Polycyclic aromatic hydrocarbons (PAHs) and organochlorines (OCs) in bottom sediments of the Guba Pechenga, Barents Sea, Russia.

Surface sediment samples from the Guba Penchenga and adjacent areas: Varangerfjord, Guba Malaya Volokovaya and Guba Bol'shaya Volokovaya (south-western Barents Sea) collected in March-April 1997 were analysed for polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), chlorinated pesticides: p,p'-DDT, p,p'-DDE, p,p'-DDD, alpha- and gamma-HCH, and hexachlorobenzene (HCB). Mean summation operator PAH (sum of the two- to six-ring PAHs) concentration in sediments from the Guba Pechenga (1481 ng/g dry wt.) was significantly higher than in sediments from adjacent areas (252 ng/g dry wt.), where PAH contamination levels were similar to reported for unpolluted sediments of the northern Norway fjords and open parts of the Barents Sea. Differences between HCB levels as well as summation operator HCH (sum of alpha- and gamma-HCH) levels found in Guba Pechenga sediments and adjacent area sediments were not significant. Concentrations of these contaminants varied in ranges 0.28-1.76 and 0.05-0.68 ng/g dry wt., respectively, and were consistent with literature data on PAH levels in sediments from the northern Norway harbours, Kola Bay (Russia) and south-eastern part of the Barents Sea. Average total DDT concentration in Guba Pechenga sediments (10.5 ng/g dry wt.) was one and 2-3 orders higher than those found in sediments from the Pechora Sea and from the seas of eastern Arctic, respectively, however, it was comparable with DDT levels reported for harbours of northern Norway and Kola Bay. Significant difference between total DDT levels in Guba Pechenga and in the adjacent areas (mean 1.8 ng/g) was found. Among compounds of DDT family, p,p'-DDT isomer prevailed in all sediment samples indicating a possible local 'fresh' DDT source. Mean summation operator PCB (sum of PCB-28, 31, 52, 101, 118, 105, 153, 138, 156, 180, 209) concentration in the Guba Pechenga sediments (12.8 ng/g dry wt.) was significantly higher than in sediments of adjacent areas (2.1 ng/g dry wt.), but it was lower in comparison with summation operator PCB levels reported for the northern Norway harbours and Kola Bay sediments. The highest levels of contaminants were found in sediments collected close to the Liinakhamari harbour. The origin of both PAHs and OCs in the Guba Pechenga sediments is a combination of local sources and long-range transport from lower latitudes.