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1.
Instrumental analysis methods for 210Pb, 226Raand 137Cs by gamma-spectrometry in sediments, as well as the sedimentationrates in cores collected from Brazilian coastal region are presented. Samplinglocations have covered the Cananeia-Iguape estuary and the continental shelfof southern Sao Paulo State. Values for 210Pb ranged from 122.5to 14.3 Bq . kg —1 for estuarine sediments and from 195.5to 23.6 Bq . kg –1 at the continental shelf. For 226Ra thevalues obtained in sediments varied from 15.2 to 2.3 Bq . kg —1 in the estuary and from 30.1 to 16.1 Bq . kg —1 atthe continental shelf. Sedimentation rates are variable, ranging from 0.53to 0.98 cm . y —1 in estuary sediments and from 0.18 to 0.40cm . y —1 at the continental shelf.  相似文献   

2.
Guajará Bay is an integral part of the Amazon Estuary system, and functions as the main receiver of urban and industrial wastes from the city of Belém, capital city of PA State (N Brazil). There is a lack of knowledge regarding quantitative measures of sedimentation, such as sedimentation rates, in the literature for this area of the Amazon Estuary. This study aimed the evaluation of recent (time range of 100 years) sedimentation rates in three sediment profiles collected in the coastal system of Guajará Bay with a radioanalytical approach of unsupported 210Pb and 137Cs modeling. The mean sedimentation rates for the cores obtained were 0.85 ± 0.12 cm year?1 for Anadim core, 1.02 ± 0.17 cm year?1 for Outeiro core and 0.53 ± 0.04 cm year?1 for Tucunduba core. With the use of three models of sedimentation rate models, it was observed that Anadim and Outeiro core presented constant sedimentation rates for the evaluated time range, but Tucunduba did not. This difference in sedimentation rates was probably due to their different sampling locations that present diverse hydrodynamic regime, with deposition of fine sediments in the upper area of the bay and stronger fluvial currents in the southernmost region.  相似文献   

3.
Journal of Radioanalytical and Nuclear Chemistry - The Constant Flux: Constant Sedimentation (CF:CS) and Constant Rate of Supply (CRS) of unsupported/excess 210Pb models have been applied to a...  相似文献   

4.
São Paulo is the largest city in Brazil and South America with about 20 million inhabitants in the metropolitan area, more than nine million motor vehicles and intense industrial activity, which are responsible for increasing pollution in the region. Nevertheless, little is known concerning metal and semi-metal content in the soils of this metropolitan region. This type of information could be extremely useful as a fingerprint of environmental pollution. The present study determined the elements As, Ba, Co, Cr, Sb, and Zn concentrations in soils adjacent to avenues of highly dense traffic in São Paulo city to assess their levels and possible sources. The analytical technique employed was Instrumental neutron activation analysis. The results showed, except for Co, concentration levels higher than the reference values for soils of São Paulo, according to the Environmental Protection Agency of the State of São Paulo guidelines. When compared to similar studies in other cities around the world, São Paulo soils presented higher levels, probably due to its high density traffic and industrial activity. The concentrations obtained for As and Cr indicate anthropogenic origin. The high levels of the traffic-related elements Ba, Sb, and Zn in soils nearby high density traffic avenues indicate they may originate from vehicular exhausts.  相似文献   

5.
The atmospheric pollution of São Paulo city is a serious problem due to the expansion of industrial area, increasing number of vehicles and population density. This work presents results obtained in the analysis of lichens collected in different sites of São Paulo city and in non-polluted areas of Atlantic Forest. Concentrations of twenty elements were determined in Canoparmelia texana species and comparisons were made between the results obtained in lichens from different sites. High concentrations of the elements As, Ba, Cd, Co, Cr, Fe, La, Mn, Sb and Zn were found for samples collected in sites located near industries and petrochemical plant. Br and Sb concentrations were also high in lichens from sites affected by vehicular emissions.  相似文献   

6.
Samples of the lichen Canoparmelia texana collected in seven differentsites of So Paulo State and one site of the Paraná State wereanalysed by neutron activation analysis in order to obtain information onthe air quality in these regions and also to select a region of interest forthe evaluation of baseline level of elements in lichen species. Concentrationsof the elements Al, As, Br, Ca, Cd, Cl, Co, Cs, Fe, Hf, K, Mg, Mn, Na, Rb,Sb, Sc, Se, Ti, Th, U, V, Zn and lanthanides were determined and a preliminarycomparisons was made between the results obtained for samples collected indifferent sites.  相似文献   

7.
Arsenic and cadmium contents in eight edible mushroom species (Agaricus bisporus, Agaricus sp, Pleurotus ostreatus, Pleorotus florida, Pleorotus eryngui, Pleurotus osteatus, Pleurotus salmoneostramineus, Lentinula edodes) consumed by Brazilian population were determined by instrumental neutron activation analysis (INAA) and graphite furnace atomic absorption spectrometry (GF AAS), respectively. Arsenic concentrations varied from 0.009 mg/kg in P. eryngui to 0.210 mg/kg dry weight in L. edodoes and Cd from 0.011 g/kg in P. eryngui to 0.229 mg/kg dw in P. salmoneostramineus. The consumption of mushrooms in São Paulo-Brazil may be considered safe from a toxicological point of view as As and Cd presented levels of ingestion are below the maximum levels recommended by the World Health Organization.  相似文献   

8.

There is no information on arsenic distribution in terrestrial invertebrates from riparian forests of urban and rural areas in Brazil. The objective of this study was to evaluate the As levels in invertebrates from riverine forests of the Piracicaba River Basin, São Paulo, Brazil, using the instrumental neutron activation analysis, k 0-comparator method. After correction of mass fractions, values higher than 0.10 mg kg−1 were quantified in invertebrates from both urban and agricultural areas. An unexpected As mass fraction of 13 mg kg−1 obtained in the Coleopteran pest Macrodactylus pumilio indicated resistance to As-containing-pesticides.

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9.
The objective of this study was to quantify major and trace elements present in sediments collected from the one of Brazil’s most important rivers, Tietê River. Sediments from 5 different sampling points (P0–P4), in 3 campaigns (2008/2009), from the headwaters to Suzano County upstream from São Paulo city were collected. X-ray fluorescence was applied for measuring total concentration of major elements and instrumental neutron activation analysis (INAA) for trace elements. The elements Cd, Hg and Pb were determined by atomic absorption spectrometry after digestion using the US EPA 3,051 procedure. These metal concentrations were compared to the PEL and TEL oriented values from CCME. The sampling sites P3 and P4, near industrialized areas, showed the highest concentrations for potentially bioavailable metals, mainly Pb and Hg. The results obtained by INAA were compared to upper continental crust values. A strong enrichment was found for the elements As, Br, Sb, Th, U and Zn. These results evidenced contamination by industrial effluents and sewage even relatively close to the Tietê River headwaters. The worst biological effects (acute toxicity) on benthonic organism Hyalella azteca were also observed at P3 and P4.  相似文献   

10.
Journal of Radioanalytical and Nuclear Chemistry - This study provides the sedimentation rates (SR) of three drainage basins at Itaipu Reservoir (Paraná State, Brazil) by applying 210Pb and...  相似文献   

11.
Journal of Radioanalytical and Nuclear Chemistry - This study aimed to evaluate the sea urchin Lytechinus variegatus as an environmental biomonitor and contribute to the knowledge of its...  相似文献   

12.
Occurrence and the effects of butyltin compounds (BTs) have been studied for some years, mainly in countries of the Northern Hemisphere. Due to widespread use of tributyltin compounds (TBTs) and considering their deleterious effects, it is necessary to conduct studies on its occurrence, especially in the marine environment because of its excessive use in coatings of ship hulls to prevent fouling. Moreover, it was important to extend the evaluation to areas where there is no current information about their occurrence. The present work reports the occurrence of BTs in marine sediments of S?o Paulo state, Brazil. Commercial and leisure harbor sampling sites were selected because these areas are potentially exposed to BTs from antifouling paints used on ship hulls. Analytical conditions for organotin analysis in marine sediments were optimized for GC with pulsed flame photometric detection. Detection limits ranged from 8A to 66.3 ng g(-1) using a 610-nm filter, and the linearity range was 20-500 ng g(-1). Concentration levels of BTs were highest in Santos harbor (360 ng g(-1) TBT in average) and Guarujá marina (670 ng g(-1) TBT in average), which seems to be related to intensive boat traffic. Lower levels of BTs were observed in Cananéia, where only fishing boats are present (50 ng g(-1) TBT in average).  相似文献   

13.
In this work, Surface Enhanced Raman Spectroscopy (SERS) was employed in the taxonomic identification of fungi found in biofilms formed on earthen architecture walls (adobe, wattle and daub, and rammed earth) of historical buildings in the region known as Paraíba Valley (or São Paulo Historical Valley), which are representative of the first phase of the Brazilian coffee cycle (1820–1880). Very few studies are reported in the literature where SERS-based techniques are used in fungi identification, most of them focused on clinical diagnosis. In the present investigation, pure colonies isolated from biofilms on earthen walls previously identified by classic taxonomy and molecular biology were selected. The genera were Trichoderma, Cladosporium, Aspergillus, Neurospora, Fusarium and Penicillium. The fungi were cultured on solid potato dextrose agar, extracted with ethyl acetate and the extracts were applied on dried Au nanoparticles. The SERS spectra exhibited bands in the 600–1800 cm−1 region which are characteristic of each genus, except Penicillium, as revealed by PCA statistical analysis. This work reports the use of a facile to prepare SERS-active substrate in the identification of microbial communities on earthen architecture walls and is the first step of an investigation aiming at the fast identification of fungi species from biofilms formed on earthen architecture buildings without the need of isolating the pure cultures.  相似文献   

14.
Biomonitoring of coastal areas using marine organisms is an attractive approach for studying pollution caused by anthropic discharges. Most of the experiments are based on the collection and analysis of native organisms, but this method has the disadvantage of dealing with many natural variations. In this work, the marine bivalve Perna perna, very abundant in the coast of the State of São Paulo, Brazil, was transplanted from a mussel farm and used for biomonitoring of four sites, situated in coastal regions close to domestic and/or industrial discharges. Hg, Cd and Pb were determined in the transplanted organisms by AAS and As, Ca, Co, Cr, Fe, Na, Se and Zn were determined by INAA.  相似文献   

15.
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17.
The Neutron Activation Analysis Laboratory (LAN-IPEN) has been analysing geological samples for many years with the INAA comparative method, for geochemical and environmental research. This study presents the results obtained in the implementation of the k 0-standardization method at LAN-IPEN, for geological samples analysis, by using the program k 0-IAEA, provided by the International Atomic Energy Agency (IAEA). The thermal to epithermal flux ratio f and the shape factor α of the epithermal flux distribution of the IEA-R1 nuclear reactor of IPEN were determined for the pneumatic irradiation facility and one selected irradiation position, for short and long irradiations, respectively. To obtain these factors, the “bare triple-monitor” method with 197Au–96Zr–94Zr was used. In order to validate the methodology, the geological reference materials basalts JB-1 (GSJ) and BE-N (IWG-GIT), andesite AGV-1 (USGS), granite GS-N (ANRT), SOIL-7 (IAEA) and sediment Buffalo River Sediment (NIST–BRS-8704), which represent different geological matrices, were analysed. The concentration results obtained agreed with assigned, with bias <10 % except for Zn in AGV-1. The U-score test showed that all results, except Mg in JB-1, are within 95 % confidence interval. These results indicate excellent possibilities of using this parametric method at the LAN-IPEN for geochemical and environmental studies.  相似文献   

18.
The Brazilian phosphate industry is the sixth worldwide producer of phosphate rock concentrate generating phosphoric acid, fertilizers, intermediates for fertilizers and other products. Two of the most important of these industries are both located in the city of Cubatão—São Paulo, Brazil, and they are responsible for the production of P2O5, generating a residue known as phosphogypsum. The raw material, phosphate rock and products are commonly transported to the industrial complex by a railroad line and present in their composition natural radionuclides from the U and Th series and rare earth elements. Lichens have been used for monitoring atmospheric pollution and radiological contamination for a long time and have proven to be an important tool. This paper aims to highlight the use of the lichen specie Canoparmelia texana (family Parmeliacea) as a bioindicator of atmospheric pollution by the natural radionuclides from the U and Th series and RREs due to the operation of these industries and the storage of their residue in the open air. Samples of these lichen specie were collected in the vicinity of the industries and the railroad. The radionuclides 226Ra, 228Ra and 210Pb were measured by alpha and beta counting, after radiochemical separation, and 238U, 232Th as well as REEs were determined by instrumental neutron activation analysis. The results showed that the lichens present the same fingerprint as the phosphate rock and phosphogypsum, furthermore the cluster analysis of the results showed that the lichen samples collected near to the railroad line presented the highest values for all the elements studied.  相似文献   

19.
This study comprises Tertiary sediments (clays, silts, and fine clayey sands) from the unsaturated zone of the Experimental Station in the University of São Paulo, taken from a nine meters depth profile; ten samples were separated in bulk and <53 m fractions. Chemical composition was determined by INAA to ascertain the distribution of trace elements throughout the sediment deposition, and to establish the background parameters, useful for mobilization studies of such elements after industrial waste disposal.  相似文献   

20.
In this study, Canoparmelia texana lichenized fungi species was used as a passive biomonitor of the atmospheric pollution from the industrial city of São Mateus do Sul, PR, Brazil. Lichen samples collected from tree barks were cleaned, freeze-dried and analyzed by neutron activation analysis. Comparisons were made between the element concentrations obtained in lichens from this city and that from a clean area of Atlantic Forest in Intervales Park, SP. The high concentrations of elements As, Ca, Co, Cr, Fe, Hf, Sb, and Th found in lichens could be attributed to the emissions from a ceramic and an oil shale plants.  相似文献   

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