Cancer Risk due to Radionuclides Concentration in Tin Ores and Sediments at Barkin-Ladi, Plateau State, North Central, Nigeria

Abstract

The specific activity concentrations of natural radionuclides 40K, 226Ra and 232Th in soil samples of abandoned tin ore and sediment from tin mining areas in Barkin-ladi were measured by gamma-ray spectrometry system using Sodium Iodide [NaI(Tl)] detector. Radiological hazard assessments due to these natural radionuclides were carried out. The aim was to assess the associated lifetime cancer risk owing to inhalation of the short life Radon gas from the tin ore and sediments by the inhabitants of this area after 70 years of exposure. The calculated activity concentrations of 40K, 226Ra and 232Th in the collected ore samples were 275.44 ± 46.14, 239.95 ± 30.82 and 778.78 ± 29.30 Bqkg-1 respectively while those of the sediment samples were 1608.25 ± 55.60, 759.62 ± 47.95 and 4861.82 ±48.78 Bqkg-1 respectively. However, the mean absorbed dose rate in ores (629.86 nGyh-1) and in sediments (3612.05 nGyh-1), the mean radium equivalent in ores (1374Bqkg-1) and in sediments (7835.88 Bqkg-1) and the mean annual effective dose rate in ores (0.77mSvy-1) and in sediments (4.43mSvy-1) were all found to be higher than the recommended global average values of 59nGy-1, 370Bgkg-1 and 0.07mSvy-1 correspondingly. The excess lifetime cancer risk (ELCR) value obtained in this study for the ores samples ranges from 0.0026 to 0.0473 with an average of 0.0107 while the ELCR value in sediments samples was found to range from 0.3205 to 0.0036 with an average of 0.0620. Although the study reveals an average excess lifetime cancer risk value to be more in the sediment samples compare to ore samples, the excess lifetime cancer value within all the sample locations were above the world average value of 0.00029. Therefore, the present study reveals a lifetime cancer risk to the general public within this study area thus precaution need to be taken by ensuring inhabitants live in well ventilated houses since no level of radioactivity is harmless.