Concentrations of polychlorinated dibenzo-p-dioxins and furans in fish downstream from a Ky-5 manufacturing

Concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD /Fs) were studied in seven fish species, burbot (Lota lota), pike (Esox luc ius), perch (Perca fluviatilis), pikeperch (Stizopedion lucioperca), bream Abramis brama), salmon (Salmo salar.) and Baltic herring (Clupea harengus m embras) in River Kymijoki and its estuary polluted by Ky-5 manufacturing. T he fish were caught at 14 localities along the river and its estuary. The s elected species represent different trophic levels and/or inhabit different environments. The concentrations of PCDD/Fs were low, in most samples belo w 1 pg g(-1) ITEQ (NATO/CCMS 1988) fresh weight (fw) in muscle, except salm on and Baltic herring. These two species graze at the open sea and conseque ntly accumulate contaminants at a large area in the Baltic Sea. The lipid c ontent in salmon and Baltic herring was an order of magnitude higher than i n other species. PCDD/Fs in fish muscle showed only slightly elevated level s in the Kymijoki area and its estuary as compared to the levels in the sam e species in Finnish freshwaters and sea areas. The concentration of the ma in impurities of the fungicide Ky-5 was higher in the Kymijoki River downst ream the Ky-5 manufacturing place compared to the upstream locations. The P CDD/F concentrations in fish liver and spawn were 10-100 times higher than the concentration in muscle, because of the much higher lipid concentration s of these organes. Consequently, the tolerable daily intake values could b e as much as 100 times smaller (M. Korhonen, M. Verta, T. Vartiainen, Organ ohalog. Comp. 32 (1997) 305-310; P. Mikkelson, J. Paasivirta, H. Kiviranta, Organohalog. Comp. 39 (1998) 59-62). (C) 2001 Elsevier Science Ltd. All ri ghts reserved.