Natural Environmental Gamma Radiation Dose Rate in Qingdao Area

Aims: The aim of our study is to reveal the natural gamma radiation dose rate in Qingdao area. Methods: The extensive large-scale environmental survey was conducted in Qingdao area in 2003. It is the first-time investigation integrating population survey and geological environment survey in China. The sampling grid was designed in 0.1 kmtimes0.1 km. For the first time the sampling area covers the whole city. Important findings: the average value of gamma radiation dose rate in environment is 91.6 nGyh^-1. Neither human-induced radiation source nor significant natural radiation background was found. The spatial pattern of gamma radiation dose rate in Qingdao area was given. The relationship of gamma radiation dose rate and geological environment was also discussed. The natural gamma radiation in Qingdao area falls within the normal scope of natural background gamma radiation level although it is a little higher than the average value of the whole country for its special geological structure. The study can provide reference for the radiation level assessment of city environment as well as the city construction plan.