Sources, vertical distribution, and migration rates of , , and in grassland soil in three localities of central Bohemia

Hölgye, Z.; Malý, M

doi:10.1016/s0265-931x(99)00036-3

Cited by 40 publications

(24 citation statements)

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“…In contrast to Keller and Domergue (1996), Hölgye and Malý (2000) reported that the relative loss rate of Pu isotopes and 137 Cs increased with depth. In effect, the Kd was lower with depth, which they attributed to lower organic matter content.…”

Section: Leachingmentioning

confidence: 79%

Assessment of long-term fate of metals in soils: Inferences from analogues

Sheppard¹

2005

Can. J. Soil. Sci.

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Sheppard, S. C. 2005. Assessment of long-term fate of metals in soils: Inferences from analogues. Can. J. Soil Sci. 85: 1-18. The assessment of the health and environmental impacts of metal contamination in soils is complicated, and in different ways than is the assessment of many other contaminants. One of the foremost problems is that the metals are often relatively immobile, so that it is necessary to verify predictions of mobility and impact far into the future. One approach is to seek analogue information: information from studies that may not have set out to measure attributes related to metal behaviour, but that none the less provide useful insights. One example would be the information on the mobility of natural clays and pedogenic metals such as iron and aluminum in soils. It is well accepted that clay particles will move downward in soils; what is less commonly inferred is that any contaminants associated with the clays will also move downward. For mobility of some metals, this may be a dominant process. Similarly, bioturbation has proven to markedly outpace leaching for many metals. This paper considers analogues related to cesium from bomb-fallout and Chernobyl, other natural radionuclide inputs to the soil, soil pedogenesis, pollen and non-metal industrialage inputs, ancient metal works, and soil fertility management. Related to biological transfers and toxicity, it considers analogy among elements and among biota, and analogy to ecotoxicology of metals to freshwater biota. Where possible, limiting values for parameters of assessment models have been derived. Key words:Terrestrial, leaching, mobility, ecotoxicity, assessment Sheppard, S. C. 2005. Évaluation du sort à long terme des métaux dans le sol : inférences à partir des analogues. Can. J. Soil Sci. 85: 1-18. Évaluer l'incidence des métaux qui contaminent le sol sur la santé et l'environnement n'est pas une tâche facile et les difficultés diffèrent de celles soulevées par l'évaluation de nombreux autres polluants. Un des principaux problèmes a trait à l'immobilité relative des métaux. On doit donc vérifier si les prévisions concernant leur déplacement et leurs incidences se véri-fient très loin dans l'avenir. Une façon d'y parvenir consiste à recueillir des données sur les analogues, bref l'information issue d'études dont l'objet principal n'était pas de quantifier les particularités du comportement des métaux, mais qui nous renseignent néanmoins sur le sujet. Les données sur la mobilité des argiles naturelles et des métaux pédogènes tels le fer et l'aluminium dans le sol en sont un exemple. On sait pertinemment que les particules d'argile s'enfoncent dans le sol, mais on songe moins souvent que les substances contaminant l'argile en font autant. Il pourrait cependant s'agir d'un processus dominant pour la mobilité de quelques métaux. Pareillement, on a prouvé que la bioturbation revêt plus d'importance que la lixiviation pour maints métaux. Dans cet article, l'auteur examine les analogues du césium venant des retombées radioactives de l'incide...

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Section: Leachingmentioning

confidence: 79%

Assessment of long-term fate of metals in soils: Inferences from analogues

Sheppard¹

2005

Can. J. Soil. Sci.

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“…In the present case, the particle is allowed to jump randomly on its one-dimensional path along the x-axis beginning from x=0 at t=0 according to Eqs. (9)(10)(11). Since the particle at the surface (x=0), or very close to it, cannot jump any further upwards, a corresponding command has to be added to the algorithm which prevents the particle from jumping to negative x-values.…”

Section: Random Walk Modelmentioning

confidence: 99%

“…[2,4,9,12,22,23,24]. From such an observation one might conclude that the mobility of this radionuclide increases with depth, for instance due to changing sorption properties of the soil (characterised, for example, by lower distribution coefficients K d in deeper layers).…”

Section: Introductionmentioning

confidence: 95%

“…Compartment models (e.g. [6,7,8,9,10,11,12]) are additionally employed where the soil layers are considered as a series of compartments and the transport of the radionuclide from one compartment to the next one is characterised by a residence half-time. Stochastic models with the variability of the soil hydraulic properties being considered by the stream tube model or capillary bundle model are also available (e.g.…”

Section: Introductionmentioning

confidence: 99%

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Migration of fallout-radionuclides in the soil: effect of non-uniformity of the sorption properties on the activity-depth profiles

Bunzl¹

2001

Radiation and Environmental Biophysics

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Experimentally observed activity-depth profiles of fallout radionuclides in the soil frequently exhibit a comparatively fast moving tail in soil layers below the peak concentration (tailing). Monte Carlo calculations on the basis of the convection-dispersion model show that this phenomenon can be explained by assuming that either the hydraulic properties of the soil (characterised by the diffusion/dispersion coefficient and pore water velocity) or the sorption properties of the soil (characterised by the distribution coefficient Kd), or both, exhibit a horizontal variability according to a log-normal distribution. Modifications of the activity-depth profile due to a Kd value which decreases linearly with depth were examined by using a random walk approach, based also on the convection-dispersion model. In this case, however, a pronounced tailing effect of the activity-depth profile did not result. Interpretation and realistic modelling of an experimentally observed activity-depth profile which exhibits a tailing effect is thus not unambiguously possible without any additional information on the spatial variability of the hydraulic parameters and, independently, also for the sorption properties.

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“…In a compartment model the soil is divided in N layers of arbitrary thickness, usually 1-2 cm (see, for example, [9,10,11,12,13,14,15]). It is assumed that the transport of the radionuclide from layer (i) into the next layer (i+1) is proportional to the amount of activity in the layer i, but independent of the activity in the layer i+1.…”

Section: Compartment Modelmentioning

confidence: 99%

Spatial variability of the vertical migration of fallout 137 Cs in the soil of a pasture, and consequences for long-term predictions

Bunzl

Schimmack

Zelles

et al. 2000

Radiation and Environmental Biophysics

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Various transport models are presently used to predict the long-term migration behaviour of fallout radiocesium on the soil. To examine to what extent the uncertainty of these predictions is influenced by the spatial variability of the migration rates, we determined the depth profiles of Chernobyl-derived 137Cs at 100 plots in a 100 m x 100 m pasture. These data were used to obtain the frequency distributions of the characteristic transport parameters of three widely used transport models (e.g. dispersion-convection model, residence time model, and back-flow model). The results show that these transport parameters are generally log-normally distributed with a coefficient of variation of about 80%. Finally, each transport model was employed to predict the resulting frequency distribution of the 137Cs inventory in the main root layer (0-7 cm) of the pasture, 20, 50, and 100 years after the deposition. If only the spatial variability of the transport parameters is taken into account, this analysis revealed that the dispersion-convection model and the back-flow model always predicted rather similar, but significantly higher median inventories than those obtained with the residence time model. If, in addition, the spatial variability of the amount of 137Cs deposited is also taken into account, the frequency distributions of the 137Cs inventories in the root layer become so wide that differences in the median inventories predicted by the three models become statistically significant only after 100 years. Several statistically significant correlations between the transport parameters of the three models were also detected.

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Sources, vertical distribution, and migration rates of , , and in grassland soil in three localities of central Bohemia

Cited by 40 publications

References 24 publications

Assessment of long-term fate of metals in soils: Inferences from analogues

Assessment of long-term fate of metals in soils: Inferences from analogues

Migration of fallout-radionuclides in the soil: effect of non-uniformity of the sorption properties on the activity-depth profiles

Spatial variability of the vertical migration of fallout 137 Cs in the soil of a pasture, and consequences for long-term predictions

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