Polychlorinated biphenyls (PCB-7)

Polychlorinated biphenyls (defined here as PCB-7, see Table 4) are a group of chlorinated organic compounds that previously had a broad industrial and commercial application. In the present study, PCB-7 was analysed in blue mussel at 30 stations, in cod liver at 16 stations and in eider blood and eggs at one station.

Environmental Quality Standards (EQS) for River Basin Specific Pollutants

When applying the EQS for PCB-7 (0.6 µg/kg w.w.) in biota on blue mussel (see Table 7), the concentrations at all stations exceeded the limit.

When applying the EQS for PCB-7 (0.6 µg/kg w.w.) on cod liver (see Table 7), all stations exceed this value.

Levels exceeding PROREF

Blue mussel exceeded the provisional high reference concentration (PROREF) for PCB-7 at all stations. The mussels exceeded the limit by a factor between five to 10 times at Akershuskaia (st. I301) and Gressholmen (st. 30A) in the Oslofjord, and at Nordnes in Bergen harbour (st. I241).

The exceedance was between a factor of two and five at Gåsøya (st. I304), Solbergstrand (st. 31A), Singlekalven (st. I023) and Kirkøy (st. I024) in the Oslofjord. This was also the result at Odderøya (st. I133) in the Kristiansandfjord, and Eitrheimsneset (st. 52A) and Kvalnes (st. 56A) in the Sørfjord.

This was also the case at Ålesund harbour (st. 28A2), Ørland area in the Outer Trondheimfjord (st. 91A2), and Bodø harbour (st. 97A3). The exceedance was by a factor up to two at the remaining 17 blue mussel stations.

The PROREF in cod liver was exceeded by a factor between five and 10 at Bergen harbour (st. 24B), between two and five in the Inner Oslofjord (st. 30B) and in the Inner Sørfjord (st. 53B), and up to two at the areas of Kristiansand harbour (st. 13B) and Ålesund harbour (st. 28B).

Increase in PROREF factor since 2016

Blue mussel at 23 stations had increased PROREF factors since 2016. The PROREF was exceeded by a factor between five and 10 in 2017, while the exceedance was between two and five in 2016 at Nordnes (st. I241) in Bergen harbour. The exceedance was a factor between two and five in 2017, while it was up to a factor of two in 2016 at Gåsøya (st. I304) in the Inner Oslofjord, Eitrheimsneset (st. 52A) in the Inner Sørfjord, and Ørland area (st. 91A2) in the Outer Trondheimfjord. The

exceedance was a factor between two and five in 2017, while it was no exceedance in 2016 at Solbergstrand (st. 31A), Singlekalven (st. I023) and Kirkøy (st. I024) in the Oslofjord. This was also the case at Odderøya (st. I133) in the Kristiansand harbour and Kvalnes (st. 56A) in the Mid Sørfjord.

At 14 blue mussel stations, the PROREF was exceeded by a factor up to two in 2017, while it was no exceedance in 2016. These stations were Mølen (st. 35A) and Færder (st. 36A) in the Oslofjord, Risøya (st. 76A2) at Risør, and Gåsøya-Ullerøya (st. 15A) in Farsund. This was also the case at Krossanes (st. 57A) and Utne (st. 64A) in the Sørfjord, and at Ranaskjer (st. 63A), Vikingneset (st. 65A) and Terøya (st. 69A) in the Hardangerfjord. The same result was found at Espevær

(st. 22A) in the Outer Bømlafjord, Mjelle (st. 97A2) in Bodø area and Svolvær airport (st. 98A2). This was also observed at Skallnes (st. 10A2) and Brashavn (st. 11X) in the Outer Varangerfjord.

In 2017, the PROREF in cod liver was exceeded by a factor of two to five in the Inner Sørfjord, and by a factor up to two at Kristiansand harbour (st. 13B) and Ålesund harbour (st. 28B), while there were no exceedances in 2016.

Upward trends

In blue mussel, there were both significant upward long- and short-term trends at Vågsvåg (st. 26A2) in the Outer Nordfjord.

Decrease in PROREF factor since 2016

In cod liver, the PROREF was exceeded by a factor between five and 10 at Bergen harbour (st. 24B) in 2017, while the exceedance was by a factor between two and five in 2016.

Downward trends

For blue mussel, there were significant downward long-term trends at 20 of the 29 stations (Table 12). At Gåsøya (st. I301) in the Inner Oslofjord, there was also a significant downward short-term trend.

For cod liver, there were significant downward long-term trends at seven of the 16 stations. These stations were Skågskjera in Farsund (st. 15B), Bømlo (st. 23B), Austnesfjord (st. 98B1) in Lofoten and Kjøfjord in the Varangerfjord (st. 10B). Significant downward short-term trends were also observed in cod liver from Kirkøy at Hvaler (st. 02B), Trondheim harbour (st. 80B), and Hammerfest harbour area (st. 45B2). A significant downward short-term trend was found in the Inner Oslofjord (st. 30B).

The Inner Oslofjord

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Cod liver caught at 100 m depth in the Inner Oslofjord (st. 30B) exceeded PROREF by a factor between two to five in both 2015, 2016 and 2017. A significant downward short-term trend was detected in 2017 (Figure 35a). When adjusting for length, a significant downward short-term trend was also registered (Figure 35b).

A

B

Figure 35. Median concentrations (mg/kg w.w.) of PCB-7 in cod liver from 1990 to 2017 in the Inner Oslofjord (st. 30B); no adjustment for length (A) and adjusted for length (B). The EQS is indicated with a horizontal red line, and provisional high reference concentration (PROREF) and the factor exceeding PROREF are indicated with horizontal dashed lines (see Figure 5 and Appendix C).

Levels in eider

In eider at Breøyane (st. 19N) in the Kongsfjord at Svalbard, the concentrations of PCB-7 were

<0.692 µg/kg w.w. in blood and 12.811 µg/kg w.w. in eggs.

Other studies

In this study, cod liver from the Inner Oslofjord revealed a median concentration of

2 615.3 µg PCB-7/kg (w.w.). Cod liver from a comparable study from the Inner Oslofjord in 2017 had almost the same mean concentration (2842.2 µg PCB-7/kg w.w.) (Ruus et al. 2018, in prep).

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surfaces is the most important contributor (2.1 kg/year). It is also anticipated that sediments in the fjord store much of the historic inputs of PCB, but their role as a current source of PCBs for uptake in biota is unclear. Parts of the Inner Oslofjord are densely populated with much urban activities.

The high concentrations of PCBs observed in cod liver are probably related to these activities both in past and possibly also at present.

In this study, the concentration of PCB-153 (median <0.255 µg/kg w.w.) in eider blood at Svalbard were higher than in a comparable study from Svalbard (mean 0.187±0.023.8 µg/kg w.w. after 5 days of incubation) (Bustnes 2010).

In this study, the median concentrations of PCB-7 were <0.692 µg/kg w.w. in blood and

12.811 µg/kg w.w. in eggs at Svalbard. In a comparable study in the Inner Oslofjord from 2017, the mean concentrations of PCB-7 in eider were 10.52 µg/kg w.w. in blood and 138.31 µg/kg w.w. in eggs (Ruus et al. 2018, in prep).

General, large scale trends

In Norway, the use of PCBs has been prohibited since 1980, but leakage from old products as well as landfills and natural deposits and contaminated sediments may still be a source of contamination.

Production and new use of PCBs are prohibited globally through the ECE-POPs protocol and the Stockholm Convention.

Emissions of PCBs to air and discharges to water from land-based industries are shown in Figure 36.

High emission to air was reported in 2008 (140 g PCB/year), while the emission was 53 g PCB/year in 2017. The discharges to water had increased to 53 g PCBs in 2017 from 40 g PCBs in 2016.

Investigations by Schuster et al. (2010) indicate that emissions in the northern Europe have declined during the period 1994-2008 by about 50 %.

Figure 36. Annual emissions of PCBs to air and discharges to water from land-based industries in the period 1997-2016 (data from www.norskeutslipp.no, 27 June 2018). No data for emissions to air are reported for 2005 and 2011-2014. No data for discharges to water are reported for 1994-1996. Note that emissions and discharges from municipal treatment plants, land runoff,

transportation and offshore industry are not accounted for in the figure. New calculation methods for data of emissions and discharges might lead to changes in calculations of present and previous data.