Combining passive sampling with recombinant receptor-reporter gene bioassays to assess the receptor activity of Victorian rivers

This pilot study was initiated to provide new information on the 'hormonal' activity of Victorian rivers. Chemcatcher TM passive sampler systems containing Empore TM C18FF disks were deployed at eight riverine sites near Melbourne. Little estrogenic activity [< 0.4-1.8 ng estradiol equivalents (EQ)/disk] and no retinoic acid activity (RAR, all samples < 0.8 ng trans-retinoic acid EQ/disk) was observed. Almost all sample extracts showed aryl hydrocarbon receptor activity (from < 4 to 29 ng β-naphthoflavone EQ/disk). Overall, the disk extracts were eminently compatible with the bioassay screening technology, enabling the relative levels of 'hormonal activity' to be observed in the surface waters in and around Melbourne. From a practical perspective, the in situ sampling and pre-concentration provided by passive sampling reduces the manual handling risks associated with sample transport, and the number of laboratory operations required to obtain assay-ready solutions for analysis.