| Summary: | The report summarises the monitoring activities within the National Swedish Contaminant Programme for freshwater biota. Each monitored contaminant has been examined in pike, perch or Arctic char from 32 lakes from the north to the south in Sweden. No general trend could be seen for mercury, and all samples were above the EU threshold. Lead was generally decreasing. Cadmium concentrations showed no consistent trends over the monitored period, and cadmium concentrations in 2017 were below the suggested threshold in all lakes. Nickel showed a general upward trend in 30% of the perch lakes. Arsenic concentrations showed no general spatial pattern and were increasing in liver from Arctic char, pike and perch from approximately 50 % of the sampling sites. Tin concentrations decreased in the majority of the perch time series during the most recent ten years. For copper, no general spatial pattern existed for concentrations in perch and about one third of the monitored lakes showed an upward trend. No general trend was observed for silver and aluminum. In general, downward trends were seen for; PCBs, HCHs, DDT, DDE and PCDD/Fs in all species (with a few exceptions). The chlorinated compounds generally showed a somewhat higher concentration in the southern parts of Sweden. Most chlorinated compounds were below the suggested target levels. No general trend was seen during the monitoring period for PBDEs. However an indication of decreasing concentrations of PBDEs is seen in the most recent years. The concentration of HBCDD was under LOQ in a majority of the samples. Several of the perfluorinated carboxylic compounds showed an increase in concentration in arctic char, while PFOS and FOSA decreased. In perch PFOS has decreased since 1995. Higher concentrations of perfluorinated compounds can in general be seen in the southern part of Sweden. In all lakes, PFOS is below the target level for all species.
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