Polychlorinated biphenyls contamination, marine organisms

Polychlorinated biphenyls (PCBs) and dioxins are two groups of toxic organic contaminants that are widespread throughout the ecosystem as a consequence of its persistence and potential for bioaccumulation in the environment. These occur in water, air, soil, sediment, and biota in different areas around the world. In general, water birds and marine mammals have accumulated the dioxins and dioxin-Uke PCBs with much higher concentrations than humans, implying higher risk from exposure to wildlife. ... 

Persistent or non-degradable environmental chemicals - even those with low volatility - may be dispersed around the globe. Polychlorinated biphenyls (PCB), polychlorinated dibenzodioxins and dibenzofurans (PCDD, PCDF), l,l,l-trichlor-2,2-bis(4-chlorphenyl)-ethan DDT, hexachlorocyclohexane (HCH) and hexachlorobenzene (HCB) have been found in samples from the Arctic and Antarctic and in the tissues of marine animals. Although the open use of many of these chemicals has been prohibited in most industrialized countries, considerable residues still remain in the environment. It is estimated that about 20% of the global production of PCBs (230 000 t/a) persists in the upper layers of the oceans and that a further 7901 are present in the atmosphere (Fiedler and Lau, 1998). Such contamination may accumulate in organisms and have negative effects that go as far as the death of whole populations in ecosystems (Jdrgensen, 1998). 

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