THE RISK OF RADON/THORON EXPOSURE TO THE PUBLIC IN GEBENG INDUSTRIAL ESTATE, KUANTAN, PAHANG
This study aims to assess radon/thoron concentrations and the potential risks of exposure to the public from the Lynas rare-earth processing plant operation in the Gebeng Industrial Estate (GIE), Pahang. The concentrations of radon and thoron in air and water (surface and ground) have been measured within a radius of 3 km from the plant. Based on the finding in this study, it can be concluded that the mean radon and thoron equivalent equilibrium concentration (EEC) in the GIE area were low i.e., 6.5 and 2.5 Bq/m3 respectively. These values were equivalent to values measured outside the GIE area. The mean radon concentration in water in the GIE area was about 1 Bq/L which is very far below the WHO (2011) reference level for drinking water. There was no thoron detected in all sources of water around the GIE. Overall, there was no enhancement of radon/thoron concentrations in air and water in the GIE due to activities carried out by Lynas. The public only received a dose from natural background radiation sources. The effective dose received by the public from exposure to radon/thoron in air and water was 0.3 mSv/y. The results indicated that no radiological hazard to the people living in the vicinity of the Lynas rare-earth processing plants.