To study the specific, receptor-mediated toxicity of oils and the effects of weathering on both in vitro and in vivo toxicity.

Investigating the specific toxicity of a series of different crude oils and refined petroleum products, with:

• In vitro bioassays using mammalian cells (DR-luc, ER-luc, T-Screen, CAFLUX, MCF-7, LNCaP);
• Yeast bioassays (hERalpha, hERbeta, hAR);
• Fractionation procedures to identify specific toxic fractions, according to chemistry and environmental behavior;
• Special emphasis on the chemistry behind dosing (i.e., developing a bioavailability-driven method for oil dosing);

Investigating the in vivo toxicity of different oils, using:

• Both fresh water and marine organisms (Lumbriculus variegatus, Chorophium volutator);

Investigating the effects of weathering on both in vitro and in vivo toxicity of different oils, by:

• Performing weathering experiments in which both marine and freshwater sediments are contaminated with different (concentrations of) oils and allowed to weather for increasing lengths of time. Both in vivo and in vitro toxicity (applying several of the above assays) is followed as a function of weathering time.

Oil is the collective noun for a complex mixture composed of thousands of individual hydrocarbons. Risk assessment of sediments and soils contaminated with oil is based on the assumption that oil causes non-specific baseline toxicity (narcosis) only. However, indications exist that oil contains specifically acting toxicants as well. In this research project, we look for the existence and identity of such chemicals in a large series of different oils. Additionally, we investigate the link between environmental fate and effects of oil, by studying the impact of weathering (i.e., the combined effect of (microbiological) breakdown, dissolution, and evaporation) on the in vitro and in vivo toxicity.

Improving risk assessment of petroleum hydrocarbon-contaminated sediments and soils (Barry Muijs).