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.Mercury concentrations in perch show no spatial pattern across Sweden and there are no consistent time trends for all lakes. Significantly decreasing concentrations in perch are seen in 25 % of the lakes. The mercury concentrations are above the EU threshold for all sampled fish throughout Sweden.Aluminium, arsenic, nickel, and lead generally show decreasing concentrations during the last ten years.Lead shows concentrations below the threshold for all the perch lakes and for cadmium concentrations are below the threshold for all except one perch lake.

For the longest time trends in pike, Arctic char and perch (starting in 1970s or 80s) downward temporal trends are observed for the chlorinated compounds, e.g. polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethylene (DDE) polychlorinated dibenzo-p-dioxins and -furans (PCDD/Fs). Concentrations of hexachlorobenzene (HCB) and HCHs are below LOQ during the last 15 years. Most chlorinated compounds were below the suggested target levels.

There is no general spatial pattern for the polybrominated diphenyl ethers (PBDEs) in perch. Concentrations of PBDEs are generally, in all three species, going down during the last ten years.The concentration of HBCDD was under LOQ in a majority of the samples.

Concentrations of PFOS are somewhat similar among perch lakes but with more lakes in the northern part of Sweden having lower concentrations. There is no spatial pattern for the perfluoroalkyl carboxylic acids (PFCAs). For PFOS no clear trends are seen during the last ten years but many lakes show decreasing trends from 2006/2007 until 2020. Significantly decreasing trends are seen for ~30 % of the long-chained PFCAs (PFUnDA, PFDoDA, PFTrDA) during the last ten years.In all lakes, PFOS is below the target level for all species.