Polycyclic aromatic hycrocarbons (PAHs) distribution and its vertical profile at Kerteh River, Terengganu

Abstract

The concentrations of P AHs in core sediments collected from 6 stations along Kerteh River were measured in unit equivalent to benzo[a]pyrene, BaP and the profile of P AHs in the core is constructed. The core samples were collected starting from river mouth heading towards upstream, where core A4 was collected nearest to the river mouth while AIO the furthest upstream. From these six core samples, core A7 and AlO were collected from direct outlet of industrial area. Maximum concentrations for overall core was found in core AIO, while highest concentration of PAHs in a layer was found in core AIO, layer 0-5 cm. The overall lowest concentration of P AHs in a core is core A4 which is situated near to river mouth, where tide system and wave actions may have diluted the P AHs from upstream before they have the time to settle down in the sediment. For all six cores, none of them has exceeded the direct exposure limit for industrial area set by Florida Soil Cleanup Targets, which is 0. 700 mg/kg. However, the direct exposure limit for residential area is exceeded are core A7, A8 and AIO. In general, the recent trend is towards a decrease of P AHs concentration, except for station A 7 and A IO which show increase of P AHs concentration. Based on the findings in this study, Kerteh River is slightly contaminated with PAHs concentration ranging from zero to 0.296 mg/kg. It is advisable that the water from Kerteh River is not applied for residential use as the concentration in sediment has already exceeded the limit allowed for residential use.