Study of Naturally Occurring Radioactive Material (NORM) distribution in soil from Gebeng industrial area, Pahang, Malaysia / Nurul Izzatiafifi Ismail

Naturally Occuring Radioactive Materials (NORM) present naturally in the environment, but the increase of the concentration of radionuclide may come from the anthropogenic activities. NORM at certain limit becomes hazardous to environment and human. The study of radionuclides concentrations (U, Th and 40K) in soil from Gebeng Industrial Area, Pahang were carries out from November 2014 to March 2016 to assess its distribution. The major sources of radionuclides in Gebeng Industrial Area may be originating from anthropogenic activities. The amount of concentration and activity concentration of NORM such as U, Th and 40K is the important factor in assessing whether it is harmful to human or vice versa. The hazard risk of NORM was determined by calculating the pollution and radiological assessment. Then to assess the spatial uptake of radionuclide in the surface soil and Acacia mangium plant as potential mitigation strategy. Concentrations of uranium, thorium and potassium were determined using Energy Dispersive X-ray Fluorescence (EDXRF) method. The distribution of radionuclides in soil shows high concentrations of uranium and thorium in the industrial area, meanwhile potassium high concentration detected in green area away from the factory. The pollution level in study area was estimated by calculating the Enrichment Factor (EF), Contamination Factor (CF), Pollution Load Index (PLI) and Geo-Accumulation (I-geo). The radiation exposure based on radium equivalent (Raeq), Absorbed dose (D), Annual Effective dose (AED) and External hazard index (Hex) via analysis of U, Th and K was calculated. The results that show most of the location have exceed the safe limit that safe for general public as stated by UNSCEAR 2010. To indicate soil quality, plants were used as bio monitors who give several important advantages over soil analyses particularly on a large scale. Acacia mangium is abundance plant in Gebeng Industrial Area and was chosen as plant bio monitor for this study. Based on the radiation index, the study area is considered slightly polluted since the level of radiation is higher than the annual dose limit. As a safety precaution, some remedial actions have to be taken to prevent occurrence of high doses to workers and general public. Therefore, mitigation procedure can be taken as public awareness.