Radiation hazard index and excess lifetime cancer risk due to natural radioactivity in environmental matrix waste dumpsite, Rivers state.

AVWIRI, G.O., NTE F.U. , OLANREWAJU, A. I.
Page No. 123-131

Evaluation of the radionuclides (238U, 232Th and 40K) content to understand the radiation hazards
from the waste dumpsite areas to mankind. Natural radioactivity analysis has been carried out for
the samples collected from different points of Eliozu reclaimed dumpsite of rivers state, Nigeria. The
determined activity concentrations of some sample sites fall within the typical world values with
variation in some showing extreme values. To assess the radiological hazard of soils and water
samples, the radiological hazard indices such as absorbed dose rate, annual effective dose
equivalent (outdoor and indoor) (AEDE), hazard indices (Hex and Hin), activity utilization index (I)
and excess life time cancer risk (ELCR) are calculated. The radiological hazard indices are below
the internationally recommended values. The present values of indoor and outdoor AEDE is lower
than 70 Sv/y and 450 Sv/y for outdoor and indoor in the world average values (Orgun et al., 2007).
Average ELCR for all samples is less than the world average (0.29 x 10-3) (Taskin et al., 2009). This
indicates that the Eliozu’s soils and waters are safe for construction purpose and for utilization.
Keywords : Absorbed dose rate, Excess life cancer risk, Annual effective dose equivalent, Hazard
indices, activity utilization.