Qingdao Urban Radiation Environmental Quality Evaluation Studies

Human being lives depend on safe environment. The natural radioactivity environment is one important part of human living surroundings. The natural radioactivity lies in all the matters surrounding human beings such as air, water and soil.The impact of radioactivity material on environment is the most dangerous although it is usually ignored. For living and health, man need to know the pollution not only from heavy metal and organic materials, but also from radioactivity.There is close relationship between the radioactivity and the area's geology in environment. In Qingdao area, because of the impact of the active magma during Yanshan period, invasive rock body was cosmically formed. Most of mother rocks are granites containing uranium and thorium. In this dissertation we chose Qingdao as radioactivity research area, where the relationship is typical between the granite and the radiation intensity in interest area.On basis of extensive measurement of surface rocks,γtotal dose in soil, radioactivity concentration of nuclide ²³⁸U,²³²Th,40K, we analyze their radioactivity feature and distribution, as well as the geological environment in the area. We analyzed the resource of Rn in environment, as well as the transportation mechanics of Rn. The transportation model of Rn was introduced. Hazard of Rn in environment was stressed. The relationship between distribution of Rn and geological environment was analyzed. Based on outer and inner radiation, many factors were integrated to systematically assess the radiation environment in Qingdao for the first time. These factors involve the specility content of ²³⁸U (²²⁶Ra),²³²Th,40 K in soil, the terrene gamma radiation absorbed air dose, annual effective dose, external irradiation index, inner irradiation index and equal radium index. The result can provide references for Olympic games and long-term development of Qingdao.The results show that the content of ²³⁸U is under the average of the country and the world. The concentration of ²³²Th is 1.1 times of the nation and 1.5 times of the world. And the concentration of 40K is 2.43 times of the nation and 2.44 times of the world. The absorbed air dose estimated from the gamma spectrometer is close to the...