Heavy Metals Contamination and Ecological Risk Assessment in Surface Sediments of Namal Lake, Pakistan
Tariq Javed1, Nasir Ahmad2, Azhar Mashiatullah1
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1Isotope Application Division (IAD), Pakistan Institute of Nuclear Science and Technology (PINSTECH), Nilore,
Islamabad, Pakistan
2Institute of Geology, University of the Punjab, Lahore 54590, Pakistan
Submission date: 2017-03-26
Final revision date: 2017-06-29
Acceptance date: 2017-07-11
Online publication date: 2018-01-08
Publication date: 2018-01-26
Pol. J. Environ. Stud. 2018;27(2):675–688
Heavy metal concentrations were determined using inductively coupled plasma-optical emission spectrometry (ICP-OES) in surface sediments of Namal Lake, Pakistan. The metals content in sediment varied significantly and were in the order of Al>Fe>Mn>V>Zn>Cr>Ni>Cu>As>Co>Pb>Cd. Except for Al, the average concentrations of metals were higher than the average value of the upper continental crust (UCC). The significant positive correlations among heavy metals (p<0.01) suggested that these metals originated from the same sources. The pollution indices indicated severe contamination of sediments with As, Cd, and Ni. The sediment quality guidelines (SQGs) revealed that 19.2% of As, 11.5% of Cr, and 88.5% of Ni from all the sampling sites exceeded the probable effect level (PEL). The computed average risk index (RI) of single elements were in the following order Cd(411.9)>As(69.0)>Ni(15.4)>Cu(10.0)>Cr(4.3)> Pb(3.66)>Zn(1.7). Principle component analysis (PCA) extracted three components explaining (76.136%) of total variance of chemical data and were highly to moderately loaded with Fe, Mn, Co, Cu, Zn, Al, As, Cd, Ni, V, Cr, TOC, pH, CaCO3, and Pb in three principal components (PCs). The results obtained from cluster analysis, correlation of heavy metals, and principal component analysis suggested the origin of metals from both anthropogenic and natural sources.