Assessment of Radioactivity Contents of Food in the Oil and Gas Producing Areas in Delta State, Nigeria

The radioactivity concentrations of 40 K, 238 U, 232 Th and 137 Cs in eighteen species of foodstuffs in the oil and gas producing areas in Delta State, Nigeria have been measured using a high purity germanium, (HPGe) detector system. The mean specific activities of 40 K, 238 U, 232 Th and 137 Cs vary between 36.48 – 68.02; 2.33 – 5.18; 1.26 – 2.98 and 0.27 – 2.47 Bq kg -1 respectively in vegetables while in fruits the mean specific radioactivities of these radio-nuclides vary between 31.22 – 61.91; 1.17 – 2.67; 0.10 – 1.60 and 0.70 – 3.26 Bq kg -1 . In tubers the mean specific radioactivities vary between 49.10 – 202.75; 9.58 – 17.78; 6.92 – 16.60 Bq kg -1 in 40 K, 238 U, 232 Th and below detection limit for 137 Cs. Similarly the specific radioactivities of the three nuclide vary between 14.41 – 18.17; 4.34 – 6.79; 3.23 – 5.66 Bq kg -1 respectively in maize and in meat its mean vary between 329.33 – 392.40; 2.85 – 6.99; 0.67 – 2.84 Bq kg -1 respectively while 137 Cs is below detection limit in the maize and meat samples. The transfer factor soil-to-food vary between 0.10 – 0.94; 0.03 – 0.57; 0.01 – 0.80 and 0.21 – 0.31 for 40 K, 238 U, 232 Th and 137 Cs respectively. Generally the results are low and within the range of internationally recommended limits and no significant radiological hazard was found. The results of this study may be considered as the baseline levels of radioactivities in the foodstuffs in these areas of Nigeria to check future activities in the area. Meanwhile regular monitoring is necessary due the presence of man-made radionuclides 137 Cs, to avoid health hazard which may arise as a result of the cumulative effects from the radionuclides.