The research undertaken involved the use of indigenous populatons of bivalve mollusks as monitors for detecting and quantifying environmental benzo(s)pyrene (BAP) in Oregon estuaries. Short-term and long-term studies were conducted in order to establish baseline levels of BAP and to identify seasonal variations in BAP concentrations in shellfish. A presumptive cellular proliferative disorder, thought possibly to be neoplastic, was also studied in mussels, Mytilus edulis, from Yaquina Bay. Histological studies revealed that mussels inhabiting polluted environments, and with high BAP body burdens, had an average 6-8% prevalence of the cellular proliferative disorder while those from clean environments and with low or undetectable levels, did not have the disorder. The cellular condition showed a definite seasonal pattern, there was a low prevalence during the summer and fall followed by an increase during the early winter and a peak prevalence occurred in January-February. The atypical, large cells that characterize the disorder in M. edulis possess many ultrastructural properties in common with malignant vertebrate cells. Further studies are required to evaluate the public health significance of these results.

"EPA 600-3-79-034." "March 1979." Cover title. Includes bibliographical references (pages 30-33). "EPA grant R804427010."