Pharmaceuticals in Wastewater Treatment Plants: A Systematic Review on the Substances of Greatest Concern Responsible for the Development of Antimicrobial Resistance

Abstract

In recent years, there is a growing concern about the alarming spread of antimicrobial resistance (AMR) in different environments. Increasingly, many species of bacteria, fungi and viruses are becoming immune to the most commonly used pharmaceuticals. One of the causes of the development of the resistance is the persistence of these drugs, excreted by humans, in municipal and hospital wastewater (WW). Consequently, wastewater treatment plants (WWTPs) are a primary source of antimicrobial resistance genes as novel pollutants. This systematic review sought to examine the relevant literature on pharmaceutical residues (PRs) responsible for AMR in municipal and hospital WW in order to propose a classification of the PRs of greatest concern and provide an updated source for AMR management in WWTPs. Among 546 studies collected from four databases, 18 were included in the present review. The internal and external validity of each study was assessed, and the risk of bias was evaluated on a 20-parameter basis. Results were combined in a narrative synthesis discussing influents and effluents PR concentrations at 88 WWTPs, seasonal variations, differences between hospital and municipal WW, environmental risk assessment values of antimicrobial substances and treatment facilities removal efficiencies. Among the 45 PRs responsible for AMR evaluated in this study, the antibiotics ciprofloxacin, clarithromycin, erythromycin, metronidazole, ofloxacin, sulfamethoxazole and trimethoprim constitute a considerable risk in terms of ubiquitous distribution, worrying concentrations, risk quotients values, and resistance to removal treatments. Gaps in knowledge, data and information reported in this review provide a valuable source for managing AMR in WWTPs.

Role of fungi in bioremediation of emerging pollutants

“…Pharmaceuticals, even though with varying chemical structures are commonly intended to be active and persistent. Pharmaceuticals are transported via hospital and municipal wastewater to wastewater treatment plants (WWTP), which have been identified as the primary source for the increase in antimicrobial resistance genes (Frascaroli et al, 2021). Some of the pharmaceuticals do not alter their chemical composition upon consumption, and not all are removed in WWTPs.…”

Physiological responses and removal pathways of Auxenochlorella protothecoides, Tetradesmus obliquus and Chlamydomonas acidophila to antibiotics commonly found in wastewater

“…When administrated, antibiotics are not completely metabolised, and via excreta, residual fractions and their metabolites reach local wastewater treatment plants (WWTPs) (Kümmerer et al, 2003b), where they may remain active (Roberts and Thomas, 2006). High concentrations of antibiotics, not removed by standard treatment approaches, have been identi ed in several studies of e uent wastewater (WW) released directly in aquatic environments (Frascaroli et al, 2021). After discharge into rivers, lakes and other aquatic environments, antibiotics may disturb the ecological balance of habitats and drive the spread of antimicrobial resistance (AMR) (Roberts, 2002).…”

Toxicity Removal of Pharmaceuticals Mixtures through Electron Beam Irradiation

“…Pharmaceuticals can be only partially metabolized during therapeutic use, resulting in the excretion and release of residual fractions into sewage, unaltered or in the form of metabolites, and may remain active in sewage treatment facilities for a long time [6,7,8]. Many studies have shown that wastewater treatment plants are not designed to eliminate these compounds, as such the main source of drug residues in the aquatic environment [6,7,9].…”