Övervakning av metaller och organiska miljögifter i limnisk biota (fram till 2018 års data)

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 and concentrations were below the target level in all lakes. Cadmium concentrations showed no consistent trends over the monitored period, and cadmium concentrations were below the target level in all lakes. Nickel, arsenic, and copper showed upward trends in 30-50 % of the sampling sites. For zink, silver, and aluminium there were no clear temporal trends. Tin concentrations were below the limit of quantification for most sampling sites and throughout all years of sampling. 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 during the most recent 10 year period, downward trends were seen in pike from Bolmen. 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 no trend was seen for PFOS. In perch, PFOS has decreased since 1980 while upward trends were seen for several carboxylic acids from 1980. 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