Source-apportionment shows why dioxin levels have not declined in Baltic fish

• Levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, “dioxins”) in fatty fish of the Baltic Sea have remained high despite declines in environmental levels since the 1980s. This has raised human health concerns and restricted marketing of Baltic herring and salmon within the European Union. Thus, there is an urgent need to identify and control current PCDD/F emission sources. Analysis presented here explains why PCDD/Fs levels in fish have stopped declining or even increased in recent decades. We show that contributions of “thermal” sources (e.g., waste incineration) of PCDD/Fs to Baltic fish have declined since the 1990s, but not contributions of sources associated with the manufacture and use of chlorophenols (particularly tetrachlorophenol and pentachlorophenol, TCP and PCP, respectively). Moreover, the discrepancy between declines in levels of dioxins in abiotic compartments (e.g. sediments and air), and stable or increasing levels in biota can be explained by the persistently high bioavailability of PCDD/Fs associated with TCP and PCP type sources.

Ämnesord

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

Nyckelord

biota

dioxin

pmf

source

temporal trend

baltic sea

Environmental Science

miljövetenskap

Publikations- och innehållstyp

vet (ämneskategori)

ovr (ämneskategori)