Natural and artificial radioactivity measurements in Eastern Black Sea region of Turkey.

In the present work, naturally occurring radionuclides of (226)Ra, (232)Th and (40)K were measured in soil samples collected from the Eastern Black Sea region of Turkey. It was found that the activity concentrations ranged from 12 to 120Bqkg(-1) for (226)Ra, from 13 to 121Bqkg(-1) for (232)Th and from 204 to 1295Bqkg(-1) for (40)K. Besides naturally occurring radionuclides, (137)Cs activity concentration was measured in soil, lichen and moss samples and it was found that (137)Cs activity concentration ranged from 27 to 775Bqkg(-1) with for soil, from 29 to 879Bqkg(-1) for lichen and from 67 to 1396Bqkg(-1) for moss samples. Annual effective doses due to the naturally occurring radionuclides and (137)Cs were estimated. Ecological half-lives of (137)Cs in lichen and moss species were estimated. The decrease of the activity concentrations in the present measurements (2007) relative to those in 1993 indicated ecological half-lives between 1.36 and 2.96 years for lichen and between 1.35 and 2.85 years for moss species.