Assessment of the occurrence of 455 pharmaceutical compounds in sludge according to their physical and chemical properties: A review

A picture of pharmaceutical pollution in landfill leachates: Occurrence, regional differences and influencing factors

Municipal solid waste (MSW) landfill sites have been identified as a significant source of pharmaceuticals in the environment because unused or expired pharmaceuticals are discarded into MSW, which eventually percolate into leachates. However, the contamination of pharmaceuticals in landfill leachate in China is not comprehensively understood. Previous research into factors influencing pharmaceutical concentrations focused on a limited number and type of target pollutants or restricted study area. In the present study, 66 pharmaceuticals were analyzed (including 45 antibiotic and 21 non-antibiotic pharmaceuticals, also categorized as 59 prescription and 7 non-prescription pharmaceuticals) in leachate samples from landfill sites with various characteristics in different regions of China. The results indicated that non-antibiotic pollutants were present at significantly higher concentrations than antibiotic pollutants, with median concentrations of 1.74 μg/L and 527 ng/L, respectively. Non-antibiotic pollutants also presented a higher environmental risk than antibiotic pollutants, by 2 to 4 orders of magnitude, highlighting that non-antibiotic pharmaceuticals should not be overlooked during the assessment of landfill leachate. Pharmaceutical concentrations in landfill leachate samples exhibited regional differences; the population size served by the landfills was the dominant factor contributing to the observed differences. In addition, landfill characteristics such as the solid waste composition and MSW loading can also affect pharmaceutical concentrations in landfill leachate. Despite the implementation of the classification and disposal policy of MSW in Shanghai, China since July 2019, specifying that unused or expired pharmaceuticals should be discarded as hazardous waste, high levels of pharmaceutical contaminations were detected in leachate from the main components of classified MSW (i.e., residual and food waste). These findings emphasize the importance of pharmaceutical management in solid waste systems.

Trace analysis of 47 psychotropic medications in environmental samples by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS)

Psychotropic medications are one of the most prescribed pharmaceuticals in the world. Given their frequent detection and ecotoxicity to the no-target organism, the emission of these medications into environments has gradually draw attention. The study developed a sensitive and reliable analytic method to simultaneously investigate 47 psychotropic medications in four matrices: wastewater, surface water, activated sludge, and sediment by ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS/MS). These 47 target analytes include 24 antidepressants, 17 antianxiety drugs, 5 anticonvulsants, and 1 relevant hormone. Solid phase extraction (SPE) was employed to extract analytes from water-phase samples. Ultrasonic Solvent Extraction method with Enhanced Matrix Removal clean-up (USE-EMR) was utilized to extract target compounds from solid-phase samples, which requires more straightforward and convenient procedures than previous methods. The extraction recoveries of all analytes ranged from 80 % to 120 % in these four sample matrices. In this study, The limit of quantitation for 47 psychotropic medications were 0.15 ng/L (estazolam) to 2.27 ng/L (lorazepam), 0.08 ng/L (desvenlafaxine) to 2 ng/L (mianserin), 0.22 ng/g (dry weight, dw) (nordiazepam) to 3.65 ng/g (dw) (lorazepam), and 0.07 ng/g (dw) (carbamazepine) to 2.85 ng/g (lorazepam), in wastewater, surface water, sludge, and sediment, respectively. In addition, the developed method was employed to analyse actual samples in two wastewater treatment plants and their receiving rivers. Carbamazepine, escitalopram, clozapine, desvenlafaxine, diazepam, lamotrigine, sertraline, temazepam, and venlafaxine were nearly ubiquitous in all matrices. Moreover, this study indicated that the inadequate removal efficiencies of psychotropic medications in wastewater treatment plants (WWTPs) had resulted in a persistent discharge of these contaminants from human sources into environments.

Embedding Mixed Sorbents in Binder: Solid-Phase Microextraction Coating with Wide Extraction Coverage and Its Application in Environmental Water Analysis

Solid-phase microextraction (SPME) is a simple and highly effective sample-preparation technique for water analysis. However, the extraction coverage of a given SPME device with a specific coating can be an issue when analyzing multiple environmental contaminants. Therefore, instead of synthesizing one sorbent material with dual or multiple functions, we investigated a new strategy of preparing SPME blades using a homogeneous slurry made by mixing three different sorbent particles─namely, hydrophobic/lipophilic balanced (HLB), HLB-weak cationic exchange (HLB-WCX), and HLB-weak anionic exchange (HLB-WAX)─with a polyacrylonitrile (PAN) binder. The developed coating is matrix compatible, as the binder functions not only as a glue for immobilizing the sorbent particles but also as a porous filter, which only allows small molecules to enter the pores and interact with the particles, thus avoiding contamination from large elements. The results confirmed that the proposed mixed-coating SPME device provides good extraction performance for polar and nonpolar as well as positively and negatively charged compounds. Based on this device, three comprehensive analytical methodologies─high-throughput SPME-LC-MS/MS (for the quantitative analysis of targeted drugs of abuse and artificial sweeteners), in-bottle SPME-LC-high resolution MS (HRMS) (for the untargeted screening of organic contaminants), and on-site drone sampling SPME-LC-HRMS (for on-site sampling and untargeted screening)─were developed for use in environmental water analysis. The resultant data confirm that the proposed strategies enable comprehensive water quality assessment by using a single SPME device.

Antidepressants in wastewater treatment plants: Occurrence, transformation and acute toxicity evaluation

Antidepressants (ATDs) are one of the most prescribed medications for psychiatric conditions. The widespread presence in aquatic environment and demonstrated ecotoxicity make ATDs a class of concerning emerging contaminants. Municipal wastewater treatment plants (WWTPs) provide important connecting channel between wastewater and aquatic environment. Herein, we present a critical overview of the occurrence, transformation and toxicity of typical ATDs during water treatments. The total concentration of the detected ATDs and their metabolites in the WWTP influents and effluents are 72.62-5011.80 ng/L and 114.48-6992.40 ng/L, respectively, on a global scale. The frequently observed negative removal of ATDs in WWTPs indicates that some ATDs exist as conjugates in wastewaters. The biotic and abiotic transformation of ATDs and the generated transformation byproducts (TPs) were identified, which occurred in WWTPs worldwide along with ATDs. Acute toxicity of ATDs and their TPs was predicated using the ECOSAR model. Compared to ATDs, the demonstrated enhanced toxicity of several TPs to aquatic organisms necessitates more attention on TPs monitoring in WWTPs. This work provides scientific support for wastewater advanced treatment to alleviate ATDs pollution in effluents.

Simultaneous detection of pesticides and pharmaceuticals in three types of bio-based fertilizers by an improved QuEChERS method coupled with UHPLC-q-ToF-MS/MS

Bio-based fertilizers (BBFs) have the potential to contain both pesticides and pharmaceutical residues, which may pose a threat to soils, crops, and human health. However, no analytical screening method is available currently to simultaneously analyze a wide range of contaminants in the complex origin-dependent matrices of BBFs. To fill this gap, our study tested and improved an original QuEChERS method (OQM) for simultaneously analyzing 78 pesticides and 18 pharmaceuticals in BBFs of animal, plant, and ashed sewage sludge origin. In spiked recovery experiments, 34-58 pharmaceuticals and pesticides were well recovered (recovery of 70-120%) via OQM at spiking concentrations levels of 10 ng/g and 50 ng/g in these three different types of BBFs. To improve the extraction efficiency further, ultrasonication and end-over-end rotation were added based on OQM, resulting in the improved QuEChERS method (IQM) that could recover 57-79 pesticides and pharmaceuticals, in the range of 70-120%. The detection limits of this method were of 0.16-4.32/0.48-12.97 ng/g, 0.03-11.02/0.10-33.06 ng/g, and 0.06-5.18/0.18-15.54 ng/g for animal, plant, and ash-based BBF, respectively. Finally, the IQM was employed to screen 15 BBF samples of various origins. 15 BBFs contained at least one pesticide or pharmaceutical with ibuprofen being frequently detected in at concentration levels of 4.1-181 ng/g. No compounds were detected in ash-based BBFs.

Simultaneous determination of fourteen pharmaceuticals in sewage sludge using online solid-phase extraction-liquid chromatography-tandem mass spectrometry combined with accelerated solvent extraction

An online solid-phase extraction (SPE) liquid chromatography tandem mass spectrometry method (HPLC-MS/MS) combined with accelerated solvent extraction (ASE) was developed for simultaneous determination of 14 pharmaceuticals in sludge. In the online SPE procedures, ultrapure water with no additives was used as the loading solvent. In addition, low molecular weight targets such as atenolol were difficult to retain on SPE column after acetone was added to the washing solvent. The response signal of analytes can be greatly improved by adding 0.2% formic acid to the mobile phase. Under the optimized conditions, the recoveries of all the analytes ranged between 75.1 and 112%. Moreover, the limit of detections ranged from 1.8 to 7.9 ug/kg. The precision of analytical data was determined with relative standard deviation (RSD) ≤ 4.87%. This method was successfully applied to determine the concentration of pharmaceuticals in sludge.

Antifungal medicines in the terrestrial environment: Levels in biosolids from England and Wales

Antifungals are used widely in clinical and agricultural practice to control fungal growth, either treating or preventing infection. There are reports of increasing prevalence of resistance to antifungals in human pathogens and concern that their use in agriculture is driving clinical resistance in patients. While crop protection products are the most obvious source in agriculture, a further source may be biosolids from wastewater treatment. In the UK, these are applied to land to provide nutrients and improve soil structure for crops. In this study, biosolids from ten sites in England and one in Wales were analysed for clinical antifungals. Ketoconazole and miconazole were detected in all samples with a median concentration of 0.87 and 0.54 mg kg^-1 dry weight (DW), respectively. Clotrimazole was detected at seven of eleven sites at a median level of 1.32 mg kg^-1 DW and its absence at four others was considered treatment related. Two prescription-only and systemic medications, itraconazole and posaconazole, were frequently detected with median concentrations of 0.14 mg kg^-1 DW and 0.09 mg kg^-1 DW, respectively. The biosolid levels of itraconazole found in this study were two orders of magnitude higher than an indicative Predicted No Effect Concentration for resistance selection (PNEC-R) in soil. Neither fluconazole, griseofulvin, and voriconazole nor flucytosine and nystatin were found above the limit of detection of 0.01 or 0.1 mg kg^-1 as received, respectively. The findings show that biosolids represent a viable pathway for antifungal agents to reach soil.

The Effect of Quinolones on Common Duckweed Lemna minor L., a Hydrophyte Bioindicator of Environmental Pollution

Plant growth and the development of morphological traits in plants are inhibited under exposure to pharmaceuticals that are present in soil and water. The present study revealed that moxifloxacin (MOXI), nalidixic acid (NAL), levofloxacin (LVF) and pefloxacin (PEF) at concentrations of >0.29, >0.48, >0.62 and >1.45 mg × L^-1, respectively, inhibited the growth (Ir) of duckweed plants and decreased their yield (Iy). In the current study, none of the tested quinolones (QNs) at any of the examined concentrations were lethal for common duckweed plants. However, at the highest concentration (12.8 mg × L^-1), LVF increased Ir and Iy values by 82% on average and increased the values of NAL, PEF and MOXI by 62% on average. All tested QNs led to the loss of assimilation pigments. In consequence, all QNs, except for LVF, induced changes in chlorophyll fluorescence (Fv/Fm), without any effect on phaeophytinization quotient (PQ) values. The uptake of NAL, MOXI, LVF by Lemna minor during the 7-day chronic toxicity test was directly proportional to drug concentrations in the growth medium. Nalidixic acid was absorbed in the largest quantities, whereas in the group of fluoroquinolones (FQNs), MOXI, LVF and PEF were less effectively absorbed by common duckweed. This study demonstrated that biosorption by L. minor occurs regardless of the plants' condition. These findings indicate that L. minor can be used as an effective biological method to remove QNs from wastewater and water and that biosorption should be a mandatory process in conventional water and wastewater treatment.

Environmental pharmacology-Dosing the environment: IUPHAR review 36

Pesticide action is predominantly measured as a toxicological outcome, with pharmacological impact of sublethal doses on bystander species left largely undocumented. Likewise, chronic exposure, which often results in responses different from acute administration, has also been understudied. In this article, we propose the application of standard pharmacological principles, already used to establish safe clinical dosing regimens in humans, to the 'dosing of the environment'. These principles include relating the steady state dose of an agent to its beneficial effects (e.g. pest control), while minimising harmful impacts (e.g. off-target bioactivity in beneficial insects). We propose the term 'environmental therapeutic window', analogous to that used in mammalian pharmacology, to guide risk assessment. To make pharmacological terms practically useful to environmental protection, quantitative data on pesticide action need to be made available in a freely accessible database, which should include toxicological and pharmacological impacts on both target and off-target species.

Continuous degradation of micropollutants in real world treated wastewaters by photooxidation in dynamic conditions

Wastewater is a major issue for the ecosystem because of its considerable quantities, the treatment methods adopted in the large majority of WWTPs, and its level of contamination by various types of pollutants, especially emerging ones. One of the solutions considered to reduce this pressure on water is the reuse of wastewater after treatment for watering green areas, road cleaning, industry, groundwater recharge but also for crop irrigation. This paper proposes to study the capabilities of a photoreactor for the removal of micropollutants contained in wastewater from wastewater treatment plants. The experiments are carried out under dynamic artificial irradiation conditions which can be controlled in order to apply irradiation representative of the sunshine conditions. The experiments aim at treating a real effluent from urban wastewater. On the basis of these data, the photo-oxidation mass capacities expressed per unit of irradiated surface and per day were evaluated. Our results show that the oxidation process acts in a selective and differentiated manner according to the categories of substances and within each category. Some molecules are not or only partially oxidized. Note that the photo-reactor fed continuously with wastewater from wastewater treatment plants containing about 80 substances, is subjected to a typical irradiation setpoint of a sunny day in April. This allows to define the instantaneous and daily capacities of the system with respect to the target molecules.