The status of natural radioactivity in Nigerian environments

Distribution dynamics and descriptive statistical analysis of radionuclides in the farmland soils near mining areas in Southwestern Nigeria

“…The location with high values implies high radiological risk which might occur, though gradually over the entire lifetime of the exposed population. Such risk involves radiation-induced cancer or development of heritable effects at some time in life(ICRP, 2007;Olatunji et al, 2022). Generally, the estimated values of the radiation risks and dose obtained in this study were lower than the permissive values set by international bodies (e.g.…”

“…However, high concentrations of radioactive elements might change the biosphere's natural ecosystem, offering serious risks to those who are exposed. The two main methods of exposure to radionuclides are external exposure from radionuclides in soils and internal exposure from eating plants grown in such farmland soil and/or inadvertent ingestion during cultivation of the farmland soil (UNSCEAR, 2008; Kakati et al, 2013;Kpeglo et al 2011;Özdiş et al, 2017;Olatunji et al, 2022). The safety of lives against potential hazards ensuing from exposure to the radionuclides requires proper understanding of their concentrations, migration within the soil and in uential knowledge of factors responsible for the entire dynamics within the soil (Adebiyi et al, 2021;Geras'kin, 2016).…”

“…Radon gas could also penetrate the bloodstream from the lungs and irradiate the whole human body through an internal gaseous exchange, leading to a permanent source of internal radiation exposure (Ogundele et al, 2021;Ononugbo et al, 2016;Özdiş et al 2017). The translocation and uptake of natural radionuclides in crops obtained from farmlands are dependent on the farmland-soil composition; arising from agricultural practices (such as deposition of mineral resources like fertilizers in the subsurface layers of soil), atmosphere deposition, plant soil characteristics, and other environmental contamination (Olatunji et al, 2022;Gbenu et al, 2016). Accidental or incidental exposure to ionizing radiations over a short period (acute exposure) or a long period (chronic exposure) can result in skin burns, cell damage, cancer, cardiovascular disease, and even death.…”

“…The concentration-to-dose conversion factors of 0.042, 0.462 and 0.604 are used for Ra eq = A Ra + 1.43A T h + 0.077A K A Ra , A T h , andA K 226 Ra and 232 Th, respectively. The United Nations Scienti c Committee on Effect of Atomic Radiation (UNSCEAR, 2000) report speci ed 0.2 as the outdoor occupancy factor (OF) and 0.70 Sv Gy − 1 as the dose convention factor (DCF) for external irradiation (which converts the external outdoor absorbed dose rate to outdoor effective dose rate)(Olatunji et al, 2022). In this regard, the outdoor annual effective dose equivalent (AEDE) was calculated using Eq.…”

“…These minerals release potassium ions during weathering, which are then transported to soil uids and adsorbed on clay cation-exchange sites (Nenadovi et al 2012). Apart from the geological composition of the soil, the high activity concentrations of40 K can also be imputed to large scale utilization of predominantly potassium-bearing fertilizers in agricultural activities(Olatunji et al, 2022).For the deep layer zone (0.5 m), the trend of the average (± SD) of the activity concentrations in the Itagunmodi, Sagamu, Olode, Igbokoda and Epe are 40 K > 232 Th > 226 Ra,40 K > 232 Th > 226 Ra,40 K > 232 Th > 226 Ra,40 K > 232 Th > 226 Ra and 232 Th > 40 K > 226 Ra, respectively. As shown, the lower concentration is observed at Epe in Lagos which is far from mining area and therefore serves as a control.…”