Annual effective dose due to natural radionuclides in building blocks in eight cities of Southwestern Nigeria.
The specific absorbed dose rates due to (226)Ra, (232)Th and (40)K in building blocks have been determined for a model dwelling dimension of 3.6 x 3.6 x 3.0 m(3), wall thickness 10 cm and density of 1.73 x 10(3) kg m(-3) in eight cities across Southwestern Nigeria. The Mustonen method of calculating gamma-ray annual exposure rate from the radioactivity concentrations (Bq kg(-1)) of (226)Ra, (232)Th and (40)K in the blocks have been adopted with modifications to suit the Nigerian situation. The specific absorbed dose rates obtained were as follows: 11.36, 14.94 and 0.92 microGy y(-1) per Bq kg(-1) for (226)Ra, (232)Th and (40)K, respectively. These dose rates were used to calculate the annual effective dose in the model dwelling. The annual effective dose obtained varied between 209.20 (Osogbo) and 400.36 microSv y(-1) (Abeokuta). The values are in the range of values obtained for the German Democratic Republic (309 microSv y(-1)) and Jordan (470 microSv y(-1)).
Ademola
J A
JA
Department of Physics, University of Ibadan, Ibadan, Nigeria. adejanet@yahoo.com
Farai
I P
IP
D016902:Air Pollution, Indoor / Q000032:analysis*; D001417:Background Radiation; D001822:Body Burden; D003198:Computer Simulation; D003252:Construction Materials / Q000032:analysis*; D006801:Humans; D008422:Materials Testing / Q000379:methods; D008954:Models, Biological; D009549:Nigeria; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000379:methods*; D011835:Radiation Protection / Q000379:methods; D011868:Radioisotopes / Q000032:analysis*; D012062:Relative Biological Effectiveness; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors
D011868:Radioisotopes