Patterns of oral contraceptives consumption and estimated concentrations of 17α-ethinylestradiol in water bodies from the municipality of Santa Maria Madalena, Southeastern Brazil

Abstract

Organic contaminants with estrogenic activity have generated increasing concerns in the scientific community since they are capable of triggering adverse effects in the endocrine system of several organisms. 17α-ethinylestradiol (EE2), a synthetic estrogen used in oral contraceptives, has been identified as one of the main responsible for causing such changes. Thereby the objective of this study was to generate information on EE2 consumption and estimate its possible impact on the water bodies of Santa Maria Madalena. Firstly, a survey was carried out about EE2 consumption through interviews with 325 women aged 15 to 59 residing in the study area, and then estimated the EE2 release in the water bodies. About 30% of the women interviewed reported using oral contraceptives. The EE2 average daily intake for each woman was 20 μg day-1. Extrapolating this intake to 30% of the population and adopting an excretion rate of 57%, it was calculated a total discharge of 4.8 mg day-1 of this estrogen into the local water bodies. It diluted by the small flow of these streams leads to an estimated environmental concentration of 0.3 ng L-1, which according to ecotoxicological studies is already enough to trigger adverse effects to the aquatic biota.