Wastewater-based epidemiology (WBE) is an approach that uses information obtained from the analysis of various metabolites or residues in wastewater with the aim of assessing the consumption of or exposure to chemicals or pathogens in a population connected to a sewage system. The aim of this work was to develop methods for the isolation and analysis of seven beta-blockers (acebutolol, atenolol, betaxolol, metoprolol, nadolol, pindolol and propranolol) in wastewater samples collected from the influent of the wastewater treatment plant in Cluj-Napoca, Romania, in order to estimate their consumption among the population in two time periods (February and October 2024) using WBE. The selected beta-blockers were extracted by solid phase extraction using a Strata C18-U cartridge and analyzed by liquid chromatography coupled with tandem mass spectrometry. The consumption was estimated using the daily mass load of pharmaceutical products reported per 1000 inhabitants (mg/day/1000inh) and varied in the following ranges: atenolol 0.03–3.74, nadolol 0.03–0.1, propranolol 0.04–0.72, betaxolol 0.07–0.38, and metoprolol 54.85–276.45. From the obtained results, it can be observed that metoprolol is the most used beta-blocker in the investigated population, followed by atenolol, propranolol and betaxolol. Other beta-blockers are consumed in small quantities or occasionally.
Beldean-Galea et al. (2026) studied this question.