Assessment of Norm-containing Food Crops/stuffs in OML 58 & OML 61 within the Niger Delta Region of Nigeria

A preliminary assessment of the levels of natural radionuclide in some commonly consumed cereals, fruits, vegetables and tubers within OML 58 and OML 61 in Niger Delta Region of Nigeria has been carried out. The areas under study were divided into six (6) zones (A,B,C,D,E,F) and investigated. An in-sit measurement approach was adopted using Nuclear Radiation Meter (Radarlert-100), and a handheld Global Positioning System (GPS 76 CSX) equipment. Sixteen (16) readings each was taken in each of the six zoned areas making a total of ninety-six (96) food crops samples which was randomly selected. Measured average radiation levels in each of the six zones ranges between 0.009±0.001 mRhr^-1 (0.479±0.038 mSvyr^-1) to 0.020± 0.001 mRhr^-1 (1.064±0.065 mSvyr^-1) for zone A, 0.011±0.001 mRhr^-1, (0.585±0.041 mSvyr^-1) to 0.022±002 mRh^-1 (1.170±0.105 mSvyr^-1) for zone B, 0.010±0.001 mRhr^-1 (0.532±0.048 mSvyr^-1 to 0.025± 0.002 mRhr^-1 (1.330±0.016 mSvyr^-1) for zone C, 0.010±0.001 mRhr^-1 (0.532±0.048 mSvyr^-1) to 0.028±0.002 mRhr (1.490±0.134 mSvyr^-1) for Zone D, 0.005±0.000 mRhr^-1 (0.266±0.021 mSvyr^-1) to 0.022±0.002 mRhr^-1 (1.170±0.105 mSvyr^-1) for Zone E, 0.010±0.001 mRhr^-1 (0.532 ± 0.048 mSvyr^-1) to 0.016±0.001 mRhr^-1 (0.851±0.068 mSvyr^-1) for Zone F. The mean food crop radiation levels ranges from 0.012±0.001 mRhr^-1 (0.798±0.065 mSvyr^-1) to 0.016±0.001 mRhr^-1 (0.849±0.067 mSvyr^-1) while the mean background radiation levels ranges from 0.011±0.001 mRhr^-1 (0.585±0.041 mSvyr^-1) to 0.015±0.001 mRhr^-1 (0.798±065 mSvyr^-1). The annual equivalent dose estimated were in the range of 0.613 mSvyr^-1 to 0.849 mSvyr^-1 far below the dose limits for radiological workers (20 mSvyr^-1) and the dose limit for the public (1 mSvyr^-1) (ICRP, 1994). Comparison of the measured radiation levels of the food crops samples with the normal background levels show that 45 samples which represent 46.8% of the whole sample exceeded the normal background level of 0.013 mRhr^-1 (ICRP, 1994). These values obtained will not pose any immediate radiological health hazard to the populace consuming these food crops/stuffs but may have some long-term health side-effects.