SVIBOR - Project code: 1-03-008

MINISTRY OF SCIENCE AND TECHNOLOGY

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SVIBOR

SVIBOR - Collecting Data on Projects in Croatia

Project code: 1-03-008


LOW LEVEL RADIOACTIVITY IN THE ENVIRONMENT;RADON


Main researcher: PLANINIĆ, JOSIP (37444)


Assistants
Type of research: applied
Duration from: 01/01/91. to 12/31/95.
Papers on project (total): 25
Papers on project quoted in Current Contents: 15
Institution name: Pedagoški fakultet, Osijek (122)
Department/Institute: Department of Physics
Address: L.Jaegera 9
City: 31000 - Osijek, Croatia
Communication
Summary: The method for measurements of concentrations of the radon(Rn-222) and its daughters was introduced as well as the equilibrium factor measurement by means of two nuclear track detectors (LR 115). Radon concentrations were systematicaly measured in Osijek's kindergartens by means of three methods (LR 115, alpha scintillation cells and semiconductor detector) and the values of 17 to 108 Bq/m3 were obtained. The relationship of the sensitivity coefficient, critical detection angle and alpha particle energy for the LR 115 detector was derived by using the measured track diameters and particle energy; the radon detection efficiency in air was also determined. Radon was specially measured in cellars and shelters of Osijek and Zagreb during the war in Croatia, and the effective dose equivalents were estimatedas 4.1 and 2.6 mSv/y,respectively. The relative error of theetching method was near 20%. Seasonal variations of indoor and outdoor radon were continually measured by the LR 115 detector during ten years at three different locations (city, west area of Osijek and Tiborjanci village). Dwelling radon distribution is going to research. An especial radon room (2x2x3 m3, without windows) constructed in order to resarch aerosols and radon progeny attachment on aerosols; the experimental room is to be used for detector calibration too. Radon concentrations inside a flat were measured with a semicoductor detector and scintillation cells. An unusual radon distribution was noticed within one room as well as in the basement. An anomalous distribution of the radon in the single house, where the radon concentration of the basement was a factor of 4 lower than that of the first floor for a few days, was explained by variations in the atmospheric pressure. Indoor radon concentrations were masured in 10 821 pupils primary schools of Osijek; the values ranged from 15 to 300 Bq/m3 with the arithmetic and geometric means of 93.4 and 70.6 Bq/m3 , respectively. Remedial actions were carried out in two kindergartens (Slovenia) with heating season radon concentrations of about 2,000 Bq/m3.

Keywords: Radon and daughters, equilibrium factor, nuclear track detector, sensitivity coefficient, dose equivalent, aerosols,

Research goals: The research is applied on the field of radioekology or applied nuclear physics in order to introduce the reliable measurement methods for radon and its daughters in air. Because the main part of the dose equivalent is coming from alpha particles of radon and its progeny, which enter into the respiratory tract together with the air, the respective doses in the human environment will be systematically measured by means of the nuclear track detector and semiconductor detector. In case of the elevated radon concentration in air (over 100 Bq/m3), a method for reduceing radon risk factor will be proposed (ventilation, isolating material, aerosol reduction, and other). In order to estimate a dose equivalent more precisely, a relation between the aerosol concentration and equilibrium factor will be researched, then the measurenent method for aerosol concentration in air and particle diameter as well as the fraction of the attached radon daughters on aerosols will be introduced.

COOPERATION - PROJECTS


  1. Name of project: 1-03-008 Niske radioaktivnosti u okolišu; radon
    Name of institution: INSTITUT ZA MEDICINSKA ISTRAŽIVANJA
    City: 41000 - ZAGREB, Hrvatska


COOPERATION - INSTITUTIONS


  1. Name of institution: Institut za medicinska istraživanja i medicinu rada
    Type of institution: University/Faculty
    City: 10000 - Zagreb, Croatia

  2. Name of institution: Institut Jožef Štefan
    Type of institution: University/Faculty
    City: 61 000 - Ljubljana, Slovenija

  3. Name of institution: Sveučilište u Goettingenu - Isotopenlaboratorium
    Type of institution: University/Faculty
    City: Goettingen, Njemačka
Other information about the project.
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Last update: 09/25/95
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