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Urban and Rural Residents’ Willingness to Pay for Desertification Prevention and Control and its Influencing Factors Texte intégral
2019
Weipeng Chao, Changjiang Zhang and Pengcheng Wang
The prevention and control of desertification cannot be separated from the active participation of local urban and rural residents. However, only a few studies on the difference in urban and rural residents’ willingness to pay for the prevention and control of desertification and its influencing factors are available. To explore the differences in urban and rural residents’ willingness to pay for desertification prevention and control, the status quo and influencing factors of willingness to pay for desertification prevention and control among urban and rural residents were analysed by linear regression analysis method and the micro-survey data of 300 urban and rural residents in the middle and lower reaches of the Tarim River in Xinjiang, China. Results show that urban and rural residents’ willingness to pay for desertification prevention and control is affected by education level, ecological environment concern, ecological environment protection needs, attention to desertification, and cognition of desertification control effect. Several preventive measures were provided with respect to enhancing residents’ awareness of desertification prevention and control, raising residents’ income and push forward systematic innovation.
Afficher plus [+] Moins [-]Natural Background Gamma Radiation Levels in the Environs of Proposed Petro-chemical Industry Near Jadcherla, Telangana State, India Texte intégral
2019
G. Srinivas Reddy, K. Vinay Kumar Reddy, B. Linga Reddy and B. Sreenivasa Reddy
A survey of environmental gamma radiation levels is attempted in the geographical site under construction to establish a petrochemical industry. The knowledge of natural background radiation is one of the significant steps in establishing the chemical industry. Some chemical operations such as chemical refinement may sometimes influence the natural radiation levels. The attempt of measurement of natural background gamma levels in the present paper is to establish the baseline data, which on further measurements will be useful to analyse the changes in natural background radiation levels at the time of operation of a chemical plant. The present investigation shows the activity levels of gamma radiation in the site under construction at 65 locations. The gamma levels are found to vary from 1459 μGyy-1 to 2765 μGyy-1 with the average of 2141±304 μGyy-1. It is to be noted from the study that the average gamma radiation levels at two sample locations, cement mixing point (2307 μGyy-1) and stone crushing point (2529 μGyy-1) have been elevated. The elevated radiation levels at the two sample locations can be attributed to the radioactive dust emitted in the process of crushing stones and cement mixing.
Afficher plus [+] Moins [-]Carbon Emission Efficiency of Construction Industry in Hunan Province and Measures of Carbon Emission Reduction Texte intégral
2019
Liu Hua and Zhu Min
The construction industry is among the pillars of China’s economic development. However, it causes high carbon emission and high energy consumption, which should be considered when drafting energy saving and emission reduction policies. The sustainable development of this industry lies in the effective estimation of carbon emission efficiency and implementation of energy-saving and emission reduction measures in accordance with local practical situations. First, investigations on the emission efficiency of the construction industry and relevant emission reduction policies in foreign developed countries were reviewed in this study. Second, the carbon emission efficiency of the construction industry in 13 prefecture-level cities in Hunan Province (China) from 2011 to 2017 were estimated using the SBM (Slack Based Measure) model involving unexpected outputs. Finally, specific suggestions on reducing the carbon emission of the construction industry were proposed. CO2 emissions in the construction industry increase annually as a response to economic development and urbanization. The carbon emission efficiency of Hunan Province’s construction industry maintained a stable growth rate in 2011-2017. The industry achieved an annual growth rate of 2.7% in 2017 from that in 2011. The carbon emission efficiency of Changsha City, Zhangjiajie City, and Yiyang City were relatively higher than those of other cities in the province. Such findings serve as a reference to the quantification of potential of Hunan Province in reducing the carbon emission, the formulation of specific carbon emission reduction goal, the augmentation of the means to evaluate energy saving and emission reduction, and the development of a low-carbon construction industry.
Afficher plus [+] Moins [-]Horizontal Distribution of Chlorophyll-a in the Gorontalo Bay Texte intégral
2019
Miftahul Khair Kadim, Nuralim Pasisingi and Sulastri Arsad
The concentration of chlorophyll-α in the Gorontalo Bay is necessary to be observed since it could describe the condition of water richness. The semi-enclosed Gorontalo Bay morphology causes the status of water fertility to be largely determined by the input of inorganic or organic materials originating from the mainland. This study aimed to figure out the concentration and horizontal distribution pattern of the chlorophyll-α then further to decide the relationship between the concentration of chlorophyll-α and the nutrients in the Gorontalo Bay. There were fifteen sub-sampling sites selected based on coastal and ecological characteristics. Results showed that the distribution pattern of chlorophyll-α in the Gorontalo Bay in June and July 2017 was dissimilar and its concentration ranged from 0.984 to 3.744 mg.m-3. In addition, there was a positive and substantial relationship between chlorophyll-α and phosphate (p<0.01). Nonetheless, there was no significant correlation between chlorophyll-α and nitrate (p>0.01) and ammonia (p>0.01).
Afficher plus [+] Moins [-]Vulnerability, well-being, and livelihood adaptation under changing environmental conditions: a case from mountainous region of Pakistan Texte intégral
2019
Shahzad, Laila | Tahir, Arifa | Sharif, Faiza | Khan, Waqas Ud Din | Farooq, Muhammad Ansar | Abbas, Azhar | Saqib, Zulfiqar Ahmad
Climatic changes pose serious risks to the rural community’s livelihoods of many developing countries whereas people in mountainous regions are exposed to multiple hazards with limited livelihood resources and heavy dependence on natural resources. The objective of the current study is to assess the livelihood practices and adaptive capacity of a mountainous region of Pakistan, the Balakot, where people are highly vulnerable to climatic changes. The study uses a triangulation method to explore various issues and options of climate change risks sand adaptation and impact of well-being on resilience capacity and livelihood strategies. For this purpose, ten focus group discussions (FGDs) with carefully selected key informants and structured interviews with randomly selected 200 local households are conducted to evaluate different hazards and their associated livelihood effects. It is observed that the changing climate has significantly influenced livelihoods of the local community in the recent past through resource degradation, gradual unavailability of sufficient basic services (quantity and quality of drinking water, crop food diversity, fuel wood, and non-timber forest products), low agricultural productivity, and social inequity viz. income distribution, health, education, and food storage. Such a brunt is felt disproportionately more by poor households due to their low adaptive capacity to climate change with constrained livelihood resources. The study emphasizes the need for targeted efforts to move from coping strategies to adaptations among people considering their social inequalities. Timely information sharing, livelihood diversification and preservation of livelihood resources such as crop and forest production, livestock grazing, creating awareness on the pace, and pattern of climate change in the region and subsequent role of adaptation options are major interventions that should be emphasized by the public bodies.
Afficher plus [+] Moins [-]Effect of temperature on tertiary nitrogen removal from municipal wastewater in a PHBV/PLA-supported denitrification system Texte intégral
2019
Xu, Zhongshuo | Dai, Xiaohu | Chai, Xiaoli
In this study, a poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/poly(lactic acid) (PHBV/PLA)–supported denitrification system was built to remove nitrogen from municipal wastewater treatment plant secondary effluent, and the influence of operating temperature on nitrogen removal was further investigated. Results indicated that a PHBV/PLA-supported denitrification system could effectively fulfill the tertiary nitrogen removal. The nitrogen removal efficiency gradually declined with the operating temperature decreasing, and the denitrification rate at 30 °C was 5 times higher than that at 10 °C. Meanwhile, it was found that a slight TOC accumulation only occurred at 30 °C (with an average of 2.03 mg/L) and was avoided at 10~20 °C. The reason for effluent TOC variation was further explained through the consumption and generation pathways of TOC in this system. Furthermore, the temperature coefficient was about 0.02919, indicating that the PHBV/PLA-supported denitrification system was a little sensitive to temperature. A better knowledge of the effect of operating temperature will be significant for the practical application of the solid-phase denitrification system.
Afficher plus [+] Moins [-]Response of Water Chemistry and Young-of-Year Brook Trout to Channel and Watershed Liming in Streams Showing Lagging Recovery from Acidic Deposition Texte intégral
2019
Josephson, Daniel C. | Lawrence, Greg B. | George, Scott D. | Siemion, Jason | Baldigo, Barry P. | Kraft, Clifford
Reductions in sulfur emissions have initiated chemical recovery of surface waters impacted by acidic deposition in the Adirondack region of New York State. However, acidified streams remain common in the region, which limits recovery of brook trout (Salvelinus fontinalis) populations. To investigate liming as a method to accelerate recovery of brook trout, the channels of two acidified streams were limed annually from 2012 to 2015, and an entire watershed of a third acidified tributary was limed by helicopter in 2013. Stream flow, water chemistry, and density of young-of-year (YOY) brook trout were measured in limed streams, an untreated acidified stream, and a buffered reference stream. Lime additions increased pH and acid-neutralizing capacity and decreased inorganic monomeric aluminum concentrations to less than 2.0 μmol/L, the minimum concentration at which in situ brook trout mortality has been documented. However, of the two channel-limed streams, only stream T8 showed a significant response (P < 0.01) in YOY density, increasing from a mean of 0.4 fish/m² before liming to 2.7 fish/m² after liming. No YOY brook trout response was observed in the stream within the limed watershed. Groundwater inputs to streams were identified by relative differences in temperature and concentrations of silica and sodium. YOY brook trout densities increased only in the channel-limed stream (T8) with suitable groundwater inputs for fall spawning and a summer nursery. Results suggest that targeted liming of acidified streams with the necessary groundwater habitat could be beneficial in accelerating recovery of brook trout populations.
Afficher plus [+] Moins [-]Coconut Shell Activated Carbon as Solid-Phase Extraction Adsorbent for Preconcentration of Selected Pesticides from Water Samples Texte intégral
2019
Kumrić, Ksenija | Vujasin, Radojka | Egerić, Marija | Petrović, Đorđe | Devečerski, Aleksandar | Matović, Ljiljana
Solid-phase extraction (SPE) on activated carbon derived from coconut shell (CSAC) for the preconcentration of four varying polarity pesticides (imidacloprid, acetamiprid, simazine, and linuron) prior to their determination using high performance liquid chromatography with diode array detector (HPLC-DAD) was investigated. The characteristics of the CSAC were analyzed through X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and Brunauer-Emmett-Teller (BET) method. The effects of the solution pH, eluent type, eluent volume, and flow rate were investigated for optimization of the presented procedure. The adsorption was achieved quantitatively on the CSAC column in the pH range of 2.0–7.0, and then the retained pesticides were eluted with dichloromethane. The detection limit was found to be 0.025–0.039 μg L⁻¹, depending on the pesticide. The proposed SPE-CSAC method was used to determine selected pesticides in tap water samples. The recoveries ranged from 58.2 to 105.3%, with low relative standard deviations. The obtained results indicated that the CSAC could be efficiently used as a low cost alternative to commercially available SPE adsorbents for the determination of the varying polarity pesticides in environmental water samples at trace levels.
Afficher plus [+] Moins [-]Urinary metabolites of polycyclic aromatic hydrocarbons in pregnant women and their association with a biomarker of oxidative stress Texte intégral
2019
Lou, Xiang-Yin | Wu, Peng-Ran | Guo, Ying
Exposure to polycyclic aromatic hydrocarbons (PAHs) during pregnancy may pose adverse health risk to both the mothers and babies. In the present study, 188 pregnant women of different trimesters were recruited in Guangzhou, south China, and nine hydroxyl PAHs (OH-PAHs) and a biomarker of DNA oxidative damage, 8-hydroxy-2′-deoxyguanosine (8-OHdG), were determined in their urine samples. All OH-PAHs except for 4-hydroxyphenanthrene and 6-hydroxychrysene were found in > 90% samples, with total concentration in the range of 0.52 to 42.9 μg/g creatinine. In general, concentration levels of OH-PAHs in pregnant women were lower than those in general population in the same research area but with higher levels in working women than in housewives. The mean daily intakes of PAHs from dietary estimated by urinary OH-PAHs were 0.021, 0.004, 0.047, and 0.030 μg/kg_bw/day for naphthalene, fluorene, phenanthrene, and pyrene, respectively, which were much lower than the reference doses (20, 30, and 40 μg/kg_bw/day for naphthalene, pyrene, and fluorene, respectively) derived from chronic oral exposure data by the United States Environmental Protection Agency. The low exposure levels of PAHs may be attributed to the traditional dietary taboo of Chinese pregnant women, which is to minimize the consumption of “toxic” food. The concentrations of 8-OHdG (4.67–49.4 μg/g creatinine) were significantly positively correlated with concentrations of several OH-PAHs, such as metabolites of naphthalene, fluorene, and phenanthrene (r = 0.3–0.6). In addition, the concentrations of 8-OHdG were higher in working women than in housewives when exposed to the same levels of PAHs, partly indicating the possible relation between work-related pressure for working women and the oxidative stress.
Afficher plus [+] Moins [-]Dietary exposure and risk assessment of organochlorine pesticide residues in rural communities living within catchment areas of iSimangaliso World Heritage Site, South Africa Texte intégral
2019
Buah-Kwofie, Archibold | Humphries, Marc S. | Pillay, Letitia
Dietary intake of contaminated food is a major route of human exposure to organochlorine pesticides (OCPs). Despite the prevalence of OCP usage in southern Africa for several decades, their impact on socioeconomically vulnerable communities remains largely overlooked. We investigated the accumulation of OCPs in crops commonly cultivated by rural communities surrounding iSimangaliso Wetland Park, South Africa. All samples analysed were found to be contaminated, with total OCP concentrations ranging between 190 and 240 ng g⁻¹ ww. Elevated levels of OCP residues were detected in all products, with the majority of samples exceeding European Commission’s maximum residue limits (MRLs). We combine these results with local OCP fish tissue estimates to assess potential dietary risks. Cumulative risk assessment indicated potential non-cancer risks associated with heptachlor epoxide, while a cancer risk as high as 1 in 10 was found to be associated with aldrin and dieldrin. This far exceeds USEPA guidelines and indicates that OCP residues in crops and fish from the study area pose a high risk to human health. The results of this study call for further attention to be given to the health implications of continued OCP use not only within the study area but also in Southern Africa in general.
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