Characterizing the marine mammal exposome by iceberg modeling, linking chemical analysis and bioassays.

The present study complements work on mixture effects measured with bioassays of passive equilibrium sampling extracts using the silicone polydimethylsiloxane (PDMS) in organs from marine mammals with chemical profiling. Blubber, liver, kidney and brain tissues of harbor porpoise (), harbor seal (), ringed seal () and orca () from the North and Baltic Seas were investigated. We analyzed 117 chemicals including legacy and emerging contaminants using gas chromatography-high resolution mass spectrometry and quantified 70 of those chemicals in at least one sample.

Activation of the xenobiotic metabolism and oxidative stress response by mixtures of organic pollutants extracted with in-tissue passive sampling from liver, kidney, brain and blubber of marine mammals.

We used in-tissue passive equilibrium sampling using the silicone polydimethylsiloxane (PDMS) to transfer chemical mixtures present in organs from marine mammals with lipid contents between 2.3 and 99%into in vitro bioassays. Tissues from five harbor porpoises (Phocoena phocoena), one harbor seal (Phoca vitulina) and one orca (Orcinus orca) from the North and Baltic Seas were sampled until thermodynamic equilibrium was reached.

Influence of Co-Dosed Lipids from Biota Extracts on the Availability of Chemicals in In Vitro Cell-Based Bioassays.

Extraction of chemicals from biota leads to co-extraction of lipids. When dosing such extracts into in vitro bioassays, co-dosed lipids act as an additional phase that can reduce the bioavailability of the chemicals and the apparent sensitivity of the assay. Equilibrium partitioning between medium, cells, and co-dosed lipids was described with an existing equilibrium partitioning model for cell-based bioassays extended by an additional lipid phase.