酒泉地区空气和环境水中的氚及其对居民所致剂量

TRITIUM IN AIR AND ENVIRONMENTAL WATER IN JIUQUAN DISTRICT AND ITS DOSE TO POPULATION

从1987年至1989年底,首次对酒泉地区空气和环境水中的氚(T,下同)含量进行了系统监测。结果表明:地表水中T的平均浓度为4.6-9.6Bq/l,比美、苏热核试验前环境水中T高几个量级;空气中T浓度约为降水及河水中T的2倍,而且波动较大,夏季值较高。摄入该地区水后由T造成的集体剂量当量为0.25人·Sv·a^(-1);待积有效剂量当量为0.19μSv·a^(-1),仅为ICRP 1977年规定的公众年剂量限值的五千分之一和UNSCEAR 1982年估算的正常本底地区天然辐射所致剂量的万分之一。

From July 1987 to Novermber 1989, the monitoring of the tritium in air and environmental water in Jiuquan District was made for the first time. The results show that the average tritium concentrations of surface water in this region remained 4.6—9.6 Bq/1 in recent years. However, these values are still an order of magnitude higher than those before thermonuclear tests era in 1952. The tritium concentration in air was approximately twice as much as that of surface water. HTO values in air exhibit a higher peak in summer. The total tritium ingested by residents of Jiuquan was 1.12×10~4 Bq. The collective dose equivalent was equal to 0.25 man·Sv per year. Because of taking environmental tritium in the area, the annual committed effective dose equivalent was 0.19 μSv which is only one five thousandth of annual limited dose to the public proposed by ICRP and one ten thousandth of the natural background estimated by UNSCEAR in 1982.