汕头市环境中氡水平及所致居民剂量的分析

Level of radon and thoron and their population dose in environment of Shantou city

本文报道了汕头市室内外环境中氡土气浓度及其子体潜能浓度。研究结果显示：本市环境天然辐射水平较高，室内外氡浓度分别为２００４、１６０５Ｂｑ／ｍ３，土气浓度分别为４１８５、３１１５Ｂｑ／ｍ３，氡子体分别为０００２５４、０００２６８ＷＬ，土气子体分别为０００３３１、０００２４５ＷＬ。汕头市居民吸入氡土气及其子体所致的年有效剂量当量为１２６ｍＳｖ，其中２２２Ｒｎ及其子体贡献了０９０３ｍＳｖ，即氡及其子体所贡献的年有效剂量当量占７５％。

The indoors and outdoors concentrations of radon, thoron and their daughters in Shantou were studied. The results showed that the natural radiation level appeared to be rather high in this area. The indoors and outdoors concentrations of radon were 20.04 Bq/m 3 and 16.05 Bq/m 3 respectively; and that of thoron were 41.85 Bq/m 3 and 31.15 Bq/m 3 respectively; the level of radon daughters were 0.00254 WL and 0.00268 WL respectively; and that of thoron daughters were 0.00331 WL and 0.00245 WL respectively. The average annual effective dose equivalents arising from inhalation of 222 Rn, and their decay products in Shantou were estimated to be 1.26 mSv, in which 75% arising from 222 Rn and its decay product. This result appeared to be higher than that in the neighboring control area (as 0.97 mSv).