the topic is widely studied in many fields such as environmental sciences, engineering, materials sciences, earth and planetary sciences, chemical engineering, and energy. Approximately 97% publications were peer-reviewed journal articles. The authors, i.e., Aresta, M., Lin, T.P., and Persily, A.K., published highest number of publications among all on topic of carbon footprint. However, other authors, i.e., Cai, W., Chen, Z., Ma, M. Paik, I., and Pomponi, F., have published two publications each on carbon footprint of buildings. The funding for research on carbon footprint of buildings is mainly received from the National Institute of Standards and Technology, Lawrence Berkeley National Laboratory, and Tianjin University. However, the National Taiwan University, George Mason University, and Universita degi Studi di Bari hold 3% share in total number of publications on carbon footprint of buildings. As China and the USA are countries with highest share in global carbon footprint, both countries also have highest contribution in research on carbon footprint, followed by South Korea, the UK, Japan, Italy, Germany, Taiwan, etc. The study also concluded that, due to its wider readability and understanding, most of the publications were in the English language.

This study aims to investigate the asymmetric fiscal decentralization effect on economic growth and environmental quality by using Pakistan data from 1984 to 2018. Our findings demonstrate that expenditure decentralization has asymmetric effects on economic growth and CO2 emissions in short- and long-run in Pakistan. Therefore, positive and negative fluctuations in expenditure decentralization affect economic growth and CO2 emissions differently in Pakistan. The results of asymmetric ARDL suggested that negative shock of revenue decentralization is reduced the economic growth and CO2 emissions in the short and long-run, while positive shock of revenue decentralization is reduced the economic growth and CO2 emissions. Our asymmetric results are country-specific and more effective in policy analysis in Pakistan. The outcomes of this study may also help Pakistan’s local governments and the central government in addressing the problem of economic growth and environmental pollution.

Azoxystrobin (AZ) is an aryloxy pyrimidine fungicide extensively applied in the agriculture field all over the world. There is a little information about the ecotoxicity of AZ fungicide on the freshwater snail Lymnaea luteola (L. luteola). The present study investigated the toxic effect of AZ fungicide on L. luteola by using various measures. We determined the mean LC₅₀ value―96 h of AZ fungicide (0.79 mg/L) for L. luteola, in a static system. Based on this value, three sublethal concentrations, viz., I (0.079 mg/L), II (~ 0.40 mg/L), and III (~ 0.53 mg/L), were determined. The snails were exposed to these three concentrations of AZ fungicide for 96 h, and hemolymph and digestive glands were collected after 24 and 96 h for assessment of oxidative stress, apoptosis, and histological and genotoxic changes. The induction of intracellular reactive oxygen species (ROS) and apoptosis in hemocyte cells was increased in a dose- and time-dependent manner. It was observed that lipid peroxide (LPO) and glutathione S transferase (GST) were increased, and glutathione and superoxide dismutase decreased in digestive glands. A similar trend was observed for the DNA damage as measured in terms of the percentage of tail DNA and olive tail moment in digestive gland cells. This study showed the collective use of oxidative stress, histological, and genotoxicity parameters in in vivo laboratory studies using snails that are useful for screening the toxic potential of environmental contaminants such as AZ fungicide.Graphical abstract

Magnesium oxide/expanded graphite (MgO/EG) catalyst was synthesized and applied for enhancing the degradation of Cu-ethylenediaminetetraacetic acid (Cu-EDTA) in an aqueous solution. The MgO/EG catalyst was characterized by XRD, SEM, EDS, and FTIR. For assessing the catalytic activity of MgO/EG, essential influencing factors were investigated including catalyst dosage, O₃ dosage, initial pH, initial Cu-EDTA concentration, and coexisting ions. The results show that the catalytic material showed high catalytic oxidation capacity for the Cu-EDTA removal in the MgO/EG/O₃ system. 100% of Cu(II) and 73.2% of TOC removal efficiency could be achieved in the MgO/EG/O₃ system at the reaction times of 90 min. This efficiency was higher than that seen for other systems, including O₃ alone (Cu(II) 81.4%/TOC 60.6%), EG/O₃ (84.2%/64.1), MgO/EG (< 4%/< 4%), and EG (< 4%/< 4%). A small decrease in the Cu(II) and TOC removal rate was observed after three runs in the stability and reusability experiments of the catalyst. Assays with radical scavenging experiments confirmed that MgO/EG-mediated oxidation was dependent on a hydroxyl radical pathway. The UV–vis spectra confirmed that the absorption peak of Cu-EDTA was gradually decreased and finally disappeared.

Pesticides in the environment can pose serious risks to aquatic ecosystems. This study focused on the existence of 27 pesticides, including 13 pesticides regulated by the Stockholm Convention as persistent organic pollutants (POPs) and 14 commonly used pesticides in three urban rivers in Beijing that receive effluents from three municipal wastewater treatment plants (MWTPs). Among the 27 pesticides, 12 were detected at least once over a period of 4 seasons. Atrazine, aldrin and dieldrin were universally found in the three rivers, with the highest concentrations being 311, 163 and 23.3 ng/L, respectively. HCHs, DDTs, heptachlor and endosulfan, which are POPs, were detected at lower concentrations (ND–16.7 ng/L). Most of the insecticides and some of the herbicides in the rivers originated from MWTP effluents. The risk assessment results showed that aldrin posed medium risk (0.1 ≤ RQ < 1) to fish, and atrazine exhibited medium risk to both fish and algae. Despite the implementation of the Stockholm Convention and the upgrades of MWTPs emitting ozone, high loads of aldrin, atrazine and dieldrin were discharged to the rivers. Efforts should be devoted to identifying POP pesticide sources and upgrading MWTPs with other technologies to ensure the ecological safety of rivers.

As the remote sensing technology develops, there are increasingly more kinds of remote sensing images available from different sensors. High-resolution remote sensing images are widely used in the detection of land cover/land change due to their plenty of characteristics of a specific feature in terms of spectrum, shape, and texture. Current studies regarding cultivated land resources that are the material basis for the human beings to survive and develop focus on the method to accurately obtain the quantity of cultivated land in a region and understand the conditions and the trend of change of the cultivated land. Pixel-based method and object-oriented method are the main methods to extract cultivated land in remote sensing field. Pixel-based method ignores high-level image information, while object-oriented method takes the image spot after image segmentation as the basic unit of information extraction, which can make full use of spectral features, spatial features, semantic features, and contextual features. Image segmentation is a key step of object-oriented method; the core problem is how to obtain the optimal segmentation scale. Traditional methods for determining the optimal segmentation scale of features (such as the homogeneity-heterogeneity method, the maximum area method, and the mean variance method), in which only the spectral and geometrical characteristics are considered, while the textural characteristics are neglected. Based on this, the Quickbird and unmanned aerial vehicle (UAV) images obtained in Xiyu Village, Pengzhou City, Sichuan Province, China, were selected as experimental objects, and the texture mean and spectral grayscale mean method (MANC method based on GLCM), which comprehensively considered the spectrum, shape, and texture features, was proposed to calculate the optimal segmentation scale of cultivated land in the study area. The error segment index (ESI) and centroids distance index (CDI) were adopted to evaluate image segmentation quality based on the method of area and position differences. The experimental results show that the MANC method based on GLCM can obtain higher segmentation precision than the traditional methods, and the segmentation results are in good agreement with the cultivated land boundary obtained by visual interpretation.

A comprehensive assessment of energy use, environmental degradation, and economic progress can play a significant role in transition towards low-carbon economy, and it can serve as a reference for the green economic development for the rest of the developing world. The objective of this paper is to empirically investigate the current status of conventional and renewable energy use and environmental degradation. Following this, we have analyzed the decoupling relation among environmental degradation, energy use, and economic progress in Pakistan. The study adopted the comprehensive data from year 1972–2017 and applied Tapio decoupling method to explore the decoupling status of environmental degradation, energy use, and economic progress in Pakistan. The key finding from the study shows that the overall value of carbon emissions in Pakistan is relatively increasing with the passage of time and shows about 5.26% average growth rate which is creating severe environmental degradation. There were observed several fluctuations in the trend of carbon emissions which is basically due to the policy changes in the country. From the decoupling point of view, we found the decoupling linkage between energy use and carbon emissions that is growth negative decoupling, whereas a weak decoupling relation has been observed among carbon emissions and economic progress which means that in most of the year’s county has achieved more economic growth compared with the carbon emissions. In addition, the similar weak decoupling relationship was found among energy use and economic progress. In the light of these findings, it is suggested to policymakers to promote technological advancement and alternate energy that will not only improve environmental quality, but it will also promote a low-carbon economy.