通过对成都市土壤中天然放射性核素含量进行分析，得出放射性其外照射指数在0.35～0.7之间，内照射指数在0.17～0.31之间，二者都在国家建筑材料放射性核素限量标准控制式的范围内；
By analyzing the content of natural radioactive nuclides in soil , it could be conclude that the external exposure index in Chengdu is between 0.35 and 0.7 ; the internal radiation is between 0.17 and 0.31 ;
建筑材料放射性核素限量