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 ...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.展开更多
文摘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.
