Radionuclide content of concrete building blocks and radiation dose rates in some dwellings in Ibadan, Nigeria.
Thirty-two samples of concrete building blocks were collected from different block making industries in Ibadan. The radioactivity concentrations of the natural radionuclides in the samples were determined by gamma-ray spectrometry with a NaI(Tl) detector. The radioactivity concentrations varied from 6.2 to 57.5 Bq kg(-1), 12.4 to 64.9 Bq kg(-1) and 95.3 to 766.1 Bq kg(-1) for 226Ra, 232Th and 40K, respectively. The radium equivalent activities of the 32 samples varied from 51.3 to 175.7 Bq kg(-1). Radiation exposure levels in 30 dwellings were determined using LiF thermoluminescent dosimeters. The annual equivalent dose rates varied from 0.318 to 0.657 mSv y(-1) with a mean of 0.433 mSv y(-1). The annual effective dose rate to the whole body was calculated as 0.236 mSv y(-1), which is less than that (mean) estimated by UNSCEAR for normal background areas.
Ademola
J A
JA
Department of Physics, University of Ibadan, Nigeria. adejanet@yahoo.com
Oguneletu
P O
PO
D001417:Background Radiation; D003252:Construction Materials / Q000032:analysis*; D004781:Environmental Exposure / Q000032:analysis; D006798:Housing; D006801:Humans; D009549:Nigeria; D011197:Potassium Radioisotopes / Q000032:analysis*; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000379:methods; D011883:Radium / Q000032:analysis*; D017687:Radon Daughters / Q000032:analysis; D013051:Spectrometry, Gamma; D013819:Thermoluminescent Dosimetry; D013910:Thorium / Q000032:analysis*; D013997:Time Factors; D014505:Urban Population
D011197:Potassium Radioisotopes; D017687:Radon Daughters; D013910:Thorium; D011883:Radium