Occurrence and risk assessment of steroidal hormones and phenolic endocrine disrupting compounds in surface water in Cuautla River, Mexico

Abstract

In this study, two hormones 17β-estradiol (E2) and 17α-ethynylestradiol (EE2), and three phenolic compounds, bisphenol A (BPA), 4-N-nonylphenol (4-NP) and 4-tert-octylphenol (4-t-OP), were determined in surface water in the Cuautla River at the State of Morelos during the dry-season in Mexico. The endocrine disrupting compounds (EDCs) were extracted from water samples using solid-phase extraction (SPE) with end-capped C18, and then the extracts were chemically derivatized to TMS (trimethylsylane)-compounds and analyzed by gas chromatography coupled to mass spectrometry (GCMS). The most abundant compound was BPA (22.46 ± 30.17 ng L-1), followed by 4-t-OP (11.24 ± 11.76 ng L-1), 4-NP (7.53 ± 14.88 ng L-1), EE2 (2.37 4.36 ng L-1) and E2 (0.97 ± 1.82 ng L-1). The residual amounts of target compounds could either reach stream surface water from direct domestic wastewater discharges, conventional wastewater treatment plant or can be a result from the use of agrochemicals in crop areas. The EDCs in Cuautla River exerted a high pressure on the aquatic ecosystem because their presences in surface water caused medium and high potential ecological risk. Besides, it was found that aquatic organisms were exposed to estrogenic activity.