TECHNOLOGICALLY ENHANCED NATURALLY OCCURRING RADIOACTIVE MATERIALS AND RADIATION PROTECTION CASE STUDIES

摘要

The building industry uses large amounts of waste products: in some cases, new construction materials with naturally or technologically enhanced levels of radioactivity (e.g. phosphogypsum, coal fly ash, oil shale ash, some rare minerals, etc.) are used. Most building materials contain naturally occurring radioactive elements, (K-40, Ra-226, and other ones). The presence of these radioisotopes can also cause exposure to Rn-222, Rn-220 and daughters. Increased interest in measuring radionuclides and radon concentration in building materials and indoors is due to health hazards due to this exposure in persons. Most individuals spend 80% of their time indoors and natural radioactivity in building materials is a source of indoor radiation exposure. Indoors-elevated dose rates may arise from high activities of radionuclides in building materials. In view of this, there is a need to develop and introduce in both international and national levels environmentally safe and economically reasonable standard regulations, which should be based on justified radiological, social and economical legislation concepts. Case studies on this problem, carried out in Greece and Italy, are reported to complete the discussion.