Cancer risk assessment after exposure from natural radionuclides in soil using Monte Carlo techniques.
OBJECTIVE
The purpose of this paper is to assess fatal cancer risk after external and internal (inhalation and ingestion) exposure from natural radionuclides in soil like (238)U, (232)Th, (40)K, and (226)Ra on the territory of Bela Crkva, Serbia. Although receiving doses are low from sources like natural radionuclides in soil, because of stochastic effects of ionizing radiation, risk for developing cancer exists and can be quantified.


METHODS
Concentrations of radionuclides from 80 soil samples are measured using HPGe detector. Fatal cancer risk is assessed from calculated ambient dose rate in the target organs of body due to external and internal exposure. Monte Carlo simulations are used to obtain conversion factors which are required to calculate absorbed dose rate in target organs.


CONCLUSIONS
Assessed cancer risk for (238)U in the case of both inhalation and ingestion exposure is from 1.11 × 10(-6) to 24 × 10(-6) for minimal and maximal activity in soil samples, from 1.02 × 10(-6) to 23.3 × 10(-6) for exposure to (226)Ra, from 1.89 × 10(-6) to 50.3 × 10(-6) for exposure to (232)Th, and from 0.265 × 10(-6) to 9.83 × 10(-6) for exposure to (40)K. Overall risk from (40)K as external and internal source is from 0.8 × 10(-6) to 31.9 × 10(-6). Calculated cancer risks from both inhalation and ingestion exposure could be related to all tissues that are on the way of distribution of particles within the body but especially to deposition sites in the body.


CONCLUSIONS
Assessed risks for fatal cancer development from inhaled and ingested natural radionuclides originating in soil are not increased.
Zupunski
Ljubica
L
Faculty of Technical Sciences, University of Novi Sad, 21000 Novi Sad, Serbia. ljubicaz@uns.ac.rs
Spasić-Jokić
Vesna
V
Trobok
Mirjana
M
Gordanić
Vojin
V
D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data; D004787:Environmental Pollution / Q000706:statistics & numerical data*; D006801:Humans; D009010:Monte Carlo Method; D009381:Neoplasms, Radiation-Induced / Q000453:epidemiology*; D011197:Potassium Radioisotopes / Q000032:analysis; D011868:Radioisotopes / Q000032:analysis*; D011883:Radium / Q000032:analysis; D018570:Risk Assessment; D012307:Risk Factors; D012990:Soil Pollutants, Radioactive / Q000032:analysis*; D013910:Thorium / Q000032:analysis; D014501:Uranium / Q000032:analysis
D011197:Potassium Radioisotopes; D011868:Radioisotopes; D012990:Soil Pollutants, Radioactive; D014501:Uranium; D013910:Thorium; D011883:Radium