Pollution assessment through trace metal analysis of sediments of four tributary rivers of Pakistan draining into the Arabian Sea

Abstract

Concentrations of metals (Ag, As, Cd, Cr, Cu, Fe., Mn, Ni, Pb, Zn and Hg) in the bottom surfacial sediments both from the mouth of four contributory rivers draining into the Arabian Sea, Pakistan, and the adjoining coastal area are reported. No strong metal concentration variation was observed suggesting an almost identical enrichment of the metals at the sites. The sediments from the area showed maximum levels of Fe (8.47%), Mn (240 mug.g-1), Ni (128.7 mug.g-1), Pb (18.7 mug.g-1), Zn (146.2 mug.g-1) and Hg (4.10 mug.g-1) while the minimum levels found were of As (0.13 mug.g-1) and Hg (0.12 mug.g-1). The study indicated the existence of a metal pollution stress in that a large flux of heavy metals was being brought into the sea by the Hub and the Malir rivers.