Heavy Metals Contamination and Ecological Risk Assessment in Surface Sediments of Namal Lake, Pakistan

Abstract

Heavy metals pollution is a worldwide problem that has grown during the past few decades because of their toxicity, extensive sources, non-biodegradable characteristics, and accumulative behaviors in aquatic environments [1][2][3]. These metals are identified as a significant indicator for degradation of aquatic environments. Enormous quantities of metals are being released into the environment both from anthropogenicrelated processes and natural sources through direct discharge into water or indirectly through stormwater runoff, domestic effluents, fossil fuel combustion, and atmospheric depositions [4]. Heavy metals ultimately Pol. J. Environ. Stud. Vol. 27, No. 2 (2018), 675-688 Original Research Heavy Metals Contamination and Ecological Risk AbstractHeavy 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, CaCO 3 , 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.

Spatiotemporal Variations of Land Use and Landscape Ecological Risk in a Resource-Based City, from Rapid Development to Recession

“…ERA has been proposed with the development and subdivision of environmental impact assessments. At first, it was popular in ecological toxicology and was useful for explaining the formation and diffusion of chemical pollution and the response of the regional ecological system [8]. In the 1990s, the research objective, content and method of ERA were greatly extended [9][10].…”

Health Risk Assessment of Nitrate Pollution in Shallow Groundwater: A Case Study in China

“…It describes the degree of harm to the human body under various exposure pathways, and proposes recommendations to protect human health [19][20][21][22][23][24][25][26]. HHRA is based on four steps; hazard identification, dose-response assessment, exposure assessment, and risk characterization [27][28][29][30][31][32][33][34][35].…”

Environmental Pollution by Heavy Metals in the Gold Mining Region of East Cameroon

“…The degree of contamination (Cdeg) is the sum of CFs. It allows the assessment of the polymetallic contamination for each sampling site (Halim et al, 2014;Tariq et al, 2018). It is calculated according to the following Equation 2:…”

“…where, n is the number of metals studied and CF is the contamination factor calculated as described in an earlier equation. The PLI value greater than 1 is polluted, while less than 1 indicates no pollution (Tariq et al, 2018;Khan et al, 2017;Krika and Krika, 2017).…”

“…It enables to differentiate heavy metals originating from anthropogenic sources and those of natural sources (Emmanuel et al, 2014;Salati and Moore, 2010). The enrichment factor was calculated using the formula used by number of authors (Abhijit and Ramkrishna, 2017;Tariq et al, 2018;Smuc et al, 2015;Zahran et al, 2015;Jiao et al, 2015) and given by the following Equation 4:…”