切尔诺贝利核电站事故后苏州市环境介质中^(134,137)Cs含量变化和剂量评价

Coneentration Variation of ^(134.137)Cs in Environmental Media and Dose Evaluation in Suzhou City After Chernobyl Nuclear Accident

切尔诺贝利核电站事故后,苏州市1986年5月14日～20日期间环境介质中^(134,137)Cs含量达最大值。3个月后逐渐降低并趋于本底水平。峰值期间由空气浸没外照射、空气吸入和叶类蔬菜摄入内照射所致居民个体(成人)有效剂量当量是1.6×10^(-7)Sv,该值为事故后第1年2.9×10^(-7)Sv/a的55%,接近正常年份值1.5×10^(-7)Sv/a,其中食入途径约占90%,吸入途径约占8.6%,外照射途径很小。

The time response for the concentration variation of ^(134,137)Cs in the environmental media and dose evaluation in Suzhoh city after Chernobyl nuclear accident is presented. The results showed in the 14～20th of May 1986 the radioactivity concentration of ^(134,137)Cs in the environmental media reachod to maximum and gradually returnod to background 3 months later. The individual effective dose equivalent for adults in that period due to external exposure of air immersion and internal exposure of inhalation and vegetable intake is 1.6×10^(-8)Sv,this value is about 55% of annual dose equivalent (2.9×10^(-7)Sv/a) of the first year after chernobyl accident, and approximately equals to normal year value(1.5×10^(-7)Sv/a). The 90% of which was through ingestion pathway, 8.6% was through inhalation pathway and external exposure was very small.