PM05 Aquatic Vertebrate/Invertebrate Toxicology
Exhibit Hall
8:00 AM - Monday, 10 November 2003
(PM085) Comparative toxicology of four crude oils.
Clarke, L1, Hodson, P1, Brown, R1, 1 Queen's University, Kingston, Ontario, Canada
ABSTRACT- The toxicity of crude oil to the early life stages of fish has been linked to the presence and concentration of polycyclic aromatic hydrocarbons (PAHs). Fish that are chronically exposed to PAHs exhibit dioxin-like toxicity characterized by the presence of blue sac disease (BSD) and the induction of cytochrome P4501A (CYP1A). We compared the relative toxicity of four crude oils, Scotian Shelf (SS), MESA, the synthetic Alberta Sweet Mixed Blend (ASMB), and Alaska North Slope Crude (ANSC), for causing BSD by exposing rainbow trout (Oncorhyncus mykiss) embryos in simulated spawning beds containing gravel contaminated with one of four oils. Each oil had different chemical characteristics and PAH compositions, and our hypothesis was that the ASMB oil would be the most toxic due to its greater PAH concentration. The larvae were sampled at swim up for immunohistochemical staining, to characterize PAH exposure, and scoring for symptoms of BSD to characterize toxicity. Preliminary data indicates that the exposure of trout to PAH is greatest for ASMB oil, which is consistent with its higher concentration of PAH. These results indicate that it is the presence, concentration, and conformation of specific PAHs which is the primary cause of toxicity.
Key words: toxicity, CYP1A, crude oil, polycyclic aromatic hydrocarbons