Övervakning av metaller och organiska miljögifter i limnisk biota, 2018

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 target level. Lead was generally decreasing. Nickel showed a general upward trend in 50% of the perch lakes. An increase, or indication of an increase, was seen for chromium during the last ten years. Zinc concentrations were decreasing in a majority of the perch samples and in pike from Lake Storvindeln. Arsenic concentrations were increasing in Arctic char and pike from all sites and in perch from a third of the sampling sites. Tin concentrations decreased in the majority of the perch time series during the most recent ten years. No general trend was observed for copper, silver, aluminum, bismuth, and cadmium. 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. Concentrations of PBDEs in Lake Bolmen increased from the 60s and peaked in 1992/1993 and have subsequently decreased. 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.