Radiological Risks Associated with Gross Alpha and Beta Activity Concentrations of Water Resources within Salt Water Lakes, Ebonyi State, Nigeria

Abstract

Background: The increasing fear on the radiological status of water sourced from proximity to salt water lakes in Ohaozara LGA, Ebonyi State, Nigeria has necessitated the need to evaluate the potential radiological risk contributions to the populace consuming the various drinking water sources. Objectives:  The study measured the radiological risk associated with gross alpha and beta activity concentrations in borehole water, Asu river, Atta stream and sachet water samples to evaluate if they are safe for drinking by the populace. Methods: The study employed experimental research design to address the statement of the problem and achieve the aim and objectives of the study. Samples of water were collected from various sources in proximity to the salt lakes, prepared and counted for gross alpha and beta activity concentrations using a low background MPC 2000DP proportional counter. Appropriate mathematical modelling/equations were used to obtain reliable data sets. Results: Gross alpha activity concentrations of water samples (except Atta stream) were lower than World Health Organization, (WHO) reference limit of 0.5 Bq L-1, whereas for gross beta activity concentrations, water samples (except Uburu sachet water) exceeded the WHO reference limit of 1.0 Bq L-1. Weak but positive linear correlation (p=0.44) was found between gross beta and gross alpha activity concentrations. Cancer risks and hereditary effects were calculated. Conclusion: The obtained values of the mean annual effective dose due to ingestion of water showed that gross beta activity concentrations in various water samples were more responsible for ingestion radiation dose contributions since water samples (except Ugwulangwu borehole water and Uburu sachet water) exceeded the ICRP reference limit of 0.1 mSv y-1. Preliminary study has been provided which advised that water samples should be consumed with caution.