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Chemical characterization of fine particles (PM2.5) at a coastal site in the South Western Mediterranean during the ChArMex experiment Full text
2020
Lemou, Abdelkader | Rabhi, Lyes | Merabet, Hamza | Ladji, Riad | Nicolas, José B | Bonnaire, Nicolas | Mustapha, Mohamed Abou | Dilmi, Redha | Sciare, Jean | Mihalopoulos, Nikolaos | Yassaa, Noureddine
As part of the ChArMEx project (Chemistry-Aerosol Mediterranean Experiment, http://charmex.lsce.ipsl.fr), one year of continuous filter sampling was conducted from August 2012 to August 2013 at a rural (coastal) site in Algeria aiming to better document fine aerosol seasonal variability and chemical composition in the Southern part of the Mediterranean. Over 350 filters have been collected, weighted, and analyzed for the main ions and organic and elemental carbon. The obtained mass concentrations varied between 2.5 and 50.6 μg/m³ for PM₂.₅. The annual modulations of PM₂.₅ showed higher concentrations in the end summer 2012 and the early summer 2013 (28.50 μg/m³ in August 2012, 20.23 μg/m³ in September 2012, 20.19 μg/m³ in July 2013, and 17.88 μg/m³in August 2013). The particulate organic matter (POM) presented the greatest contribution (50%), followed by the secondary inorganic aerosols (SIA, 27%). The average organic carbon OC concentrations ranged from 1.66 to 6.05 μgC/m³. The average elemental carbon EC concentrations ranged from 0.92 to 3.49 μgC/m³ and contributed 7% of the PM₂.₅ mass to Bou-Ismail. The average value of the OC /EC ratio was close to 5.1 in Bou-Ismail, and was close to that found in Finokalia 4 (Greece 2004, 2006) but was lower than that of Montseny 11 (Spain 2002–2007) Western Mediterranean Basin (WMB). The concentrations of water-soluble organic carbon WSOC in the PM₂.₅ ranging from 0.66 to 3.70 μg/m³ recorded the minimum level in March 2013, and the maximum level in August 2012, with an average of 2.02 μg/m³.
Show more [+] Less [-]The effect of environmental regulation on air pollution, productivity, and factor structure: a quasi-natural experiment evidence from China Full text
2020
Zhang, Ning | Zhao, Keke | Yu, Yantuan
This paper makes a first empirical attempt at estimating the effects of environmental regulation on air pollution, total factor productivity (TFP), and factor structure based on a quasi-natural experiment method using a novel dataset of 216 prefectural-level cities during the years 1998–2016 in China. Specifically, we are focused on the policy impact of the listed key environmental protection (KEP) prefectures which subject to more stringent environmental regulations than non-KEP prefectures. Our empirical results show that the PM₂.₅ intensity, environmental performance, and TFP of the KEP prefectures are significantly lower than the non-KEP prefectures. The environmental policy also affects the factor structure of KEP cites. Heterogeneity analysis indicates that the policy significantly lowered the PM₂.₅ for central and western cities while it is unclear for eastern cities. Our findings also document that the policy effects are unclear in the long term. Various robustness checks confirm the internal validity. These estimation results are instructive to the policymakers. We suggest that the central government should measure the effectiveness of policies within 5 years of policy formulation. Governments at all levels should make targeted adjustments based on actual impact effects. The central government should be granted local governments more speaking power and flexibility in policy implementation when formulating environmental regulatory policies. Otherwise, the central government also needs to improve the communication medium with provincial governments.
Show more [+] Less [-]Spatiotemporal variations of DOM components in the Kushiro River impacted by a wetland Full text
2020
Shafiquzzaman, Md | Haider, Husnain | Bhuiyan, Muhammed A. | Ahmed, Abdelkader T. | AlSaleem, Saleem S. | Ghumman, Abdul Razzaq
Dissolved organic matter (DOM) has been recognized as a serious water quality problem in natural water bodies receiving pollution loads from point and nonpoint sources. The present study investigates the spatiotemporal variability of DOM composition in the Kushiro River and its tributaries (Eastern Hokkaido, Japan) impacted by the Kushiro wetland. Water samples were collected in the wet and dry seasons from several locations of the river and analyzed for DOM characteristics by UV–visible and excitation–emission matrix fluorescence spectroscopy techniques and by developing water quality index. Rather than the spatial effect, significant seasonal impacts on DOM pollution in the Kushiro River were observed. Overall concentrations of DOM decreased during the dry season. The increase of specific ultraviolet absorbance in the dry season indicated an increasing trend of humification, aromaticity and molecular weight of DOM. Five fluorescent peaks, including peaks A, C, M, B, and T were predicted by EEM spectra. Peaks A and C were found to be the most dominating peaks in both the seasons and indicated enrichment of humic-like matters in river water. The intensities of poly-aromatic humic substances as well as DOM components of microbial origin increase in the wet season and proteins like autochthonous DOM increase during the dry season. The study recognized the contribution of freshly produced DOM component by the decomposition of wetland plants in wet season and effect of snowfall in the dry season. Analysis of three fluorescence indices revealed that the river water primarily contains terrestrially dominated DOM. A significant impact of the adjacent WWTPs and wetland to the river water DOM were also observed. The water quality index of river water DOM showed low to medium levels of DOM pollution in the Kushiro River.
Show more [+] Less [-]Asymmetric effects of energy efficiency and renewable energy on carbon emissions of BRICS economies: evidence from nonlinear panel autoregressive distributed lag model Full text
2020
Akram, Rabia | Majeed, Muhammad Tariq | Fareed, Zeeshan | Khalid, Fahad | Ye, Chengang
Embracing energy efficiency (EE) and renewable energy (RE) is essential for improving environmental quality. This research investigates the asymmetric impacts of EE, RE, and other factors on CO₂ emissions in BRICS (i.e., Brazil, Russia, India, China, and South Africa) countries from 1990 to 2014. In contrast to previous studies, the present study considers EE as a major cause of CO₂ emissions in BRICS countries. By using the new hidden panel cointegration and nonlinear panel autoregressive distributive lag model, this study is the first of its kind that unfolds the asymmetric links among EE, RE, and CO₂ emissions. Findings clearly explain that the impact of the selected variables on CO₂ emissions is asymmetric, and both EE and RE help to lower CO₂ emissions in BRICS countries. In the long run, positive shocks in EE and RE can significantly mitigate CO₂ emissions in BRICS economies. In particular, a 1% fluctuation in the positive sum of EE reduces CO₂ emissions by 0.783% in the long run. On the other hand, a 1% fluctuation in the positive component of RE reduces CO₂ emissions by 0.733%. Moreover, individual country estimates suggest the heterogeneous effects among BRICS countries. Based on the empirical findings, policymakers should consider the asymmetric behavior of the EE, RE, and economic growth while formulating, energy, environment, and growth policies of BRICS countries. Graphical abstract
Show more [+] Less [-]Assessment of seasonal and spatial variations of biochemical markers in Corydalus sp. (Megaloptera: Corydalidae), a non-conventional biomonitor, in a mountain cloud forest in Mexico Full text
2020
Rico-Sánchez, Axel Eduardo | Rodríguez-Romero, Alexis Joseph | Sedeño Díaz, Jacinto Elías | López López, Eugenia
Rivers are critical ecosystems for protecting and harboring high biodiversity. Tropical rivers particularly are unique for facing extreme climatic events under the current accelerated disruption from human activities. The Bobos-Nautla river basin is exposed to climatic events and disturbances from anthropogenic impacts that stress aquatic organisms. We assessed the health condition of this river system using a non-conventional biomonitor, Corydalus sp., with a set of early-warning biomarkers including lipid peroxidation levels (LPO) and antioxidant activity, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and the neurotransmitter acetylcholinesterase (AChE) considering their spatial and temporal variations. Biomarkers and water quality parameters were analyzed, and the integrated biomarker response (IBR) was assessed as a stress index. Biomarkers showed no significant spatial differences; however, a high-stress period during the rainy season was detected, evidenced by the highest LPO levels; this period is related to the leaching of allochthonous materials from agricultural and urban zones. The peak IBR value during the rainy season confirmed the seasonality of biomarkers. A slight increase in IBR was recorded in lowlands, seemingly associated with agricultural land and human settlements. A principal component analysis showed nutrient enrichment during the rainy season and depletion during the cold-dry season, together with a peak activity of antioxidant enzymes. These results highlight the importance of climatic events such as the rainy season on the health condition of Corydalus sp., which is highly sensitive to the complex mixtures of pollutants that enter the waterbody during extreme climatic events, promoting oxidative stress. Our results also showed the ability of Corydalus sp. to recover and return to a basal level.
Show more [+] Less [-]Fabrication of Pt-Pd@ITO grown heterogeneous nanocatalyst as efficient remediator for toxic methyl parathion in aqueous media Full text
2020
Mahar, Ali Muhammad | Balouch, Aamna | Talpur, Farah Naz | Abdullah, | Panah, Pirah | Kumar, Raj | Kumar, Ameet | Pato, Abdul Hameed | Mal, Dadu | Kumar, Sagar | Umar, Akrajas Ali
In this study, nano-sized ITO supported Pt-Pd bimetallic catalyst was synthesized for the degradation of methyl parathion pesticide, a common extremely toxic contaminant in aqueous solution. On the characterization with different techniques, a beautiful scenario of honeycomb architecture composed of ultra-small nanoneedles or fine hairs was found. Average size of nanocatalyst also confirmed which was in the range of 3–5 nm. High percent degradation (94%) was obtained in 30 s using 1.5 × 10⁻ ¹ mg of synthesized nanocatalyst, 0.5 mM NaBH₄, and 110 W microwave radiations power. Recyclability of nanocatalyst was efficient till 4th cycle observed during study of reusability. The supported Pt-Pd bimetallic nanocatalyst on ITO displayed many advantages over conventional methods for degradation of methyl parathion pesticide, such as high percent degradation, short reaction time, small amount of nanocatalyst, and multitime reusability. Graphical abstract Schematic illustration of reaction for degradation of methyl parathion
Show more [+] Less [-]Antibiotic consumption in developing countries defies global commitments: an overview on Brazilian growth in consumption Full text
2020
Neves e Castro, Paulo Bernardo | da Silva Rodrigues, Daniel Aparecido | Roeser, Hubert Mathias Peter | da Fonseca Santiago, Aníbal | de Cássia Franco Afonso, Robson José
Faster spread of epidemics has turned local concerns into global crises; antimicrobial resistance (AMR) is being considered a major threat to public health in the twenty-first century. Antibiotic misuse plays a great role in accelerated AMR; thus, understanding and discussing consumption patterns has been a trend topic over the past years. Developing countries, such as Brazil, have high growth rates in antibiotic consumption, potentially impacting global environmental safety. This study presents the compiled information from the Brazilian Health Regulatory Agency (ANVISA) on antibiotic dispensation across the country and maps the consumption trends between the years of 2013 and 2016. The most consumed substances were beta-lactams (amoxicillin and cephalexin) and macrolides (azithromycin). National relative growth consumption in the mentioned period was 18%. At the local level, growth of consumption ranged from 4 to 85%, with rampage growth concentrated in the North and Northeast regions. Brazilian laws, such as restriction of over-the-counter sales and mandatory report on dispensation, seem to have little effect on the national antibiotic consumption growth. This phenomenon growth is still elevated if compared with developed countries, demonstrating the need for further surveillance as well as coordinated efforts aiming at antibiotic use and AMR prevention.
Show more [+] Less [-]Impact of board characteristics on environmental disclosures for listed mining companies in China Full text
2020
Agyemang, Andrew Osei | Yusheng, Kong | Ayamba, Emmanuel Caesar | Twum, Angelina Kissiwaa | Chengpeng, Zhu | Shaibu, Ali
This paper examines the impact of board characteristics on environmental accounting information disclosure for listed mining companies in China. Board characteristics were categorized into board size, independence characteristics, diversity characteristics, behavioral characteristics, and incentive characteristics. The study further extended to analyze the impact of board characteristics on environmental disclosure before and after the promulgation of Environmental Information Disclosure Degree (EIDD). Using multiple regression analysis with a sample of 34 listed mining companies from both Shanghai and Shenzhen Stock Exchanges covering 2000–2018 period, we find a significant positive correlation between board size and Environmental Accounting Disclosure Index (EADI). Also, board independence measured by independent directors and the separation of the chief executive officer from board chairman revealed a positive and significant relationship with EADI. Similarly, behavioral characteristics measured by board meeting were positively correlated with EADI at 1% significant level. In terms of diversity characteristics, both females on board and foreign nationals revealed a negative and insignificant relationship with EADI, while incentive characteristics saw an inconclusive correlation with EADI. Our findings are useful to top managers and regulators who are interested in improving corporate governance practices and environmental information disclosure.
Show more [+] Less [-]Numerical simulation and field experiment study on onboard dust removal technology based on airflow–dust pollution dispersion characteristics Full text
2020
Mo, Jinming | Yang, Junlei | Ma, Wei | Chen, Fang | Zhang, Sheji
To solve the problem of dust production by the caving coal seam on the weather side of a fully mechanized coal face with a large mining height, this study proposes coal cutter onboard dust removal technology for the first time. In this work, taking the 12511 fully mechanized coal face of the Bulianta Coal Mine with a large mining height as an example, a mathematical model was built to study the influence of the onboard dust collector on airflow–dust dispersion pollution and the key technological parameters of the dust collector, and field tests were performed for verification. The results of numerical simulation showed that the dust-carrying airflow, after being blocked by the coal cutter, dispersed in the lateral direction, leading to an increase of airflow velocity on the walkway side to 1.75 m s⁻¹, and a dust concentration as high as 2500 mg m⁻³. At the same time, an airflow vortex area with the largest diameter of 3 m was formed near the surface of the coal cutter body, which attracted dust to gather there. However, after the application of the onboard dust removal technology, the lateral dispersion of dust-carrying airflow weakened, and the dust concentration on the walkway side was reduced to below 600 mg m⁻³. In addition, this technology also obviously reduced the influence scope of the vortex and the dust concentration area. It was also found that the installation height of the suction inlet of the dust collector and the air capacity had a large impact on the dust suppression efficiency. The optimum dust suppression efficiency was reached at an installation height of 1.15 m and air capacity of 120 m³ min⁻¹. Field test verification demonstrated that the dust concentration on the walkway side could be reduced by as much as 49.3% with the application of the proposed onboard dust removal technology.
Show more [+] Less [-]Grey water footprint evaluation and driving force analysis of eight economic regions in China Full text
2020
Cui, Shibo | Dong, Huijuan | Wilson, Jeffrey
The grey water footprint (GWF) can be used to connect wastewater quality and quantity, making it a powerful tool for policy makers and those responsible for managing wastewater systems. As a supplementary to existing GWF research, this study explores the GWF evolution of eight economic regions in China by taking into consideration the GWF of livestock feeding. In addition, we use the logarithmic mean division index method to study the background driving forces of GWF in primary industry for eight economic regions. Results show that the overall GWF in China fluctuates from 6082 billion m³ to 6238 billion m³ between the years 2003 and 2015. Primary industry contributes most to the GWF because of livestock feeding, particularly for the northwest economic region, accounting for 84.81% in 2015. The southwest economic region has the highest total GWF, and east coast region has the lowest total GWF. An analysis of driving forces shows that economic scale and industrial structure are the driving forces that best explain the GWF for the East coast, middle of Yellow River, Northwest, and Southwest economic regions. The effects of economic scale and pollution producing intensity are driving the GWF in the Northeast Regions. For the North coast and middle Yangtze River Regions, economic scale, industrial structure, and pollution producing intensity are driving forces for GWF. While for the South coast region, population is an important contributor apart from economic scale and industrial structure. Policy implications from perspective of the agriculture GWF and endowment of different regions were finally discussed.
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