ESTIMATION OF EFFECTIVE DOSE CAUSED BY 40K, 90SR AND 137CS IN DAILY FOOD

Abstract

This paper presents 137Cs, 90Sr and 40K activity concentrations in daily food and an annual effective dose caused by these radionuclides. Samples were taken during the period 28 October 2004–23 June 2005 once a month in a students’ canteen of Vilnius Gediminas Technical University (VGTU). The weight of samples varied from 1,37 kg to 2,26 kg, and an average weight was 1,89 kg. The volume of liquids varied from 500 cm3 to 1000 cm3, and the average was 816 cm3. The average of activity concentration of 90Sr in daily food from the students’ canteen was (0,03±0,01) Bq/kg, of 137Cs – (0,02±0,01) Bq/kg and of 40K – (34±3) Bq/kg. An annual effective dose caused by these radionuclides was estimated using measured activity concentrations in daily food and dose coefficients. An annual effective dose caused by 90Sr was in the range of (1,9–14)·10−8 Sv, by 137Cs – (0,47–6,2)·10−8 Sv and by 40K – (6,8–21)·10−5 Sv.