Toxics source reduction and sewage upgrades eliminated winter flounder liver neoplasia (1984-2017) from Boston Harbor, MA, USA.

Chemical carcinogen biomarkers can validate public investment in environmental remediation. A major factor driving the clean-up of Boston Harbor, MA, USA, induced by the federal Clean Water Act legislation of 1972, was the high prevalence of petroleum and halogenated aromatic hydrocarbon contaminant-associated liver neoplasia in winter flounder Pseudopleuronectes americanus in the harbor in the 1980s. In the present study, we examined the spatial and temporal relationships between the suspended solids and contaminants in the municipal sewage discharge, and liver neoplasia and histopathology in flounder, from 1987 to 2017.