ABSTRACT
Crude oils are naturally occurring mixtures of thousands of known chemicals and potentially hundreds of thousands of unknown chemicals that are still not analytically resolved using standard techniques. Despite the large suite of potentially toxic chemicals within oil, only a small subset of PAHs and their alkylated products is usually reported during routine chemical analyses and considered as potentially toxic to aquatic animals in laboratory and field-based toxicity testing. Chapter 15 provides an overview of the chemical behavior of crude oil in water and describes how the chemical and physical diversity of these complex mixtures influence the results of laboratory toxicity testing. The concept of narcosis and how it is applied in the target lipid model to predict the toxic effects of a mixture based on the underlying lipid–water partitioning of the chemical constituents. Finally, the chapter reviews recent research highlighting the sublethal effects of crude oil in developing fish embryos. Most of the discussion highlights the specific actions of tricyclic and tetracyclic PAHs on various targets impacting cardiovascular development in fish embryos and describes the role that the aryl hydrocarbon receptor pathway plays in mediating the sublethal responses to tricyclic and tetracyclic PAHs.
