Patterns of estrogenic activity in the Baltic Sea

Abstract

Compounds such as estradiol and ethinylestradiol belong to contaminants of emerging concern, as they can disrupt the endocrine system of an organism with a hormonal system. The determination of such compounds is still challenging due to required low detection and quantification limits. Bioassays have proved to be sensitive tools for investigating the full potential of all compounds that can elicit an estrogenic response. In this study, surface water samples from different sampling sites and seasons in the Baltic Sea were analyzed for estrogenic activity with the Arxula adeninivorans yeast estrogen screen. Observed estradiol equivalent concentrations were in the range of <LOD - 0.38ngL^-1. In general, a seasonal trend was observed, i.e., with an increase in water temperature in late spring, estradiol equivalent concentrations rose suddenly and decreased as abruptly when the temperature declined in autumn. An initial risk assessment shows that observed estradiol equivalent concentrations potentially affect organisms at a medium risk level based on determined risk quotients.

Keywords: Baltic sea; Bioassay; Estradiol equivalents; Estrogenic activity; Seasonality; Surface water.