Spatial variation of trace elements in seawater and sediment samples in a heavily industrialized region

Surface seawater and coastal sediment samples were collected concurrently at 22 sampling sites during two sampling periods in the Aliaga industrial region, Turkey. In the study area there are two major bays, with many ports belonging to a petrochemical plant, a petroleum refinery, scrap steel production plants, and a fertilizer plant. Samples were analyzed for 48 trace elements using an ICP-MS system. The concentrations of P, Al, Zn, Fe, Se, Mo, and Ba were found to be higher than those of the other elements in the seawater samples but with no significant spatial and temporal variations. Similarly, concentrations of Al, Ba, Ca, Fe, K, Mg, Mn, Na, P, Sr, and Zn were high in sediment samples from almost all sampling sites. The concentrations of the elements Pb, Cd, Cr, Cu, Co, Sn, Mo, Ni, and Hg showed significant spatial variations due to different distances from industrial facilities. In order to determine the contribution of anthropogenic sources in sediment samples, the levels of pollution were evaluated using pollution indicators, enrichment factors and index of geoaccumulation. The effects on aquatic environments were also determined in accordance with the sediment quality guidelines. Principal component analysis was also employed to find out the factors affecting the elemental composition of the sediments. Principal component analysis indicated that the possible sources in the region were iron-steel production, refinery and petrochemical processes, ship breaking facilities, seawater, crustal sources and re-suspended dust