|
(417) PCBs in wildlife: the info is in the patterns. van den Brink, Nico1, Bosveld, Albertus1, 1 ABSTRACT- In terrestrial ecosystems a large mixture of contaminants, among which PCBs, pose a threat to the structure and functioning of these systems. PCBs are a group of compounds (congeners) each with an unique chlorine substitution pattern, and as a result with unique properties which may determine the fate of the specific congener in the environment. A detailed pattern analysis of the occurring PCB congeners in a given sample, which incorporates these congener specific information, may reveal information on for instance the origin of the PCBs in soil, the foodweb structure accumulating the PCBs or on the effects of PCBs in vertebrates up in the foodweb. Origin of PCBs. Recent results of PCBs in earthworms from areas less than 50 km apart show that the congener pattern in worms from a farming area was relatively more volatile than the pattern in worms from floodplains. This implies that the source of PCBs in the farming area was atmospheric transport, while in the floodplains the PCBs were transported sorbed to (organic) particles in the river water. Effects of PCBs. Recent research has shown that changes in PCB patterns in organisms can be related to CYP1A1 induction (EROD), indicating Ah-receptor mediated metabolism of PCBs by P450 iso-enzymes. These findings suggest that a PCB pattern analysis, which can be performed in bloodsamples, is a non-destructive biomarker for effects of Ah-receptor active compounds like PCBs and dioxins. These and other examples will be presented, to show that a (multivariate) analysis of PCB patterns, based on PCB congener specific information, will take the interpretation of environmental data on contaminants a step further. Key words: PCB pattern analysis, non-destructive biomarker, exposure route, EROD alternative |
