41. 吸入氡气（及其衰变产品）的年人均剂量一般为公众从所有天然电离辐射源获得的有效剂量的大约一半。对某些职业而言，氡气是职业辐射照射的主要来源。在核燃料循环中，铀矿残渣释放的氡大大增加了这一过程所产生的有效剂量。
41. The annual per capita dose from inhalation of radon gas (and its decay products) represents typically about half of the effective dose received by members of the public from all natural sources of ionizing radiation. For certain occupations, radon gas is the predominant source of occupational radiation exposure. In the nuclear fuel cycle, the release of radon from uranium mine tailings makes a substantial contribution to the effective dose from this practice.