Validation of bioassays for assessing the contamination of marine environments

Various biomarkers were used to determine the exposure offish (Arius felis and Micropogon undulatus) from Galveston Bay (GB), Texas, USA to organic contaminants. Sediment levels of polynuclear aromatic hydrocarbons (PAHs) in GB ranged from 81 to >1000 ng/g and polychlorinated biphenyls (PCBs) were <20 ng/g at all stations. No significant differences in hepatic concentrations of contaminants and ethoxyresorufin O-deethylase (EROD) activity, CYP1A mRNA levels, and DNA adducts were found in A. felis from GB. However, significant differences in biliary concentrations of naphthalene, phenanthrene, and benzo[a]pyrene metabolites were observed. Induced EROD activities and elevated levels of biliary PAH metabolites were measured in M. undulatus from the two most contaminated sites in GB. Induction toxic equivalents (I-TEQs), derived from dosing rat hepatoma H4IIE cells with hepatic extracts of A. felis, were correlated with tissue levels of ≥4-ring PAHs.