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81.
Vertical emission profiles for Europe based on plume rise calculations   总被引:1,自引:0,他引:1  
The vertical allocation of emissions has a major impact on results of Chemistry Transport Models. However, in Europe it is still common to use fixed vertical profiles based on rough estimates to determine the emission height of point sources. This publication introduces a set of new vertical profiles for the use in chemistry transport modeling that were created from hourly gridded emissions calculated by the SMOKE for Europe emission model. SMOKE uses plume rise calculations to determine effective emission heights. Out of more than 40 000 different vertical emission profiles 73 have been chosen by means of hierarchical cluster analysis. These profiles show large differences to those currently used in many emission models. Emissions from combustion processes are released in much lower altitudes while those from production processes are allocated to higher altitudes. The profiles have a high temporal and spatial variability which is not represented by currently used profiles.  相似文献   
82.
This study characterizes the cholinesterasic forms present in the bivalve Corbicula fluminea, through the analysis of differential affinity towards various substrates and inhibitors. This approach also permitted the validation of cholinesterase inhibition in the mentioned species for monitoring purposes by evaluating the inhibitory activity of a detergent (SDS) and a pesticide (chlorfenvinphos), both in vitro and in vivo. The cholinesterasic form present in the tissues of C. fluminea showed intermediate properties in terms of its relation with substrates and inhibitors. Furthermore, it was not inhibited by the detergent SDS under any of the test conditions, but was clearly inhibited by the selected organophosphate. The data show clearly that the main cholinesterasic form in C. fluminea is responsive to the organophosphate chlorfenvinphos, thus supporting the use of this biomarker for the environmental monitoring of specific contaminants such as anticholinesterasic pesticides. Despite not being commonly attained in the wild, the levels of chlorfenvinphos required to elicit a significant ChE inhibition were only one order of magnitude above actual values of aquatic contamination by this pesticide.  相似文献   
83.
Korean water quality managers are required to promptly develop national assessment standards for freshwater sediment quality due to the Four Major River Restoration Project in Korea in 2009. We conducted this study to develop sediment management standards (SMSs), determining obviously and severely polluted sediment, which could have adverse impacts on water quality and aquatic ecosystem. The SMSs values were derived from the 95th percentile of concentration distribution for organic matter and nutrients in sediment quality database. For the SMSs of metals, foreign sediment quality guidelines (SQGs) were adopted. As a result, 13 % for loss on ignition (LOI), 1,600 mg/kg for total phosphorus (TP), and 5,600 mg/kg for total nitrogen (TN) were set as the SMSs for freshwater sediment in Korea. These values were higher than the range of heavily polluted sediment from USEPA Region 5 guideline derived by the similar approaches for the Great Lakes harbor sediments, and similar or lower than the severe effect level (SEL) from provincial sediment quality guideline (PSQG) of Ontario, Canada by screening level concentration (SLC) approach. However, SMSs in the present study are appropriate considering the concentration ranges and the Korean SMSs’ definition for freshwater sediments in Korea. The Puget Sound marine sediment cleanup screening level (CSL) in Washington State, USA were adopted as the Korean SMSs for As (93 mg/kg), Cd (6.7 mg/kg), Cr (270 mg/kg), Cu (390 mg/kg), Pb (530 mg/kg), and Zn (960 mg/kg) in freshwater sediments. Hg concentration (0.59 mg/kg) of CSL was too low to determine the polluted freshwater sediments in Korea, and the SEL of Ontario, Canada for mercury concentration (2 mg/kg) was selected as the SMS for Hg. These values were found reasonable through the assessment of applicability with the datasets from locations directly affected by obvious point sources. These results indicate that SMSs for organic matter, nutrient, and metals derived within the present study can successfully determine obviously and severely polluted sediment in Korea. However, the SMSs have limits to specifically determine the effects of polluted sediment on water quality and aquatic ecosystem in Korea. Thus, we will revise and specify SMSs considering those effects and further sediment quality assessment framework in the near future.  相似文献   
84.
Exposure to specific metallic compounds can cause severe deleterious modifications in organisms. Fishes are particularly prone to toxic effects from exposure to metallic compounds via their environment. Species that inhabit estuaries or freshwater environments can be chronically affected by persistent exposure to a large number of metallic compounds, particularly those released by industrial activities. In this study, we exposed yellow eels (European eel, Anguilla anguilla) for 28 days to environmentally relevant concentrations of four specific metals; lead (300, 600, and 1,200 μg/l), copper (40, 120, and 360 μg/l), zinc (30, 60, and 120 μg/l) and cadmium (50, 150, and 450 μg/l). The selected endpoints to assess the toxicological effects were neurotransmission (cholinesterasic activity in nervous tissue), antioxidant defense, and phase II metabolism (glutathione-S-transferase [GST] activity, in both gills and liver tissues), and peroxidative damage. The results showed an overall lack of effects on acetylcholinesterase for all tested metals. Lead, copper, and cadmium exposure caused a significant, dose-dependent, increase in GST activity in gill tissue. However, liver GST only significantly increased following zinc exposure. No statistically significant effects were observed for the thiobarbituric acid reactive substances assay, indicating the absence of peroxidative damage. These findings suggest that, despite the occurrence of an oxidative-based response after exposure to lead, copper, and cadmium, this had no consequence in terms of peroxidative membrane damage; furthermore, cholinergic neurotoxicity caused by lead, copper, and cadmium did not occur. The implications of these results are further discussed.  相似文献   
85.
Acetaminophen is globally one of the most prescribed drugs due to its antipyretic and analgesic properties. However, it is highly toxic when the dosage surpasses the detoxification capability of an exposed organism, with involvement of an already described oxidative stress pathway. To address the issue of the ecotoxicity of acetaminophen, we performed acute exposures of two aquatic plant species, Lemna gibba and Lemna minor, to this compound. The selected biomarkers were number of fronds, biomass, chlorophyll content, lipid peroxidation (TBARS assay), and proline content. Our results showed marked differences between the two species. Acetaminophen caused a significant decrease in the number of fronds (EC50?=?446.6 mg/L), and the establishment of a dose-dependent peroxidative damage in L. minor, but not in L. gibba. No effects were reported in both species for the indicative parameters chlorophyll content and total biomass. However, the proline content in L. gibba was substantially reduced. The overall conclusions point to the occurrence of an oxidative stress scenario more prominent for L. minor. However, the mechanisms that allowed L. gibba to cope with acetaminophen exposure were distinct from those reported for L. minor, with the likely involvement of proline as antioxidant.  相似文献   
86.
The presence of pharmaceutical residues in the aquatic environment has recently received great attention, as potential adverse effects may arise from their presence. Inhibition of cholinesterases (ChE) has been widely used as an environmental biomarker of exposure to organophosphates (OP) and carbamate (CB) pesticides. However, other widespread anthropogenic contaminants - including pharmaceutical drugs - can exert toxic effects through ChE inhibition. Studies with aquatic species have shown that inhibition of ChE is associated with behavioral changes. Bearing this in mind, this work aimed to study the effects on individual behavior and acetylcholinesterase (AChE) activity of selected tissues of Lepomis gibbosus, after exposure to the anticholinesterasic drugs neostigmine and pyridostigmine. Results revealed that neostigmine significantly decreased the activity of AChE in the head (LOEC = 100 mg L(-1)), but not in dorsal muscle. On the other hand, pyridostigmine significantly decreased the activity of AChE in both the head (LOEC = 0.001 mg L(-1)) and dorsal muscle homogenates (LOEC = 100 mg L(-1)). The impairment of this enzymatic form was attained at ecologically relevant concentrations (in the case of pyridostigmine, for head AChE), which is an interesting finding, specially considering that these toxic effects occurred for a pharmaceutical compound. Contrarily, there were no significant differences in the behavior of L. gibbosus in any parameter, for neither drug. These results suggest that the behavioral parameters analyzed (scototaxis and lethargy) in L. gibbosus could not be regarded as suitable markers to assess the effects of drugs such as neostigmine and pyridostigmine. In contrast, the pattern of response elicited by cholinesterasic inhibition showed the usefulness of this toxicological parameter for the assessment of pharmaceuticals in the environment, namely anticholinesterasics.  相似文献   
87.
88.
Caucasian wingnut (Pterocarya fraxinifolia (Poiret) Spach) is a relict tree species having limited natural distribution in Turkey. In this study, a new distribution of this species in the Kahramanmaras region was explained. This distribution occurs in Onsenhopuru and Yavuzlar villages and Yesilyore town of Turkoglu district, at elevations between 600 and 640 m along Orcan stream, and continues about 4 km. In this area, Caucasian wingnut had about 100 trees. This distribution area of the species, quite important for biodiversity, should be protected and the existing individuals should be evaluated as a gene resource. Especially vegetative reproduction of the species should be started and the seedlings obtained should be used at the margins of lakes and streams, parks and large gardens, avenues, boulevards, and streets in the region.  相似文献   
89.
Effects of meteorological variables and air pollutants on child respiratory morbidity are investigated during two consecutive summers (December-March 1992/1993 and 1993/1994) at the Metropolitan Area of S?o Paulo (MASP), Brazil. The MASP, with almost 17 million inhabitants, is considered the most populous region in South America. Due to warmer temperatures, increased rainfall and consequent low levels of air pollutants during the summer compared to winter, less attention has been paid to epidemiological studies during this season, especially in tropical urban areas such as S?o Paulo. In the present work, principal component analysis (PCA) is applied to medical end environmental data to identify patterns relating child morbidity, meteorological variables and air pollutants during the summer. The following pollutant concentrations are examined: SO2, inhalable particulate matter (PM10), and O3. The meteorological variables investigated are air temperature, water vapor (water vapor density) and solar radiation. Although low correlation between respiratory morbidity and environmental variables are, in general, observed for the entire dataset, the PCA method indicates that child morbidity is positively associated with O3 for the 1992/1993 summer. This pattern is identified in the third principal component (PC3), which explains about 19% of the total variance of all data in this summer. However, the 1993/1994 summer shows a more complex association between both groups, suggesting stronger ties with meteorological variables. Marked changes in synoptic conditions from the end of January to end of March of the 1993/1994 summer seem to have played an important role in modulating respiratory morbidity. A detailed examination of meteorological conditions in that period indicates that prefrontal (postfrontal), hot (cold) and dry (wet) days favored the observed decrease (increase) of respiratory morbidity.  相似文献   
90.
The biology, population dynamics, and production of Tylos europaeus were studied in two sandy beaches of the western coast of Portugal. At both sites, reproduction occurred seasonally, from April to July, with only one new cohort produced per year. Regarding population dynamics, cohort-splitting events were detected in males at the beginning of the reproduction period (April/May), resulting in two groups with distinct growth rates (fast-growing vs slow-growing males). Different biological characteristics were consequently detected in these two groups, namely regarding body size, lifespan, and contribution to the reproductive effort. Lifespan was estimated as approximately 3 years, for females and fast-growing males, and 4 years for slow-growing males. Cohort-splitting among males appeared as a possible strategy to cope with the highly male-biased sex ratios observed, which could lead to a strong male-male competition for mating. T. europaeus appeared as an annual species, with a univoltine life-cycle (one generation per year), and iteroparous females reproducing twice during their lifespan. Average growth production (P) was estimated at 0.082 g.m–2.yr–1 AFDW (ash-free dry weight) and the average annual biomass () (standing stock) at 0.052 g.m–2, resulting in a P/ ratio of 1.58. These results produced baseline information for the construction of a population-dynamics model and highlighted the potential of this species as an environmental quality-assessment bioindicator on sandy shores.Communicated by S.A. Poulet, Roscoff  相似文献   
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