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1.
Distribution in Portugal of some pollutants in the lichen Parmelia sulcata   总被引:2,自引:0,他引:2  
During the months of July and August 1993 a lichen (Parmelia sulcata Taylor) collection campaign was held in Portugal where samples were obtained from olive tree bark at 228 sites, following a grid of 10 x 10 km along the Atlantic coast and 50 x 50 km in the interior of the country. The samples were analysed by instrumental neutron activation analysis and proton induced X-ray emission techniques. Concentration data patterns for the pollutants As, Cr, Hg, Ni, Pb, S, Sb, Se, and V were obtained for the whole country surface by making use of an extinction rule of 1/r(3), preventing any cut-off distance from being artificially introduced. Some pollution sources were identified: (1) oil-powered plants on the Lisbon-Setúbal axis (V, Ni), (2) coal-power plants in Porto and Sines (S, Se), (3) traffic in the northern area and the Lisbon-Setúbal axis (Pb), (4) a chemical industry south of Porto (Hg, As), and (5) soil influence (Cr, Sb). Arsenic and chromium results largely exceed, in a few areas, the concentrations acceptable to plants, and in a few spots also Hg, Ni, and Pb data.  相似文献   
2.
Monte Carlo-assisted factor analysis has been applied to a data set of 20 trace-element concentrations in tree-bark samples obtained from 123 locations in The Netherlands, with the aim to investigate the suitability of bark as a biomonitor for air pollution. A Monte Carlo approach was used to give more insight to the uncertainties and significance levels of the factor analysis results. Notwith-standing a rather strong influence of soil material on the concentration levels, factor analysis enabled the identification of five significant pollution source types, all of which corresponded with source types found in an earlier biomonitoring study in The Netherlands using epiphytic lichens. A more detailed comparison with the lichen results showed a remarkable difference in lead concentrations between bark and lichen. It was concluded that bark can be successfully employed as a biomonitor for air pollution. The power of factor analysis to adequately determine the soil contribution may render extensive sample washing procedures superfluous.  相似文献   
3.
The amount of copper taken up via algae and water byMacoma balthica from the Oosterschelde sea arm, S.W. Netherlands, was established using the radioisotope64Cu. As far as we know, this isotope has never been used before in marine flod chain studies. As a model food source the marine diatomPhaeodactylum tricornutum was allowed to accumulate64Cu for 1 d. These labelled algae were fed to the clams in the presence of the complexing agent EDTA (0.27mM). EDTA was added to prevent uptake of dissolved64Cu that could be leaking from the labelled diatoms. In control experiments, unlabelled diatoms were fed toM. balthica in the presence of dissolved64Cu (with and without EDTA) in order to assure a similar filtration activity. In repeated experiments with varying particulate/dissolved copper ratios, uptake through food always turned out to be at least as efficient as uptake from the water. It was concluded that Cu, associated with food, is well available for uptake byM. balthica.  相似文献   
4.
Experiments were carried out in order to obtain information on the uptake characteristics of metals in the algal and fungal components of lichens. The uptake of 115Cd, 65Zn, 64Cu, 140La, 187W and 76As in the alga Scenedesmus pannonicus, subsp. Berlin and the fungus Aureobasidium pullulans was determined at pH 7 and 5 respectively, in 4 h experiments varying with respect to temperature and Ca2+ solution concentrations. Furthermore, the effects of pre-rinsing the cell suspensions on metal uptake were investigated.Pre-rinsing resulted in decreased uptake of W and As by algae and in increased uptake of all elements measured by fungi, which may be attributed to combined effects of starvation and changing densities.For algae, the uptake rates of As, W, Zn and Cd were markedly increased at the highest temperature employed. For Cu and La hardly any effects of temperature were observed, indicating the absence of metabolically controlled uptake. For fungi, but for As no relation of uptake with temperature could be determined.The presence of Ca2+ ions in the solution applied hardly affected the uptake of As but resulted in increased uptake of W by both the algae and the fungi. The effects of Ca2+ on the uptake of Cu and La were relatively small, probably due to specific binding sites in the cell walls for Cu and to the supercalcium status of the La-ion.The presence of Ca2+ caused decreased uptake of Cd2+ and Zn2+ by algae, but hardly affected the uptake of Zn2+ by fungi.The results indicate component-specific uptake and accumulation behaviour in intact lichens.  相似文献   
5.
This study addresses the significant effects of both well-known contaminants (particles, gases) and less-studied variables (temperature, humidity) on serious, if relatively common, respiratory and circulatory diseases. The area of study is Lisbon, Portugal, and time series of health outcome (daily admissions in 12 hospitals) and environmental data (daily averages of air temperature, relative humidity, PM10, SO2, NO, NO2, CO, and O3) have been gathered for 1999–2004 to ascertain (1) whether concentrations of air pollutants and levels of temperature and humidity do interfere on human health, as gauged by hospital admissions due to respiratory and circulatory ailments; and (2) whether there is an effect of population age in such admissions. In general terms, statistically significant (p?<?0.001) correlations were found between hospital admissions and temperature, humidity, PM10, and all gaseous pollutants except CO and NO. Age appears to influence respiratory conditions in association with temperature, whereas, for circulatory conditions, such an influence likely involves temperature as well as the gaseous pollutants NO2 and SO2.  相似文献   
6.
This paper compares the dynamics, i.e. the rates of change in element concentrations of young and older lichen thallus parts, of one foliose and one fruticose lichen, during a transplant experiment to a polluted site. Both lichen parts respond to environmental changes. Here, differential accumulation suggests that differential constitution leads to differential uptake and release, and/or the overall behaviour is partly due to internal translocation and regulation mechanisms within the whole lichen. For thallus parts, internal translocation should be taken into account as one more factor affecting lichen “memory length”. Young parts of the thallus presented higher rates of change, but different lichen parts accumulate different elements to different extents. Therefore tissue selection in monitoring may depend on the element of interest, and cannot be made into a generalized approach in survey set-ups: the choice depends on the element.  相似文献   
7.
    
A study was conducted to determine the joint effect of gaseous atmospheric pollutants and trace elements on epiphytic lichens. We used our data to test the hypothesis that lichens are generally insensitive to toxic effects of trace elements, and can therefore be used as accumulator organisms to estimate concentrations of these elements in the environment. In a field study in The Netherlands the abundance of epiphytic lichen species was estimated, and their supporting bark was collected. Concentrations of a range of trace elements were determined in the bark, and concentrations of atmospheric trace gases were estimated at the sites of collection. Multivariate statistics were used to determine the relation between the abundance of the species and pollutant concentrations. Atmospheric SO2 and NO2 appeared to be the most important factors determining lichen biodiversity. Nearly all species were sensitive to these compounds. The effect of the other trace elements was very slight; only Sb had a significantly negative effect on the abundance of a few species. It is concluded that lichens can safely be used as accumulator organisms in pollution studies, provided that concentration in lichen thalli reflect atmospheric concentrations.  相似文献   
8.
    
Studies of the acute health effects of air pollution have used exposure windows of different spans and related them to single‐day responses. Little is known about whether an increased response window span might be a viable alternative to single‐day responses. Our aim is to compare a new model specification where both the exposure and response variables are represented as 7 day moving averages (CMA&CMA model) with the most widely used model specifications in the literature, where the response variable is usually a single‐day, in terms of coefficients and their precision and robustness. To this end, daily series of 12 emergency‐related hospital admissions and 6 air pollutants spanning 5.5 years in Lisbon were analysed through single‐pollutant linear regression and, when necessary M‐estimation. With our data, the CMA&CMA model yields coefficients that are very close to models where only the exposure variable is specified as a moving average whether the latter are estimated by OLS or robust M‐estimation. In addition, the CMA&CMA model leads to more precise and robust estimates than other model specifications. The new model specification is a straightforward tool for adjusting weekend effects and errors. It is also analogous to robust estimation, with the added advantages of being sensitive to extreme values that are clustered in time, and leading to more precise and robust estimates without loss of high‐frequency information. One drawback is the induction of autocorrelation in the residuals. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
9.
To study the role of food in Cu accumulation by bivalves, algae spiked with Cu can be used. With spiked algae, however, redistribution of Cu between the disolved solved and the particulate phase hampers the assessment of the contribution of food. This occurred in efforts to label algae with the radiotracer64Cu. A method was designed to overcome this problem of redistribution. By adding excess EDTA to seawater, the biological availability of dissolved Cu was minimized. The effectiveness of complexation by EDTA was controlled through adsorption onMacoma balthica shells and uptake inM. balthica tissue.Communication number 644 of the Centre for Estuarine and Coastal Ecology, Yerseke, The Netherlands  相似文献   
10.
The linearity of the interspecies relation between the elemental contents in Parmelia sulcata and Lecanora conizaeoides, sampled in a polluted area, was examined by the function y=az+b and yz –1=a+bz –1, with y and z being the elemental content in Parmelia and Lecanora, respectively. For As, Co, V and Zn significant positive a and b values were found, allowing interspecies calibration. For Br, Cd, Cr, Fe, La, Sb, Se and W the a values were zero and the b values were positive, indicating saturation of Parmelia and thus ruling out interspecies calibration. For Cu a part of the data set showed saturation effects in Lecanora. The results showed that the average concentration ratio could not be used for intercalibration purposes, because the concentration ratios were dependent on the concentrations.  相似文献   
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