title: Variation in airborne134Cs,137Cs, particulate131I and7Be maximum activities at high-altitude European locations after the arrival of Fukushima-labeled air masses.
abstract: The Fukushima-labeled air mass arrival, and later the cesium-134 (134Cs), cesium-137 (137Cs) and particulate iodine-131 (hereafter noted131Ip) maximum levels were registered in Europe at different dates depending on the location. Most of those data were obtained at low-altitude sampling areas. Here, we compare the airborne levels registered at different high-altitude European locations (from 850 m to about 3500 m). The integrated137Cs activity concentration was not uniform with regard to the altitude even after a long travel time/distance from Japan. Moreover, the relation of integrated137Cs vs. altitude showed a linear decrease up to an altitude of about 3000 m. A similar trend was noticed for131Ip(particulate fraction) while it increased above 3000 m. Comparison with7Be activity concentration showed that, as far as the high altitude location is concerned, the137Cs and134Cs maximum concentrations corresponded to the7Be maximum, suggesting downdraft movements from high tropospheric or stratospheric layers to be responsible for137,134Cs increase and peak values. This was also confirmed by high potential vorticity and low relative humidity registered during the peak values.
authors.affiliation: Institut de Radioprotection et de Sûreté Nucléaire (IRSN), BP 3, 13115, St Paul lez Durance, Cedex, France. Electronic address: olivier.masson@irsn.fr.
authors.forename: Olivier
authors.initials: O
authors.lastname: Masson
authors.affiliation: Bundesamt für Strahlenschutz (BfS), 79098 Freiburg, Germany.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Bieringer
authors.affiliation: Laboratorio di Chimica e Radioattività ambientale, University of Bologna, 40126 Bologna, Italy.
authors.forename: Erika
authors.initials: E
authors.lastname: Brattich
authors.affiliation: Deutscher Wetterdienst (DWD), Referat TI 24, Frankfurterstraße 135, 63067 Offenbach, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Dalheimer
authors.affiliation: Federal Office of Public Health, (FOPH), Schwarzenburgstrasse 165, CH-3003 Bern, Switzerland.
authors.forename: Sybille
authors.initials: S
authors.lastname: Estier
authors.affiliation: Institute for Nuclear Research and Nuclear Energy (INRNE), 72 Tzarigradsko shosse, Blvd Bulgarian Academy of Sciences, 1784 Sofia, Bulgaria.
authors.forename: Ilia
authors.initials: I
authors.lastname: Penev
authors.affiliation: Austrian Agency for Health and Food Safety (AGES), Radon and Radioecology, 4020 Linz, Austria.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Ringer
authors.affiliation: Bundesamt für Strahlenschutz (BfS), 79098 Freiburg, Germany.
authors.forename: Clemens
authors.initials: C
authors.lastname: Schlosser
authors.affiliation: Deutscher Wetterdienst (DWD), Referat TI 24, Frankfurterstraße 135, 63067 Offenbach, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Steinkopff
authors.affiliation: Federal Office of Public Health, (FOPH), Schwarzenburgstrasse 165, CH-3003 Bern, Switzerland.
authors.forename: Philipp
authors.initials: P
authors.lastname: Steinmann
authors.affiliation: Laboratorio di Chimica e Radioattività ambientale, University of Bologna, 40126 Bologna, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Tositti
authors.affiliation: Laboratoire d'Etudes en Géophysique et Océanographie Spatiales (LEGOS), Observatoire Midi Pyrénées, 14 avenue Edouard Belin, 31400 Toulouse, France.
authors.forename: Pieter
authors.initials: P
authors.lastname: Van Beek
authors.affiliation: Institut de Radioprotection et de Sûreté Nucléaire (IRSN), LMRE, 501, Bois des Rames, 91400 Orsay, France.
authors.forename: Anne de
authors.initials: A
authors.lastname: Vismes-Ott
mesh_terms: D000396:Air Pollutants, Radioactive / Q000032:analysis*; D000531:Altitude; D001272:Atmosphere / Q000737:chemistry; D001608:Beryllium / Q000032:analysis; D002588:Cesium Radioisotopes / Q000032:analysis*; D005060:Europe; D062406:Fukushima Nuclear Accident; D007564:Japan; D011834:Radiation Monitoring
chemical_list: D000396:Air Pollutants, Radioactive; D002588:Cesium Radioisotopes; D001608:Beryllium
keywords: (134)Cs; (137)Cs; Europe; Fukushima; High-altitude; Radionuclide; Vertical distribution