Dioxins, dioxin-like PCB compounds and indicator PCBs

Despite their good nutritional properties, the consumption of salmon, sea trout, river lamprey or large herring caught in the Baltic Sea may expose people to higher than normal quantities of industrial pollutants that is detrimental to health: dioxins and furans, dioxin-like PCB (DL -PCB) compounds and non-dioxin-like compounds (= indicator PCBs).

Being fat-soluble, these compounds accumulate in the fat tissue of fish, and from fish in people, who eat fish. They accumulate in the body with age. Old and large fish contain more dioxin and PCB than young fish. Fish are the most important source of dioxin and PCB:s intake in Finland.

Dioxins and PCBs may cause endocrinological disorders. In high levels they are carcinogenic compounds.

Regulatory maximum levels have been laid down for dioxins and PCB compounds. However, Finland and Sweden have been granted a permanent derogation to exceed maximum limits amended in the regulation as far as salmon, herring, arctic char, river lamprey and trout caught in the Baltic Sea are concerned. The exemption is conditional and requires that restrictions be defined in general advice on fish consumption and the consumers informed about them.

The accumulation of dioxins and PCB compounds in fish varies between species and habitats. Levels of dioxins and PCB compounds are low in lake fish and farmed fish (rainbow trout and Atlantic salmon) fed with feed. In polluted areas, however, fresh water fish can show high levels.

Dioxins (PCCB/F compounds)

  • 17 compounds containing chlorine
  • Dioxins are produced as a result of incomplete combustion and chlorination. Chlorophenols used in sawmills, for example, contain dioxins as impurities.
  • The most significant environmental pollutants are airborne emissions from energy production as well as from metal and pulp industries.

PCB compounds

  • 12 dioxin-like PCBs
    (= DL -PCB)
    as well as
    6 indicator PCBs
  • Used in industry as flame retardants, in transformer oils and in plastic industry.
  • Their use was forbidden everywhere in Europe in the 1980s. PCB levels are expected to continue to decrease.