Impact of produced water discharge on the gross alpha and gross beta activity concentrations and radiological health risk on drinking water sources in coastal areas of Nigeria

摘要

Gross alpha and gross beta activity concentrations in drinking water samples from coastal areas of Nigeria has been investigated using an MPC-2000-DP model proportional counter. A total of 60 drinking water representative samples (four each from communities' drinking water sources) were collected from the study area. The mean gross alpha activity concentrations values obtained ranged from 0.02 ± 0.00 Bq I~(-1) to 1.37 ±0.01 Bq I~(-1) with an average value of 0.38 ± 0.03 Bq I~(-1) while the mean gross beta activity concentrations values ranged from 0.41 ± 0.04 Bq I~(-1) to 7.32 ± 0.33 Bq I~(-1) with an average value of 2.96 ± 0.41 Bq I~(-1). These revealed that the gross alpha and gross beta activity levels obtained in the drinking water were above the recommended permissible limit of 0.1 and 1.0 Bq I~(-1), respectively, and that of the control values. The annual effective dose equivalent, annual gonadal equivalent dose, excess lifetime cancer risk and committee effective dose due to drinking of these drinking water sources by infants, children and adults from gross alpha activity concentration when compared with their world average standards, were found to be higher than the world allowable average values. These high values obtained were attributed to anthropogenic activities (oil and gas activities) in the study area. This anthropogenic activities of discharging produced water into water bodies of these 15 communities studied has contaminated the drinking water radiolog-ically, which might pose significant radiation health threat to both human system and the environment. Further study on the specific activity to identify the radionuclide of concern was recommended.