Pollution Loads and Ecological Risk Assessment of Metals and a Metalloid in the Surface Sediment of Keenjhar Lake, Pakistan

Abstract

This study aims to analyze the concentrations of heavy metals and a metalloid in the surface sediments of Keenjhar Lake, Sindh, Pakistan that pose a risk to the lake ecosystem. The concentrations and ecological risks associated with eight metals and a metalloid (As, Pb, Cd, Cu, Mn, Fe, Ni, Hg, and Cr) from surface sediments of the lake, was evaluated at 10 sampling locations. The overall 95 th percentile concentrations of trace elements were observed as As (29.1), Pb (7.6), Cd (0.68), Cu (9.3), Mn (56.43), Fe (352.3), Ni (10.36), and Cr (29.61) mg/kg. Metal wise as well as aggregated levels of contamination were studied. It was observed that all metals except Hg were detected in the lake sediment. Based on the geo-accumulation index and enrichment factor, Cr, Cu, Mn, Ni, and Pb showed low pollution levels, while As, Cd, and Fe showed a high degree of contamination. Based on the 95 th percentile, the average values of EF for As, Cd and Fe were observed as 274%, 300% and 907% respectively. Pollution Load Index reflected metals and metalloid contamination near the warning threshold, with an average value of 0.825. The Nemerow integrated pollution index (range 6.79-7.59, i.e., >3) and degree of contamination (range 12-24) suggested strong pollution levels. According to the findings of the ecological risk index, Cd showed high ecological risk (between 160-320) at all sampling sites, and potential ecological risk index was at moderate risk level (between 150-300) at all locations. Multivariate analysis of the metals and a metalloid classified as As, Cd, and Fe in one group with the remaining metals in another group show that metals of each group originate from the same source.

Native plant species growing on the abandoned Zaida lead/zinc mine site in Morocco: Phytoremediation potential for biomonitoring perspective

“…The calculated values for As, Cu, Ni, Cd, Sb, Zn, and Pb are 44, 6.22, 1.60, 31.1, 80.9, 2.76, and 517, respectively. According to Ntakirutimana, Du [ 37 ], Cu, Ni, Cd, and Zn exhibit a low ecological risk with Ei values less than 40. As falls within the moderate Ei category (40 ≤ Ei < 80).…”

“…According to Ntakirutimana, Du [ 37 ], the potential ecological risk Ei is categorized into five classes: low (Ei < 40), moderate (40 ≤ Ei < 80), considerable (80 ≤ Ei < 160), high (160 ≤ Ei ≤ 320), and very high (Ei > 320).). The ERI was categorized into four classes: low (ERI <150), moderate (150 < ERI ≤ 300), high (300 < ERI ≤ 600), and very high (ERI > 600) [ 38 ].…”

Ecological risk assessment of heavy metals after dredging in Mogan Lake, Turkey

“…According to Imran et al (2020), elevated Igeo and EF values discovered for As, Fe, and Cd in the surface sediment of Lake Keenjhar (Pakistan) are produced by human activity in the lake's surroundings. According to Zhang et al (2013), the geoaccumulation index (Igeo) of six heavy metals in Lake Yangzonghai (China) sediment is Cu>As>Cr>Zn>Mn>Pb in general, with copper reaching a value of 2.42.…”

Ecological Risk of Toxic Metal Contamination in Soil around Coal Mine and Thermal Power Plant

“…In order to measure Ecological Risk Assessment, the following were used: Contamination factor (CF), Pollution Load Index (PLI), Pollution Load Index (PLI), Ecological risk assessment (ERI), Geoaccumulation Index (I geo ) and Degree of soil load [35][36][37][38][39][40][41][42][43][44][45][46].…”