title: Baseline trace metals in water and sediment of the Baleh River-a tropical river in Sarawak, Malaysia.
abstract: Quantitative indices are classically employed to evaluate the contamination status of metals with reference to the baseline concentrations. The baselines vary considerably across different geographical zones. It is imperative to determine the local geochemical baseline to evaluate the contamination status. No study has been done to establish the background concentrations in tropical rivers of this region. This paper reports the background concentrations of metals in water and sediment of the Baleh River, Sarawak, derived based on the statistical methods where the areas possibly disturbed are distinguished from the undisturbed area. The baseline levels of six elements in water determined were Al (0.34 mg/L), Fe (0.51 mg/L), Mn (0.12 mg/L), Cu (0.01 mg/L), Pb (0.03 mg/L), and Zn (0.05 mg/L). Arsenic and selenium were below the detection limit. For sediment, the background values were established according to statistical methods including (mean + 2σ), iterative 2σ, cumulative distribution frequency, interquartile, and calculation distribution function. The background values derived using the iterative 2σ algorithm and calculated distribution function were relatively lower. The baseline levels calculated were within the range reported in the literatures mainly from tropical and sub-tropical regions. The upper limits proposed for nine elements in sediment were Al (100,879 mg/kg), Cr (75.45 mg/kg), Cu (34.59 mg/kg), Fe (37,823 mg/kg), Mn (793 mg/kg), Ni (22.88 mg/kg), Pb (27.26 mg/kg), Zn (70.64 mg/kg), and Hg (0.33 mg/kg). Quantitative indices calculated suggest low risk of contamination at the Baleh River.
authors: Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, 94300, Kota Samarahan, Sarawak, Malaysia. sfsim@unimas.my.
authors: Siong Fong
authors: SF
authors: Sim
authors: Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, 94300, Kota Samarahan, Sarawak, Malaysia.
authors: Hui Ping
authors: HP
authors: Chai
authors: Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, 94300, Kota Samarahan, Sarawak, Malaysia.
authors: Lee
authors: L
authors: Nyanti
authors: Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, 94300, Kota Samarahan, Sarawak, Malaysia.
authors: Teck Yee
authors: TY
authors: Ling
authors: Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, 94300, Kota Samarahan, Sarawak, Malaysia.
authors: Jongkar
authors: J
authors: Grinang
mesh_terms: D001151:Arsenic / Q000032:analysis; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D008296:Malaysia; D019216:Metals, Heavy / Q000032:analysis*; D045483:Rivers / Q000737:chemistry*; D014131:Trace Elements / Q000032:analysis; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D019216:Metals, Heavy; D014131:Trace Elements; D014874:Water Pollutants, Chemical; D001151:Arsenic
keywords: Geochemical baseline; Quantitative indices; Trace metals; Urbanization