Po-210, Pb-210 AND Po-210/Pb-210 IN SEDIMENT CORE FROM SURROUNDING SUNGAI LINGGI ESTUARY
This study was performed to observe the variation in the distribution of 210Po, 210Pb and 210Po/210Pb activity ratio through their vertical profile of the sediment cores taken at surrounding Sungai Linggi estuary. Five sediment cores were taken in February 2011 and were cut to an interval of 2 cm layer. Activity concentrations of 210Po and 210Pb were determined using alpha radiochemical analysis and gamma direct measurement, respectively. Generally, the measured activity of 210Po, 210Pb and 210Po/210Pb were in the ranges of 22.73 – 139.06 Bqkg-1 dw., 37.88 – 176.24 Bqkg-1 dw. and 0.23 – 1.34, respectively. The variation in the distribution profile for the radionuclides are believed to be influenced by human activities such as agriculture, fertilizer, vehicles, burned fuel fossil and forest, industrial and others via river input from land-base. Other factor is due to organic matter content played important role as the geochemical carrier to transport those radionuclides at study area. It was proved that has a strong correlation between the radionuclide distribution and the sediment composition of organic matter. Furthermore, in those ranges reflected that 210Pb activities were higher than 210Po with an activity ratio average of 0.79. This is probably due to dramatic increase of excess 210Pb supplied from atmospheric deposition, in situ decay of 226Ra and as a result of diagenetic remolibilazation of 210Pb in deeper layes of the sediment column. Thus, those factors are major contributions on the variation of 210Po and 210Pb in the sediment core at surrounding Sungai Linggi estuary.