Analysis of non-ortho polychlorinated biphenyls and polychlorinated naphthalenes in Swedish dioxin survey samples

The coplanar (non-ortho) polychlorinated biphenyls (pPCB) 3,3′4,4′-tetrachlorobiphenyl (IUPAC 77), 3,3′4,4′5-pentachlorobiphenyl (IUPAC 126), 3,3′4,4′5,5′-hexachlorobiphenyl (IUPAC 169) and polychlorinated naphthalenes (PCN) were analyzed in biological and sediment samples. The predominant congeners found in biological samples were IUPAC 77, IUPAC 126, two early eluting pentachloronaphthalenes and one early eluting hexachloronaphthalene. Baltic herring show seasonal differences in pPCB and PCN levels. The lipid weight levels in cod muscle and liver are very similar despite differences in fat content. Pike and sediment from a PCB-contaminated river contain very high levels of pPCB and PCN but have PCDD/F levels that are not unusually high. There are differences in the levels and isomer pattern between the sediment and pike indicating metabolism and bioaccumulation. There is a significant correlation between total and planar PCB content in herring and cod samples. The toxic potential of pPCB in most of the fish samples expressed as TCDD toxic equivalents more than equals that of PCDD/F.