Exposure to high background radiation level in the tin mining area of Jos Plateau, Nigeria.
The present work deals with the radioactivity of samples of tin tailings collected from a mining site in Jos, Nigeria. The activity concentrations of the samples were measured using a gamma-ray spectrometer with a hyper-pure germanium detector. In situ dose rates at the site were also measured using a precalibrated survey meter. Potassium-40 was not detected in any of the studied samples. The activity concentrations of (238)U and (232)Th ranged from 17.1 x 10(2) to 16.6 x 10(3) Bq kg(-1) and from 52.9 x 10(2) to 47.5 x 10(3) Bq kg(-1), with mean values of 72.2 x 10(2) and 16.8 x 10(3) Bq kg(-1), respectively. The absorbed dose rates were between 4.0 and 36.3 microGy h(-1), with a mean value of 13.5 microGy h(-1), which is much higher than the world average of 0.06 microGy h(-1) for soil. The calculated effective dose rates varied between 2.8 and 25.4 microSv h(-1), with a mean value of 9.4 microSv h(-1), whereas the effective dose rates obtained for the in situ measurement varied between 6.0 and 28.0 microSv h(-1). The annual gonadal dose equivalent was calculated as 92.4 mSv. This is much higher than the world average dose equivalent rate to individuals from soil (0.30 mSv y(-1)).
Ademola
J A
JA
Department of Physics, University of Ibadan, Ibadan, Nigeria. jaaademola@yahoo.com
D004781:Environmental Exposure; D006801:Humans; D008906:Mining; D009549:Nigeria; D011829:Radiation Dosage; D011834:Radiation Monitoring; D012990:Soil Pollutants, Radioactive / Q000032:analysis*; D013051:Spectrometry, Gamma; D013910:Thorium / Q000032:analysis; D014001:Tin; D014501:Uranium / Q000032:analysis
D012990:Soil Pollutants, Radioactive; D014501:Uranium; D013910:Thorium; D014001:Tin