Assessment of Radionuclide Concentrations and Absorbed Dose from Consumption of Community Water Supplies in Oil and Gas Producing Areas in Delta State, Nigeria

摘要

A survey of radioactivity concentration in water supplies used for domestic and industrial purposes in the oil and gas producing communities of Delta State, Nigeria was carried out using a well-calibrated High-Purity Germanium (HPGe) detector system. The study area was partitioned into ten sections and a total of two samples per partition were collected for analysis. Samples of water from a non-producing area were also collected as control. In all, a total number of forty three samples were collected and analyzed. Each sample was acidified at the rate of 10 ml of 11 M HCl per litre of water to prevent the absorption of radionuclides into the wall of the container and sealed in a properly cleaned container for at least one month so as to attain a state of secular radioactive equilibrium before analysis. The photopeaks observed with reliable regularity belong to the naturally occurring series-decay radionuclide headed by 238U and 232Th, as well as the non-series decay type 40K. The mean specific activity obtained for 40K was 49 ± 15 Bq L–1 with a range of 6 - 177 Bq L–1 while for 238U, the mean specific activity was 3 ± 1 Bq L–1 with a range of 1 - 12 Bq L–1 and the mean specific activity for 232Th was 3 ± 2 Bq L–1 with a range of 2 - 10 Bq L–1 and the total annual effective dose, which vary between 0 - 2 μSv y–1, did not show any significant health impact.