Natural and anthropogenic radioactivity and radiological hazard indices in organic Sangyod rice samples collected from Don Pradu sub-district in Pak Phayun district in Phatthalung province, Thailand

Abstract

It is well known that Thai people and many other Asian countries consume rice as the main dish. Minor contamination of natural and anthropogenic radionuclides in rice dishes may cause illness, fever or unwell for no apparent reason. For this reason, the research team was interested in the measurement and analysis of the concentrations of natural and anthropogenic radionuclides in 28 samples of organic Sangyod rice from courtesy of rice farmers in the Don Pradu sub-district, Pak Phayun District, Songkhla province. In addition, the research team was also received courtesy of the National Institute of Nuclear Technology (Public Organization) or TINT to use semiconductor detector measuring instruments and gamma spectrometry analysis systems for this research. It was found that the mean specific activity values of 40K, 226Ra, 232Th and 137Cs were 24.11 ± 2.01, 0.28 ± 0.07, 0.17 ± 0.06 and 0.10 ± 0.03 Bq/kg, respectively. The four relevant radiological indices which were gamma-absorbed dose rate (D), radium equivalent activity (Raeq), external hazard index (Hex) and annual external effective dose rate (AEDout), were also calculated and presented. Furthermore, the excess lifetime cancer risk (ELCR(outdoor)) was also evaluated by using the AEDout value from the investigated area. The results of this research were taken to compare with the values measured by the Office of Atoms for Peace (OAP) and research groups that have been measured and analyzed both at home and abroad. In conclusion, the results in this study were found to be lower than the values recommended by some international organizations and is safe for consumers and farmers who produce organic Sang Yod rice in the study area.