Pollution assessment of the Red Sea-Gulf of Aqaba seawater, northwest Saudi Arabia.

Abstract

The water pollution index (PIj), degree of contamination (Cd), heavy metal pollution index (HPI), and statistical analyses were used to assess seawater pollution and identify the possible sources of heavy metals from the Red Sea-Gulf of Aqaba coastline, northwest Saudi Arabia. Concentrations of Cr, Sb, Co, Ni, Cu, Zn, Cd, As, Fe, Mn, Hg, and Pb were analyzed and interpreted in 33 surface seawaters samples. The mean heavy metals of seawater were in the following order: Zn (5.51μg/l) > Ni (2.45) > As (2.43) > Cu (2.34) > Mn (2.20) > Fe (1.81) > Pb (1.31) > Sb (0.64) > Co (0.31) > Cr (0.26) > Cd (0.05) > Hg (0.008). The spatial distribution of heavy metals showed high levels in some individual samples, especially nearby the residential cities, may be due to anthropogenic sources. PIj and Cd indicated light and low pollution for the seawater samples, respectively, while HPI indicated low pollution for 10 samples and medium pollution for the rest ones. The lack of significant correlations between metal pairs (except Cu and As) indicated different sources of pollution. Pollution indices, principal component analysis, and Pearson's correlation coefficient reveal that the quality of seawater in the Red Sea-Gulf of Aqaba coastline is mainly controlled by geogenic processes with minor anthropogenic input.