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Influence of nutrient mitigation measures on the fractional export of watershed inputs in an urban watershed Full text
2020
Gao, Wei | Duan, Zhongzhao | Yan, Chang’an | Liu, Change
Enhanced nutrient inputs due to human activities have been noted as a significant driving force for riverine nutrient exports which are responsible for the eutrophication issues in freshwaters. Current studies are mostly focused on the relationship between anthropogenic inputs and riverine exports, and little has been done to assess the role of nutrient mitigation measures in the fractional export of watershed nutrient inputs in urban regions. A highly urbanized watershed in Yun-Gui plateau of China, Lake Dianchi basin was studied as a case to assess the impact of nutrient mitigation measures on riverine nutrient exports. Based on net anthropogenic nitrogen and phosphorus inputs (NANI and NAPI, respectively) models, nutrient inputs from human activities in the basin from 1980 to 2015 were calculated, and the impact of nutrient mitigation measures were identified using a statistical model incorporating land use, precipitation, and temperature. Nutrient inputs from human action in the basin has increased rapidly, mainly from fertilizer application and food and feed imports. Enhanced riverine nutrient exports were found at the same time, and significantly correlated to nutrient inputs. The construction of water transfer projects and wastewater treatment plants in the basin has changed the controlling factors and processes of the fractional export of watershed nutrient inputs, which is weak in explanatory ability and eliminated the role of the land use. A modified model was established by incorporating the effect of water transfer projects and wastewater treatment plants, which showed a significant increase in model performance. The results from the modified model reveal that urban land percentage has become a positively driving force for the fractional export of watershed N and P inputs, and temperature a positive driving force for the fractional export of watershed N inputs while precipitation a negative driving force for the fractional export of watershed P inputs.
Show more [+] Less [-]Effect of biodegradation on haloacetic acid formation potentials of anthropogenic compounds during chlorination Full text
2020
Cordero, José Andrés | He, Kai | Okuta, Erika | Echigo, Shinya | Itoh, Sadahiko
During drinking water treatment processes, anthropogenic compounds act as important precursors of disinfection by-products such as haloacetic acids (HAAs). Several transformations in these precursors occur prior to the disinfection stage, such as partial biodegradation. We hypothesized that this partial biodegradation of anthropogenic compounds potentially affects their HAA formation potentials (HAAFPs). In this study, the HAAFPs of 51 anthropogenic compounds after short-term contact (less than 1 h) and long-term contact (24 h) with activated sludge were compared. Considerable changes were observed particularly in trichloroacetic acid (TCAA) formation potentials (FPs) of phenols, demonstrating that biodegradation should be considered in investigations of potential precursors of HAAs. Phenols with low HAAFPs, such as hydroquinone, show higher HAAFPs after biodegradation, but HAAFPs of most phenols and anilines decreased after biodegradation. Thus, biodegradation will most likely have a positive impact on water quality from the standpoint of HAAFP reduction. For most aliphatic compounds, changes in HAAFP were negligible, but the dichloroacetic acid (DCAA) FP of acrylic acid largely increased. This study illustrates that biodegradation may have a large effect on the HAAFPs of anthropogenic compounds.
Show more [+] Less [-]FDI and environmental degradation: the role of political institutions in South Asian countries Full text
2020
Sabir, Samina | Qayyum, Unbreen | Majeed, Tariq
This study examines the impact of foreign direct investment (FDI) on environmental degradation by keeping in view the role of institutional quality (IQ) in the South Asian region. Second-generational unit root test is used to address the issue of cross-sectional dependency. Mixed order of integration enabled us to use panel autoregressive distributed lag (ARDL) method to investigate short-run and long-run association. Moreover, this study also employs Granger causality test to explore causalities among the selected variables. Empirical results reveal that FDI has a positive and statistically significant effect on environmental degradation. Institutional quality is measured as rule of law has insignificant impact on ecological footprint both in short run as well as long run. However, government stability decreases environmental degradation while corruption enhances environmental hazards tremendously. This study also supports environmental Kuznets curve (EKC) for the South Asian countries. This study emphasized the role of political institutions in environmental degradation. South Asian countries must focus on the implementation of environmental laws and regulations by improving the quality of institutions to achieve the goal of sustainable development.
Show more [+] Less [-]Physical limitation of pesticides (chlordecone) decontamination in volcanic soils: fractal approach and numerical simulation Full text
2020
Woignier, Thierry | Rangon, Luc | Clostre, Florence | Mottes, Charles | Cattan, Philippe | Primera, Juan | Jannoyer, Magalie
In the French West Indies, the chlordecone (organochloride pesticide) pollution is now diffuse becoming new contamination source for crops and environment (water, trophic chain). Decontamination by bioremediation and chemical degradation are still under development but the physical limitations of these approaches are generally not taken into account. These physical limitations are related to the poor physical accessibility to the pesticides in soils because of the peculiar structural properties of the contaminated clays (pore volume, transport properties, permeability, and diffusion). Some volcanic soils (andosols), which represent the half of the contaminated soils in Martinique, contain nanoclay (allophane) with a unique structure and porous properties. Andosols are characterized by pore size distribution in the mesoporous range, a high specific surface area, a large pore volume, and a fractal structure. Our hypothesis is that the clay microstructure characteristics are crucial physico-chemical factors strongly limiting the remediation of the pesticide. Our results show that allophane microstructure (small pore size, hierarchical microstructure, and tortuosity) favors accumulation of chlordecone, in andosols. Moreover, the clay microporosity limits the accessibility of microorganisms and chemical species able to decontaminate because of poor transport properties (permeability and diffusion). We model the transport properties by two approaches: (1) we use a numerical model to simulate the structure of allophane aggregates. The algorithm is based on a cluster–cluster aggregation model. From the simulated data, we derived the pore volume, specific surface area, tortuosity, permeability, and diffusion. We show that transport properties strongly decrease because of the presence of allophane. (2) The fractal approach. We characterize the fractal features (size of the fractal aggregate, fractal dimension, tortuosity inside allophane aggregates) and we calculate that transport properties decrease of several order ranges inside the clay aggregates. These poor transport properties are important parameters to explain the poor accessibility to pollutants in volcanic soils and should be taken into account by future decontamination process. We conclude that for andosols, this inaccessibility could render inefficient some of the methods proposed in the literature.
Show more [+] Less [-]The role of financial development on carbon emissions: a meta regression analysis Full text
2020
Gök, Adem
The study analyzes the role of financial development on CO2 emissions based on the primary studies in the existing literature. However, the heterogeneity in reported effect size estimates of the primary studies complicates to test the competing hypotheses for the role of financial development on CO2 emissions. The paper tries to determine and quantify the representative empirical genuine effect of financial development on CO2 emissions, if any. To address the issue, a meta-regression analysis has been carried out for 275 estimation results from 72 primary studies. We have found a substantial publication selection bias in the literature due to the design characteristics of the primary studies. The results suggest the presence of an authentic positive empirical effect of financial development on CO2 emissions beyond publication selection bias. Hence, financial development leads to environmental degradation. The effect of financial development on carbon emissions changes both in magnitude and direction depending on which financial development indicator is used, which estimation technique is employed, which countries or region are included and which time period is analyzed.
Show more [+] Less [-]Linking environment, malaria, and agricultural returns: a labor time use analysis at different stages of production using 3SLS Full text
2020
Rose, Sobia | ʻAlī, Muḥammad Faiṣal | Khuda Bakhsh, | Ashfaq, Muhammad | Hassan, Sarfraz
The present study was designed to investigate the effects of disease on time spent by family and hired labor on farm activities. The effect of illness on cost incurred on farm activities and revenue earned from agriculture has also been examined in detail. The reason behind choosing malaria is because of its strong association with the quality of surrounding environment especially in the case of farm workers who are compelled to work in the environmental conditions quite suitable for the transmission of malaria. The effects of health shocks due to malaria are segregated according to three stages of production: land preparation, field management, and harvesting stages. Simultaneous equation model was employed using cross-sectional data collected from 252 farm workers through a pre-tested questionnaire. Farmers’ living environment was found to be contributing in the spread of disease. Results also show that malaria affects labor time at harvesting stage as it is more labor-intensive stage of production. We find that malaria significantly affects the health of farm workers and their families forcing farm families to substitute family labor with hired labor. Further, the cost incurred on cure of disease significantly adds to the cost on agricultural production. This consequently leads to a substantial reduction in revenue. The effect of the cost incurred on prevention and cure of disease was also found negative on revenue. The study suggests that, in order to make farmers more productive, there should be malaria interventions specifically targeting the health of farmers. It is also suggested that, for successful malaria interventions especially in irrigated areas, the magnitude of the disease on different stages of production should be given due consideration.
Show more [+] Less [-]Systemic resistance induced by Phoma sp. GS8-3 and nanosilica against Cucumber mosaic virus Full text
2020
Elsharkawy, Mohsen Mohamed | Suga, Haruhisa | Shimizu, Masafumi
Cucumber mosaic virus (CMV) is a very serious hazard to vegetable production worldwide. This study is focused on evaluation of resistance stimulated by the plant growth-promoting fungus, Phoma sp. GS8-3, or nanosilica against CMV under pot and field conditions. The specific aim was to illustrate the mechanism of resistance stimulated by GS8-3 against CMV using microarray technology. Treatments with GS8-3 as well as nanosilica significantly decreased CMV severity and titer in tobacco and cucumber under pot and field conditions, respectively. Growth characters of tobacco and cucumber were significantly increased due to GS8-3 inoculation followed by nanosilica compared with control and BTH treatments. Microarray results showed highly upregulation of defense-related genes expression specially those related to heat shock proteins. Therefore, GS8-3 as well as nanosilica is suitable to serve as effective inducers against CMV in cucumber plants.
Show more [+] Less [-]Remediation techniques for removal of heavy metals from the soil contaminated through different sources: a review Full text
2020
Dhaliwal, Salwinder Singh | Jasawindara Siṅgha, | Taneja, Parminder Kaur | Mandal, Agniva
Heavy metal pollution is one of the serious problems and contaminates the environment by different means with the blow of industries in several countries. Different techniques like physical, chemical, and biological have been used for removal of heavy metal contaminants from the environment. Some of these have limitations such as cost, time consumption, logistical problems, and mechanical involvedness. Nowadays, in situ immobilization of metals, phytoremediation and biological techniques turned out to be best solution for elimination of metal(loid) s from the soil. Here, we reviewed the different remediation techniques for extraction of heavy metals from soil and especially highlighting in situ immobilization technique. The aim of remediation efforts at the contaminant site is to restrict the heavy metal to enter in the environment, food chain, and exposure to humans beings. The type of method used at a given site depends on the various factors like natural processes take place at the contaminated site, soil type, type of chemicals, and the depth of contaminated site.
Show more [+] Less [-]The effect of expected financial performance on corporate environmental responsibility disclosure: evidence from China Full text
2020
Zeng, Yanqi | Gulzar, Muhammad Awais | Wang, Zongjun | Zhao, Xinxin
Nowadays, firms spend a great deal of effort on Corporate Environmental Responsibility (CER) disclosure. From prospect theory, firms might disclose more CER information when they fail to achieve expected financial performance of the organization. We have constructed a CER disclosure index based on the “Guidelines for Environmental Information Disclosure of Listed Companies” issued by the Ministry of Environmental Protection of China in 2010. Using content analysis, we analyze 397 Chinese manufacturing Shanghai A-share listed firms from 2011 to 2017 (2090 firm-year observations) to investigate the relationship between corporate expected financial performance and CER disclosure. Our results show that, firstly, when the firm does not achieve the expected performance that is when the actual expectation is lower than the expected performance of the organization, the disclosure of corporate environmental responsibility increases; secondly, we have explored the moderating effect of industry categories; we have found that when firms fail to achieve the expected performance of the organization, light polluting firms are more inclined towards disclosing the environmental responsibility information than heavy polluting firms. Additionally, we have also studied the behavior of corporate environmental responsibility disclosure in the case of analysts expecting performance as a point of reference and got the same results.
Show more [+] Less [-]Concentrations and mortality due to short- and long-term exposure to PM2.5 in a megacity of Iran (2014–2019) Full text
2020
Hajizadeh, Yaghoub | Jafari, Negar | Mohammadi, Amir | Momtaz, Seyed Mojtaba | Fanaei, Farzad | Abdolahnejad, Ali
The present study aimed to survey the spatial and temporal trends of ambient concentration of PM₂.₅ and to estimate mortality attributed to short- and long-term exposure to PM₂.₅ in Isfahan from March 2014 to March 2019 using the AirQ⁺ software. The hourly concentrations of PM₂.₅ were obtained from the Isfahan Department of Environment and Isfahan Air Quality Monitoring Center. Then, the 24-h mean concentration of PM₂.₅ for each station was calculated using the Excel software. According to the results, the annual mean concentration of PM₂.₅ in 2014–2019 was 29.9–50.9 μg/m³, approximately 3–5 times higher than the WHO guideline (10 μg/m³). The data showed that people of Isfahan in almost 58% to 96% of the days of a year were exposed to PM₂.₅ higher than the WHO daily guideline. The concentrations of PM₂.₅ in cold months such as October, November, December and January were higher than those in the other months. The zoning of the annual concentrations of PM₂.₅ in urban areas showed that the highest PM₂.₅ concentrations were related to the northern, northwestern, southern and central areas of the city. On average, from 2014 to 2019, the number of deaths due to natural mortality, lung cancer (LC), chronic obstructive pulmonary disease (COPD), ischemic heart disease (IHD) and stroke associated with ambient PM₂.₅ were 948, 16, 18, 281 and 60, respectively. The present study estimated that on average, 14.29% of the total mortality, 17.2% of lung cancer (LC), 15.54% of chronic obstructive pulmonary disease (COPD), 17.12% of ischemic heart disease (IHD) and 14.94% of stroke mortalities were related to long-term exposure to ambient PM₂.₅. So provincial managers and politicians must adopt appropriate strategies to control air pollution and reduce the attributable health effects and economic losses.
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