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| Titel |
Short-term and short-range variations of ²²²Rn concentrations and fluxes from soils in Krakow, Poland |
| VerfasserIn |
Michal Bonczyk, Paulina Wach, Przemysław Wachniew, Zbigniew Gorczyca, Michal Gasiorek |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250032071
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| Zusammenfassung |
| Measurements have been made of 222Rn concentrations and release from two soils of
different degrees of anthropogenic impact in the city of Krakow (Southern Poland). Radon
fluxes were estimated by use of two methods. Direct method (static chamber) bases on
observation of the growth rate of radon activity under the leakproof chamber covering soil. A
closed-circuit analytical system consisting of a static accumulation chamber, pump,
dryer and active radon monitor RAD7 was used to measure activity of radon via
its short-lived daughter 218Po. The second method, indirect one, uses the 222Rn
concentration measurements at several depths in soil profile to estimate radon flux.
Stainless steel tubes with an internal diameter of 1 cm were used to pump soil air
from the depths of 20, 30, 40, 60, 100, 150 and 200 cm into the active volume of
the RAD7 monitor. The obtained depth profiles provided insights into the vertical
variability of radon concentrations and allowed for the estimation of radon fluxes to the
atmosphere.
Short-term (diurnal) variations in radon concentrations and fluxes were significant in
some cases and negligible in others. The depth profiles of radon concentrations were
very rarely monotonous. Occasionally radon was not detected in water-logged soil
layers. The highest concentrations reached 9600Â (±800) Bq-
m-3 at the heavily
anthropogenically disturbed site and 20Â 000Â (±1000) Bq-
m-3 at the alluvial soil of the
Vistula river valley. Radon concentrations differed considerably, even by two orders of
magnitude, among profiles separated by only around 1 m. These spatial and temporal
variations seem to be driven by the variability of soil properties such as 226Ra content,
porosity, water content and by the hydrological and meteorological conditions. |
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