Estimation of Radiation Risk Due to Exposure to Terrestrial Radiation

An in-situ measurement of background radiation level of Ewoi community in Ogbia Local Government
Area of Bayelsa State Nigeria was done using two radiation meters (Digilert-200 and Radalert-100).
Exposure rate measured ranged from 0.010 to 0.028 mRh-1 with mean value of 0.016 mRh-1. The
mean value of absorbed dose was 128.67 nGyh-1 while the mean indoor and outdoor annual effective
dose equivalents were 0.40 mSvy-1 and 0.13 mSvy-1 respectively. The mean excess lifetime cancer
risk estimated from both indoor and outdoor effective doses were 1.0 × 10-3 and 0.33 × 10-3
respectively. It was observed that all the radiological parameters estimated from the radiation
exposure rate were higher than their world average values except the annual effective doses. The
result of this study shows that Ewoi community recorded slightly high background radiation level and
this may be attributed to oil and gas exploration activity in the area. The result of this work serves as
radiological baseline data of the area for future studies.
Considering the values obtained in this research work and the likely health impact, it is important that
further studies be carried out on activity concentration of radionuclide on the soil, water (drinking
water resources of the community), and food crops from Ewoi community for identification of
radionuclides present and their concentrations in order to quantify their radiological health implication
and ways to control it.