Assessment of toxic elements in sediments of Linggi River using NAA and ICP-MS techniques

Fourteen sediment samples were collected along Linggi River, Malaysia. Neutron activation analysis (NAA) and inductively coupled plasma-mass spectrometry (ICP-MS) techniques were used in the determination of toxic element contents. The results showed that As, Cd and Sb concentrations were higher at all sampling stations, with enrichment factor values ranging from 17.7 to 75.0, 2.1 to 19.5 and 6.6 to 28.4, respectively. Elements of Pb and Zn) were also enriched at most of the sampling stations whilst Cu, Cr and Ni were shown as background levels. The sediment of Linggi River can be categorised as low (32.0). The mean concentrations of elements viz. Cd, Cr, Ni, Pb, Sb and Zn were lower than the threshold effect level (TEL) of FSQGs values except for As. The concentration of As (arsenic) was higher than PEL and PEC of FSQGs values. Keywords: Linggi River, Enrichment factor, Degree of contamination, Freshwater sediment quality guidelines, NAA, ICP-M

The evaluation of Brunei Bay sediment cores sedimentation rate using 210Pb radiometric dating technique

The use of radioisotopes 210Pb and 226Ra in establishing the geochronology of pollutants in the sediment core and sediment dating is be-ing widely used in the world. The present study was conducted in Brunei Bay region of Malaysian waters to define the sedimentation rate and sediment age as well as to investigate the possible sources of pollutants into this bay. Sediment core samples were cut by layers, dried and analyzed using High Purity Germanium (HPGe) Spectrometer. Results obtained marked the time interval of 1875, 1956, 1962 and 1945 for sediment core B5, B9, B13 and LB consecutively. Sediment core of B9 and LB showed higher sedimentation rate compared to B5 and B13 due to the rapid development of urban and industrial. The increasing of sedimentation rate over the last 25 years was in line with the increasing of human activities surround the bay. Additionally, the health and distribution of mangroves surround Brunei Bay were important to determine the sediment movement which will affect the sedimentation rate in the bay. Overall, by controlling human activities as well as sustaining the mangroves population, could maintain and preserve the natural and unique environment of Brunei Bay