An integrated analysis of the use and potential risks of pharmaceutical drugs in hospital wastewater: Consumption and occurrence by suspect screening analysis, and antibiotic resistance

Hospital wastewater (HWW) contains pharmaceutical drugs, antibiotic-resistant bacteria (ARB), antibiotic resistance genes (ARG), and pathogens, posing potential risks to environmental and public health. However, data on the occurrence of these contaminants are scarce, especially in low- and middle-income countries. This study employed LC-QTOF MS for a qualitative suspect screening of 1922 pharmaceutical drugs and metabolites in HWW (n = 8 samples). Results were used in an environmental risk assessment applied with the support of in silico tools, to predict potential risks to aquatic organisms. ARB were analyzed using plate count agar method and ARG by Real-time PCR. 113 drugs were identified in HWW, and antibiotics were the most frequently detected (15 compounds). Environmental risk assessment indicated that 29 compounds have the potential to cause toxic effects to aquatic fauna, among which 4 compounds (ampicillin, escitalopram, iopromide, and topiramate) may pose a very high potential risk (RQ > 2). In addition, ARB resistant to azithromycin and cefazolin (10⁶-10⁷ CFU/mL) were abundant in HWW samples, while low levels of bacteria resistant to meropenem (10⁵ CFU/mL) were detected. The relative number of copies of blaKPC, catA1, sul1, ermB, qnrS, vanB, floR, and aadA were higher in HWW from one of the hospitals. However, there was no significant difference for blaOXA (p value = 0.1271) or mecA genes (p value = 0.6077) in HWW samples. These results call attention to potential risks posed by the discharge of HWW and reveal the need to raise data for improving management practices for environmental protection.