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1.
Epidemiological data indicate that exposure to diesel exhaust particles (DEPs) from traffic emissions is associated with higher risk of morbidity and mortality related to cardiovascular and pulmonary diseases, accelerated progression of atherosclerotic plaques, and possible lung cancer. While the impact of DEPs from combustion of fossil diesel fuel on human health has been extensively studied, current knowledge of DEPs from combustion of biofuels provides limited and inconsistent information about its mutagenicity and genotoxicity, as well as possible adverse health risks. The objective of the present work was to compare the genotoxicity of DEPs from combustion of two first-generation fuels, 7% fatty acid methyl esters (FAME) (B7) and 20% FAME (B20), and a second-generation 20% FAME/hydrotreated vegetable oil (SHB: synthetic hydrocarbon biofuel) fuel. Our results revealed that particulate engine emissions from each type of biodiesel fuel induced genotoxic effects in BEAS-2B and A549 cells, manifested as the increased levels of single-strand breaks, the increased frequencies of micronuclei, or the deregulated expression of genes involved in DNA damage signaling pathways. We also found that none of the tested DEPs showed the induction of oxidative DNA damage and the gamma-H2AX-detectable double-strand breaks. The most pronounced differences concerning the tested particles were observed for the induction of single-strand breaks, with the greatest genotoxicity being associated with the B7-derived DEPs. The differences in other effects between DEPs from the different biodiesel blend percentage and biodiesel feedstock were also observed, but the magnitude of these variations was limited.  相似文献   

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Environmental Science and Pollution Research - Anaerobic ammonium oxidation (anammox) is one of the most promising processes for the treatment of ammonium-rich wastewater. It is more effective,...  相似文献   

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In this work, the development and usability of kapok oil in diesel engine was intended. With this purpose, the piston crowns are coated with mullite–lanthanum (ML) ceramic composite at varying compositions in order to reduce the heat rejection during combustion process. The kapok oil is blended with diesel fuel consisting of (20% kapok oil–80% diesel) volumetrically named B fuel. The B and diesel (D) fuels are taken for the engine performance test with different coated piston (ML1, ML2, and ML3) and exhaust gas recirculation (EGR—10%, 20%, and 30%), compression ratio (CR—16, 17, and 18) and engine load (50%, 75%, and 100%). Also, the engine performance study on brake thermal efficiency (BTE), brake-specific fuel consumption (BSFC), hydrocarbons (HCs), oxides of nitrogen (NOx), carbon monoxide (CO), smoke opacity, and numerical study using ANSYS software is carried out. When operated with ML2-coated pistons with B fuel, maximum BTE value of 29.2%, minimum BSFC value of 0.224 kg/kW-h, CO emission of 0.2%, and smoke opacity of 39 ppm were observed. The results showed that ML2-coated piston considerably improved the performance of the test engines when compared with ML1 and ML3 coatings. Except for NOx emission, all other pollutant emission values were reduced. The numerical analysis using ANSYS software for ML2-coated pistons showed better retention of in-cylinder chamber temperature.

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A set of continuity equations describing the evolution of sulphur dioxide, sulphate and ammonia distributions within rain systems is formulated. By means of a simple bulk parameterization of microphysical and chemical processes, several parameters characteristic of acidic precipitation are investigated within the framework of a steady updraft column. The sensitivity of the results to the parameterization is also examined. The techniques described may be readily adapted to more complicated models.  相似文献   

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The collection efficiency of charged water droplets of 500 μm diameter for charged particles of 0.2 μm diameter is examined as a function of the nondimensional Coulombic parameter. The present paper provides an experimental technique to determine the contribution of the phoretic forces in particle collection by comparing the collection efficiencies of water droplets to that of oil droplets for which the vapor pressure and the phoretic forces are negligible. Reasonable agreement is obtained between the experimental data and the values predicted by a collection efficiency model considering only Coulombic force, thermophoresis and diffusiophoresis.  相似文献   

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Environmental Science and Pollution Research - The effect of polystyrene (PS) particles on the toxicity of triphenyltin (TPT) to the marine diatom Skeletonema costatum was investigated. The...  相似文献   

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Industrial wastewater flow caused operational difficulties in the wastewater treatment plant in Debrecen, Hungary. Bioaugmentation was successfully applied to maintain effluent quality in the periods when wastewater of high starch content was accepted, but, at the end of 2008, the nitrification capacity of the plant decreased considerably due to improperly pre-treated pharmaceutical wastewater.  相似文献   

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The Yangtze River has been a source of life and prosperity for the Chinese people for centuries and is a habitat for a remarkable variety of aquatic species. But the river suffers from huge amounts of urban sewage, agricultural effluents, and industrial wastewater as well as ship navigation wastes along its course. With respect to the vast amounts of water and sediments discharged by the Yangtze River, it is reasonable to ask whether the pollution problem may be solved by simple dilution. This article reviews the past two decades of published research on organic pollutants in the Yangtze River and several adjacent water bodies connected to the main stream, according to a holistic approach. Organic pollutant levels and potential effects of water and sediments on wildlife and humans, measured in vitro, in vivo, and in situ, were critically reviewed. The contamination with organic pollutants, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans, polybrominated diphenyl ethers (PBDEs), perfluorinated compounds (PFCs), and others, of water and sediment along the river was described. Especially Wuhan section and the Yangtze Estuary exhibited stronger pollution than other sections. Bioassays, displaying predominantly the endpoints mutagenicity and endocrine disruption, applied at sediments, drinking water, and surface water indicated a potential health risk in several areas. Aquatic organisms exhibited detectable concentrations of toxic compounds like PCBs, OCPs, PBDEs, and PFCs. Genotoxic effects could also be assessed in situ in fish. To summarize, it can be stated that dilution reduces the ecotoxicological risk in the Yangtze River, but does not eliminate it. Keeping in mind an approximately 14 times greater water discharge compared to the major European river Rhine, the absolute pollution mass transfer of the Yangtze River is of severe concern for the environmental quality of its estuary and the East China Sea. Based on the review, further research needs have been identified.  相似文献   

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Environmental Science and Pollution Research - Optimization of fuel injection strategies can maximize the utilization of ternary fuel by addressing the issues concerning fuel consumption, engine...  相似文献   

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When annual average PM2.5 (fine particulate matter sized 2.5 microns and less) data for 2005 became available in April 2006 and the 3-yr average PM2.5 concentration in an area just north of the Houston Ship Channel reached 15.0 µg/m3, the Texas Commission on Environmental Quality (TCEQ) initiated daily collection of quartz fiber as well as Teflon PM2.5 filter samples for chemical speciation analysis. The purpose of the chemical speciation analysis was to use the speciation data, together with meteorological data and hourly TEOM (tapered element oscillating microbalance) PM2.5 mass data, to identify the causes of the high PM2.5 concentrations affecting the monitoring site and the neighborhood. The ultimate purpose was to target emission reduction efforts to sources contributing to the high measured PM2.5 concentrations. After a year of data collection, it was recognized that a specific source, unpaved driveways and loading areas along the Ship Channel and dirt tracked onto Clinton Drive, the main artery running east-west north of the Ship Channel, were the primary cause for the Clinton Drive site's measuring PM2.5 concentrations significantly higher than other sites in Houston. The source characterization and remediation steps that have led to sustained reduced concentrations are described in this paper.

Implications: With PM2.5 exceedances it can be essential to have or develop chemical speciation data as part of the process of identifying the source types causing exceedances of an annual standard. Positive matrix factorization (PMF) analysis proved to be a powerful tool that identified the two locally emitted species contributing to exceedances, which did not occur at other sites in the region. They were calcium sulfate (gypsum), an industrial by-product, and soil minerals. Other data analysis approaches were necessary to distinguish North African dust events, which PMF failed to identify.  相似文献   

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The continuous discharge of diverse chemical products in the environment is nowadays of great concern to the whole world as some of them persist in the environment leading to serious diseases. Several sampling techniques have been used for the characterization of this chemical pollution, although biomonitoring using natural samplers has recently become the technique of choice in this field due to its efficiency, specificity, and low cost. In fact, several living organisms known as biomonitors could accumulate the well-known persistent environmental pollutants allowing their monitoring in the environment. In this work, a review on environmental biomonitoring is presented. The main sampling techniques used for monitoring environmental pollutants are first reported, followed by an overview on well-known natural species used as passive samplers and known as biomonitors. These species include conifer needles, lichen, mosses, bees and their byproducts, and snails, and were widely used in recent research as reliable monitors for environmental pollution.

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Lead and bromide in atmospheric particles were measured at two sites in the vicinity of a tetraalkyllead manufacturing plant. The Br results were used to estimate the relative proportions of vehicular and non-vehicular (presumably industrially-derived) particulate lead present in the atmosphere. The non-vehicular component was very variable over the 2-month study period, overall contributing about a quarter of the observed Pb. The relative proportions were found to be in good agreement with estimates of ground-level concentrations of Pb originating from the lead works stack derived from a Gaussian plume dispersion model.  相似文献   

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Environmental Science and Pollution Research - The pollution emissions trading system (PETS) pilot policy is China’s first large-scale implementation of market-based environmental...  相似文献   

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Chiral polychlorinated biphenyl (PCB) congeners, such as PCB 136, are atropselectively metabolized to various hydroxylated PCB metabolites (HO-PCBs). The present study investigates the effect of two thiol antioxidants, glutathione and N-acetyl-cysteine (NAC), on profiles and chiral signatures of PCB 136 and its HO-PCB metabolites in rat liver microsomal incubations. Liver microsomes prepared from rats pretreated with phenobarbital were incubated with PCB 136 (5 μM) in the presence of the respective antioxidant (0–10 mM), and levels and chiral signatures of PCB 136 and its HO-PCB metabolites were determined. Three metabolites, 5-136 (2,2′,3,3′,6,6′-hexachlorobiphenyl-5-ol), 4-136 (2,2′,3,3′,6,6′-hexachlorobiphenyl-4-ol), and 4,5-136 (2,2′,3,3′,6,6′-hexachlorobiphenyl-4,5-diol), were detected in all incubations, with 5-136 being the major metabolite. Compared to microsomal incubations without antioxidant, levels of 4,5-136 increased with increasing antioxidant concentration, whereas levels of PCB 136 and both mono-HO-PCBs were not affected by the presence of either antioxidant. PCB 136, 4-136, and 5-136 displayed significant atropisomeric enrichment; however, the direction and extent of the atropisomeric enrichment was not altered in the presence of an antioxidant. Because 4,5-136 can either be conjugated to a sulfate or glucuronide metabolite that is readily excreted or further oxidized a potentially toxic PCB 136 quinone, the effect of both thiol antioxidants on 4,5-136 formation suggests that disruptions of glutathione homeostasis may alter the balance between both metabolic pathways and, thus, PCB 136 toxicity in vivo.  相似文献   

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In this study, the relationship between the form and materials of urban blocks and sensible heat flux from total surfaces was analyzed in the case of `Tama New Town', which is one of the largest housing developments in Japan and is under continuing development. First, urban blocks were divided into five categories depending on the building plot types. The characteristics of the form and thermal properties of each building, as well as the land cover condition (area of vegetation, bare soil, asphalt pavement, and built area) of each category was considered. Furthermore, 6 urban blocks were selected for numerical simulation of heat balance of the total surfaces, and sensible heat flux from the total surfaces of each urban block on clear sky summer day was calculated. It was confirmed that the influence of the direction that buildings faced and floor area ratio was as great as that of building materials upon the amount of sensible heat flux in each urban block.  相似文献   

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