Determination of Excess Lifetime Cancer Risk Due to Gamma Radiation in Some Agricultural Products Obtained From Two Oil Fields in the Niger Delta Region of Nigeria

Radioactivity measurements for naturally occurred radionuclides of 40K, 226Ra, 228Ra were carried out in some agricultural products harvested from two oil fields within the Nigeria Delta Region of Nigeria. The values obtained were used to determine the excess lifetime cancer risk (ELCR) and the radiation health hazard indices. Results show that the mean calculated ELCR values obtained from vegetables ranged from 0.049 x 10-3 – 0.105 x 10-3, mean 0.68 x 10-3, for fruits, 0.035 x 10-3–0.088 x 10-3, mean 0.056 x 10-3, absorbed dose D (nGyh-1) in vegetables ranged from 11.05 – 15.52 mean 13.07, for fruits, it ranged from 8.19 -12.34, mean 10.39.Mean Specific Activity values obtained for 40K,226Ra,228Ra in Vegetables are 95.95± 18.85 Bqkg-1, 10.79 ± 3.46 Bqkg-1, 6.83 ± 2.32 Bqkg-1and in fruits, the Mean Specific Activity values for 40K, 226Ra, 228Ra, are 77.67 ± 18.90 Bqkg-1, 8.12 ± 3.00 Bqkg-1, 6.17 ± 2.15 Bkg-1.The Mean Radium Equivalent Activity (Raeq) calculated for vegetables and fruits ranged from 27.81 Bqkg-1 to 18.60 Bqkg-1.The Mean Effective dose calculated in all surveyed samples ranged from 0.014 mSvy-1 to 0.030mSvy-1respectively which did not show any significant health impact. The overall results obtained agreed with other earlier works in Nigeria and all over the world (Arogunjo et al., 2005, Olomo., 1990, Shanthi et al., 2009., Mlwilo et al., 2007; Jibiri et al., 2007, Badaret al.,2003,Baeza et al.,2001 etc). All the above listed mean values had earlier been reported (Avwiri et al, 2013). With all these results all values obtained were less than the world permissible standards. It could therefore be concluded that the potential carcinogenic risk from gamma radiation doses obtained in this work is low.