Radon concentrations in three underground lignite mines in Turkey

RADON CONCENTRATION MEASUREMENT AND DOSE ESTIMATION IN NON-URANIUM MINES IN CHINA (2019-21)

The radon concentration in selected non-uranium mines from 2019 to 2021 in China are presented. By using of solid-state nuclear track detector, a total of 110 non-uranium mines in 13 provinces and autonomous regions were monitored, and the data were analyzed according to the mineral categories. The arithmetic mean of radon concentration in underground metal mines and nonmetallic mines were 1180 and 162 Bq m-3, respectively, and the standard deviations were 2850 and 151 Bq m-3, respectively. Correspondingly, the average annual effective dose of metal miners was 12.7 mSv and that of nonmetal miners was 1.75 mSv. It was noted that the radon concentration in some metal mines is not optimal in China. It is suggested that the ventilation should be strengthened in some metal mines. Besides, it is still necessary to control occupational radon exposure of non-uranium miners as low as reasonably achievable, and non-uranium mines should be managed by classification.

A Review of Radon Exposure in Non-uranium Mines-Estimation of Potential Radon Exposure in Canadian Mines

ABSTRACT

A worldwide review of radon exposure in non-uranium mines was conducted. Based on the reported radon measurements in a total of 474 underground non-uranium mines, the average radon concentration in underground non-uranium mines was calculated to be 570 Bq m -3 (varied from below detection limit to above 10,000 Bq m -3 ), and the average equilibrium factor between radon and its short-lived progeny was 0.34 (varied from 0.02 to 0.9). Using the average values from the review, annual effective radon doses to workers in Canadian non-uranium mines were estimated. For underground workers, the estimated annual effective radon dose to non-uranium miners was 3.8 mSv with the possibility of varying from 0.22 to 10 mSv depending on ventilation and other operation conditions. In Canada, the majority of mines are open-pit surface mines; only a small portion of the workforce in non-uranium mines physically work underground where radon concentration can be elevated. Averaged over the entire mining workforce, occupational exposure to radon in non-uranium mines is estimated to be 0.9 mSv. The results of this study indicate that there is potential for workers in non-uranium mines to reach or exceed Canadian thresholds for mandatory monitoring and reporting radiation doses, at least for underground operations.

Radon dose assessment in underground mines in Brazil

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)).