Quantifying the effect of weathering on acute oil toxicity using the PETROTOX model.

Following accidental release into marine environments, crude oil progressively weathers, influencing composition, fate, and toxicity. However, published studies draw conflicting conclusions on the effects of oil weathering on ecotoxicity. Using the PETROTOX model, this study characterized the effect of weathering on acute oil toxicity for four aquatic species. Results indicated that predicted acute toxicity decreased with increased oil weathering, due to reductions in overall concentrations and bioavailability of hydrocarbon constituents.