title: Cesium-137 concentration of soils in Pest County, Hungary.
abstract: This paper presents the results of measurements of (137)Cs in soils in Pest County, Hungary. We investigated forty five soil monoliths from monitoring locations of a countrywide Soil Information and Monitoring System (SIMS) at depths of 0-30, 30-60, 60-90, 90-120 and 120-150 cm. The (137)Cs concentrations were determined by gamma spectroscopy. We found that only the upper layer of soil (0-30 cm) contained (137)Cs above the detection limit (0.5 Bq kg(-1)). The (137)Cs concentration values ranged from the detection limit to 61.1 Bq kg(-1) ± 2.2 Bq kg(-1) and were lognormally distributed. The concentrations had a geometric mean 6.4 Bq kg(-1) and a geometric standard deviation 2.3 (an arithmetic mean 9.5 Bq kg(-1), an arithmetic standard deviation 11.3 Bq kg(-1)). We constructed a (137)Cs map for Pest County this is the first detailed (137)Cs map in Hungary. Concentrations were systematically higher (10.0-61.1 Bq kg(-1)) than average in the Pilis and Buda Mountains and the Northern part of the Gödöllő Hills. In contrast, low concentrations (0.0-10.0 Bq kg(-1)) characterized the southern part of the Gödöllő Hills, the Pest Plane and the Börzsöny Mountains. Two highest values were 46.9 Bq kg(-1) and 61.1 Bq kg(-1): one of these localities, a loamy brown forest soil was chosen to study relationship between (137)Cs migration and clay materials of the soil. According to differential thermal analysis (DTA) and x-ray diffraction (XRD) analyses, illite and kaolinite were dominant in the soil. The amount of clay was closely proportional to (137)Cs concentration (R = 0.89). At the locality having the highest surface concentration, 78% of the total detected (137)Cs concentration was measured in the top 3 cm layer of soil profile and there was no detectable concentration below 20 cm. This result indicates that penetration of (137)Cs into the soil is a very slow process in this case. Analysis of this depth profile showed lower (137)Cs migration parameter values (effective diffusion coefficient and migration velocity) than predicted in a previous study for brown forest soils in the same area of Hungary.
authors.affiliation: Lithosphere Fluid Research Laboratory, Department of Petrology and Geochemistry, Eötvös University, Budapest, Hungary.
authors.forename: Katalin Zsuzsanna
authors.initials: KZ
authors.lastname: Szabó
authors.forename: Beatrix
authors.initials: B
authors.lastname: Udvardi
authors.forename: Akos
authors.initials: A
authors.lastname: Horváth
authors.forename: Zsófia
authors.initials: Z
authors.lastname: Bakacsi
authors.forename: László
authors.initials: L
authors.lastname: Pásztor
authors.forename: József
authors.initials: J
authors.lastname: Szabó
authors.forename: László
authors.initials: L
authors.lastname: Laczkó
authors.forename: Csaba
authors.initials: C
authors.lastname: Szabó
mesh_terms: D002588:Cesium Radioisotopes / Q000032:analysis*; D004784:Environmental Monitoring; D006814:Hungary; D012990:Soil Pollutants, Radioactive / Q000032:analysis*
chemical_list: D002588:Cesium Radioisotopes; D012990:Soil Pollutants, Radioactive