Trace metal and TBT pollution in the Gulf and Oman: spatial variation and hot spots.

This review assesses trace metal concentrations in nearshore and offshore bottom sediments in the Arabian Gulf and Oman focusing particularly on targeted monitoring studies of point sources of contamination near industrial zones (sometimes with ports) and desalination and power plants (often co-located). Concerns have been raised about harmful impacts from accumulation of metals in the semi-enclosed Gulf. The sediment trace metal contaminants of the greatest concern are highlighted with maximum levels of toxic trace metals such as As, Cd, Cu, Pb, Hg, Ni, Zn, and TBT recorded near port and ship repair yards/dry docks as well as industrial and power/desalination plant discharge outfalls. The levels of metals such as Cd, Pb, and Hg exceeding sediment quality guidelines at identified hot spots are of concern. Efforts to mitigate future impacts are recommended.