Annual Evaluation of 17 Oestrogenic Endocrine Disruptors and Hazard Indexes in the Douro River Estuary—The Atlantic Discharge of the Highest-Flow River of Southwestern Europe

The concentrations of seventeen endocrine disruptor compounds (EDCs) that included oestrogens, phytoestrogens, sitosterol, and banned industrial pollutants were investigated at ten sites the Douro River estuary. Surface waters collected during 2019. After evaluating physicochemical data (ammonia, nitrates, nitrites phosphates), filtrated submitted to solid-phase extraction (SPE) extract pre-concentrate (4000-fold) EDCs. extracts derivatized with BSTFA + 1% TMS analysed by gas chromatography-mass spectrometry (GC-MS). All EDCs showed a high detection rate (97%, on average), exhibiting ubiquity in this finding biologically relevant amounts oestrogens (up 8.5 ng/L for oestradiol, E2), phytoestrogens 827 biochanin A, BIO-A) 2.7 µg/L nonylphenol di-ethoxylated, NP2EO) strongly support ongoing risks disruption local aquatic wildlife. Globally, there was an E2-equivalents (E2-EQs) concentration 25 hazard index (HI) 26, which further indicates considerable potential adverse effects biota. Moreover, suggest direct sewage discharges. Beyond possible toxicological fauna, detected contaminants may pose humans via contact (bathing fluvial beaches) or ingestion (local fish).