沈阳地区环境放射性水平及切尔诺贝利核电站事故影响

Investigation on Environmental Radioactivity in Shenyang Area.

本文报道1981—1987年沈阳地区环境介质中总β、^(90)Sr、^(137)Cs、^(131)I、U、Th、^(226)Ra、^(40)K的放射性水平。1986年4月26日切尔诺贝利核电站事故后,于5月13日放射性沉降物中有大量的总β和^(131)I,其值分别为131.0Bq/m^2·d和281.2Bq/m^2·d。牛奶和蔬菜中^(131)I最高值分别为5.1Bq/L和48.1Bq/kg.这就说明,环境已被污染诺贝利核电站事故放射性沉降物所污染。估算了沈阳居民甲状腺的剂量,成人甲状腺有效剂量当量小于2μSv,婴儿小于11pSv,均低于国家放射卫生防护标准的剂量限值。

This paper deals with the radioactive levels of gross β, 90Sr, 137Cs, 131I,U,Th,226Ra,40K in some environ-mental media in Shenyang area during 1981-1987. After Chernobyl accident on April 26, 1986, large amounts of gross β and 131I were found in radioactive fallout on May 13 of that year, their values were 131 Bq/m2.d and 281.2 Bq/m2.d respectively. The highest value of 131I in milk was 5.1 Bq/L and that in spinach 48,1 Bq/ kg. So It is shown that the environment was affected by Chernobyl accident. However, the residents' thyroid doses in the area were estimated, and the effective dose equivalents for adults were less than 2 μSv, and for infants less than 11 μSv not beyond the dose limits, according to 'Basic Sanitary Standard for Radioactive Protection'.