Assessment of radiological health hazard in building materials in Ijebu North LGA, Ogun State Nigeria

Abstract

The gamma ray spectrometry carried out using Sodium lodide (doped with Thallium (Nal(Tl)) detector on building sample materials of two (2) different samplesof cement blocks (9inches and 6inches blocks), from four blocks making industry under Ijebu North Local Government were collected for analysis with samples of sharp sand, soft sand, stony sand (gravel), two different brands of cement , floor tiles and wall tiles were analyzed for the radioactivity counts of Thorium (Th-232), Uranium( U-238),and Potassium K-40. The results obtained from these samples after gamma ray spectrometry showed that the radium equivalents calculated from Specific Activities of the samples are all very low at the range of 24.58Bq/Kg to108.38Bq/Kg and the mean radium equivalent is 63.17Bq/Kg which is very low compared to370Bq/Kg as the upper safety limit recommended by World Health Organization (WHO) and International Atomic Energy Agency (IAEA). All the safety hazard indices such as Alpha index, Gamma index, External hazard index and Internal hazard index are all very well below unity which is the recommended maximum limits. Hence all the building materials in the study area are safe for use