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801.
A novel Life-Cycle Assessment model (Fire-LCA) has been defined for the determination of the environmental impact of measures taken to attain a high level of fire safety. This study, which represents the first application of this LCA model, concentrates on a comparison between a TV with an enclosure manufactured with a flame retardant (FR) plastic (V0-rated high impact polystyrene, HIPS, typical for the US market) and one manufactured with a non-flame retardant (HB-rated HIPS, typical for the European market). A fire model has been defined based on international statistics, which indicate that use of V0 rated enclosure material essentially removes the risk of TV fires while approximately 165 TV fires occur per million TVs in Europe each year where the enclosure material is breached. The application of the model indicates that emissions of some key species (such as dibenzodioxins and PAH) are actually lower for the TV with the FR enclosure than for the TV with the NFR enclosure. This has direct reprercussions for the assessment of the environmental impact of the FR TV relative to that of the NFR TV. Finally, when considering the risk associated with the use of flame retardants, it is also important to consider the risk associated with fires. Based on the in-depth analysis of available fire statistics, conducted as a part of this study, it has been estimated that as many as 160 people may die each year in Europe as a direct result of TV fires and as many as 2000 may be injured in the same period.  相似文献   
802.
Variability refers to real differences in emissions among multiple emission sources at any given time or over time for any individual emission source. Variability in emissions can be attributed to variation in fuel or feedstock composition, ambient temperature, design, maintenance, or operation. Uncertainty refers to lack of knowledge regarding the true value of emissions. Sources of uncertainty include small sample sizes, bias or imprecision in measurements, nonrepresentativeness, or lack of data. Quantitative methods for characterizing both variability and uncertainty are demonstrated and applied to case studies of emission factors for lawn and garden (L&G) equipment engines. Variability was quantified using empirical and parametric distributions. Bootstrap simulation was used to characterize confidence intervals for the fitted distributions. The 95% confidence intervals for the mean grams per brake horsepower/hour (g/hp-hr) emission factors for two-stroke engine total hydrocarbon (THC) and NOx emissions were from -30 to +41% and from -45 to +75%, respectively. The confidence intervals for four-stroke engines were from -33 to +46% for THCs and from -27 to +35% for NOx. These quantitative measures of uncertainty convey information regarding the quality of the emission factors and serve as a basis for calculation of uncertainty in emission inventories (EIs).  相似文献   
803.
The hydroxyl radical (*OH) is generated in polluted dew on the needle surfaces of Japanese red pine (Pinus densiflora Sieb. et Zucc.). This free radical, which is a potent oxidant, is assumed to be a cause of ecophysiological disorders of declining trees on the urban-facing side of Mt. Gokurakuji, western Japan. Mists of *OH-generating N(III) (HNO2 and NO2-) and HOOH + Fe + oxalate solutions (50 and 100 microM, pH 5.1-5.4) simulating the dew water were applied to the foliage of pine seedlings grown in open-top chambers in the early morning. Needles treated with 100 microM N(III) tended to have a greater maximum CO2 assimilation rate (Amax), a greater stomatal conductance (g(s)) and a greater needle nitrogen content (Nneedle), suggesting that N(III) mist acts as a fertilizer rather than as a phytotoxin. On the other hand, needles treated with 100 microM HOOH + Fe + oxalate solution showed the smallest Amax, g(s), and Nneedle, suggesting that the combination of HOOH + Fe + oxalate caused a decrease in needle productivity. The effects of HOOH + Fe + oxalate mist on pine needles were very similar to the symptoms of declining trees at Mt. Gokurakuji.  相似文献   
804.
Bioaccumulation and elimination of 14C-lindane in Enchytraeus albidus was studied in artificial OECD soil and a silty loam from an agricultural field in Central West Portugal. Results showed that enchytraeids were able to bioaccumulate the chemical with a kinetic pattern similar to that of earthworms: fast uptake within a few days and a biphasic elimination pattern. A 10 day period to study uptake was sufficient, but a few more days were probably necessary for elimination. Bioaccumulation was influenced by soil type. The authors suggest that higher organic matter (OM) content and also the higher content on sand particles in the OECD soil may have led to a faster elimination: hydrophobic chemicals tend to adsorb to OM being in this way less bioavailable and therefore less bioaccumulated having bioaccumulation factor value around 6 while in natural soil is 10; the sand could act as abrasive particles (helpers) in the elimination process leading to an elimination of 90% of the chemical in two days while in natural soil 67% was eliminated in the same period of time.  相似文献   
805.
The effect of three species of hypoglycemic herbs (Termis, Halfa barr, or Kammun Quaramany) on the lipid profile was investigated in plasma and liver tissues of diabetic and herbs-treated diabetic rats. This profile includes total lipids (TL), triglycerides (TG), cholesterol, high-density lipoprotein (HDL) and low-density lipoprotein (LDL). A dose of 1.5 ml of aqueous suspension of each herb/100 g body weight (equivalent to 75 mg/100 g body weight) was orally administered daily to alloxan-diabetic rats for four weeks. The present study showed 2-fold increase (p<0.05) in the plasma glucose level of diabetic rats, which received alloxan as a single dose of 120 mg/kg body weight, relative to the mean value of control group. This elevated glucose level was restored to its normal level after treatment with any one of the three herbs. Furthermore, the levels of TL, TG, cholesterol, LDL and VLDL were significantly (p<0.05) increased in the plasma and the liver tissues of diabetic rats compared to the control group, whereas HDL level was significantly (p<0.05) decreased. The plasma levels of all above parameters were normalized after treatment of the diabetic rats with Kammun Quaramany. Treatment of diabetic rats with Tennis normalized TG, cholesterol, LDL and VLDL levels, but Halfa barr restored the induced levels of plasma cholesterol, LDL and HDL to their normal levels. On the other hand, treatment with any of the three herbal suspensions could not restore the concentrations of the all tested parameters in the liver. These data demonstrated that the glycemic control of any of the three herbal suspensions was associated with their hypocholesterolemic effects on the hypercholesterolemia of the alloxan-induced diabetic rats. Moreover, the Kammun Quaramany showed the most potent effect.  相似文献   
806.
This paper assesses the feasibility of using atmospheric measurement of fluorinated greenhouse gases (HFCs, PFCs and SF6) for the review and verification of greenhouse gas inventories provided by national governments. For this purpose, available data were compiled. It was found that atmospheric measurements of these gases are available and provide an indication of global annual emissions with sufficient certainty to reach the following conclusions: Within the uncertainty of the method, it was found that emissions of HFC-23, a by-product of HCFC-22 production, as obtained from atmospheric measurements did not decrease as fast, as the countries have reported. In contrast, SF6 concentrations in the atmosphere suggest higher emissions than reported by countries. Regional emission estimates from atmospheric measurements are still in a more pioneering state and cannot be compared to national estimates. Intensified efforts to measure HFCs, PFCs and SF6 in the atmosphere are recommended.  相似文献   
807.
The effect of cadmium on sediment processing by laboratory-cultured specimens of Capitella sp I and Capitella sp B was investigated. Specimens were exposed to 0, 60, 90 and 140 microg Cd g(-1) dry weight sediment for a 10 day period (two census days) to observe effects of cadmium on their feeding activity. Under unstressed conditions, Capitella sp I specimens were larger, had higher biomass and produced more fecal pellets than Capitella sp B. Cadmium concentrations had no effect on pellet production and body mass of the studied populations. However, cadmium exposure time significantly affected Capitella sp B pellet production and body mass of both populations following different trends: after 10 days of exposure, the average processed sediment per unit worm mass decreased in Capitella sp I but increased in Capitella sp B. The latter population did not reduce its feeding activity in the presence of cadmium maybe related to the fact that it is derived from a highly polluted environment. This study has shown an unimpaired response of Capitella sp I and Capitella sp B to cadmium in their sediment processing activity, which indicates the potential importance of this species complex in the trophic transfer of metals from sediments to other marine organisms.  相似文献   
808.
We have observed the effect of copper and zinc on the biology of Euglena gracilis. The cells displayed different sensitivities to these metals, as the apparent LC50 for Cu2+ was 0.22 mM, and for Zn2+ it was 0.88 mM. While Zn2+ was able to increase cell proliferation even at 0.1 mM, the minimal CuCl2 concentration tested (0.02 mM) was sufficient to impair cell division. Higher concentrations of these metals not only inhibited cell division in a concentration-dependent manner, but also interfered with the metabolism of E. gracilis. A higher accumulation of proteins and lipids per cell was observed at the DI50 concentration for metal-treated cells. These results suggest that the test concentration of both metals leads to a failure in completing cell division. Ultrastructural analysis indicated a chloroplast disorganization in copper-treated cells, as well as the presence of electron dense granules with different shapes and sizes inside vacuoles. Microanalysis of these granules indicated an accumulation of copper, thus suggesting a detoxification role played by the vacuoles. These results indicate that E. gracilis is an efficient biological model for the study of metal poisoning in eukaryotic cells. They also indicate that copper and zinc (copper being more poisonous) had an overall toxic effect on E. gracilis and that part of the effect can be ascribed to defects in the structure of chloroplast membranes.  相似文献   
809.
In the last two decades, there has been a rich debate about the environmental degradation that results from exposure to solid urban waste. Growing public concern with environmental issues has led to the implementation of various strategic plans for waste management in several developed countries, especially in the European Union. In this paper, the relationships were assessed between economic growth, renewable energy extraction and greenhouse gas (GHG) emissions in the waste sector. The Environmental Kuznets Curve hypothesis was analysed for the member states of the European Union, in the presence of electricity generation, landfill and GHG emissions for the period 1995 to 2012. The results revealed that there is no inverted-U-shaped relationship between income and GHG emissions in European Union countries. The renewable fuel extracted from waste contributes to a reduction in GHG, and although the electricity produced also increases emissions somewhat, they would be far greater if the waste-based generation of renewable energy did not take place. The waste sector needs to strengthen its political, economic, institutional and social communication instruments to meet its aims for mitigating the levels of pollutants generated by European economies. To achieve the objectives of the Horizon 2020 programme, currently in force in the countries of the European Union, it will be necessary to increase the share of renewable energy in the energy mix.  相似文献   
810.
In this work, the main objectives were to assess the mutagenic and genotoxic effects of fine particulate matter collected in an industrial influenced site in comparison with a non-industrial influenced one (rural site) and to relate the particulate matter (PM) composition to the observed genotoxic effects. At the industrial influenced site, higher concentrations of phosphates, trace metals, and polycyclic aromatic hydrocarbons (PAHs) in particles could be related to the contributions of quarries, fertilizer producer, cement plants, and tires burning. Gasoline and diesel combustion contributions were evidenced in particles collected at both sites. Particles collected under industrial influence showed a higher mutagenic potential on three tested strains of Salmonella typhimurium (TA98, YG1041, and TA102), and especially on the YG1041, compared to particles from the rural site. Furthermore, only particles collected in the vicinity of the industrial site showed a tendency to activate the SOS responses in Escherichia coli PQ37, which is indicative of DNA damage as a result of exposure of the bacteria cells to the action of mutagenic samples. The mutagenicity and genotoxicity of the industrial PM2.5–0.3 particulates may be attributed to its composition especially in organic compounds. This study showed that proximity of industries can affect local PM composition as well as PM genotoxic and mutagenic potential.  相似文献   
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