Risk Assessment of Natural Radionuclides in Surface and Ground Water of Oil and Gas Producing Communities, Rivers State, Nigeria

Abstract

The natural radioactivity and radiological health risk associated with the use of water from hand-dug wells, tap/boreholes and river/creeks in three communities with history of oil spillage, gas flaring, oil bunkering and operation of illegal artisanal oil refining activities in Rivers State, Nigeria was here assessed and measured with gamma ray spectroscopy. The results showed that the mean activity concentration of water samples for hand-dug well water ranged from 11.94±1.12 to 12.77± 1.12Bq/l for 238U, 7.88±1.05 to 9.20±1.82Bq/l for 232Th and 13.50±0.62 to 20.13±3.88Bq/l for 40K. The mean activity concentration for the tap/borehole water ranged from 2.42±0.45Bq/l to 5.31±0.80Bq/l for 238U, 1.02±1.01 to 2.24±0.90Bq/l for 232Th and 9.71±5.04 to 11.73±3.77Bq/l for 40K. The 238U, 232Th and 40K activity concentrations in the river/creek waters ranged respectively from 6.81±0.80 to 8.82±1.20Bq/l, 4.25±0.65 to 9.52±1.16Bq/l and 25.01±3.23 to 30.03±1.96Bq/l. These values are higher than the mean activity concentrations of the 3 radionuclides in the control samples and some are higher than the international permissible standards. Results further revealed that there was statistically significant difference at p