Environmental contamination and cancer in fish

Field investigations of liver neoplasia in feral fishes indicate that tumor-bearing animals are of advanced age, have bottom-dwelling life style, and reside in polluted areas near urban centers. Laboratory investigations have shown that neoplasia in fish liver, like that of its mammalian counterparts, is a multistage process involving initiation, promotion, and progression. This paper reviews laboratory bioassay data and presents stages of carcinogenesis seen in livers of exposed fishes. Based on intervals of time between initiation and tumor formation in laboratory exposures, tumor laden livers in multiyear feral fishes could have been the result of exposure to initiating carcinogen(s) as an embryo, larva, or adult. Promotion of carcinogenesis likely results by exposure of previously initiated fish to substances within sediments or food. While linkage between fish liver neoplasia and carcinogens in the water table, sediment, or food has been sought, the presence or absence of tumors may be related more to the concentration of promoter substances at specific environmental sites. Biomarkers for initiation and means to investigate promotion are presented and suggestions made for application to field studies. © 1990.

Duke Scholars

Author David E. Hinton Environmental Sciences and Policy