Measurement of radon concentration and dose assessment of miners for non-uranium mines in Shandong Province / 中华放射医学与防护杂志

ABSTRACT

Objective To measure 222Rn and 220Rn concentrations in the underground non-uranium mines in Shandong Province,and to estimate the annual effective dose to the miners.Methods Concentrations of 222Rn and 220Rn in selected gold,iron,coal and clay mines were determined by passive time-integrating detectors with CR-39.Activity concentrations of 226Ra,232Th and 40K were determined using gamma spectrometry equipped with HPGe detector.Results The average concentrations of 220Rn in the gold,iron,coal and clay mines were estimated to be 1200,280,120 and 40 Bq/m3,respectively.The activity concentrations of 226Ra,232Th,40K in the ores for gold,iron,coal and clay mines ranged the same as the soil in China.The annual effective dose due to radon exposure in gold and iron mine was 7.70 mSv and 1.74 mSv,respectively.The annual doses received by miners in the coal and clay mines were lower than 1 mSv.Conclusions Underground miners in some gold and iron mines should be treated as workers occupationally exposed to ionizing radiation.The measurement such as increasing ventilation should be implemented to reduce underground radon concentration in these mines.