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Pollution levels and risk assessment of perfluoroalkyl acids (PFAAs) in beef muscle and liver from southern Xinjiang Полный текст
2018
Wang, Gehui | Lu, Jianjiang | Li, Shanman | Liu, Zilong | Chang, Haisha | Xie, Chunbin
The presence of perfluoroalkyl acids (PFAAs) in animal foods is worldwide, and their fate and spatial distribution in Xinjiang are not well understood. In this study, beef muscle and liver collected from five major cities in southern Xinjiang were analyzed (n = 70) for 13 PFAAs using an ion-pairing method combined with HPLC-MS/MS. Overall, PFAA contamination was widespread, exceeding 50% of samples with concentrations ranged from below the limits of detection to 6.118 ng/g. Perfluorooctane sulfonate, perfluorooctanoic acid, and perfluoroundecanoic acid were the predominant PFAAs of ten detected compounds, with maximum concentrations in Korla liver samples of 2.543, 0.856, and 1.386 ng/g, respectively. When comparing the five cities, the highest levels and detection frequencies were observed in samples from Korla (muscle, 0.013 ng/g; liver, 3.336 ng/g), followed by Yanqi, Akesu, Kashgar, and Hotan. The different pollution patterns and distribution profiles of PFAAs among cities were significantly related to local economy and geographical conditions. In addition, the dietary intake assessments for PFAAs showed that samples originating from Korla had the greatest impact on human health, but the total hazard ratio was 0.814 × 10⁻³, which is far less than 1, indicating that consumption of beef muscle and liver poses no immediate harm to local residents.
Показать больше [+] Меньше [-]Inhibition of 1, 4-dioxane on the denitrification process by altering the viability and metabolic activity of Paracoccus denitrificans Полный текст
2018
Luo, Jingyang | Zhang, Qin | Wu, Lijuan | Cao, Jiashun | Feng, Qian | Fang, Fang | Chen, Yinguang
1,4-Dioxane is an emerging pollutant, which widely exists in natural environments and poses potential risks to the living organisms. However, its effect on the denitrification process is still unknown. In this study, the effects of 1,4-dioxane on the denitrification process were therefore investigated by using Paracoccus denitrificans as the model denitrifier. The obtained results showed that the exposure of 1,4-dioxane exhibited remarkable lag or inhibition on the denitrification process, especially with high dose. In the control without 1,4-dioxane exposure, Paracoccus denitrificans showed high denitrification efficiency (98.5%). However, the efficiency decreased to 78.5, 63.9, and 9.3% with 0.50, 0.75, and 1.0% (v/v) 1,4-dioxane dose, respectively. The dose-induced inhibition of denitrification by 1,4-dioxane could be partially attributed to the negative effects on proliferation and viability of functional microorganisms by conjugating and disrupting the cell membranes. Furthermore, 1,4-dioxane caused biotoxicity to the intracellular activities of denitrifiers via disturbing carbon source utilization and interfering the key enzymes responsible for glycolysis. The decrease of microbial viability and activity inevitably resulted in the decline of key enzymes (NAR, NIR, NOR, and N₂OR) closely related with denitrification process, which could be the direct reason for the decrease of denitrification performance.
Показать больше [+] Меньше [-]Erratum to: Effects-based spatial assessment of contaminated estuarine sediments from Bear Creek, Baltimore Harbor, MD, USA Полный текст
2018
Hartzell, Sharon E. | Unger, Michael A. | McGee, Beth L. | Yonkos, Lance T.
The original publication of this paper contains an error. The correct image of figure 5 is shown in this paper.
Показать больше [+] Меньше [-]The ecological competition and grazing reverse the effects of sulfamethoxazole on plankton: a case study on characterizing community-level effect Полный текст
2018
Wang, Changyou | Liang, Shengkang | Zhang, Yong
The toxic effects of sulfamethoxazole (SMX) on densities of two algae, Platymonas helgolandica var. tsingtaoensis, Isochrysis galbana, and of a rotifer, Brachionus plicatilis, were tested by the population and community experiments. Two endpoints, the carrying capacity and the densities array of community in steady state (DACS), were used to characterize the toxic effects at a population level and a community one, respectively. The results showed that the carrying capacity of P. helgolandica var. tsingtaoensis and B. plicatilis did not decline significantly in population test when the concentration of SMX was lower than 6.0 mg L⁻¹ and 12.0 mg L⁻¹, respectively. However, I. galbana was sensitive to SMX and had presented toxic effect at 3.0 mg L⁻¹. By extrapolation of toxic effect at a population level to a community one, a derived community-NOEC was 3.0 mg L⁻¹, representing an inference from data of toxic effects at population level. In community experiment, when the customized community was in steady state, the density of I. galbana increased as a whole with SMX concentration in the range of tested concentration (0–144 mg L⁻¹), while that of P. helgolandica var. tsingtaoensis assumed the trend of a reversed “v” in this range. Only the density of B. plicatilis decreased with SMX concentration. With the DACS as endpoint, a NOEC for the customized community was determined to be 6.0 mg L⁻¹. This indicates that interspecific interactions can reverse the toxic effects of SMX on phytoplankton. The DACS was reliable and stable, serving as the endpoints in assessment of the effects of the pollutants on the ecosystems.
Показать больше [+] Меньше [-]Chemical characterization and receptor modeling of PM10 in the surroundings of the opencast lignite mines of Western Macedonia, Greece Полный текст
2018
Samara, Constantini | Argyropoulos, George | Grigoratos, Theodoros | Kouras, Αthanasios | Manoli, Εvangelia | Andreadou, Symela | Pavloudakis, Fragkiskos | Sahanidis, Chariton
The Western Macedonian Lignite Center (WMLC) in northwestern Greece is the major lignite center in the Balkans feeding four major power plants of total power exceeding 4 GW. Concentrations of PM₁₀ (i.e., particulate matters with diameters ≤10 μm) are the main concern in the region, and the high levels observed are often attributed to the activities related to power generation. In this study, the contribution of fugitive dust emissions from the opencast lignite mines to the ambient levels of PM₁₀ in the surroundings was estimated by performing chemical mass balance (CMB) receptor modeling. For this purpose, PM₁₀ samples were concurrently collected at four receptor sites located in the periphery of the mine area during the cold and the warm periods of the year (November–December 2011 and August–September 2012), and analyzed for a total of 26 macro- and trace elements and ionic species (sulfate, nitrate, chloride). The robotic chemical mass balance (RCMB) model was employed for source identification/apportionment of PM₁₀ at each receptor site using as inputs the ambient concentrations and the chemical profiles of various sources including the major mine operations, the fly ash escaping the electrostatic filters of the power plants, and other primary and secondary sources. Mean measured PM₁₀ concentrations at the different sites ranged from 38 to 72 μg m⁻³. The estimated total contribution of mines ranged between 9 and 22% in the cold period increasing to 36–42% in the dry warm period. Other significant sources were vehicular traffic, biomass burning, and secondary sulfate and nitrate aerosol. These results imply that more efficient measures to prevent and suppress fugitive dust emissions from the mines are needed.
Показать больше [+] Меньше [-]The ‘333’ integrated strategy for effective pollution control and its application to the heavily polluted Jialu River in north China Полный текст
2018
Huang, Yu | Sun, Jie | Li, Aimin | Xie, Xianchuan
In this study, an integrated approach named the ‘333’ strategy was applied to pollution control in the Jialu River, in northern China, which is heavily burdened with anthropogenic pollution. Due to a deficiency of the natural ecological inflow, the Jialu River receives predominantly industrial and municipal effluent. The ‘333’ strategy is composed of three steps of pollution control including industrial point-source pollution control, advanced treatment of municipal wastewater, and ecological restoration; three increased stringency emission standards; and three stages of reclamation. Phase 1 of the ‘333’ strategy focuses on industrial point-source pollution control; phase 2 aims to harness municipal wastewater and minimize sewage effluents using novel techniques for advanced water purification; phase 3 of the ‘333’ strategy focuses on the further purification of effluents flowing into Jialu River with the employment of an engineering-based ecological restoration project. The application of the ‘333’ strategy resulted in the development of novel techniques for water purification including modified magnetic resins (NDMP resin), a two-stage internal circulation anaerobic reactor (IC reactor) and an ecological restoration system. The results indicate that water quality in the river was significantly improved, with increased concentrations of dissolved oxygen (DO), as well as reduction of COD by 42.8% and NH₃-N by 61.4%. In addition, it was observed that the total population of phytoplankton in treated river water notably increased from only one prior to restoration to 8 following restoration. This system also provides a tool for pollution control of other similar industrial and anthropogenic source polluted rivers.
Показать больше [+] Меньше [-]Toxicological assessment of lambda-cyhalothrin and acetamiprid insecticides formulated mixture on hatchability rate, histological aspects, and protein electrophoretic pattern of Biomphalaria alexandrina (Ehrenberg, 1831) snails Полный текст
2018
Ibrahim, Amina Mohamed | Sayed, Sara S. M. | Shalash, Ibrahim R. A.
Several formulated mixtures of pesticides are widely used in modern agriculture. Nevertheless, the agriculture runoff causes a serious damage to the aquatic ecosystem. Therefore, the present study aims to use B. alexandrina snails as bioindicators for 30 g/l lambda-cyhalothrin and 17 g/l acetamiprid as a formulated mixture insecticide. Results showed that it has a molluscicidal activity against snails at LC₅₀ 7.9 mg/l. The hatchability percent of both treated 1-day-aged and/or 3-day-aged groups were less than that of the control group. The sublethal concentrations of the tested insecticide caused a remarkable abnormal necrosis in male and female gametogenic cells, besides a severe damage in both secretory and digestive cells. The results of SDS-PAGE protein profiles of treated snails showed that the least number of protein bands was noticed in snail groups that subjected to LC₁₀ (6.6 mg/l) and LC₂₅ (7.2 mg/l) concentrations when compared to control protein fractions.
Показать больше [+] Меньше [-]Distributions, influencing factors, and risk assessment of Dechlorane Plus and related compounds in surficial water and sediment from the Jiulong River Estuary, Southeast China Полный текст
2018
Chen, Xiangping | Zhu, Yaxian | Huang, Qi | Liu, Jun | Liu, Bin | Zhang, Yong
Dechloranes, a type of additive polychlorinated flame retardant, which include Dechlorane (Dec) Plus (DP), Dec 602, Dec 603, and Dec 604, were detected in surficial water and sediment from the Jiulong River Estuary (JRE). The total concentration of dechloranes in the water and sediments ranged from 1.4 to 4.1 ng/L and 9.3 to 36.2 ng/g dry weight, respectively. The distribution patterns of dechloranes in the water and sediments were both dominated by DP. The average values of the anti-DP fractional abundances (fₐₙₜᵢ) in the water and sediment samples both were fell in the range of commercial DP mixtures. The relationships of DP in the water with suspended particulate matter (SPM), total organic carbon (TOC), and tides indicated that the combined actions of these environmental factors influenced the distribution of DP in the JRE. The deleterious risk associated with exposure to dechloranes via the water for adults was very low, suggesting that exposure of the local population of dechloranes via water is relatively safe in the JRE.
Показать больше [+] Меньше [-]Correction to: Brevibacillus laterosporus isolated from the digestive tract of honeybees has high antimicrobial activity and promotes growth and productivity of honeybee’s colonies Полный текст
2018
Khaled, Jamal M. | Al-Mekhlafi, Fahd A. | Mothana, Ramzi A. | Alharbi, Naiyf S. | Alzaharni, Khalid E. | Sharafaddin, Anwar H. | Kadaikunnan, Shine | Alobaidi, Ahmed S. | Bayaqoob, Noofal I. | Govindarajan, Marimuthu | Benelli, Giovanni
The original publication of this paper contains a mistake. The correct affiliation no. 3 is shown in this paper.
Показать больше [+] Меньше [-]A revisit of the environmental Kuznets curve hypothesis for Turkey: new evidence from bootstrap rolling window causality Полный текст
2018
Özcan, Burcu | Apergis, Nicholas | Shahbaz, Muhammad
This study aims at analyzing the Environmental Kuznets Curve (EKC) hypothesis for Turkey, spanning the period of 1961–2013. Unlike previous studies, instead of carbon emissions, the ecological footprint is used as a proxy for environmental degradation. Moreover, a bootstrap time-varying causality approach is used to detect the possible changes in causal relations and to obtain the parameters across subsample periods. The results clearly indicate that there are feedback relationships between economic growth and the ecological footprint in some subsample periods. In addition, the impact of economic growth on environmental degradation is positive and has a slowly increasing trend in all subsample periods. Therefore, the EKC hypothesis is not confirmed for the Turkish economy. Based on these results, some crucial policy implications are suggested.
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