Lead (Pb)

In the present study, lead (Pb) was analysed in blue mussel at 31 stations, in cod liver at 17 stations and in eider blood and eggs at one station.

Levels exceeding PROREF

Blue mussel at Odderøya (st. I133) in the Kristiansandfjord exceeded the provisional high reference concentration (PROREF) for Pb by a factor between 10 to 20. The exceedance was by a factor between five and 10 at Eitrheimsneset (st. 52A) in the Inner Sørfjord and Mjelle (st. 97A2) in Bodø area. The exceedance was by a factor between two and five at Gressholmen (st. 30A) in the Inner Oslofjord, Bjørkøya (st. 71A) in the Langesundfjord, Krossanes (st. 57A) in the Outer Sørfjord and Nordnes (st. I241) in the Bergen harbour area. Blue mussel exceeded PROREF by a factor of up to two at 11 stations (Table 12). These stations were Akershuskaia (st. I301) and Gåsøya (st. I304) in the Inner Oslofjord, and Kirkøy (st. I024) in the Outer Oslofjord. This was also the result at Risøya at Risør (st. 76A2), Lastad in Søgne (st. I131A) and Gåsøya-Ullerøya in Farsund (st. 15A). This was also observed at Utne (st. 64A), Ranaskjer (st. 63A) and Vikingneset (st. 65A) in Hardanger. This was also the case at Vågsvåg (st. 26A2) in the Outer Nordfjord and at Bodø harbour (st. 97A3).

Cod liver from the Inner Oslofjord (st. 30B) exceeded PROREF of Pb by a factor between two and five (Table 12). Cod liver from the Inner Sørfjord (st. 53B) exceeded PROREF of Pb by a factor of up to two.

Increase in PROREF factor since 2016

Blue mussel at Mjelle (st. 97A2) exceeded PROREF of Pb by a factor between five and 10 in 2017, while the exceedance was between two and five in 2016. At Bjørkøya (st. 71A) in the

Langesundfjord, the exceedance was between two and five in 2017, while it was no exceedance in 2016. Blue mussel at Kirkøy (st. I024) at Hvaler in the Outer Oslofjord, at Vikingneset (st. 65A) in the Mid Hardangerfjord and at Vågsvåg (st. 26A2) in the Outer Nordfjord exceeded PROREF by a factor up to two in 2017, while there were no exceedances in 2016.

Cod liver from the Inner Oslofjord exceeded PROREF of Pb by a factor between two and five in 2017, while it was no exceedance in 2016.

Upward trends

There were both significant upward long- and short-term trends in blue mussel from Gressholmen (st. 30A) in the Inner Oslofjord.

There were both significant upward long- and short-term trends in cod liver at Tromsø harbour (st. 43B2) (Figure 17 A). There were significant upward short-term trends in cod liver from Bømlo (st. 23B) (Figure 17 B) in the Outer Selbjørnfjord, Austnesfjord (st. 98B1) in Lofoten (Figure 18 A), and Kjøfjord (st. 10B) in the Outer Varangerfjord (Figure 18 B). As is apparent from these figures, the trends were largely influenced by changes in LOQ, and caution is advised when interpreting these results.

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A

B

Figure 17. Median concentrations (mg/kg w.w.) of lead (Pb) in cod liver from 1990 or 2009 to 2017 at Tromsø harbour (st. 43B2) (A) and in the Outer Selbjørnfjord at Bømlo (st. 23B) (B). The

provisional high reference concentration (PROREF) and the factor exceeding PROREF are indicated with horizontal dashed lines (see Figure 5 and Appendix C).

A

B

Figure 18. Median concentrations (mg/kg w.w.) of lead (Pb) in blue mussel from 1992 or 1994 to 2017 in Lofoten at Outer Selbjørnfjord, Austnesfjord (st. 98B1) (A) and in the Outer Varangerfjord at Kjøfjord (st. 10B) (B). The provisional high reference concentration (PROREF) and the factor exceeding PROREF are indicated with horizontal dashed lines (see Figure 5 and Appendix C).

Decrease in PROREF factor since 2016

Blue mussel at Eitrheimsneset (st. 52A) exceeded PROREF of Pb by a factor between five and 10 in 2017, while the exceedance was between 10 and 20 in 2016.

Downward trends

Of the trend analysis performed for blue mussel, 13 revealed significant downward long-term trends (Table 12). Both significant downward long- and short-term trends were observed at Ranaskjer (st. 63A) and Terøya (st. 69A) in the Hardangerfjord, at Nordnes (st. I241) in Bergen harbour, at Espevær (st. 22A) on the west coast and at Skallnes (st. 10A2) in the Varangerfjord. Significant downward long-term trends were found at Akershuskaia (st. I301) and Solbergstrand (st. 31A) in the Oslofjord, at Eitrheimsneset (st. 52A) and Krossanes (st. 57A) in the Sørfjord, and at Vikingneset

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In cod liver, significant downward long-term trends were found in Skågskjera in Farsund (st. 15B), and in the Inner Sørfjord (st. 53B).

Levels in eider

In eider at Breøyane (st. 19N) in the Kongsfjord at Svalbard, the Pb-concentrations were 0.051 mg/kg w.w. in blood and 0.008 mg/kg w.w. in egg.

Other studies

In this study, cod liver from the Inner Oslofjord showed higher concentration (median

0.145 mg/kg Pb w.w.) than observed in a comparable study (mean 0.063 mg/kg Pb w.w.) in the Inner Oslofjord in 2017 (Ruus et al. 2018, in prep). The collection of cod in both studies took place during the autumn.

In this study, Pb-concentration (median 0.008 mg/kg w.w.) in eider egg at Svalbard was on the same level as in a comparable study (median 0.005 mg/kg w.w.) (Hill 2018).

General, large scale trends

There were low levels of Pb in cod liver, except for in the Inner Oslofjord (st. 0.145 mg/kg w.w.).

EU banned leaded-fuel in road vehicles 1 January 2000, but some countries had banned the fuel beforehand (e.g. Sweden, Germany, Portugal). The results indicate that the ban of Pb in gasoline has had a positive effect.

OSPAR (2010) found 50-80 % reduction in riverine and direct discharges of Pb to the North Sea for the period 1990-2006. While the total riverine input of Pb in Norway was 38 tonnes in 2016

(Skarbøvik et al. 2017 – M-862|2017), the riverine inputs of Pb in different areas were 25 tonnes to Skagerrak, 9 tonnes to the North Sea, 3 tonnes to the Norwegian Sea and 1 tonne to the Barents Sea, indicating higher input in the southern part of Norway. Total Pb load dropped 28 % to 38 tonnes in 2016 compared to the mean for the period 1990-2015 (53 tonnes). In addition to riverine inputs, comes the contribution by direct discharges from industrial (1 tonnes) effluents amounting about 2.6 % of the total (38 tonnes). The riverine input to the Inner Oslofjord from Alna river was 0.02 tonnes Pb in 2016. VEAS sewage treatment plant reported a discharge of 36 kg Pb in 2017 (VEAS 2018).

Discharges of Pb to water from land-based industries in Norway showed a decrease from 2010 (6841 kg Pb/year) to 2017 (1870 kg Pb/year) (Figure 19).

Figure 19. Annual emissions of Pb to air and discharges to water from land-based industries in the period 1994-2017 (data from www.norskeutslipp.no, 27 June 2018). 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.