Contamination and environmental risk assessment of heavy metals in coastal sediments of Ras Abu Ali Island, Saudi ArabiaKhaled Al-Kahtanya and Abdelbaset S. El-Sorogya

ABSTRACT

Metal pollution is a global environmental issue and considers one of the most serious problems in coastal environments. Present work aimed to document the distribution, ecological risk, and the potential sources of heavy metals (HMs) in coastal sediments of Ras Abu Ali Island, Arabian Gulf, Saudi Arabia. V, Fe, Sr, Al, As, Hg, Sb, Cd, Co, Mn, Ni, Zn, Cr, Pb, Cu were determined in 34 coastal sediment using Inductively Coupled Plasma - Atomic Emission Spectroscopy (ICP - AES) and several pollution indices, and multivariate analysis were applied. The lower HM levels were recorded in the medium to coarse sized samples in the northern part of the study area faced to the open sea. The average values of Ni, Zn, Cu, As, Pb, and Cr were less than the sediment quality guideline (SQG) and the background continental crust. Most applied pollution indices revealed minor enrichment, low contamination and low risk for all HMs, except Sr, which indicated extremely severe enrichment and very high contamination. Sr is incorporated in calcite and aragonite of the invertebrate skeletons and sorbed in hydrated form by clay minerals. The petrochemical wastes from nearby Al-Jubail industrial city, Zn refineries, and intensive use of phosphate fertilizers might be the potential anthropogenic sources of Sr in the study area.

Keywords: Heavy metals, Pollution index, Coastal sediment, Strontium, Ras Abu Ali Island.