Antibiotics (ABs) in the aquatic environment is a major problem due to the emergence of antibiotic resistance. The long-term ecological impact on the aquatic environment is unknown. Many sources allow entry of ABs into the environment, including Wastewater Treatment Plants (WWTPs), agricultural run-off, hospital effluent and landfill leachate. Concentrations of ABs in the aquatic environment vary significantly, studies have shown fluoroquinolones, tetracycline, macrolides, sulphonamides and penicillins to reach 2900, 1500, 9700, 21400 and 1600 ngL -1 in wastewater effluent samples, however, concentrations are highly variable between different countries and depend on several factors including seasonally variation, prescription, and WWTP operating procedures. Likewise, the reported concentrations that cause environmental effects varies greatly between ABs, even within the same This article is protected by copyright. All rights reserved. Accepted Articleclass, however, this predicted concentration for the ABs considered was frequently <1000 ngL -1 indicating that when discharged into the environment along with treated effluent, these have a potential detrimental effect on the environment. Antibiotics are generally quite hydrophilic in nature; however, they can ionise in the aquatic environment to form charged structures, such as cations, zwitterions, and anions.Certain classes, particularly fluoroquinolones and tetracyclines, can adsorb onto solid matrices, including soils, sediment, and sludge, making it difficult to fully understand their chemical fate in the aquatic environment. The adsorption coefficient (K d ) varies between different classes of ABs, where tetracyclines and fluoroquinolones show the highest K d values. Adsorption coefficients values for fluoroquinolones, tetracyclines, macrolides and sulphonamides have been reported as 54600, 7600, 130 and 1.37 Lkg -1 . Factors such as pH of the environment, solid matrix (sediment/soil sludge) and ionic strength can influence the K d , therefore, several values exist in literature for the same compound.

Present study evaluated the relationship between estrogenic hormones concentrations (17ethinylestradiol and 17β-estradiol) in surface waters in the Metropolitan Region of São Paulo (Brazil) and environmental variables. Four sampling stations were monitored ranging from a protected area to streams discharging human effluent in and around Billings Reservoir. Four sampling campaigns were carried out in each seasonal period: DRY and WET. Samples for hormone analysis (in ng L -1 ) were concentrated (1000X) using solid phase extraction C 18 cartridges and analysed by liquid chromatography coupled to quadrupole mass spectrometry detection, with 100 ng L -1 limit of quantification. Water temperature, pH, electrical conductivity (EC) and total dissolved solids were determined in situ; total phosphorus and Sinapis alba bioassays were performed subsequently. Reservoir active capacity (AC) and precipitation were also obtained. Estrogenic hormones concentrations were always below limit of quantification at pristine site; at the other sampling stations, 17β-estradiol concentrations varied from below limit of quantification to 1,720 ng L -1 and 17ethinylestradiol from below limit of quantification to 1,200 ng L -1 , with the highest concentrations found in the streams discharging into the reservoir. These streams showed higher Pearson's correlation between 17-ethinylestradiol, total phosphorus, and electrical conductivity when compared with reservoir stations. Germination index and EC presented negative correlation (Pearson's r = -0.61), denoting a phytotoxicity increase with EC increment. AC influenced the dilution of pollutants and showed negative correlations with total phosphorus (Pearson's r = -0.56). These results highlight the relevance of including streams in water monitoring programs, since they are important pollutants loads into watersheds.

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A newly available dataset on pharmaceuticals used in Scottish hospitals enabled an environmental risk assessment that includes hospital consumption of pharmaceuticals, as previous United Kingdom rankings have been based on community prescriptions only. Although health and the environment are devolved issues for the Scottish government, it is merited to consider a Scottish ranking separately; regional differentiation is particularly relevant in the spatial context of the European Commission's Water Framework Directive. Nine pharmaceuticals are identified as having a risk quotient greater than 1. Four of these, the antibacterials piperacillin, tazobactam, flucloxacillin, and ciprofloxacin, had high hospital contributions and had not been highlighted previously in rankings based on community prescriptions. Some drugs with a risk quotient < 0.1 are used almost exclusively in hospitals and could be more concentrated near effluents carrying hospital wastewater, where they may be of local concern. Although treating hospital effluents separately is a policy option, specifically including hospital consumption is important. Continually increasing the availability of ecotoxicological data and trends in consumption further contributes to a substantially different prioritization than in previous rankings. This leads the authors to conclude that regular review of risk is necessary.

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 influent and effluent 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 quotient values and resistance to removal treatments. Gaps in knowledge, data and information reported in this review will provide a valuable source for managing AMR in WWTPs.