Comprehensive Risk Assessment of Heavy Metal Accumulation in Surface Sediment of Lake Tortum Based on Ecological Indices

Abstract

In this study, ecological risks arising from the accumulation of some heavy metals in surface sediments of Lake Tortum are discussed based on the use of ecological indices, such as enrichment factor (EF), contamination factor (CF), pollution load index (PLI), potential ecological risk index (PER) and the mean probable effect concentration quotient (mPEC-Q). Sediment samples were collected from six different sites using Van Veen grab and heavy metal and organic carbon content of sediments were determined. Results testify to the existence of minimal to moderate contamination in lake sediment. The highest value for the enrichment factor pertains to Cd caused by the use of fossil fuels in settlement areas in the lake catchment. PLI and PER estimations, on the other hand, reveals the presence of low heavy metals-induced ecological risk in lake sediments. Ranging between 15% and 29%, mPEC-Q values are indicative of the fact that Lake Tortum is a low-moderate priority site in terms of toxicity level caused by heavy metals.