Screening of human and veterinary pharmaceuticals in estuarine waters: A baseline assessment for the Tejo estuary

We investigated the presence of 66 human and veterinary pharmaceuticals from seven therapeutic groups in surface waters of the Tejo estuary. Collection sites covered the entire estuary and included areas near main river inflows and wastewater treatment outfalls, traversing urban, agriculture, aquaculture, and nature reserve areas. Detection of pharmaceuticals was performed via UHPLC-TOF-MS. Pharmaceuticals were found in all sites (32 different compounds in total). Antibiotics, β-blockers, antihypertensives and anti-inflammatories were the most frequently detected (>90%), with variation in concentrations reflecting the multifaceted nature of estuarine surroundings (accumulated site contamination between 15 and 351 ng L-1). Higher concentrations of antidepressant Sertraline (304 ng L-1), non-steroidal anti-inflammatory Diclofenac (51.8 ng L-1), lipid regulator Gemfibrozil (77.0 ng L-1), antihypertensive Ibersartan (161.9 ng L-1) or antibiotic Doxycycline (128.0 ng L-1), among others, though localized may potentially impact key estuarine functions or services. Ultimately, results provide a baseline for regulatory information and future biota evaluations.