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991.
992.
993.
Identifying natural and anthropogenic sources of metals in urban and rural soils using GIS-based data,PCA, and spatial interpolation 总被引:2,自引:0,他引:2
Harley T. Davis C. Marjorie Aelion Suzanne McDermott Andrew B. Lawson 《Environmental pollution (Barking, Essex : 1987)》2009,157(8-9):2378-2385
Determining sources of neurotoxic metals in rural and urban soils is important for mitigating human exposure. Surface soil from four areas with significant clusters of mental retardation and developmental delay (MR/DD) in children, and one control site were analyzed for nine metals and characterized by soil type, climate, ecological region, land use and industrial facilities using readily available GIS-based data. Kriging, principal component analysis (PCA) and cluster analysis (CA) were used to identify commonalities of metal distribution. Three MR/DD areas (one rural and two urban) had similar soil types and significantly higher soil metal concentrations. PCA and CA results suggested that Ba, Be and Mn were consistently from natural sources; Pb and Hg from anthropogenic sources; and As, Cr, Cu, and Ni from both sources. Arsenic had low commonality estimates, was highly associated with a third PCA factor, and had a complex distribution, complicating mitigation strategies to minimize concentrations and exposures. 相似文献
994.
New best estimates for the solid–liquid distribution coefficient (Kd) for a set of radionuclides are proposed, based on a selective data search and subsequent calculation of geometric means. The Kd best estimates are calculated for soils grouped according to the texture and organic matter content. For a limited number of radionuclides this is extended to consider soil cofactors affecting soil–radionuclide interaction, such as pH, organic matter content, and radionuclide chemical speciation. Correlations between main soil properties and radionuclide Kd are examined to complete the information derived from the best estimates with a rough prediction of Kd based on soil parameters. Although there are still gaps for many radionuclides, new data from recent studies improve the calculation of Kd best estimates for a number of radionuclides, such as selenium, antimony, and iodine. 相似文献
995.
S. Fesenko N. Isamov B.J. Howard N.A. Beresford C.L. Barnett N. Sanzharova G. Voigt 《Journal of environmental radioactivity》2009
Over 150 publications reporting studies conducted in the former USSR were reviewed to provide transfer coefficients (Ff) to the muscle of domestic animals from experiments using chronic administration, often for long timescales in large scale experiments. Only a few of these studies were made available in the English language literature or taken into account in international reviews. The values derived have been compared with expected values reported by the IAEA's Handbook of parameter values for the prediction of radionuclide transfer in temperate environments (TRS 364) where possible. The information presented here has been used in the current updating of parameters recommended for environmental assessments by the IAEA. Many of the reported values are for Sr due to the Mayak accident and Cs due to the Chernobyl accident. Nevertheless, the reported data for a wide range of radionuclides, in particular for Ru, Sb, and Zn markedly improve the extent of available data. 相似文献
996.
F. Monna F. van Oort P. Hubert J. Dominik J. Bolte J.-L. Loizeau J. Labanowski J. Lamri C. Petit G. Le Roux C. Chateau 《Journal of environmental radioactivity》2009
An 80-year soil archive, the 42-plot experimental design at the INRA in Versailles (France), is used here to study long-term contamination by 137Cs atmospheric deposition and the fate of this radioisotope when associated with various agricultural practices: fallow land, KCl, NH4(NO3), superphosphate fertilizers, horse manure and lime amendments. The pertinence of a simple box model, where radiocaesium is supposed to move downward by convectional mechanisms, is checked using samples from control plots which had been neither amended, nor cultivated since 1928. This simple model presents the advantage of depending on only two parameters: α, a proportional factor allowing the historical atmospheric 137Cs fluxes to be reconstructed locally, and k, an annual loss coefficient from the plow horizon. Another pseudo-unknown is however necessary to run the model: the shape of historical 137Cs deposition, but this function can be easily computed by merging several curves previously established by other surveys. A loss of ∼1.5% per year from the plow horizon, combined with appropriate fluxes, provides good concordance between simulated and measured values. In the 0–25 cm horizon, the residence half time is found to be ∼18 yr (including both migration and radioactive decay). Migration rate constants are also calculated for some plots receiving continuous long-term agricultural treatments. Comparison with the control plots reveals significant influence of amendments on 137Cs mobility in these soils developed from a unique genoform. 相似文献
997.
S. Fesenko B.J. Howard N. Isamov N.A. Beresford C.L. Barnett N. Sanzharova G. Voigt 《Journal of environmental radioactivity》2009,100(10):815-822
Data on radionuclide transfer to domestic chickens and ducks obtained from research performed in the former Soviet Union were reviewed to provide transfer coefficient values (Ff) to poultry and edible egg contents. The majority of the data are from experiments with 90Sr and 137Cs, reflecting the importance of these radionuclides after global fallout and major radiation accidents. Data for 3H, 54Mn, 59Fe, 60Co, 22Na 65Zn, 131I and U are also given. The values derived have been compared with those in the current IAEA Handbook of parameter values for the prediction of radionuclide transfer in temperate environments (TRS 364) and the recent revision which incorporates the values from this paper. The Russian-language data give improved estimates for many radionuclides and the revised handbook is now based on the better quality data given for chronic administration. 相似文献
998.
Use and knowledge of fuelwood in three rural caatinga (dryland) communities in NE Brazil 总被引:1,自引:0,他引:1
I. M. M. Sá e Silva L. C. Marangon N. Hanazaki U. P. Albuquerque 《Environment, Development and Sustainability》2009,11(4):833-851
The woody species known, used, and preferred as fuelwood were examined in three rural communities within the county of Soledade,
Paraíba State, NE Brazil. Ethnobotanical information was collected using semi-structured interviews with more than 90% of
the local households (55 adult residents; 31 women, and 24 males). The interviewees cited 36 plant species as fuelwoods, distributed
among 30 genera and 15 families, in addition to two unidentified plants. The plant families represented by the largest numbers
of species were Euphorbiaceae, Anacardiaceae, Mimosaceae, Caesalpiniaceae, Sapotaceae, and Fabaceae. The species Caesalpinia pyramidalis Tul. (“catingueira”) was cited with the greatest frequency in all three communities. Within the communities we found significant
differences on the number of plants cited and actually used (p < 0.05), indicating that the residents knew more fuelwood species than they effectively harvest. The different distances
from the communities to the urban centers were not related to differences on the use or the size of the stocks of fuelwood.
Additionally, the study revealed that the communities examined still maintain a significant knowledge of the use of energy-providing
plants in spite of the widespread use of liquefied petroleum gas (LPG).
Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue. 相似文献
999.
The impact of emissions from the Siberian Chemical Plant (Tomsk oblast) on reproduction and embryonic development of the fieldfare was studied. Bird abundance, clutch size, and egg volume in the impact and background (control) zones were similar, but partial brood mortality in the impact zone proved to be significantly higher, and the frequency of embryonic pathologies (including developmental abnormalities) was also several times higher than in the control. 相似文献
1000.
Species composition of fishes was studied in rivers (capture sites) inhabited by the riffle minnow. In some localities, this species proved to occupy a leading position in the ichthyofauna, being obviously dominant. In small rivers, 16 species were caught together with it, including seven species regularly occurring in catches. The relative abundance of riffle minnow showed a moderate positive correlation with that of the gudgeon (0.568) and a nonsignificant negative correlation (?0.399) with that of the bleak. It is probable that the population dynamics of riffle minnow are determined mainly by natural intraspecific mechanisms rather than by water quality, which has changed only slightly in the rivers studied. 相似文献