Contaminants in fish from potentially polluted sites along the Swedish coast with the nationalmonitoring programme as reference

In this report, fish from potentially polluted sites along the coast of Sweden were analysed for several contaminants and when possible also compared with concentrations in fish from reference sites used within the national monitoring programme for contaminants in marine biota. However, it is important to have in mind that for the polluted sites, sampling has only been carried one single year and only two pooled samples were analysed from each site, which could have effects on the representativeness and the uncertainty of the results. Generally, perch and herring from Lilla Värtan had the highest concentrations of mercury, lead, nickel, silver, CB-153 and CB-118, DDE, dioxins, brominated flame retardants, perfluorinated chemicals, chlorinated paraffins and organotin compounds compared to the other polluted sites. Among the stations where eelpout and cod were sampled, Rivöfjord had highest concentration of several contaminants. The contaminants include mercury, lead, chromium, CB-153 and CB-118, dioxins, brominated flame retardants, perfluorinated chemicals, chlorinated paraffins and organotin compounds. It is not very surprising that these two areas show the highest concentrations of several of the investigated contaminants in fish. Lilla Värtan is situated in Stockholm and hence is affected by the big city, in addition, heavy boat traffic of different kinds are taking place in this water along with several other harmful environmental activities in this area. SCCP showed the highest concentrations in herring from Lilla Värtan, while perch on the contrary had the lowest concentration of SCCP among all of the perch sites. This is however difficult to explain. Rivö fjord is situated just outside Gothenburg city and is thus affected by activities in the city. Also, the main part of Gothenburg’s harbor activities takes place close by Rivö fjord. Moreover, Ryaverken, which is a sewage treatment plant, and two refineries are also affecting the water. Thus, the two largest cities in Sweden contribute with a cocktail of contaminants to its surrounding waters. In addition, fish from Skelleftebukten, herring and/or perch, had elevated concentrations of lead, cadmium, nickel, copper, HCB and BDE-47 and -154. The elevated concentrations of different metals in this area could be caused by Rönnskärsverken, which releases metals. In addition, there are several industries and mining practices in the area that could have contributed with high metal levels. Furthermore, dismantlement activities might contribute with the high levels of brominated flame retardants found in this area. Kungsbackafjorden, on the Swedish west coast, had high concentrations of cadmium and copper in cod and high concentrations of perfluorinated chemicals in both eelpout and cod. There is a sewage treatment plant in the area, which might be one explanation for elevated concentrations of perfluorinated chemicals. Most of the other selected polluted sites for this study had none or just a few contaminants that differed from the reference sites in the vicinity. Thus it seems that these sites might not be as burdened by local sources of the investigated substances as has been assumed. On the other hand, when comparing the concentrations with their target values, a few of the contaminants at these sites were above the target values, this included mercury, CB-118, PBDEs and TBT. However, the concentrations were not significantly different from reference values, which indicates a more widespread problem concerning these contaminants. When comparing contaminant concentrations with their respective target value, mercury concentrations exceeded the target value for all species at all sites except for herring from Örnsköldsviksfjärden. Lead was below the target value at all sites and cadmium was also below at all sites except for perch from Skelleftebukten, which exceeded the target value. 4 CB-153 was in general below the target value, but cod from Rivö fjord and perch from Lilla Värtan exceeded it. In contrast, most polluted sites were above the target value for CB-118 with a few exceptions. Concentrations of DDE were generally below the target value, however perch and herring from Lilla Värtan exceeded it and concentrations of DDE in cod liver were also above, while the concentration in cod muscle were below target value. HCHs, HCB, dioxins, PFOS and HBCDD were below target values for all species at all sites. PBDEs on the other hand exceed the target value for all species at all sites. Concentrations of the priority substances, DEHP (Di-(2-ethylhexyl)-phthalate), HCBD (Hexachlorobutadiene), and PeCB (Pentachlorobenzene) were below the target values, these compounds were even below LOQ at most sites. SCCP (short-chained chlorinated paraffins) were well below the target level for all species at all sites. TBT on the other hand, were in perch above the target value at all sites except at Inre Slätbaken and Skelleftebukten. Yttre fjärden and Lilla Värtan had the highest concentrations of TBT and here the target value was also exceeded in herring. Eelpout and cod had concentrations of TBT below the target value. In conclusion, Lilla Värtan seems to be the site with the highest concentrations of several contaminants and also where several of these exceed the target values. Rivö fjord and Skelleftebukten also had higher concentrations of several contaminants compared to the other polluted sites