文摘
Elevated concentrations of planar, halogenated hydrocarbons have been linked to reproductive problems in avariety of fish-eating birds and mammals in the GreatLakesand in particular Saginaw Bay. Currently, there arenoaccurate procedures to assess bioavailability of thesecontaminants. Polychlorinated dibenzo-p-dioxinsanddibenzofurans and mono- andnon-ortho-chloro-substitutedbiphenyls in water at the femtogram to picogram per literrange were passively concentrated in semipermeable membrane devices (SPMDs), and these data were comparedto the bioconcentration in co-exposed (caged) channelcatfish.Sediment-derived water concentration estimates,calculatedfrom a steady-state partitioning model, did not correlatewell to those derived from either fish or SPMDs. The useofSPMDs demonstrated the utility of in-situ passivesamplingover inference of water concentrations from accumulationin biota or partitioning with sediment. Residues accumulated by SPMDs have been shown to be proportionalto analyte water concentration, whereas this does notappear to be the case for fish tissues. The greateramountsof 3,3',4,4'-tetrachlorobiphenyl and 2,3,7,8-tetrachlorodibenzofuran accumulated in SPMDs than in exposed channelcatfish indicated those non-passive aspects of bioconcentration in organisms, such as biotransformation andelimination, introduced 50-500% error in the assumeddegree of exposure.
