PCB concentrations and metabolism patterns in common terns (Sterna hirundo) from different breeding colonies in the Netherlands

PCB levels in blood of common terns (Sterna hirundo) from Terneuzen, a bree ding colony in The Netherlands with relatively low breeding success, were s ignificantly higher than in birds from two Dutch reference colonies, one ne arby (Oesterdam) and one further away (the Isle of Griend). However, a deta iled analysis of the patterns of PCB congeners in birds from the different colonies indicated that birds from Terneuzen and to a lesser extent birds f rom the Oesterdam showed Ah-receptor mediated activity of P-450 iso-enzymes . It is concluded that the induction of tills enzyme activity in Terneuzen may be related to PCBs as well as other non-identified compounds, In contra st to this, it is likely that at the Oesterdam non-identified compounds are mainly responsible for the enzyme activity, resulting in a shift of PCB co ngener patterns. (C) 2001 Elsevier Science Ltd. AII rights reserved.