Avaliação da presença de estrógenos na água no braço rio grande da represa billings – Sao Paulo

Estrogens are responsible for most of the endocrine effects triggered by the provision of sanitary sewage, treated or untreated, in water supply sources. The present study evaluated the concentrations of the hormones 17β-estradiol (E2, of natural origin) and 17β- ethinylestradiol (EE2, synthetic) in surface waters of the Rio Grande branch, located at Metropolitan Region of Sao Paulo. Four sampling stations were evaluated: (S1 and S2), respectively, a preserved area (reference) and a water supply caption station; (S3 and S4) streams that flow into the reservoir and receive raw and treated effluents, respectively, from residential areas of the reservoir drainage basin. Eight sampling campaigns were carried out between June 2017 and February 2018. For analysis of the hormones, samples were preconcentrated using solid phase extraction cartridges (C18) and analyzed by liquid chromatography coupled to mass spectrometry, with limits of quantification (LOQ) of 100 ng L-1. The pH, water temperature, electrical conductivity and total dissolved solids variables were determined in situ. S1 presented concentrations of hormones below the LOQ; at the other sampling stations, E2 concentrations varied from <LOQ to 1720 ng L-1 and EE2 from <LOQ to 1200 ng L-1, with the highest concentrations found in streams.