Comparison of the estrogenic activities of seawater extracts from Suruga Bay, Japan, based on chemical analysis or bioassay

Abstract

The present study compared estrogenicity measured by in vitro bioassay and estrogenicity estimated by the chemical analysis of seawater from Suruga Bay, Japan. Nonylphenol, bisphenol A, estrone, 17beta-estradiol, nonhydroxy polycyclic aromatic hydrocarbons, and hydroxy polycyclic aromatic hydrocarbons, some of which show estrogenic activity, were selected as the target compounds. The yeast two-hybrid system was used to evaluate the estrogenic activities of seawater and chemicals with or without rat liver S9. Concentrations of estrogenic compounds in seawater were measured by chemical analysis using gas chromatography/ mass spectrometry. The main estrogenic compounds in seawater were estrone (< or = 9.2 ng/L), bisphenol A (< or = 1,070 ng/L), and nonylphenol (< or = 276 ng/L). The highest estrogenic activities in seawater were observed near a sewage treatment plant, but the predicted potencies based on the chemistry data were higher than those observed experimentally for the estrogenic activity in seawater. The estrogenicity measured by bioassay was raised considerably after S9 treatment; this observation was limited to the zone of freshwater immediately adjacent to the wastewater outfall.