ABSTRACT
Underground miners are internally exposed to radon, thoron and their short-lived decay products during the mineral processing. There is also an external exposure due to the gamma emitters present in the rock and dust of the mine. However, the short-lived radon decay products are recognised as the main radiation health risk. When inhaled, they are deposited in the respiratory system and may cause lung cancer. To address this concern, concentration measurements of radon and its progeny were performed, the equilibrium factor was determined and the effective dose received was estimated in six Brazilian underground mines. The radon concentration was measured by using E-PERM, AlphaGUARD and CR-39 detectors. The radon progeny was determined by using DOSEman. The annual effective dose for the miners was estimated according to United Nations Scientific Committee on the Effects of Atomic Radiation methodologies. The mean value of the equilibrium factor was 0.4. The workers' estimated effective dose ranged from 1 to 21 mSv a(-1) (mean 9 mSv a(-1)).
Subject(s)
Mining , Occupational Exposure/analysis , Radiation Monitoring , Radioactive Pollutants/analysis , Radon/analysis , Uranium/analysis , Brazil , Dose-Response Relationship, Radiation , HumansABSTRACT
Bunodosoma caissarum, a carnivorous marine species exclusive to the Brazilian southern coast, recognized as a sensitive bioindicator of artificial radioactive pollution, also shows a great capacity for concentrating natural alpha-emitters. The authors have measured the alpha-emitters 210Po and its precursor 210Pb in this animal. The average concentrations found are greater (by a factor of 4.6) for 210Po measured in samples gathered on Ponta Negra Beach (protected outer coast) than the values obtained in specimens collected on Boa Viagem Beach (closed bay) along the Rio de Janeiro coast, Brazil. The same was also found for 210Pb (a factor of 2.5).
