Trace metals and major elements in the Persian Gulf sediments

The concentrations of sixteen elements and organic carbon were determined in 78 marine sediments in the Iranian coastal waters of the Persian Gulf. Nine transects perpendicular to the coastline were sampled. Sixteen elements, including As, Ba, Cd, Co, Cu, Mn, Ni, Pb, Zn (trace metals) and Ca, Fe, Mg, Na, P, S, Si (major metals), were determined by Inductively Coupled Plasma Mass Spectrometry (ICP MS) and Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) respectively, after digestion in a CEM (Mars 5) microwave oven using nitric acid and hydrogen peroxide. The present study indicates that the levels of elements in sediment of the Persian Gulf were below the threshold effect levels (TEL) established in sediment quality guidelines, with the exception of arsenic, copper, nickel and iron. Results revealed that concentration of arsenic in 50 % of data exceeded the threshold effect level. The organic carbon (OC) and organic matter contents ranged from 0.4 to 1.8 % and 4 to 13 %, respectively. Significant correlations could be found between almost all the elements. Enrichments factors using Fe and Cu as normalizers, and correlation matrices associated with relatively high organic carbon and organic matter content showed that metal pollution was the product of anthropogenic sources, except for arsenic, cadmium and silicon.

Keywords:

Persian Gulf , Sediment , Trace metals , Major elements , ICPMS , AES