title: Population dose distribution due to soil radioactivity concentration levels in 18 cities across Nigeria.
abstract: The natural radioactivity concentrations in soil samples collected from 186 locations across 18 cities in the six geo-political zones of Nigeria have been determined using gamma-ray spectrometry. Results show that the concentrations of (40)K, (238)U and (232)Th in the soil samples varied from below detection limits (BDL) to 1459.4 Bq kg(-1) with a mean of 73.3 +/- 18.5 Bq kg(-1) for (40)K, whereas for (238)U and (232)Th values varied from 9.2 to 113.7 Bq kg(-1) with a mean of 33.9 +/- 7.4 Bq kg(-1) and from BDL to 175.7 Bq kg(-1) with a mean of 12.4 +/- 3.1 Bq kg(-1), respectively. The average gamma absorbed dose rate in air across the cities ranged between 19 +/- 5 and 88 +/- 44 nGy h(-1) and the gross mean was 42.0 +/- 21.0 nGy h(-1). Using available population data in the study areas, about 2.84% of the population is exposed to a radiation dose rate of less than 20 nGy h(-1), 52.40% to a radiation dose rate between 20 and 30 nGy h(-1), 31% to a radiation dose rate between 30 and 60 nGy h(-1) and about 13.76% to dose rates greater than 60 nGy h(-1).
authors.affiliation: Department of Physics, University of Ibadan, Nigeria. rachelobed@yahoo.com
authors.forename: R I
authors.initials: RI
authors.lastname: Obed
authors.forename: I P
authors.initials: IP
authors.lastname: Farai
authors.forename: N N
authors.initials: NN
authors.lastname: Jibiri
mesh_terms: D006801:Humans; D009549:Nigeria; D011829:Radiation Dosage; D018570:Risk Assessment; D012990:Soil Pollutants, Radioactive / Q000032:analysis*; D013051:Spectrometry, Gamma
chemical_list: D012990:Soil Pollutants, Radioactive