Natural radionuclides are present in every constituent of the environment. Monitoring of environmental radionuclides is very vital to avoid exposure above the threshold limit. Due to this, the background radiation from 238U, 232Th, and 40K of Bell University of Technology and Canaan Land City was determined from 20 sample points each in the two areas using RS230 Gamma Spectrometer. The mean activity concentration of 40K, 238U, and 232Th for Bells University of Technology was 442.66 Bq/kg, 41.98 Bq/kg, and 48.35 Bq/Kg, respectively. In Canaan City, mean activity concentration of 40K, 238U, and 232Th was 373.65 Bq/kg, 18.85 Bq/kg, and 67.22 Bq/kg, respectively. The mean absorbed dose rates recorded by the spectrometer directly were 70.03 nGy/h and 66.65 nGy/h, while that estimated from the activity concentration were 67.06 and 64.89 nGy/h for Bells University and Canaan City, respectively. The measured and estimated absorbed dose rates were higher than the safe limit of 57 nGy/h. The mean values of other radiological parameters estimated, except that of the gamma index and excess lifetime cancer risk were lower when compared to the recommended limit. It could be concluded that the possibility of suffering any radiation risk is low in these two areas, but there is possibility of cancer risk for someone that has stayed in the area for 70 years and above.

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The background radiation of Maryland School Complex was taken using RS-125 hand-held gamma spectrometer. The average concentration of the measured radionuclides were 19.16, 46.14, 165.00 Bq/kg for 238U, 232Thand 40K, respectively. The average value of measured dose rate and the estimated dose rate were 44.93 and 43.55Bq/kg. The mean values of the estimated radiological parameter were 53.45, 213.78μSv/y for indoor and outdoor annual effective dose. The excess lifetime cancer risk averaged 0.17, the hazard indices were 0.26 and 0.32 for external and internal respectively. The annual gonadal dose and radium equivalent were 303.90 μSv/y and 97.85 Bq/kg, while the gamma representative index was 0.69. The mean concentration of radionuclides measured and the estimated radiological parameter were within the recommended values. This therefore follows that the risk of exposure to ionizing radiation for both the staff and the students of the community is within acceptable limits.

The concentration of NORMs and some toxic heavy metals in some nuts and seeds commonly consumed in the south-western states of Nigeria were investigated. The analysis was done with NaI(TI) spectrometry and Inductively Coupled Plasma (ICP) respectively. The concentration of 226Ra, 232Th, and 40K in the samples was found to be below the world average. The mean values are 6.6±1.8, 3.6±1.0 and 98.2±13.5 Bq/kg, in nuts and 8.4±2.6, 2.6±1.3 and 97.6±15.0 Bq/kg in seeds respectively. The effective dose in nuts was calculated to be 13.99 and 12.0 µSv in seeds. The fatal and hereditary cancer risk estimated from the consumption of the nuts and seeds are lower than 1.0 x 10-6 which is the lowest limit. Concentration of metals in the samples descend as Fe > Zn > Cu > Cr. The Hazard Indices of heavy metals are lower than 1 except for in Cocoa which is higher than 1 due to the high concentration of Cu and Fe. Therefore, the nuts and seeds analyzed in this study are contaminated with Cu and Fe and so must be taken with care so that consumers will not be exposed to excessive concentration of these metals which may have undesirable effects.