青岛市区土壤天然放射性核素的外照射水平估算研究

Natural terrestrial external exposure level of nuclides in soils in Qingdao area

城市的辐射环境质量对于人居和发展规划有重要意义。利用伽玛能谱仪对青岛市区内的天然放射性核素进行了大规模高密度的现场测量,采用Beck公式计算了离地面1m高处的空气吸收剂量率,进而计算了外照射年有效剂量、外照射指数和等效镭浓度,对研究区的外照射水平进行了系统的评价。与和其他国家全国比较,虽然该区的空气吸收剂量率较高,但是其他衡量天然放射性核素外照射水平的指标均在容许范围之内。因此该区属于外照射水平的安全区域,人居环境不受影响。

The radiogeological environment of the city is very important to dwelling and development plan. The radioactivity concentrations of natural nuclides in Qingdao area were extensively measured using Gamma spectrometry. The dose rate above lm ground was calculated according to Beck Formula. Effective annual dose rate, external hazard index and radium equivalent activity were also obtained. So the exposure level were systematically evaluated. Compared with other countries （regions）, although the absorbed dose rate in the study area is a little high, the other indices for natural terrestrial γ exposure level are lower than the recommended value. So Qingdao is safe in radiological level and the dwelling environment is not affected.