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Polycyclic aromatic hydrocarbons (PAH) have been identified and quantified in dated layers of freshwater and marine sediments in Norway. Furthermore, profiles of the individual PAH (22 different) have been used to evaluate possible PAH sources. There is a significant increase in total PAH levels (sum of the 22 PAH) in freshwater sediments from the south-western part of Norway representing the 1800-1950 period, whereas the concentrations have decreased with a factor of approximately four since the 1950s. This pronounced trend was observed in two independent surveys. In northern Norway, the PAH levels in lake sediments have increased slightly during the past decades. In spite of this, the levels are considerably lower than in lake sediments from the south-western part of Norway. In fact, the PAH levels are decreasing northwards on the Norwegian mainland for both freshwater and marine surface sediments. Generally, the regional total PAH levels are higher (three to four times) in freshwater sites compared to the corresponding marine sites. Results of PAH source allocation indicate that pyrogenic sources are important in almost all sediment samples studied. Sediment samples were also collected at Svalbard where the local coal reserve is the major contributor to PAH. [ABSTRACT FROM AUTHOR]

In order to reveal possible multi-year dynamics in sediment PAH concentrations and composition, data sets from the years 2001-2005 have been compared with data sets obtained during the years 1992-1998. K-means-clustering of the 2001-2005 data sets suggests dividing the sampling area into five geographical areas based upon levels and compositions of PAHs. The five areas are Svalbard offshore, Bear Island Trough, SW Barents Sea, NE Barents Sea and SE Barents Sea. Comparison of the two groups of data sets revealed no significant differences between geometric means of PAH concentrations and PAH ratios for sediments from Svalbard offshore, Bear Island Trough and NE Barents Sea. These results are supported by down core analyses of PAH distributions. In the SW Barents Sea area, mean total PAH concentrations found in the 2000s and 1990s did not differ significantly. However, the sum of two- to three-ring PAH compounds and Fossil Fuel Pollution Index in samples of 2000s were significantly higher than in data sets from the 1990s. In the SE Barents Sea area, both total concentrations of pyrogenic PAHs and PAH ratios in the data sets from the 2000s were significantly higher than the 1990s data sets, which suggest higher input of combustion and/or anthropogenic PAHs. [ABSTRACT FROM AUTHOR]

The top 2cm of forest soils were collected along a 120km long south–north transect running through Norway''s largest city Oslo. Forty samples were analysed for their polycyclic aromatic hydrocarbon (PAH16 as defined by the U. S. Environmental Protection Agency) concentrations and compositions. Local variations in the PAH values are high and the reported concentrations are in general low (maximum sumPAH16: 2. 6mg/kg). The transect shows distinct differences of sumPAH16 values from south to north. PAH concentrations are substantially lower in the less populated areas at the north end of the transect than at the urbanised and much more populated south end. Several high values occur in a forested area to the north of Oslo, used for recreation purposes. The PAH distribution patterns point towards a predominantly pyrogenic origin. Local Cambrian carbon-rich black shales can be excluded as sources for PAHs in the forest soils. [Copyright &y& Elsevier]