Migration of (137)Cs, (90)Sr, and (239+240)Pu in Mediterranean forests: influence of bioavailability and association with organic acids in soil
| Autor: | Antonio Baeza, J. G. Muñoz-Muñoz, J.A. Corbacho, Javier Guillén |
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| Rok vydání: | 2014 |
| Předmět: |
Mediterranean climate
Radioactive Fallout Health Toxicology and Mutagenesis media_common.quotation_subject Biological Availability Forests Convection Diffusion Soil Radiation Monitoring Environmental Chemistry Soil Pollutants Radioactive Ecosystem Benzopyrans Waste Management and Disposal Humic Substances media_common Anthropogenic radionuclides Radionuclide Chemistry General Medicine Models Theoretical Pollution Plutonium Bioavailability Speciation Cesium Radioisotopes Spain Environmental chemistry Environmental behavior Strontium Radioisotopes |
| Zdroj: | Journal of environmental radioactivity. 144 |
| ISSN: | 1879-1700 |
| Popis: | The understanding of downward migration of anthropogenic radionuclides in soil is a key factor in the assessment of their environmental behavior. There are several factors that can affect this process, such as the radionuclide source, their chemical form, soil and environmental characteristics, etc. Two Mediterranean pinewood ecosystems in Spain, which were affected mainly by global fallout, were selected to assess the migration of 137 Cs, 90 Sr, and 239+240 Pu. Using auxiliary modeling (diffusion–convection equation and compartmental model), it followed from field observations that the migration velocities of 90 Sr and 239+240 Pu were similar and higher than that of 137 Cs. The downward migration of radionuclides can be considered a consequence of their association with soil particles. A sequential speciation procedure also confirmed that 90 Sr was the most bioavailable radionuclide followed by 239+240 Pu and 137 Cs. Although this can explain the different velocity of 90 Sr and 137 Cs, bioavailability could not explain by itself the similar velocities of 239+240 Pu and 90 Sr. The presence of organic acids in the soil can also influence the migration of radionuclides attached to them, which decreased in the order: 239+240 Pu > 90 Sr > 137 Cs. Thus, the joint consideration of bioavailable and humic + fulvic acid fractions can explain the observed differences in the downward velocities. |
| Databáze: | OpenAIRE |
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