Radon Levels of Water Sources in the Southwest Coastal Region of Peninsular Malaysia

Across populations, the dominating source of public exposure to radiation is radon gas. In the present study, we aimed at determining the concentration of radon in water sources from the southwest coastal region of Peninsular Malaysia. A total of 27 water samples were taken from various water sources which included groundwater, as well as hot spring, lake, river, seawater, and tap water; the radon concentrations were measured using a RAD7 portable radon detector. The radon concentrations ranged from 0.07 ± 0.12 to 187 ± 12 Bq l−1, with an average of 21 ± 12 Bq l−1. The highest concentration was found in hot spring water, with an average concentration of 99 ± 6 Bq l−1, while the lowest concentration was found in tap water, with an average concentration of 1.95 ± 0.61 Bq l−1. The average concentrations of radon for all categories of sampled water were below the 100 Bq l−1 WHO guidance level for safe drinking water. According to the ICRP effective dose conversion factor and UNSCEAR (2000), the total effective dose from the summation of inhaled and imbibed water was calculated from the aqueous radon concentrations, with an average effective dose of 4.45 µSv y−1, well within the WHO safe drinking water guideline value of 100 µSv per year. The results of this study could support the efforts of authorities and regulators who are responsible for controlling and strategizing to ensure public safety against radon exposures.