An ecological risk assessment of sediments in a developing environment — Batticaloa lagoon, Sri Lanka

Abstract

The land-sea interface is considered as a threatening environment due to anthropogenicdevelopment activities. Unplanned developments can cause effects on important ecosystems, wa-ter and human health as well. In this study, the influence of rapid regional development on theaccumulation of trace elements to the sediments of an important ecosystem, Batticaloa lagoon, SriLanka was examined. Surface sediment pollution status and ecological risk was compared with thatof the recent sedimentary history of about 1 m depth. Sediment core samples were collected andanalyzed for grain size, organic matter and carbonate contents and trace elements (As, Pb, Zn, Cu, Niand Cr) by the X-Ray Fluorescence (XRF) technique. The chemical results of core samples and recentlypublished data of surface sediments of the same project were evaluated by pollution load index(PLI), potential ecological risk index (PERI) and sediment quality guidelines (SQG). Except for Cr,all other elements in cores show lower concentrations than the SQGs confirming the high Cr contentsas recorded in the most of other Sri Lankan sediments. The sediment cores indicate an unpolluted,low ecological risk sedimentary history for all core sampling locations, whereas most of the surfacesediments of the lagoon are less polluted with low potential ecological risk. Present anthropogenicpractices and illiteracy of this rapid developing region can damage the green environment and henceenvironmental management planning is suggested for a sustainable future