Baseline radioactivity and associated radiological hazards in soils around a proposed nuclear power plant facility, South-South Nigeria

Abstract

Increased concerns about human population exposure to increased ionizing radiations emanating from anthropogenic sources of radiation, as well as the associated environmental risk, have necessitated radioactivity baseline studies in many regions. This work based on standard procedures designed suite nuclear power plant (NPP) radiological monitoring plan was conducted to assess the radiological baseline of Itu, Nigeria (5ο10′0 N, 7°59′0 E). A total of 44 soil samples were collected and analyzed using High Purity Germanium detector. The average activity concentration values for soil samples were 47.98 ± 8 Bqkg−1226 for Ra, 15.15 ± 1 Bqkg−1 for 238U, 38.65 ± 6 Bqkg−1 for 232Th, and 41.55 ± 6 Bqkg−1for 4 K. These mean values were lower than the UN Scientific Committee on the effects of atomic radiation's world mean values of 33, 45, and 420 Bqkg−1 for 238U/226Ra, 232Th, and 4 K, respectively. The hazard indices calculated using the measured activity concentrations indicated 32.04 nGy/h, 0.042 mSv/yr, and 0.17 mSv/yr for mean GDR, outdoor, and indoor AEDE, respectively. In addition, the average radium equivalent resulting from terrestrial gamma of activity concentration was 113.94 Bqkg−1, with a mean ELCR of 0.15 × 10−3. These baseline data show that there is no substantial radiological concern for human health.