INDUCTION OF FOCI OF CELLULAR ALTERATION AND OTHER HEPATIC-LESIONS IN ENGLISH SOLE (PAROPHRYS-VETULUS) EXPOSED TO AN EXTRACT OF AN URBAN MARINE SEDIMENT

Epizootiological analyses of field data on prevalances of hepatic neoplasms and other hepatic lesions in English sole (Parophrys vetulus) from Puget Sound suggest a link between these lesions and sediment-associated xenobiotics, particularly aromatic hydrocarbons (AHs). To further investigate this relationship, English sole from a minimally contaminated site were parenterally exposed at monthly intervals for 1 yr to an organic solvent extract of a contaminated urban sediment containing high levels of AHs (30 or 75 mg/kg body weight) or to the model carcinogen benzo[a]pyrene (BaP, 12 mg/kg body weight). Control groups included English sole exposed to an extract of a relatively uncontaminated reference sediment, sole exposed to the carrier only, and untreated sole. Eighteen months after the initial injections, examination of livers revealed a significantly different (increased, p less-than-or-equal-to 0.05) incidence of a spectrum of hepatic lesions, including presumptive preneoplastic foci of cellular alteration, in sole exposed to the urban sediment extract or BaP. Sole in control groups did not develop any of these hepatic lesions. These results represent the first direct demonstration of the hepatotoxicity of sediment-associated chemical contaminants in English sole and strengthen the case for a cause-and-effect relationship between exposure to AHs and epizootic neoplastic hepatic lesions in this species.