Natural Radioactivity and Radiological Impact Assessment of Soil, Food and Water around Iron and Steel Smelting Area in Fashina Village, Ile-Ife, Osun State, Nigeria

Abstract

This study assessed the natural radioactivity and radiological health impact of thirty-eight (38) samples of soil, food and water in Fashina village, Ile-Ife, Osun State, Nigeria using portable survey meter with a Global Positioning System (GPS) and well-calibrated NaI(Tl) detector system The mean exposure rates in the study area were 0.14 μSv hr^-1 and 0.12 μSv hr^-1 in soil/food and water samples respectively. The mean radioactivity content obtained for ²³⁸U, ²³²Th and 40K were 12.14 ± 4.17Bq kg^-1, 23.23 ± 7.67 Bq kg^-1 and 270.14 ± 61.79Bq kg^-1 respectively in soil samples and 8.56 ± 2.80Bq kg^-1, 13.17 ± 4.48Bq kg^-1 and 89.41 ± 24.15Bq L^-1 respectively for ²³⁸U, ²³²Th and 40K in water samples. The mean values of 30.91, 15.64 and 12.47 nGy h^-1 were obtained for the absorbed dose rate in soil, food and water, respectively, while 37.90,  178.79 and 1085.23 μSv y^-1 were obtained for the Annual Effective Doses (AED). Similarly, the Radium equivalent (Raeq) were 66.16 Bq kg^-1, 34.28Bq kg^-1 and 27.31BqL^-1, in soil, food and water, respectively. The external and internal radiation hazard indices were 0.18 and 0.21, 0.09 and 0.12, 0.07 and 0.09, respectively for soil, food and water. The values obtained for the Excess Lifetime Cancer Risk (ELCR) in (x 10^-3) were also 0.13, 0.63 and 3.80 for the soil, food and water samples, respectively. It was found that the values of some exposure rate, radioactivity contents and radiological impact parameters in the study area which were higher than those of the control area and the world average values poses a serious health risk to the environment and its inhabitants.

Keywords: Radioactivity, Scrap Metal, Gamma Spectrometry, Radiological Impact Parameter