成都居民膳食中天然放射性核素水平及所致内照射剂量的研究

Study on the intaking level of natural radionuclide and internal irradiation dose in urban and rural resident dietary of Chengdu city/

为了解成都市城乡居民膳食中天然放射性核素摄入水平以及所致内照射剂量，应用总膳食研究方法，测定了１２ 种混合食物试样中天然放射性核素铀、钍、镭、钾含量。结果：４ 种放射性核素的比活度大小依次为４０ Ｋ＞ ２２６ Ｒａ ＞ ２３８ Ｕ＞ ２３２ Ｔｈ 。贡献率城乡均以４０ Ｋ 最大。所致的全身剂量当量城乡分别为每年１１７ ．２ μ Ｓｖ 和１７３ ．２ μ Ｓｖ ，平均为１４５ ．２ μ Ｓｖ ，高于我省人均内照射剂量当量１０８ ．６ μ Ｓｖ ，但仍属于天然辐射水平。

The content of natural radionuclide, which include uranium( 238 U),thorium( 232 Th), radium( 226 Ra)and potassium ( 40 K) were determined by means of total diet study in urban and rural resident dietary of Chengdu city. The results showed that specific activity of natural radionuclide were as follow: 40 K> 226 R> 238 U> 232 Th. Accumulated dose equivalent per year of urban and rural was respectively 117.2 μSv and 173.2 μSv, which were higher than the revel of Sichuan province(108.6 μSv) but just in the range of natural radionuclide. Author's address Hou Weidao, Health and Anti-epidemic Station of Chengdu city, 610021 PRC.