Environmental Natural Radioactivity

The most important primordial K-40, U- 238 and Th-232 radionuclides in terms of radiological risk for humans are K, U, Th and their decay products. Rb and U are second-rate primordial radionuclides, to be neglected by their contribution to the human dose. Generally speaking, the concentrations of natural radionuclide activity observed in soils re¿ect the natural background concentrations of the rocks from which they are derived. On the other hand, human activities such as mining activities including surface and subsurface methods cause the enrichment of natural radioactivity concentrations, giving rise to our knowledge about radiation risk and dangers of radiation to the workers. The studying of environmental radiation levels in the Arabian-Nubian Shield, where very much felsic igneous rocks occur, the main source of the natural radioactivity triggered little investigations back to about 30 years before. In the present book which include five chapters.