Assessment of arsenic, heavy metals and natural radionuclides in estuaries of Sungai Langat, Selangor / Tengku Nurliyana Tuan Mohd Rosli

Human and aquatic lives are affected by water pollution. This global issue which has also taken place in Sungai Langat, Selangor that covers two estuaries of Area A and Area B. The activities of agricultural, housing, industrial and domestic sewage are the possibility sources released pollutants into water of Area A while the activities of shipping, housing and industrial are the possibility sources that contribute pollutants into the river water of Area B. The present study focused on elements of heavy metals (Mn, Cr, Ni, Cd, Hg, Cu and Zn), As, U, Th and natural radionuclides (226Ra, 228Ra and 40K). Twenty five sampling points of Area A were taken for the water samples while twelve sampling points for the Area B. The concentration of heavy metals in water samples were measured using Inductively Coupled Plasma Mass Spectrometer (ICP-MS) which the concentration trend is Cu>Mn>As>Cr>Zn>Ni>Cd>Hg in Area A while for water of Area B, the concentration trend is Cu>Hg>Mn>As>Zn>Cr>Ni>Cd. From the concentration of heavy metals, the value of Enrichment Factor (EF), Contamination Factor (CF) and Pollution Load Index (PLI) were obtained to determine the status of water pollution. For Principal Component Analysis (PCA), elements of heavy metals, arsenic, U and Th are related to each other. For the activity concentration of 226Ra, 228Ra and 40K in water samples, gamma spectrometry was used. The activity concentrations of 40K are higher in water for both areas than 226Ra and 228Ra in Area A and Area B. For radiological assessment, the value of radium equivalent, absorbed dose rate, hazard index and annual effective dose in water of Area A and Area B are below the maximum limit.