Levels and distribution of polychlorinated biphenyls in Jeddah Coastal Sediments,Red Sea,Saudi Arabia

Thirty sediment samples were collected from six sites in jeddah coast,red sea to assess the concentration levels of polychlorinated biphenyls (pcbs). concentrations of σ19 pcbs at the study area were ranged from 0.58 to 15.63 ng/g dry weight. the highest concentrations were recorded in the semi closed lagoons al-shabab and al-arbaeen (sites 4 and 5) which are highly influenced by sewage dumping. textural classification of the sediments was found to be highly correlated with pcbs concentrations. pcb congener # 87 (penta-cb) showed the highest concentration among the 19 pcbs congeners. the descending order of different pcbs congeners was: penta-cb > tetra-cb > hexa-cb > mono-cb > tri-cb > hepta-cb > nona-cb. the medium pcbs congeners penta-,tetra- and hexa-cbs represented the major components at all sites. aerobic and anaerobic environmental conditions change the homologue percentage in all stations. the contamination levels of pcbs in all sites were found to be below the two common sediment quality guidelines; the effects range-low value (erl) and the threshold effects level (tel). © 2015,chemical society of pakistan. all rights reserved.