Assessment of Radiation Hazard Indices Due to Natural Radionuclides in Soil Samples from Imo State University, Owerri, Nigeria.

A total of 30 soil samples from different sampling points at Imo State University (IMSU), Owerri, Nigeria were collected for the study. The activity concentrations of naturally occurring radionuclides (238U, 232Th, and 40K) were measured in the samples by gamma-ray spectrometry using NaI (TI) detector. Absorbed dose rate (D), annual effective dose (AED), radium equivalent activity (Raeq), and radiological hazard index parameters (activity utilization index [AUI], external hazard index [Hex], internal hazard index [Hin], and excess lifetime cancer risk [ELCR]) due to the naturally occurring radionuclides were determined. The mean activity of 238U, 232Th, and 40K were found to be 20.32 ± 3.22, 22.55 ± 0.68, and 91.63 ± 1.54 Bqkg-1 which were lower than the world average reference mean values of 33, 45, and 420 Bqkg-1for 238U, 232Th, and 40K, respectively, as reported by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The average value of D, Raeq, AUI, ELCR, Hex, and Hin in the soil samples was 26.86 ± 1.97 nGyh-1, 59.62 ± 4.14 Bqkg-1, 0.42 ± 0.03, 0.14 ± 0.01 (×10-3), 0.16 ± 0.01, and 0.22 ± 0.02, respectively. The annual effective dose to the general public was 33.07 ± 2.40 µSvy-1. This value lies well below the average worldwide reference value of 0.7 mSvy-1, as reported by UNSCEAR. Soil samples from IMSU pose no significant radiological health hazards to the university community.

Radionuclide contents in sediment and seafood from Makoko Lagoon, Lagos State, Nigeria.

Sediment and seafood samples were collected from Makoko Lagoon, Lagos state, Nigeria. Gamma-ray spectrometry was used to determine the activity concentrations of 40K, 226Ra and 232Th in the samples. The average activity concentrations of 40K, 226Ra and 232Th in the sediment were 41.04 ± 6.41, 10.15 ± 3.19 and 4.39 ± 2.10 Bq kg-1, respectively, while the annual effective dose was 0.01 mSv/year. In seafood, the average activity concentrations of 40K, 226Ra and 232Th were 15.66 ± 8.07, 1.72 ± 1.51 and 1.93 ± 0.30 Bq kg-1, respectively. The cumulative effective ingestion dose obtained ranged from 0.016 µSv/year (giant prawn) to 1.08 µSv/year (Parrotgrunt). The mean activity concentrations and absorbed dose rate in sediment were below the worldwide average values. The cumulative dose from the ingestion of seafood was also significantly low. Sediment and seafood from the lagoon in Makoko pose no health risk from a radiological point of view to the population.

Radiological Dose Assessment due to the Presence of Norms in the Top Soil of the Imo State Polytechnic, Imo State Nigeria.

A study on the radiological dose assessment due to the presence of natural radionuclides in the top soil of Imo state Polytechnic was carried out using a gamma spectroscopic method. From the activity concentrations of natural radionuclides in the topsoil, the absorbed dose rate and annual effects of doses were established. The activity concentrations ranged from 59.20 to 203.78 Bqkg-1, 8.74 to 45.78 Bqkg-1, and 12.73 to 44.01 Bqkg-1 for the radionuclides 40K, 226Ra, and 232Th respectively. The absorbed dose rates ranged from 16.70 to 52.10 nGyh-1 while the indoor and outdoor annual effective doses ranged from 20.48 to 63.89 µSvy-1 and 81.94 to 255.58 µSvy-1 respectively. From the results, it shows that the radiation from natural radionuclides in the top soil posed no radiological threat to the population of the institution.

Radioprotective potential of Costus afer against the radiation-induced hematological and histopathological damage in mice.

PURPOSE: This study investigated the possible radioprotective effect of Costus afer extract (CAE) on hematological and histopathological parameters of mice. MATERIALS AND METHODS: Fifty-four male mice with mass between 37-43 g, 11-13 weeks old were used for this study. We divided the mice into six different groups containing nine animals, which were then further sub-divided into irradiated groups and un-irradiated groups. Animals received 250 mg/kg body weight extract of CAE by oral gavage for 6 days in addition to feeding and water ad libitum. Animals in the irradiated group were exposed to radiation at the Department of Radiotherapy and Oncology, Grey's Hospital using a linear accelerator. Blood samples were collected at 48-hour post-irradiation for the hematology test followed by histopathology examination of kidney and liver. RESULTS: Our findings revealed that 3 Gy and 6 Gy dose of X-ray radiation caused a significant reduction in the white blood cell, packed cell volume, hemoglobin, neutrophils, lymphocytes, eosinophils, and platelet counts compared with the control group. However, the administration of CAE before irradiation significantly increased the mentioned parameters. There was no increase in red blood cell and monocyte among treated groups compared with the control. Histopathological changes in the kidney and liver sections revealed that no visible lesion in the pretreated mice. Hepatocytes seem to be within normal histological limits. CONCLUSIONS: This study concludes that CAE offered some protection against radiation-induced hematological alterations, but there was no significant improvement in the histopathological parameters. Thus, further studies are needed to validate its radioprotective effect on histopathological variables.