Uptake and distribution of natural radioactivity in rice from soil in north and west part of peninsular malaysia for the estimation of ingestion dose to man

Paddy is the third most widely planted crop in Malaysia and most of the Malaysian people consume rice as their staple food. Hence, studies on the uptake of naturally occurring radionuclides by rice from soil of widely rice cultivated areas in Malaysia have been performed under normal field environments in order to evaluate various radiation hazards via rice consumption. The soil-to-rice grain transfer factors and the annual effective dose have been assessed for the natural radionuclides Ra-226, Th-232 and K-40. The estimated transfer factors for Ra-226 and Th-232 were found far beyond compared to the IAEA reported value for rice. Among the detected radionuclides, K-40 shows the highest transfer factor in all study locations but close to the IAEA reported range. The total effective dose obtained due to an ingestion of radionuclides via rice consumption was within the range of world average value (290 mu Sv y(-1)) compiled by the UNSCEAR (2000) in all study areas. On an average, the excess life time cancer risk (ELCR) values via rice consumption were found below the acceptable limit of 10(-3) for radiological risk. (C) 2014 Elsevier Ltd. All rights reserved.