POLYCHLORINATED-BIPHENYLS AND POLYCHLORINATED NAPHTHALENES IN SWEDISHSEDIMENT AND BIOTA - LEVELS, PATTERNS, AND TIME TRENDS

Levels of non-ortho-polychlorinated biphenyls (PCB), some mono-ortho-P CB, and resolved peaks of tetra- to heptachloronaphthalenes are report ed in biological and sediment samples from the Swedish environment. Th e results show that levels of individual PCB congeners, and especially PCB 126, may pose a greater threat to the environment than the 2,3,7, 8-chlorinated dioxins and furans when expressed as 2,3,7,8-tetrachloro dibenzodioxin (TCDD) toxic equivalents. Polychlorinated naphthalenes a re as widespread pollutants as PCB, and at some locations the pollutio n situation indicates a specific source, leading to a bioaccumulating hexachloronaphthalene contributing considerably to the total TCDD-like toxicity. A time trend study of guillemot eggs from the Baltic Proper seems to indicate that levels of non-ortho-PCB and -PCN have decrease d since the 1970s.