Evaluation of Radiation Emission and Associated Health Hazards from Refuse Dumps in the Federal University of Technology Owerri, Nigeria

Abstract

Aims: To determine the natural radionuclide concentrations and the associated health hazard implications in samples from refuse dumps in the Federal University of Technology, Owerri, Nigeria. Study Design: Forty (40) samples from refuse dump sites were collected at different locations inside the Federal University of Technology, Owerri, Nigeria. Each prepared sample was placed symmetrically on top of a lead-shielded NaI (Tl) detector for analysis. Materials and Methodology: A lead-shielded NaI (Tl) γ – ray spectrometry in the Radiation and Health Physics Research Laboratory, University of Ibadan, Nigeria was employed to carry out the radioactivity measurement of the forty (40) samples. The values of the activity concentrations were determined and used to compute the absorbed dose rate in air, annual effective dose equivalent, annual gonad dose equivalent, radium equivalent dose, excess lifetime cancer risk and radiological health hazards using standard analytical methods. Results: The result shows that the mean activity concentrations of Potassium (40K), is 468.35 ±3.27 Bqkg-1which is slightly higher than the world permissible (UNSCEAR) value of 400.00 BqKg-1. However, the activity concentrations of Uranium (238U) 8.53 ±1.12 Bqkg-1 and Thorium (232Th) 6.78 ± 2.30 Bqkg-1 are much lower than the world permissible (UNSCEAR) values of 35.00 BqKg-1 and 25.00 BqKg-1 respectively. The value of the mean absorbed dose rate obtained in this research is 26.89 nGyh-1 compared to the world permissible (UNSCEAR) value of 60.00 nGyh-1. While the annual effective dose equivalent obtained is 32.98 mSvy-1, compared to the world permissible (UNSCEAR) value of 70.00 mSvy-1. The mean values of annual gonad dose equivalent and the radium equivalent are 202.09 BqKg-1 and 54.48 BqKg-1 respectively, compared to their world permissible (UNSCEAR) values of 300.00 BqKg-1 and 370.00 BqKg-1 respectively. While the mean values of health hazard implications and the lifetime risk of cancer risk are 0.15 and 0.114 respectively compared to their world permissible values of 1.0 and 0.290 respectively.  Conclusion: All the parameters measured are much lower than their world permissible (UNSCEAR) values. Hence the risk of radiological health hazards due to the refuse dump sites in the Federal University of Technology, Owerri, Nigeria is very inconsequential.