title: Assessing exposure of sediment biota to organic contaminants by thin-film solid phase extraction.
abstract: Differences in bioavailability among sediments are a source of variability and uncertainty in sediment quality assessment. We present three sets of studies designed to test a thin-film solid phase extraction technique for characterizing the bioavailability of organic chemicals in sediments. Laboratory studies with spiked natural sediments reveal highly reproducible thin-film extractions for chemicals with octanol-water partition coefficients between 10(4.5) and 10(8.5), with 95% equilibration times between 1 and 600 h. Studies with field-collected sediments illustrate that method detection limits are sufficiently low for field application at contaminated sites. Bioaccumulation studies with clams (Macoma balthica) show excellent correlations between thin-film and animal tissue concentrations. We conclude that thin-film extraction provides an ecologically relevant, fugacity-based measure of chemical exposure that can be expected to improve sediment quality assessments.
authors.affiliation: School of Resource and Environmental Management, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia V5A 1S6, Canada.
authors.forename: Lizanne M
authors.initials: LM
authors.lastname: Meloche
authors.forename: Adrian M H
authors.initials: AM
authors.lastname: DeBruyn
authors.forename: S Victoria
authors.initials: SV
authors.lastname: Otton
authors.forename: Michael G
authors.initials: MG
authors.lastname: Ikonomou
authors.forename: Frank A P C
authors.initials: FA
authors.lastname: Gobas