Environmental radiation measurements and remedial actions (Hantepe/Ezine/Canakkale)

There are some regions in the world that are known as high background radiation areas. Intensive scientific investigations in the field of radiation dose and health effects, risk estimates, radiation protection, environmental transportation routes and ecological effects related with natural radiation have been carried out in these regions. Also natural radiation dosimetry, in vitro and in vivo biological studies which take into account the measurements in the field of low level radiation, radon, thoron and cosmic rays have been carried out, again in these regions. The well-known high natural background radiation areas in the world are Guarapari in Brazil, Ramsar in Iran, Kerala in India and Yangjiang in China. In addition to above mentioned areas, other relatively lower high background radiation areas are exist. Since 1960s, radiological, geological, epidemiological and ecological studies have been carried out in order to determine the risks and possible health effects of long-term low level natural radiation exposure. In the framework of surveying the background radiation of Turkey, the background radiation measurements were carried out in 56 different points around the area of Canakkale city. The radiation levels at Hantepe beach of Geyikli which is located in Ezine town of Canakkale was found higher than the mean background radiation level of the region. The radiation dose rates were measured in between 0.20 and 10.88 Gy h-1 in contact and 0.27 and 3.11 Gy h-1 above 1 meter of the ground level where the thorium-containing sand is dense. After the rehabilitation studies, the radiation dose rate were measured in between 0.15 and 8.09 Gy h-1 in contact and 0.17 and 2.88 Gy h-1 above 1 meter of the ground level. It was observed that the radiation dose rates were decreased seriously after the rehabilitation studies when the arithmetic mean value of the dose rates was taken into account. The effective dose calculations were performed by taking into account the arithmetic mean value of whole measurements. The annual effective doses are 1.223 mSv and 0.953 mSv before and after the rehabilitation, respectively. (Includes 19 tables, 19 figures, 16 pictures)