n.放射性元素
Experts noted that the current urban living environment is the main source of radioactive hazards of indoor radon and radioelement content standard building materials. 專家指出,目前城市生活環(huán)境中主要放射性危害的來源有室內(nèi)氡氣及放射性元素含量超標(biāo)的建筑材料等。