Radiological hazards assessment of laterite miningfield in Ilorin, North-central Nigeria

Background: assessment of activity concentrations of 238u, 232th, 40k andgamma dose rate (dr) was carried out over a laterite mining field in ilorinsouth,nigeria. materials and methods: a well calibrated super-spec (rs-125)gamma spectrometer was used to measure the activity concentrations of 40k,238u, 232th and gamma doses rate at 1 m above the ground level over thelaterite mining field. fifty (50) measurements of the activity concentration ofthe radionuclides were obtained at about 1 meter above the topsoil. for eachpoint, measurements were taken four (4) times for better accuracy. results:the overall mean of the activity concentrations of 40k, 238u and 232th are81.38, 43.89 and 38.79 bqkg-1 respectively. the mean value for dr was foundto be 46.44 ngyhr-1. the mean activity concentrations of 238u and 232th arehigher than the recommended limits provided by unscear. this is a cause forworry as significant enhancement in the concentration of 238u and 232th willincrease the level of the background radiation and possibly render the soilunfit for use in building and construction. the results of most of theradiological impact parameters (rip) are above the limits provided byunscear. conclusion: from the results, it implies that the risk of indoorgamma radiation exposure is high for this lateritic soil. so the lateritic soilfrom this mine field may not be too suitable for building and constructionpurposes.