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21.
A multivariate statistical technique, cluster analysis, was used to assess the logged surface water quality at an irrigation project at Al-Fadhley, Eastern Province, Saudi Arabia. The principal idea behind using the technique was to utilize all available hydrochemical variables in the quality assessment including trace elements and other ions which are not considered in conventional techniques for water quality assessments like Stiff and Piper diagrams. Furthermore, the area belongs to an irrigation project where water contamination associated with the use of fertilizers, insecticides and pesticides is expected. This quality assessment study was carried out on a total of 34 surface/logged water samples. To gain a greater insight in terms of the seasonal variation of water quality, 17 samples were collected from both summer and winter seasons. The collected samples were analyzed for a total of 23 water quality parameters including pH, TDS, conductivity, alkalinity, sulfate, chloride, bicarbonate, nitrate, phosphate, bromide, fluoride, calcium, magnesium, sodium, potassium, arsenic, boron, copper, cobalt, iron, lithium, manganese, molybdenum, nickel, selenium, mercury and zinc. Cluster analysis in both Q and R modes was used. Q-mode analysis resulted in three distinct water types for both the summer and winter seasons. Q-mode analysis also showed the spatial as well as temporal variation in water quality. R-mode cluster analysis led to the conclusion that there are two major sources of contamination for the surface/shallow groundwater in the area: fertilizers, micronutrients, pesticides, and insecticides used in agricultural activities, and non-point natural sources.  相似文献   
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Ambient aerosol concentrations along the roadside of metropolitan cities of Pakistan were measured using a Grimm 1.109 dust monitor. Considering the high ambient aerosol concentrations, regional lung deposition of aerosol particles in the human respiratory tract was calculated to assess extent of exposure. Lung deposition was computed in terms of mass concentration and the associated surface area for 12 male traffic wardens using the latest version of the stochastic lung deposition code Inhalation, Deposition, and Exhalation of Aerosols in the Lung. The results have revealed 4 to 10 times higher concentrations than recommended by WHO guidelines. The deposition results derived from the model disclose that extrathoracic deposition is in the range of 22 to 28 % with total lung deposition ranging from 40 to 44 % for the scanned particle window of 0.25–10 μm. Considering an average 8-h shift per day and an average breathing rate of 1.3 m3?h?1, it is approximated that in a worker, up to 1.6 mg of inhalable particle mass can deposit per day.  相似文献   
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Leptophos (O-[4-bromo-2,5 dichlorophenyl] O-methyl phenylphosphonothioate) (PhosvelR) was administered orally to chickens and rats in doses of 0.5 and 5.0 mg/kg/day for 26 weeks. Hens fed 5.0 mg/kg, except one, showed ataxia and became paralysed in the legs at varying times from 8 to 19 weeks. A fifth hen showed ataxia early in the experiment but recovered fully for the remainder of the experiment. Rats fed both doses and chickens fed 0.5 mg/kg showed no signs of delayed neurotoxicity. All hens fed 5.0 mg/kg stopped laying by about the third week. Animals of both species fed 5.0 mg/kg either lost weight (chickens) or gained less weight (rats) than the others. Erythrocyte acetylcholinesterase (AChE) of the chickens given both doses was significantly depressed at first, then increased, and later dropped to control levels. AChE of rats fed 0.5 mg/kg was significantly inhibited but soon recovered to within control levels. On the other hand, the AChE of rats fed 5.0 mg/kg was inhibited throughout the experiment. Plasma cholinesterase (ChE) of both species was first inhibited and then recovered erratically for both insecticide concentrations. Histological alterations in the spinal cord of paralysed hens included axon and myelin degeneration in the ventral, lateral and posterior columns. In the paralysed hens, 79% of the neurotoxic esterase in the brain were inhibited, whereas in the non-paralysed hens (including the one non-paralysed hen receiving 5.0 mg/kg/day) and all rats only about half as much was inhibited.  相似文献   
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Environmental Science and Pollution Research - Mixed matrix membranes (MMMs) were fabricated by the hydrothermal synthesis of ordered mesoporous KIT-6 type silica and incorporating in polyimide...  相似文献   
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Environmental Science and Pollution Research - The current study investigated the influence of organic amendments on cadmium (Cd) uptake and its effects on biochemical attributes of young and old...  相似文献   
26.
Microorganisms have great potential to control environmental pollution, particularly industrial sources of water pollution. Currently, leather industry is regarded as the most polluting and suffering from negative impacts due to the pollution it adds to the environment. Chromium, one of the hazardous pollutants discharged from tanneries, is highly toxic and carcinogenic in nature. Effective treatment of tannery effluent is a dire need of the era as a part of environmental management. Among all the wastewater treatment technologies, bioremediation is the most effective and environment-friendly tool to manage the water pollution. The present study evaluated the potential of 11 previously isolated bacterial strains, tolerant to high concentrations of salts and Cr for the bioremediation of tannery effluent. Among all the tested strains, Enterobacter sp. HU38, Microbacterium arborescens HU33, and Pantoea stewartii ASI11 were found most effective in reducing biological oxygen demand (BOD), chemical oxygen demand (COD), total dissolved solids (TDS), total suspended solids (TSS), and chromium (Cr) 70, 63, 57, 87, and 54%, respectively, of tannery effluent and proliferated well under highly toxic conditions, at 9 days of incubation. The pollutant removal efficacy of these bacterial strains can be improved by extending the incubation period or by increasing the amount of inoculum.  相似文献   
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Environmental Chemistry Letters - In aqueous systems, heavy metal ions, when present in excess than permissible limits, are dangerous for human beings and aquatic life. Heavy metals cannot be...  相似文献   
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Environmental Science and Pollution Research - Climate action got attention from the United Nation’s Sustainable Development Goals (SDGs). Although a large number of studies are investigating...  相似文献   
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