Assessment of gamma dose rates around Istanbul (Turkey)

Natural radionuclide activity concentrations in surface soils of Istanbul h ave been measured using gamma spectroscopy, The activity concentrations of the radionuclides in soils are directly relevant to outdoor exposure. The n atural gamma radioactivity of the terrestrial radionuclides in soil samples and the gamma-absorbed dose rates of these radionuclides in air were calcu lated throughout different areas of Istanbul. The average activity concentr ations of U-238, Th-232 and K-40 were found to be 21, 37 and 342 Bq kg(-1), respectively. The average outdoor gamma dose rate in air at 1 m above grou nd was determined as 65 nGy h(-1). Using the data obtained in this study th e average annual effective dose equivalent for a person living in Istanbul was found to be about 80 mu Sv. (C) 1999 Elsevier Science Ltd. All rights r eserved.