Activity concentrations of ~(137)Cs, ~(40)K, and ~(210)Pb radionuclides in selected medicinal herbs from Central Serbia and their effective dose due to ingestion

摘要

Specific activity of Cs-137, K-40, and Pb-210 radionuclides in fifteen selected medicinal herbs from three locations in Central Serbia (two mountains, Kopaonik and Zlatar, and a valley, Sokobanja) was measured using two semiconductor HPGe spectrometer systems. The obtained values are in intervals (<0.3 divided by 9.7) Bq/kg, (<0.2 divided by 24.7) Bq/kg, and (<0.2 divided by 5.7) Bq/kg for Cs-137; in intervals (125 divided by 1100) Bq/kg, (104 divided by 872) Bq/kg, and (103 divided by 954) Bq/kg for K-40, and in intervals (3.6 divided by 49.0) Bq/kg, (3.9 divided by 57.9) Bq/kg, and (2.8 divided by 103) Bq/kg for Pb-210, for herbs from Kopaonik, Sokobanja and Zlatar, respectively. The highest activity measured in individual herbs was: 24.7 Bq/kg for Cs-137 (Sokobanja valley), 1100 Bq/kg for K-40 (Mt. Kopaonik) and 103 Bq/kg for Pb-210 (Mt. Zlatar). The corresponding individual annual effective doses due to ingestion calculated from the measured activity concentrations, of the radionuclides are: in intervals (<1.7 divided by 82.9) nSv, (<1.4 divided by 211) nSv, and (<1.1 divided by 48.7) nSv for Cs-137; in intervals (0.76 divided by 4.5) mu Sv, (0.64 divided by 4.4) mu Sv, and (0.63 divided by 4.9) mu Sv for K-40, and in intervals (1.1 divided by 18.2) mu Sv, (1.3 divided by 21.6) mu Sv, (0.9 divided by 38.3) mu Sv for Pb-210, respectively. The specific activity concentration values of Cs-137 and K-40 obtained for the investigated herbs are similar to the literature data, while no information was found in literature about specific activity concentration of Pb-210. The all values obtained for individual annual effective dose due to ingestion are less than 100 mu Sv, which means that the daily use of 200 mL of herbal infusion during a year made from the investigated herbs does not represent a radiological risk for health. However, a high individual annual effective dose of ingestion of Pb-210 obtained for some herbs indicate that their consumption in larger amounts 23 cups of infusion daily over a year could make the dose to exceed the recommended level, and points to necessity for extensive investigation of Pb-210 activity concentration worldwide. (C) 2019 Elsevier B.V. All rights reserved.