Investigation of the Transfer Influence and Health Threat from the Intake of Maize and Exposure to Soil in Different Geological Formations in Akwa Ibom State, Nigeria

Abstract

The consumption of maize contaminated by radionuclides may pose certain health challenges to the body. This research was conducted to investigate the possible danger radionuclides could cause. Soil and maize samples were obtained from different geological formations. They were analyzed using a Sodium Iodide-Thalium (NaI(TI)) detector. The activity concentration results from the soil samples show the highest values of 238U, 232Th and 40K as 14.74±0.26 Bqkg-1, 40.34±0.73 Bqkg-1 and 444.89±8.12 Bqkg-1 respectively which correspond to Ogwashi-Asaba, Ogwashi-Asaba and Imo shale geological formations. The findings from maize samples indicate the maximum values of 238U, 232Th and 40K as 16.46±0.25 Bqkg-1, 18.12±0.46 Bqkg-1 and 435.17±7.89 Bqkg-1 respectively which correspond to Benin, Ogwashi-Asaba and Ogwashi-Asaba geological formations. The outcome of mean transfer factor of 238U, 232Th and 40K corresponds to 0.942, 0.460 and 1.002. The absorbed dose rate ranges from 28.91 nGyh-1 to 36.08 nGyh-1. Radium equivalent varies from 49.40 Bqkg-1 to 98.75 Bqkg-1. Almost equal value (0.15×10-3) was assessed for the mean excess lifetime cancer risk. Although the activity concentration noted from maize is high, the evidence obtained shows that there is no geological formation with health risk problem as the external, internal and radioactivity hazard indices are less than unity.