Acta Facultatis Ecologiae - Technická univerzita vo Zvolene

125ACTA FACULTATIS ECOLOGIAE, 16: Suppl. 1, 125–128 Zvolen (Slovakia), 2007CONCENTRATIONS OF 222 RN AND ITS PROGENY 210 PBIN LOWER ATMOSPHERE IN BRATISLAVAMiroslav Ješkovský – Karol Holý – Ivan Sýkora – Jana Merešová– Monika Müllerová – Martin Bulko – Anna PoláškováDepartment of Nuclear Physics and Biophysics, Faculty of Mathematics, Physics and Informatics, ComeniusUniversity, Mlynská dolina F1, 842 48 Bratislava, e-mail: m.jeskovsky@gmail.comABSTRACTJeškovský M., Holý K., Sýkora I., Merešová J., Müllerová M., Bulko M. & Polášková A. Concentrationsof 222 Rn and its Progeny 210 Pb in Lower Atmosphere in BratislavaMonitoring of atmospheric radioactivity in Bratislava has been carried out by the Department ofNuclear Physics and Biophysics of Faculty of Mathematics, Physics and Informatics of Comenius University.Air activity concentration of gaseous 222 Rn and its progeny 210 Pb, bound to aerosol particles, weremeasured. The concentrations of 222 Rn varied from 0.59 to 11.1 Bq.m –3 (average value 3.73 ± 0.17 Bq.m –3 )and concentrations of 210 Pb from 0.22 to 2.37 mBq.m –3 (average value 0.83 ± 0.02 mBq.m –3 ). Temporalvariation with seasonal behaviour was observed. The correlation study has been carried out between themeteorological factors and concentrations of radionuclides.Key words: seasonal variations, 222 Rn, 210 Pb, air radioactivityINTRODUCTIONThe atmospheric pollution is a very topical problemat present. Study of emission processes andchemical-physical transformations of pollutants,associated with meteorological processes of turbulentdiffusion and transport is therefore important.Useful tools to study these processes are radon andits progeny, even if are measured at ground level,because the atmospheric processes are dependenton the dynamic evolution of the boundary layer.222Rn originates from the decay chain of 238 U,which is a component of rocks and soils since nucleosynthesis.Radon is produced in soil and afterthat is exhalated to the ground level of atmospherewhere is decayed and its progeny are bounded tothe atmospheric aerosols. The 222 Rn exhalation ratedepends on the soil type and concentration of 226 Rain soil. The variations of exhalation rate are causedby precipitation and soil moisture. The variationsof 222 Rn air concentrations and subsequently of itsdecay products are induced mainly by atmosphericmixing. Air activity concentration of 222 Rn showsseasonal variations with maximum values in winterand minimum in summer [1]. It also exhibits diurnalvariations with the maximum in the night hoursand the minimum in the afternoon [2].The radon daughter product with half-live longenough to stay in the atmosphere longer than fewhours is 210 Pb. It is transported through the atmospherebounded to aerosol particles and precipitatedback to the Earth surface by dry or wet deposition.The level of volume activity of 210 Pb is influencedby several meteorological factors.The aim of this paper is to present the resultsof the long-term measurement of radioactivity concentrationin low level atmosphere [3–6]. In particularit is concerned with 222 Rn and 210 Pb, comparedwith basic meteorological parameters.