细化搜索
结果 4271-4280 的 4,937
Environmental implication of offshore economic activities in Indonesia: a dual analyses of cointegration and causality 全文
2019
Global warming issues have become a pertinent theme for many economies and policy initiatives. The Indonesian economy is no exception as government officials and stakeholder are working seriously to decouple carbon emission from economic growth. It is on this premise that the present study attempts to investigate the nexus between the environmental implication of offshore economic activities, economic growth, energy use, and environment (CO₂) with the integration of foreign direct investment (FDI) and trade openness over recent time series data from 1980 to 2017. A series of analysis were conducted with Pesaran’s autoregressive distributed lag (ARDL) methodology and the Granger causality test as estimation techniques over the outlined variables. Empirical findings from ARDL long-run (elasticity) shows that economic growth is significantly positively associated with carbon emissions at the initial stage but a negative association is established at lags 1 and 2. A significant positive relationship is witnessed between economic growth and FDI. Also, statistical positive relationship is observed between economic growth and energy use, while an inverse relationship is observed between openness and economic growth. For causality analysis, we observe that a uni-directional causality is running from economic growth to foreign direct investment at 5% significant level. This outcome is in support of the growth-induced FDI hypothesis in Indonesia. Furthermore, a one-way causality is seen from energy to openness, CO₂ emissions, and from FDI to CO₂ emissions while there is a feedback causality between openness and CO₂ emissions. The findings of this study have implications to the environmental quality of Indonesia via economic growth; hence, the higher and better the economic growth of the country, the lesser the carbon emissions and the better the environmental quality. This proposition aligns with the pollution halo hypothesis (PHH), where FDI inflow enhances economic growth as well as impacts energy consumption and reduces carbon emissions in the host country.
显示更多 [+] 显示较少 [-]A proteomic study of Cunninghamella echinulata recovery during exposure to tributyltin 全文
2019
A proteomic study of Cunninghamella echinulata recovery during exposure to tributyltin was conducted with 2-D SDS-PAGE protein separation and profiling, MALDI-TOF/TOF protein identification, and PCA analysis. The presence of TBT resulted in an upregulation of enzymes related to energy production via cellular respiration. The unique overexpression of NADH dehydrogenase and mitochondrial malate dehydrogenase, together with an increased level of cytochrome c oxidase, ATP synthase subunits, and inorganic pyrophosphatase, indicates a strong energy deficit in the cells, leading to an increase in the ATP production. The overexpression of Prohibitin-1, a multifunctional protein associated with the proper functioning of mitochondria, was observed as well. The data also revealed oxidative stress condition. Among reactive oxygen species (ROS)–scavenging enzymes, only superoxide dismutase (SOD) showed active response against oxidative stress induced by the xenobiotic. The induction of a series of ROS-scavenging enzymes was supported by a microscopic analysis revealing a considerably large concentration of ROS in the hyphae. The overexpression of cytoskeleton-related proteins in the TBT presence was also noticed. The obtained results allow explaining the recovery strategy of the fungus in response to the energy depletion caused by TBT.
显示更多 [+] 显示较少 [-]Use of fatty acids as tracer of organic matter input associated with level of land urbanization 全文
2019
Suspended sediments (SSs) were examined regarding the content of fatty acids (FAs) to associate them with sources of soil entry into the river. The source of organic matter was traced through fatty acid distribution, as well as erosion. Also, TOC, TN, and TOC/NT were used to support the results of FAs. For this, a tropical river was chosen to understand the main source of input considering the level of land occupation along the river. The Barigui river, in southern Brazil, was segmented in four distinct areas regarding the soil occupation (P1, P2, P3, and P4). Nine sampling campaigns were conducted from Nov/2014 to Nov/2015 using a time-integrated sampler. Site P1 has the lowest level of urbanization and showed the lowest concentration of FAs (16.35 μg⁻¹). In contrast, site P4, the most urbanized, showed the highest content of fatty acids, including those associated with erosion, 378.53 μg g⁻¹, specifically those with long chains. The mean concentrations of the saturated fatty acids (FAs) was 283.40 μg g⁻¹, monounsaturated fatty acids (MUFAs) was 79.46 μg g⁻¹, and polyunsaturated fatty acids (PUFAs) was 15.66 μg g⁻¹. Twenty-seven fatty acids were examined, nevertheless C15:0, C16:0, C18:0, and C18:1ω9 prevailed in all samples. Generally, those acids indicate sewage inputs. Statics analyses were used to find the relation between the source of organic matter (autochthonous, allochthones, and anthropogenic) and FAs. Finally, the input of organic matter is associated with land occupation, which can be distinguished by FA distribution.
显示更多 [+] 显示较少 [-]Arsenic removal by copper-impregnated natural mineral tufa part II: a kinetics and column adsorption study 全文
2019
This batch and column kinetics study of arsenic removal utilized copper-impregnated natural mineral tufa (T–Cu(A–C)) under three ranges of particle size. Non-competitive kinetic data fitted by the Weber–Morris model and the single resistance mass transfer model, i.e., mass transfer coefficient kfa and diffusion coefficient (Dₑff) determination, defined intra-particle diffusion as the dominating rate controlling step. Kinetic activation parameters, derived from pseudo-second-order rate constants, showed low dependence on adsorbent geometry/morphology and porosity, while the diffusivity of the pores was significant to removal efficacy. The results of competitive arsenic adsorption in a multi-component system of phosphate, chromate, or silicate showed effective arsenic removal using T–Cu adsorbents. The high adsorption rate—pseudo-second-order constants in the range 0.509–0.789 g mg⁻¹ min⁻¹ for As(V) and 0.304–0.532 g mg¹ min¹ for As(III)—justified further application T–Cu(A–C) in a flow system. The fixed-bed column adsorption data was fitted using empirical Bohart–Adams, Yoon–Nelson, Thomas, and dose–response models to indicate capacities and breakthrough time dependence on arsenic influent concentration and the flow rate. Pore surface diffusion modeling (PSDM), following bed-column testing, further determined adsorbent capacities and mass transport under applied hydraulic loading rates.
显示更多 [+] 显示较少 [-]Metals in wild fish from Gaotang Lake in the area of coal mining, China: assessment of the risk to human health 全文
2019
Environmental pollution can cause metal accumulation in aquatic organisms, but information on metal bioaccumulation in wild fish from coal mining areas is limited. We investigated tissue-specific metal accumulation in six economically important fish species common to Gaotang Lake, China, located in a coal mining area. We also conducted an assessment of potential risks to human health from consumption of these fish. Mean concentrations of arsenic, cadmium, cobalt, copper, mercury, lead, and antimony in the muscle of six fish species were below the corresponding Chinese maximum allowable concentrations except chromium and generally comparable with levels in fish reported by other studies. Tissue distribution patterns suggested that chromium and mercury were easily transported to the muscle, but concentrations of the other six metals were higher in the liver and gills. The daily intake of each metal was estimated at 0.002–0.220 g/day/kg body weight, and the non-carcinogenic health risks associated with the consumption of the fish from Gaotang Lake were acceptable. The results suggest that metal bioaccumulation in wild fish is not high in this coal mining area.
显示更多 [+] 显示较少 [-]Establishment of suitable separation distance by using different methods for malodor mitigation from palm oil mill 全文
2019
Malaysia is the second-largest producer and exporter of palm oil amounting to 39% of world palm oil production and 44% of world exports (MPOB, 2014). An enormous amount of palm oil mill effluent is released during palm oil milling, and the effluent causes a major odor problem. Many methods, such as biofiltering, can be adopted to manage the malodor. However, these methods are expensive and require high maintenance. The separation distance method can be used as an alternative due to its low cost and effectiveness. This research was conducted to verify the performance of three different methods, namely, in-field monitoring by using an olfactometer, CALPUFF model, and Gaussian plume model. Given that no research has compared the three methods, this study examined the effectiveness of the methods and determined which among them is suitable for use in Malaysia. The appropriate separation distances were 1.3 km for in-field monitoring, 1.2 km for the CALPUFF model, and 0.5 for the Gaussian plume model. These different values of separation distance were due to the various approaches involved in each method. This research determined an appropriate means to establish a proper separation distance for reducing odor nuisance in areas around palm oil mills.
显示更多 [+] 显示较少 [-]Cation-group interaction as the predominant force for adsorption of substituted dinitrobenzenes by smectite clays 全文
2019
Li, Liang | Sheng, G Daniel
Elucidation of the interaction between NACs and smectites is important to the understanding of the potential for transport of nitroaromatic compounds (NACs) in soils and to implementation of NAC-contaminated soil remediation. The adsorption of dinitrotoluene isomers (DNTs) and substituted dinitrobenzenes (SDNBs) by smectite was determined by batch equilibration and characterized by FTIR and XPS, along with molecular dynamics simulations. The adsorption of DNTs differed substantially among the isomers, attributed to the overall degree of nitro deflection relative to the aromatic ring plane. The substituents in SDNBs strengthened the electrostatic interaction between smectite K⁺ and nitro groups, facilitating SDNB adsorption to smectite. The competition between 2,4-DNT and 1,3-DNB, as well as the inclusion complexation of K⁺ by crown ether 18c6e, both reduced 2,4-DNT adsorption to smectite by weakening the K⁺-nitro interaction. All the results demonstrated that the electrostatic interaction between smectite K⁺ and nitro of NACs was the predominant force in mediating their adsorption. This was supported by FTIR spectra that the N–O bands shifted due to the weakening of N–O bonds and strengthening of C–N bonds via the electron transfer to cations. The XPS of smectite further manifested the cation-nitro interactions that the binding energies of K 2p 1/2, K 2p 3/2, and Si 2p shifted higher with 1,3-DNB adsorbed. Molecular dynamics simulations indicated the aromatic planes of 2,4-DNP and 2,4-DNAs were parallel to the basal plane of smectite and the oxygens of nitro groups in the molecules were directly coordinated with smectite K⁺.
显示更多 [+] 显示较少 [-]Phthalate exposure and cumulative risk in a Chinese newborn population 全文
2019
Li, Xueyan | Liu, Liangpo | Wang, Heng | Zhang, Xueqin | Xiao, Tonghu | Shen, Heqing
Phthalates have been attracted as a considerable attention in toxicological research as well as public health context due to their ubiquitous occurrence and potential adverse health effects. Newborns are susceptible to the environmental risk factors; however, data are still limited on newborn phthalate exposure and risk assessment worldwide, especially in China. This study was nested in a cross-sectional retrospective study of 1359 pregnant women recruited in Xiamen Maternity and Child Care Hospital, China, during June to July 2012. All urine samples from newborn were collected using disposal diapers during the first two postnatal days, and seven phthalate metabolites were measured by LC-ESI-MS/MS. Phthalate exposure and accumulation risk were evaluated based on the measured newborn urinary internal doses. The detection rate (96.5%) and the median concentration (17.5 ng/mL) of mono-n-butyl phthalate (MBP) were the highest, while monobenzyl phthalate (MBzP) concentration was the lowest with a detection rate (1.50%). By estimating the daily intakes of the parent phthalates, their EDI were 0.04, 0.10, 0.32, 0.00, and 0.12 μg/kg-bw/day for dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalates (DBP), benzyl butyl phthalate (BBzP), and di-(2-ethylhexyl) phthalate (DEHP), respectively. The newborns were commonly exposed to phthalates but no one exceeds the regulated tolerable daily intake (TDI) values in this large newborn population.
显示更多 [+] 显示较少 [-]Assessment of intake of copper and lead by sheep grazing on a shooting range for small arms: a case study 全文
2019
Johnsen, Ida Vaa | Mariussen, Espen | Voie, Øyvind
The Norwegian Armed Forces’ shooting ranges contain contamination by metals such as lead (Pb) and copper (Cu) and are often used as grazing pastures for livestock. To determine whether the sheep were at risk from grazing at a shooting range in Nord-Trøndelag (the Leksdalen shooting field), a study was conducted wherein the aim was to determine the amount of soil the sheep were eating, the accumulation of Cu and Pb in the livers of lambs grazing on the shooting ranges, and the accumulation of Pb and Cu in the grass. The grazing behavior of the sheep was mapped using GPS tracking and wildlife cameras. Soil, grass, feces, and liver samples were collected. All the samples were analyzed for Pb, Cu, and molybdenum (Mo), and soil and feces were also analyzed for titanium (Ti). Mean concentrations in grass, soil, feces, and liver was 41–7189, 1.3–29, 4–5, and 0.3 mg/kg Pb, respectively, and 42–580, 4.2–11.9, 19–23, and 273 mg/kg Cu, respectively. The soil ingestion rate was calculated using Ti in feces and soil. From these results, the theoretical dose of Cu and Pb ingested by grazing sheep was calculated. The soil ingestion rate was found to be 0.1–0.4%, significantly lower than the soil ingestion rate of 5–30% usually used for sheep. Little or no accumulation of Cu and Pb in the grass was found. There was no difference between the metal concentrations in the washed and unwashed grass. According to the calculated dose, the sheep were at little or no risk of acute or chronic Pb and Cu poisoning from grazing on the Leksdalen shooting range. The analysis of liver samples showed that lambs grazing on the shooting range did not have higher levels of Cu or Pb than lambs grazing elsewhere. None of the lambs had concentrations of Cu or Pb in their livers indicating poisoning.
显示更多 [+] 显示较少 [-]Histological and immunohistochemical evaluation of the effect of tartrazine on the cerebellum, submandibular glands, and kidneys of adult male albino rats 全文
2019
El-sakhawy, Mohamed A. | Mohamed, Dina W | Ahmed, Yasmine H.
Tartrazine is one of the most widely used food additives. The present investigation was carried out on 40 adult male albino rats. They were divided into four groups of ten animals for each. Group I was considered as a control group. Group II was treated with tartrazine daily in a dose 7.5 mg/kg body weight by oral gavage for 30 days. Group III was received 15 mg/kg body weight of tartrazine for the same period. Group IV was administered tartrazine in a dose 100 mg/kg body weight for the whole duration of the experiment. At the end of experiment, samples from the cerebellum, submandibular salivary glands, and kidneys were fixed in neutral buffered formalin 10% and prepared routinely for paraffin sectioning and staining for histopathological and immunohistochemical investigations of proliferating cell nuclear antigen “PCNA” and glial fibrillar acidic protein “GFAP”. Tartrazine-treated groups revealed histopathological degenerative changes in the obtained organs. In group II, the cerebellum showed subcortical edema, congestion of the blood vessels, cytoplasmic vacuolations, and pyknosis of the nuclei in the gray matter neurons. Concerning the submandibular glands, they expressed cytoplasmic vacuolations and pyknosis of the nuclei of the acinar cells, congestion of the interacinar blood capillaries, and degenerative changes in the striated duct. The kidneys appeared with interstitial hemorrhage and dilatation of the glomerular capillaries. The PCT and DCT showed ill-defined cell boundaries. The collecting tubules in the renal medulla appeared with flattened epithelial cells. The severity of these changes increases by increasing the dose of tartrazine in group III and reach to the highest level in group IV. The immunoexpression of the GFAP in the cerebellum of the experimental groups was intense compared to the control group. The immunoreactivity of PCNA in the nuclei of the acinar and ductal cells of the submandibular gland and the cells of the renal cortex and medulla was strong in the tartrazine-treated groups compared to the control group. The current study concluded that the tartrazine had serious effect on the cerebellum, submandibular glands, and kidneys that adversely affect the functions of these organs.
显示更多 [+] 显示较少 [-]