Sedimentary record of anthropogenic chemical and organic pollution in a Mediterranean coastal area (Gulf of Palermo, Italy).

Abstract

The relatively high influx of unregulated industrial and domestic effluents has progressively degraded the Palermo coastal environment in NW Sicily. To evaluate the poorly known effects of these inputs on the Palermo Gulf, three sediment box-cores were collected along a transect perpendicular to the coast, in front of the Oreto river mouth, in water depths of 20—750 m. The samples, dated by 210Pb and 137Cs, were analysed for concentration of major/trace elements, total polycyclic aromatic hydrocarbon (PAH), total organic carbon (TOC) and for organic carbon and nitrogen isotopic compositions. Total organic carbon concentrations show relatively high values (0.4—2.9%), with a decreasing seawards trend. An increasing contamination over the last 80 years was revealed by trace metal (notably Pb, Hg, As, and Cr) and PAH concentration patterns. These concentrations appear to be potentially hazardous, grossly exceeding national and international regulatory guidelines. In the central sector of the Palermo Gulf, changes in the Corg/Ntot ratios and δ13Corg values suggest that a eutrophication process, rather than direct land runoff, is currently developing.