Radioactivity estimation of baobab (Adonsonia digitata) in katsina metropolis, katsina state Nigeria

Radioactivity estimation of baobab plants was carried out in Katsina metropolis, Katsina State, Nigeria. Samples of soil, roots, and leaves were collected, prepared and analyzed to estimate the activity concentration of the natural radionuclides of U-238, Th-232, and K-40using NaI (TI) gamma ray spectrometry detector. The results obtained showed that the activity concentration ranged from 0.1 Bq/kg to 33.26 Bq/kg, 1.98 Bq/kg to 64.98 Bq/kg and 65.89 Bq/kg to 1009.69 Bq/kg with overall mean values of 11.35, 18.87 and 545.14 in Bq/kg for U-238, Th-232 and K-40 respectively. In order to assess the radiological parameters of the natural radioactivity; the radium equivalent activity (Raeq), an absorbed dose rate and the measured annual effective dose equivalent were calculated and lies in the ranges of 18.83 to 183.22 (Bq/kg), 9.07 to 85.90 nGy/h and 0.011 to 0.105 mSv/y respectively; mean values obtained are 87.20 Bq/kg, 40.55 nGy/h and 0.050 mSv/y respectively. However, the calculated values obtained for all the radiological parameters falls below the world acceptable limits of 370 Bq/kg for Raeq; 89 nGy/h for the absorbed dose rate and 1 mSv/y annual effective dose rate for the general public; for the annual effective dose due to ingestion or inhalation of NORMS in the soil, medicinal plants and food is 0.07 mSv/y and the value is within the acceptable limit of intake; external and internal hazard index were calculated and found to have values of 0.23 Bq/kg for Hex and 0.30 Bq/kg for Hin and are lower than unity set by ICRP. Base on the radiological hazards evaluations, there is no any health risk due to radiation from the natural sources in using the roots and leaves parts of baobab plants for any purposes in the study area. Moreover, the measured soil around the study area was found to be safe and will not pose any radiation exposure to the population. Hence, the research will serve as the baseline for detection of any future released activities of related natural radionuclides especially around the consumable plants. However, effort should be made to ensure that the radiological parameters of the study area are kept as low as reasonably achievable.