Abstract:
This research aimed to measure radioactivity levels in marine sediment collected in some areas of Pattani Bay and compared with typical values of those in soil reported by UNSCEAR (2008). Sediment samples were collected from 7 sites along the seashore of Pattani Bay, Pattani province during the summer and rainy season. Radioactivity were analysed using gamma spectrometry with a high purity germanium detector (HPGe) using IAEA Soil-6 as a reference material. The samples were counted for 7,200 seconds. The artificial radionuclide 137Cs was found in this study. The detected radionuclides were related to the naturally occurring isotopes 40K, 238U and 232Th. The average specific activities were found to be 803107.16 Bq/kg of 40K, 59.9316.13 Bq/kg of 238U and 79.4712.44 Bq/kg of 232Th in summer; 648212.46 Bq/kg of 40K, 44.4220.42 Bq/kg of 238U และ 66.2030.16 Bq/kg of 232Th in rainy, which were higher than the UNSCEAR (2008)s reported values of 412, 35 and 45 Bq/kg for 40K, 238U and 232Th respectively. However, the values of hazard index of natural radionuclides in sediment samples were found to be normal. Other factors including particle size and amount of organic matter in sediment were found to be relative with the radioactivity level found in sediment, whereas the amount of heavy metal and kind of benthos were not related to the detectedradionuclides