Abstract: A large number of long-lived α radioactive nuclides exist in uranium dust. Their contribution to uranium mine worker dose can not be ignored. The monitoring data of diameter and concentration of uranium dust particles after filtering with two commonly used masks were studied using the respiratory exposure risk evaluation model of uranium dust particles. The respiratory exposure dose and risk index were calculated for workers in a southern uranium mine. The results showed that: 1) Blind drift, stope and the main ventilation mashine room were the main places with more respiratory exposure dose than other places in uranium mine. 2) The respiratory exposure dose after using gauze mask and KN95 mask were 0.14-2.01 mSv/a and 0.03-0.53 mSv/a,respectively. The respiratory exposure dose and risk index for workers wearing KN95 masks was significantly lower than those wearing gauze mask. 3) When uranium grade was between 0.01% to 1% and uranium dust mass concentration was between 0.01 to 0.2 mg/m³,the workers’ respiratory exposure dose and risk index caused by the uranium ore dust particles were both increased with the increase of mass concentration of uranium dust.

Key words: uranium dust, respiratory exposure dose, risk assessment, mask, uranium mine