Drugs of abuse in drinking water – a review of current detection methods, occurrence, elimination and health risks

Oxidative treatment of micropollutants present in wastewater: A special emphasis on transformation products, their toxicity, detection, and field-scale investigations

Micropollutants have become ubiquitous in aqueous environments due to the increased use of pharmaceuticals, personal care products, pesticides, and other compounds. In this review, the removal of micropollutants from aqueous matrices using various advanced oxidation processes (AOPs), such as photocatalysis, electrocatalysis, sulfate radical-based AOPs, ozonation, and Fenton-based processes has been comprehensively discussed. Most of the compounds were successfully degraded with an efficiency of more than 90%, resulting in the formation of transformation products (TPs). In this respect, degradation pathways with multiple mechanisms, including decarboxylation, hydroxylation, and halogenation, have been illustrated. Various techniques for the analysis of micropollutants and their TPs have been discussed. Additionally, the ecotoxicity posed by these TPs was determined using the toxicity estimation software tool (T.E.S.T.). Finally, the performance and cost-effectiveness of the AOPs at the pilot scale have been reviewed. The current review will help in understanding the treatment efficacy of different AOPs, degradation pathways, and ecotoxicity of TPs so formed.

Monitoring Pharmaceuticals and Personal Care Products in Drinking Water Samples by the LC-MS/MS Method to Estimate Their Potential Health Risk

(1) The occurrence and accumulation of pharmaceuticals and personal care products in the environment are recognized scientific concerns. Many of these compounds are disposed of in an unchanged or metabolized form through sewage systems and wastewater treatment plants (WWTP). WWTP processes do not completely eliminate all active substances or their metabolites. Therefore, they systematically leach into the water system and are increasingly contaminating ground, surface, and drinking water, representing a health risk largely ignored by legislative bodies. Especially during the COVID-19 pandemic, a significantly larger amount of medicines and protective products were consumed. It is therefore likely that contamination of water sources has increased, and in the case of groundwater with a delayed effect. As a result, it is necessary to develop an accurate, rapid, and easily available method applicable to routine screening analyses of potable water to monitor and estimate their potential health risk. (2) A multi-residue UHPLC-MS/MS analytical method designed for the identification of 52 pharmaceutical products was developed and used to monitor their presence in drinking water. (3) The optimized method achieved good validation parameters, with recovery of 70-120% of most analytes and repeatability achieving results within 20%. In real samples of drinking water, at least one analyte above the limit of determination was detected in each of the 15 tap water and groundwater samples analyzed. (4) These findings highlight the need for legislation to address pharmaceutical contamination in the environment.

From market to environment - consumption-normalised pharmaceutical emissions in the Rhine catchment

Direct and indirect threats by organic micropollutants can only be reliably assessed and prevented if the exposure to these chemicals is known, which in turn requires a confident estimate of their emitted amounts into the environment. APIs (Active Pharmaceutical Ingredients) enter surface waters mostly through the sewer system and wastewater treatment plants (WWTPs). However, their effluent fluxes are highly variable and influenced by several different factors that challenge robust emission estimates. Here, we defined a dimensionless, theoretically consumption-independent 'escape factor' (k_esc) for estimating the amount of APIs (expected to be) present in WWTP effluents. The factor is determined as the proportion of marketed and actually emitted amounts of APIs. A large collection of German and Swiss monitoring datasets were analyzed to calculate stochastic k_esc values for 31 APIs, reflecting both the magnitude and uncertainty of consumption-normalised emissions. Escape factors provide an easy-to-use tool for the estimation of average API emissions and expected variability from numerous WWTPs given that consumption data are provided, thereby supporting simulation modeling of the fate of APIs in stream networks or exposure assessments.

Advances in Ultra-small Fluorescence Nanoprobes for Detection of Metal Ions, Drugs, Pesticides and Biomarkers

Identification of trace level chemical species (drugs, pesticides, metal ions and biomarkers) plays key role in environmental monitoring. Recently, fluorescence assay has shown significant advances in detecting of trace level drugs, pesticides, metal ions and biomarkers in real samples. Ultra-small nanostructure materials (metal nanoclusters (NCs), quantum dots (QDs) and carbon dots (CDs)) have been integrated with fluorescence spectrometer for sensitive and selective analysis of trace level target analytes in various samples including environmental and biological samples. This review summarizes the properties of metal NCs and ligand chemistry for the fabrication of metal NCs. We also briefly summarized the synthetic routes for the preparation of QDs and CDs. Advances of ultra-small fluorescent nanosensors (NCs, QDs and CDs) for sensing of metal ions, drugs, pesticides and biomarkers in various sample matrices are briefly discussed. Additionally, we discuss the recent challenges and future perspectives of ultra-small materials as fluorescent sensors for assaying of wide variety of target analytes in real samples.

Recent Advances in Metal Nanocomposite-Based Electrochemical (Bio)Sensors for Pharmaceutical Analysis

Rising rates of drug abuse and pharmaceutical pollution throughout the world as a consequence of increased drug production and utilization pose a serious risk to public health and to environmental integrity. It is thus critical that reliable analytical approaches to detecting drugs and their metabolites in a range of sample matrices be developed. Recent advances in the design of nanomaterial-based electrochemical sensors and biosensors have enabled promising new approaches to pharmaceutical analysis. In particular, the development of a range of novel metal nanocomposites with enhanced catalytic properties has provided a wealth of opportunities for the design of rapid and reliable platforms for the detection of specific pharmaceutical compounds. The present review provides a comprehensive overview of representative metal nanocomposites with synergistic properties and their recent (2017-2022) application in the context of electrochemical sensing as a means of detecting specific antibiotic, tuberculostatic, analgesic, antineoplastic, antipsychotic, and antihypertensive drugs. In discussing these applications, we further explore a variety of testing-related principles, fabrication approaches, characterization techniques, and parameters associated with the sensitivity and selectivity of these sensor platforms before surveying the future outlook regarding the fabrication of next-generation (bio)sensor platforms for use in pharmaceutical analysis.

Environmental occurrence and ecological risks of psychoactive substances

Psychoactive substances are ubiquitous in the environment at low concentrations, and tobacco, cannabis, etc. are all widely-existing examples. Given their potent biological activity, psychoactive substances are suspected to be harmful to the environment, and reports of their ecological risks are gradually increasing. Since the 1990s, the investigations into psychoactive substances have made remarkable progress, yet some research fields still need to be modernised. For example, the unification of standardised analytical methods as well as the supplementation of occurrence literature. In addition, a relatively lagging risk evaluation system caused by a lack of toxicity data is particularly in need of improvement. The purpose of this article is to develop a review of current research on psychoactive substances, including analytical methods, distribution in environmental compartments, and ecological risk assessment, as well as to point out deficiencies and development prospects and to offer motivation for enhancing the research level in this field.

Estimation of the psychoactive substances consumption within 12 wastewater treatment plants service areas in a certain city of Guangxi, China applying wastewater-based epidemiology

The abuse of psychoactive substances has been increasing dramatically over the last few years, which is becoming a concern for human health and social stability. How to accurately estimate psychoactive substances' total consumption in certain areas is the key to manage such substances. In order to control psychoactive substances, 8 psychoactive substances' consumption within 12 wastewater treatment plants (WWTPs) service areas in a certain city of Guangxi, China was investigated in 2019. Firstly, a solid-phase extraction-liquid chromatography-tandem mass spectrometry method was used to determine the influent concentrations. Morphine (MOR), 3, 4-methylenedioxymethamphetamine (MDMA), methamphetamine (METH), ketamine (KET), and norketamine (NK) were detected, with the concentrations ranging from less than method detection limit (NK, MDMA) to 170.91 (METH) ng/L. Then, the back-estimation of consumption was conducted according to the objective and near real-time wastewater-based epidemiology (WBE). The results demonstrate that KET, MOR, and METH are the most abused psychoactive substances, with the mean consumption of 682.42, 167.81, and 44.56 mg/day/1000 inh, respectively. The psychoactive substance residues of WWTPs influent were analyzed to estimate such substances' consumption in specific areas, so as to provide support for risk prevention and control.

Sonophotocatalytic degradation of sodium diclofenac using low power ultrasound and micro sized TiO2

The nonsteroidal anti-inflammatory drug sodium diclofenac (DC) is an emerging water pollutant which resists conventional wastewater treatments. Here the sonophotocatalytic degradation of DC was carried out using micrometric TiO₂ (both pristine and Ag-decorated), UV-A irradiation and 20 kHz pulsed ultrasound. Sonophotocatalytic tests were compared with photolysis, sonolysis, sonophotolysis, sonocatalysis and photocatalysis data performed in the same conditions. A synergy index of over 2 was determined for tests with pristine TiO₂, while values close to 1.3 were observed for Ag-TiO₂. Reaction intermediates were studied by HPLC-MS, showing degradation mechanisms activated by hydroxyl radicals. Similar pathways were identified for photocatalytic and sonophotocatalytic tests, although the latter led to more oxidized compounds. Different reactor configurations (static and dynamic set ups) were studied. Sequential and simultaneous application of UV light and ultrasound led to similar performance. The role of water matrix was investigated using ultrapure and drinking water, showing marked detrimental effects of electrolytes on the DC degradation. Overall, the combined treatment proved more efficient than photocatalysis alone especially in demanding working conditions, like in drinking water matrices.

A suspect screening analysis for contaminants of emerging concern in municipal wastewater and surface water using liquid-liquid extraction and stir bar sorptive extraction

The presence of contaminants of emerging concern (CECs) in wastewater effluent and surface waters is an important field of research for analytical scientists. This study takes a suspect screening approach to wastewater and surface water analysis using comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GC × GC-TOFMS). Two extraction procedures, traditional liquid-liquid extraction (LLE) and stir bar sorptive extraction (SBSE), were utilized and evaluated for their application to wastewater and surface water samples. Both techniques were evaluated regarding their recovery rates, range of compound classes extracted, and on their application to discovery of CECs. For the 14 surrogate compounds analyzed, LLE was able to extract all of them in each matrix with a recovery range of 19% to 159% and a median value of 74%. For SBSE, the recovery rates ranged from 19% to 117% with the median value at 66%, but only 8 of the compounds were able to be extracted because of the polarity bias for this extraction method. A new method of SBSE calibration was also developed using direct liquid injection of the internal standards before desorption of the stir bars. Initial findings indicate increased sensitivity and a greater range of unknown analyte recovery for SBSE, especially in the more dilute effluent and surface water samples. With the methods used in this study, SBSE has a concentration factor of approximately 416, improving that of LLE, which is 267. Suspect screening analysis was utilized to tentatively identify 32 CECs in the samples, the majority of which were pharmaceuticals and personal care products. More CECs were found using SBSE than LLE, especially in the surface water samples where 13 CECs were tentatively identified in the SBSE samples compared to 6 in the LLE samples.

Cytostatic pharmaceuticals as water contaminants

Due to the growing problem of cancer diseases, cytostatic drugs have become a great environmental threat. Their main sources are hospital effluents, household discharge and drug manufacturers. As these compounds are not removed during wastewater treatment with sufficient efficiency, they are found in the surface, ground and drinking water in quantities up to 2.12 × 10^-4 mg/l. The current knowledge about their harmful influence on humans does not indicate a significant risk to the health of water consumers, although it points to certain groups of risk (children and lactating women) in particular. In aquatic organisms, anticancer drugs in detected concentrations can cause chronic toxicity and have a detrimental impact on their genetic material. The acute toxicity effect is less likely. The HC₅ value calculated by us (the concentration at which 5% of the species is potentially affected) equalling 2.1 × 10^-4 mg/l shows that anticancer drugs are real hazardous contaminants for the environment. It indicates that effective elimination of cytostatics from water still requires intensive research.

Psychoactive substances in mussels: Analysis and occurrence assessment

This work presents an analytical methodology based on a "Quick, easy, cheap, effective, rugged, and safe" (QuEChERS) extraction and liquid chromatography-tandem mass spectrometry detection (LC-MS/MS) for the simultaneous determination of 35 psychoactive substances in fresh mussel samples. The compounds investigated include illicit drugs, new psychoactive substances, commonly prescribed psychiatric pharmaceuticals, and caffeine. The methodology was validated in terms of recovery (relative recoveries 77-118%), repeatability (relative standard deviation values <20%), and sensitivity (limits of detection and quantification <2 ng/g fresh weight (f.w.) and <6.7 ng/g f.w., respectively, for most compounds). The method was applied to the analysis of 15 samples, covering both commercially available mussels purchased from local food markets and wild fresh mussels collected in the Northeast coast of Spain in the Mediterranean Sea. Only one sample corresponding to wild mussels was found to contain 2 of the target analytes, namely, sertraline (1.5 ng/g f.w.) and caffeine, (12.8 ng/g f.w.).

The detection of drugs of abuse and pharmaceuticals in drinking water using solid-phase extraction and liquid chromatography-mass spectrometry

Pharmaceuticals and drugs of abuse including novel psychoactive substances (NPS) are emerging as newer contaminants in the aquatic environment. The presence of such pollutants has implications on the environment as well as public health and therefore their identification is important when monitoring water quality. This research presents a new method for the simultaneous detection of 20 drugs of abuse and pharmaceuticals in drinking water, including 15 NPS, three traditional illicit drugs and two antidepressants. The developed method is based on the use of solid-phase extraction (SPE) followed by liquid chromatography-mass spectrometry (LC-MS). The SPE recoveries for the majority of target analytes ranged between 62 and 107%. The method detection and quantification limits ranged between 0.01 and 1.09 ng/L and 0.02-3.64 ng/L respectively. Both instrumental and method precisions resulted in relative standard deviations <15.04%, with an accuracy of < ±8.66%. The results show that LC-MS can be an alternative to the more popular technique of liquid chromatography-tandem mass spectrometry for the analysis of drugs of abuse and pharmaceuticals in drinking water. This newly developed simultaneous detection method has been applied to drinking water collected from the East Anglia region of the UK. Citalopram, cocaine, fluoxetine, ketamine, mephedrone, methamphetamine and methylone were detected at the range of 0.14 and 2.81 ng/L. This is the first time that the two NPS mephedrone and methylone, have been detected in UK drinking water.

Carcinogenic and non-carcinogenic health risks of metal(oid)s in tap water from Ilam city, Iran

One of the most important pathways for exposure to metals is drinking water ingestion. Chronic or acute exposure to metals can endanger the health of the exposed population, and hence, estimation of human health risks is crucial. In the current study for the first time, the concentrations of Mercury (Hg), Arsenic (As), Zinc (Zn), Lead (Pb) and Cobalt (Co) in 120 collected tap water samples (2015, July-November) from Ilam city, Iran were investigated using flame atomic absorption spectrophotometer. Also, the metal-induced carcinogenic and non-carcinogenic risks for consumers exposed to tap drinking water were calculated. The average (range) concentrations of Hg, Zn, As, Pb and Co were defined as 0.40 ± 0.10 μg/L (ND-0.9 μg/L), 5014 ± 5707 μg/L (2900.00-5668.33 μg/L), 21.008 ± 2.876 μg/L (3.5-62 μg/L), 30.38 ± 5.56 μg/L (6-87 μg/L), and 11.34 ± 1.61 μg/L (0.1-50 μg/L), respectively. Average concentrations of all examined metals were significantly higher than WHO and national standard recommended limits. The ranking order of metals concentrations in the tap drinking water was Zn > Pb > As > Co > Hg. Except for Hg and Co, at least one age group consumers were at considerable non-carcinogenic risks induced by Zn, As and Pb [Target Hazard Quotient (THQ > 1)]. The rank order of age groups consumers based on THQ and Incremental lifetime cancer risk (ILCR) was <1 years >1-9 years > 20 + years > 10-19 years. The calculated ILCR for As in all age groups were higher than 10^-3 value. All age groups of consumers in Ilam city, especially infants (<1 years) and children (1-10 years), are at considerable non-carcinogenic and carcinogenesis risk.

Immediate drop on demand technology (I-DOT) coupled with mass spectrometry via an open port sampling interface

Aim: The aim of this work was to demonstrate and evaluate the analytical performance of coupling the immediate drop on demand technology to a mass spectrometer via the recently introduced open port sampling interface and ESI. Methodology & results: A maximum sample analysis throughput of 5 s per sample was demonstrated. Signal reproducibility was 10% or better as demonstrated by the quantitative analysis of propranolol and its stable isotope-labeled internal standard propranolol-d7. The ability of the system to multiply charge and analyze macromolecules was demonstrated using the protein cytochrome c. Conclusion: This immediate drop on demand technology/open port sampling interface/ESI–MS combination allowed for the quantitative analysis of relatively small mass analytes and was used for the identification of macromolecules like proteins.