共查询到20条相似文献,搜索用时 15 毫秒
1.
Dry deposition samples were collected using a smooth surrogate surface at the Kaynaklar Campus of the Dokuz Eylul University in Izmir, Turkey. Concurrently ambient aerosol samples were collected. All samples were analyzed for anthropogenic and crustal trace elements. The average trace element concentrations and fluxes measured in this study were generally higher than those reported previously for urban and rural areas. The contribution of local terrestrial and anthropogenic sources were also investigated using enrichment factors (EFs) calculated relative to the local soil. Relatively lower EFs for ambient samples and high ambient concentrations indicated that the local soil was polluted and contributed significantly to ambient trace element concentrations. Deposition samples had higher EFs than the air samples. The EF sequences of trace elements were also different for deposition and ambient samples, probably due to the fact they have different mass median diameters and deposition velocities. The overall dry deposition velocities for trace elements calculated by dividing the particulate fluxes measured with the surrogate surfaces by ambient concentrations ranged from 0.6 (Al) to 6.2 cm s −1 (Fe). The agreement between the experimental dry deposition velocities determined in this study and the previously reported ones using similar techniques for trace elements was good. 相似文献
2.
Using ICP emission spectrometry, the temporal variation of the concentration of dissolved Al, Fe. Si, Mn, Zn. Cu and B in rain-water during an event was observed at Tsukuba, Japan. The relationships between trace element variations and rainfall characteristics were compared with those for major elements such as Na, K, Ca and Mg. In many cases, the concentration of minor elements was highest in the initial stage. The exception was in rain with very short duration or very strong intensity at the initial stage of rainfall.No significant relationship was observed between rainfall intensity and soluble elemental concentration, although in a few cases AI, Zn, Na and Fe showed an inverse correlation with rainfall intensity. It was found that the concentration of minor elements such as Fe, Al and Zn fluctuated, whereas those of Na and other major elements changed smoothly. This difference is considered to be caused by differences in the scavenging process of the elements as well as the heterogeneous and varying distribution of atmospheric particles which supply minor elements in rain-water. 相似文献
3.
Fine particles (PM2.5) were collected during all four seasons, from April 2001 to February 2002, in Seoul, South Korea, using an annular denuder system. Elemental compositions of ambient PM2.5 were analyzed using the proton-induced X-ray emission method. The greatest contributors (> or = 2%) to the PM2.5 mass were sulfur (S), silicon (Si), chlorine (Cl), aluminum (Al), and iron (Fe) in the spring; S in the summer; and S and Cl in the fall. S, Cl, and Si were the major elements in the winter. S was the most abundant species among the elements, ranging from 5.3 to 7.9%, followed by Si and Cl. From analysis of variance, PM2.5 mass, Al, Si, potassium, calcium, and Fe showed significant seasonal differences during the four seasons (p < 0.001). Enrichment factor (EF) analysis was carried out to identify the sources affecting the aerosol in the Seoul area. On the basis of the mean EF values, elemental S, copper, zinc, and lead may be emitted from anthropogenic sources (EF > 50). Elemental Al, Si, titanium, and Fe may be emitted from crustal sources (EF < 3). Additionally, a correlation analysis was carried out for source identification. The results of the correlation analysis were confirmed by the results of the EF analysis. 相似文献
4.
Atmospheric concentrations of polychlorinated biphenyls (PCBs) and trace elements were measured at two sites (Industrial and Urban) located around the Aliaga industrial region, Izmir, Turkey. Average sigma 36PCB concentrations were 3136+/-824 and 1371+/-642 pg m(-3) for summer and winter periods, respectively in the Industrial site and they were 314+/-129 and 847+/-610 pg m(-3) in the Urban site. The elemental content showed that the PM(10) measured at the Industrial site was dominated by terrestrial elements and trace elements emitted by the iron-steel plants (Fe, Zn and Pb). The elemental profile at the Urban site was typical for Aegean Region that was dominated by terrestrial elements (Ca, Al, Mg) and sea salt (Na). Sources of particle-phase PCBs and trace elements were identified using factor analysis (FA) and were apportioned by chemical mass balance (CMB) model. FA suggested that the steel industry, fuel oil combustion, or the nearby vinyl chloride process in the petrochemical plant, and soil were significant PCB sources. CMB results showed that at the Industrial site, the contribution of steel industry and soil to particle-phase PCBs were 71% and 22%, respectively, while at the Urban site, the contributions were 33% and 49%, respectively. Steel industry was also the dominant contributor for trace elements around the site. Fugacity calculations in air and soil showed that the soil acts as a secondary source to the atmosphere for low molecular weight PCBs especially in summer and as a sink for the higher molecular weight ones. 相似文献
5.
An intensive 1-month atmospheric sampling campaign was conducted concurrently at eight monitoring sites in central Illinois, USA, from June 9 to July 3, 2011 to assess spatial patterns in wet and dry deposition of mercury and other trace elements. Summed wet deposition of mercury ranged from 3.1 to 5.4 μg/m 2 across sites for the total study period, while summed dry deposition of reactive mercury (gaseous oxidized mercury plus particulate bound mercury) ranged from 0.7 to 1.6 μg/m 2, with no statistically significant differences found spatially between northern and southern sites. Ratios of summed wet to summed dry mercury deposition across sites ranged from 2.2 to 4.9 indicating that wet deposition of mercury was dominant during the study period. Volume-weighted mean mercury concentrations in precipitation were found to be significantly higher at northern sites, while precipitation depth was significantly higher at southern sites. These results showed that substantial amounts of mercury deposition, especially wet deposition, occurred during the study period relative to typical annual wet deposition levels. Summed wet deposition of anthropogenic trace elements was much higher, compared to summed dry deposition, for sulfur, selenium, and copper, while at some sites summed dry deposition dominated summed wet deposition for lead and zinc. This study highlights that while wet deposition of Hg was dominant during this spring/summer-season study, Hg dry deposition also contributed an important fraction and should be considered for implementation in future Hg deposition monitoring studies. 相似文献
7.
The objective of this study was to determine the concentrations of Cu, Cd, Pb, Mn, Cr, Co, Ni, Zn, and Hg in the white and fruit parts of commercially available yogurts ( n = 30) from Nitra markets (Slovak Republic). The results were correlated to determine their relationships. Three yogurt fruit flavors were chosen and tested, strawberry ( n = 10), blueberry ( n = 10), and cherry ( n = 10). The elements were analyzed using atomic absorption spectrophotometry. Higher concentrations of toxic elements, such as Cd and Pb, were found in the fruit parts of the yogurt, and in some cases, the tolerable limit was exceeded. The white part of the yogurt was not contaminated by toxic elements. White yogurt is a good source of nutrients for humans, but the fruit part in yogurt requires detailed monitoring and improvements in the processing techniques. 相似文献
8.
Carbonized wood is a biofuel from cellulose pyrolysis with frequent smoke and life-threatening carcinogenic emissions. Carbon monoxide (CO), particulate matter (PM2.5), metalloids and trace elements from charcoals from six commonly used tropical timbers for carbonization in Donkorkrom (Ghana) were assessed. During combustion, Anogeissus leiocarpa charcoal emitted the least CO (4.28 ± 1.08 ppm) and PM2.5 (3.83 ± 1.57 μg/m3), while particulate matter was greatest for Erythrophleum ivorense (28.05 ± 3.08 ppm) and Azadirachta indica (27.67 ± 4.17 μg/m3) charcoals. Erythrophleum ivorense charcoal produced much lead (16.90 ± 0.33 ppm), arsenic (1.97 ± 0.10 ppm) and mercury (0.58 ± 0.003 ppm) but the least chromium (0.11 ± 0.01 ppm) and zinc (2.85 ± 0.05 ppm). Nickel was greatest for A. indica charcoal (0.71 ± 0.01 ppm) and least for Vitellaria paradoxa (0.07 ± 0.004 ppm). Trace elements ranged from 342.01 ± 2.54 ppm (A. indica) to 978.47 ± 1.80 ppm (V. paradoxa) for potassium and 1.74 ± 0.02% (V. paradoxa) to 2.24 ± 0.10% (A. indica) for sulphur. Besides A. leiocarpa charcoal, which ranked safest during combustion, the high PM2.5 and CO emissions make the other biofuels hazardous indoors. Kitchens need air filters to absorb these emissions together with the use of improved cook stoves. These carcinogenic metalloids would necessitate that their ashes be properly discarded without human contact. Yet, the charcoals would be much suitable as soil amendment bio-char for plant growth quality improvement. 相似文献
9.
Trace elements found in aerosols were monitored in Jerusalem during the 1979 winter season utilizing an X-ray fluoresence technique. Most of the particulate mass was associated with the natural soil elements, such as Ca, Fe, K and Ti. Only a small fraction of the mass was comprised of elements clearly emitted from human sources, e.g. Pb, Br, V, Ni and Zn. An excellent correspondence was found between the enrichment factors observed in this study and those postulated for other parts of the world. However, the concentration of Ca and Sr in the Jerusalem suspended dust is substantially higher when compared with world averages of urban aerosols. 相似文献
10.
Rain and snow samples from different sites, varying in altitude, in western Switzerland were taken from January 1990 to November 1991. The samples were collected with ultraclean material and analysed for the major elements Na, Cl, NO 3, SO 4, K, Si, Ca, Mg and the trace elements B, V, Cr, Mn, Ni, Fe, Zn, Cu, Pb, Rb, Sr, and Ba content. A comparison with published data shows that the measured concentration and fluxes are typical for slightly contaminated rural European regions. Analysis of variance suggests that the region is fairly homogeneous for atmospheric deposition although the sites differ in altitude and human influence. Enrichment factors indicate that most of the elements are originating from seawater or continental crust and that the elements released by human activities are submitted to long-range transport. Temporal evolution in concentrations and differences between rain and snow composition could originate from the general atmospheric circulation. 相似文献
11.
A total of 549 samples of rice, maize, wheat, sorghum and millet were obtained from markets in Ghana, the EU, US and Asia. Analysis of the samples, originating from 21 countries in 5 continents, helped to establish global mean trace element concentrations in grains; thus placing the Ghanaian data within a global context. Ghanaian rice was generally low in potentially toxic elements, but high in essential nutrient elements. Arsenic concentrations in rice from US (0.22 mg/kg) and Thailand (0.15 mg/kg) were higher than in Ghanaian rice (0.11 mg/kg). Percentage inorganic arsenic content of the latter (83%) was, however, higher than for US (42%) and Thai rice (67%). Total arsenic concentration in Ghanaian maize, sorghum and millet samples (0.01 mg/kg) was an order of magnitude lower than in Ghanaian rice, indicating that a shift from rice-centric to multigrain diets could help reduce health risks posed by dietary exposure to inorganic As. 相似文献
13.
Surface snow samples have been analyzed for a total of 37 elements including Na, Mg, Al, K, Ca, Fe, Ba, Cd, Fe, Cd, Cr, Cu, Ga, Li, Mn, Pb, Se, Sr, V, Zn, As, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Th by inductively coupled plasma mass spectroscopy (ICP-MS). Rare earth elements in surface snow were evaluated after preconcentration of the samples in a class 1000 clean room. These samples were collected between 1991–1993 during the oversnow traverses along a 2200 km route in East Queen Maud Land, Antarctica. They include one at Dome Fuji Station (77°32′S, 24°08′E; 3810 m a.s.l.) built on the top of the second highest dome. In coastal area, fallout flux for Na, Mg, Sr and Cu or more weakly for Ca and Ba shows an apparent decrease according to the distance from the coast. On the other hand, fallout flux for Co, Ni and Cd shows an increase at 2500–3000 m or >3500 m above sea level. For Mn, Se, Zn and As, it shows a combined pattern of these two types. For Al, V and Pb, a constant profile with an intermittent peaks along this route was indicated. These geographical distributions of fallout flux for each element could reflect polar stratospheric precipitation or long-range tropospheric transport from the southern hemisphere. In the present study, concentrations of rare earth elements in Antarctic surface snow at sub-ppt level are first reported. A clear rare earth pattern is noticed in the Antarctic samples and rare earth ratios are also valuable to estimate anthropogenic emissions to the Antarctica. 相似文献
14.
While marine organisms such as bivalves, seagrasses and macroalgae are commonly used as biomonitors for the environment pollution assessment, widely distributed sponges received little attention as potential helpful species for monitoring programmes. In this study, the trace element and radionuclide bioaccumulation and retention capacities of some marine sponges were estimated in a species-comparative study using radiotracers technique. Six Mediterranean species were exposed to background dissolved concentrations of 110mAg, 241Am, 109Cd, 60Co, 134Cs, 54Mn, 75Se and 65Zn allowing the assessment of the uptake and depuration kinetics for selected elements. Globally, massive demosponges Agelas oroides, Chondrosia reniformis and Ircinia variabilis displayed higher concentration factor (CF) than the erectile ones ( Acanthella acuta, Cymbaxinella damicornis, Cymbaxinella verrucosa) at the end of exposure, suggesting that the morphology is a key factor in the metal bioaccumulation efficiency. Considering this observation, two exceptions were noted: (1) A. acuta reached the highest CF for 110mAg and strongly retained the accumulated metal without significant Ag loss when placed in depuration conditions and (2) C. reniformis did not accumulate Se as much as A. oroides and I. variabilis. These results suggest that peculiar metal uptake properties in sponges could be driven by specific metabolites or contrasting biosilification processes between species, respectively. This study demonstrated that sponges could be considered as valuable candidate for biomonitoring metal contamination but also that there is a need to experimentally highlight metal-dependant characteristic among species. 相似文献
15.
Environmental Science and Pollution Research - Alpine lakes are extreme ecosystems located in remote areas and populated by few but well-adapted species. Because of their remote location, they are... 相似文献
16.
This study describes the spatial and the seasonal variation of flux and concentration of 11 metals (Al, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Zn), organic matter and C and N in settling particulate matter collected with sediment traps during seven interconnective, continuous periods totalling 15 months. Ten sediment traps were placed out along the metropolis-affected fresh water outflow of Lake M?laren, out through a non-tidal estuarine-like region with a low salt content, through the Stockholm archipelago to the Baltic. The metal concentrations of the particles were analysed with AAS using the flame technique and the amounts of C and N were determined with elemental analysis (CHN). The flux of particulate matter and of all metals decreased rapidly outwards in a gradient from the innermost stations. The distribution and composition of the particles were dominated by variations in the runoff from Lake M?laren and by the seasonal dependence on primary production. However, they were also influenced locally by the supply of nutrients via water treatment plant effluents and probably by the special sedimentation conditions in the mixing zones and by resuspension. The concentrations of Cu, Hg, Pb and Cd in the interior of the area under investigation were the most elevated of the elements and decreased markedly further out in the archipelago, indicating local anthropogenic input. Zn, Cr and Fe also showed signs of supply from the urbanized environment. The flux of most of the metals studied displayed both spatial and seasonal correlation with the weight (TPM) of the material, whereas seasonal variation of Cd was correlated to its volume (TPV) and concentration of organic matter (POM, PC and PN). 相似文献
17.
A total of 197 bulk precipitation samples from different rural and suburban stations in Bavaria, F.R.G., were analysed for the following trace substance concentrations: PAH (fluoranthen, benzo-ghiperylene, benzo-a-pyrene), chlorinated hydrocarbons (α- and γ-BHC, HCB, PCB) and trace metals (Zn, Cd, Pb, Cu, Fe). Data analysis was carried out with multivariate principal component analysis separately for suburban and rural sites, and for summer and winter events. The resulting principal component loadings matrices are characterized by typical patterns indicating differences of the emission of the single pollutants in their temporal and spatial distribution. PAH and Pb are concentrations parameters for the interpretation of the data structure of suburban sites. While Pb concentrations are elevated in the rainwater samples of these stations during all seasons, PAH indicate space-heating by showing elevated levels during winter. Rural sites are characterized by a lower interrelation between the various parameters and chlorinated BHC pesticides as further pollution variables. These substances are highly enriched in rainwater samples from spring and summer events. 相似文献
18.
In order to gain more information on the possible use of four gastropod species as metal biomonitors for the Mediterranean area, the influence of body weight upon Cd, Cr, Cu, Pb and Zn concentrations was studied in specimens collected at locations with different degrees of environmental pollution. The selected species were the marine snails Monodonta turbinata Born and Monodonta mutabilis Philippi, and the limpets Patella caerulea L. and Patella lusitanica Gmelin. Significant differences between metal concentrations in individuals from different stations were tested by ANCOVA on log-transformed data with log body weight as covariate. For all species a positive correlation between metal concentrations and body weight was observed, which means that the largest individuals contained the highest levels of metals. The inclusion of body weight as covariate in the statistical analysis explained from 81% to 99% of the metal variability within the organisms and enabled the achievement of improvements in the detection of differences among sites. The four selected species provided a rather univocal picture of bioavailable metal loads at the different stations of the experimental area. Except for Cd, the metal concentrations recorded at the clean stations were found to lie in the range of the lowest values reported in the literature and can be employed as useful background levels which can be referred to for intraspecific comparison within the Mediterranean area. It is concluded that in view of its distribution, unambiguous identification, resistance to pollution and accumulation patterns M. turbinata has considerable potential as a biomonitor of trace metals over the Mediterranean. 相似文献
19.
The steady state probability distribution of chemical tracers in the atmosphere and in rain can be calculated from stochastic models, under explicit assumptions. We compare predictions from two such models, one based upon a linear stochastic equation in which random removal events … or storms … form a Poisson process, and the other based upon multiplicative random processes which produce a lognormal distribution. The two models predict different shapes for the resulting distributions of concentrations and fluxes of atmospheric tracers such as sulfates in ‘acid rain’. Consequently, estimates of the frequencies of extreme events, if based upon an assumed parametric form of a distribution function whose parameters are fitted by measurements of typical events, are model sensitive.To establish a preferred model for wet deposition, we have examined the statistics of sulfate deposition from the “European Network for the Study of Long Range Transport of Air Pollutants” (LRTAP), during the years 1973–1975. The shapes of the distributions of airborne sulfur species (SO 2+ SO 42−), and of raincarried sulfate fluxes to the ground, are between those predicted by the two models.Our results are of operational significance to efforts directed to establishing national standards for rain quality. 相似文献
20.
A sampler, employing nine single stage impactors placed in parallel within a portable wind tunnel, has been used to determine the metal content of coarse atmospheric aerosol. The wind tunnel maintains a constant flow environment for the collectors housed inside it, so that representative sampling conditions are achieved compared to the varied ambient wind conditions. At a flow rate of 8 m s −1 the 50% cut-off diameters of the impactors ranged from 7.8 to 38.8 μm. Measurements were conducted at a rural and urban site near Colchester in south east England. The samplers were analysed by PIXE for P, K, Ca, Fe, Ti, Mn, Cu, V, Co, Cr, Br, Zn, Ni, Sc and Pb. It is found that the sampler can be employed to quantitatively characterise the elemental mass size distribution for aerosol larger than 10 μm. The results indicate that a small fraction of the above earth and trace elements’ metal mass is present in particles greater than 10 μm. This fraction for earth metals (Ca, K, Ti) is comparatively greater in the rural site than the urban site, while for trace metals (Mn, V, Cu, Cr) this fraction constitutes a more significant part of the coarse mass at the urban site. Trace element concentrations were of a similar order of magnitude to earlier literature reports. Although the number of measurements was limited it can be concluded that the size distributions obtained were characteristic of an unpolluted area. 相似文献
|