Distribution and occurence of polycyclic aromatic hydrocarbons (PAHs) in sediments from the Mar Grande and Gulf of Taranto (Ionian Sea, southern Italy).

Marine sediments from the Mar Grande and Gulf of Taranto were analysed for 17 parent PAHs, with molecular weight from 128 to 278 Daltons. The analyses were performed by gas chromatography coupled to mass spectrometry (GC-MS). Total PAHs content in sediments ranged from 464 to 12522 microg kg(-1) dry wt for Mar Grande and from 593 to 72275 microg kg(-1) dry wt for Gulf of Taranto. The analytical results were compared with the published results for other coastal areas in the Mediterranean Sea. PAHs levels in the Gulf of Taranto sediments were the highest in the Mediterranean sea, while PAHs concentrations in Mar Grande were higher than the ones reported in the Adriatic and Cretan Sea and with the same order of magnitude of the ones known for coastal areas of the Western and the Eastern Mediterranean Sea. PAHs concentration ratios were consistent with the main source of these compounds, in most areas, being pyrolysis. Based on the comparison of both the individual and the total PAHs concentrations with proposed sediment quality guidelines, the acute biological effects on the marine organisms were probable, especially for the Gulf of Taranto, in which almost all PAHs concentrations in sediments were higher than the guidelines limit values. The statistical analysis effected by HCA and PCA methods was used in order to classify sediment samples and to identify accumulation areas.