Evaluation of eight psychoactive drugs used in Chinese cities by wastewater-based epidemiology

Advancing health equity in wastewater-based epidemiology: A global critical review and conceptual framework

Population health data from wastewater-based epidemiology (WBE) are being used at unprecedented scales worldwide, yet there is limited focus on how to advance health equity in the field. Addressing this gap, we conducted a critical review of published literature in PubMed, targeting studies at the intersection of WBE and health equity. Of 145 articles assessed in full-text screening, we identified 68 studies with health equity considerations. These studies spanned various spatial scales and biochemical targets, addressing domains such as study design and methodologies, ethical and social considerations, and the feasibility and implementation of WBE monitoring. We summarize and synthesize health equity-oriented considerations across the identified domains. We further propose five key considerations to advance health equity in WBE research and practice, and integrate these considerations into a conceptual framework to illustrate how they apply to major steps in the process of conducting WBE. These considerations include global inequities in WBE access, the need to prevent potential harms and stigma via data misuse (inappropriate reporting of data and potential use of WBE for criminal surveillance), and the importance of regulation and community engagement, particularly amidst the growing privatization of WBE, especially in the United States.

Utilizing national wastewater and sales data to derive and validate the correction factors of five common antidepressants for wastewater-based epidemiology

Monitoring antidepressant use is important for understanding mental health treatment status in populations and detecting potential misuse. Wastewater-based epidemiology (WBE) is a cost-effective approach to conduct such monitoring but requires valid correction factors (CFs) to accurately convert wastewater mass loads into consumption estimates. Most existing CFs are calculated from pharmacokinetic studies with small cohorts and are not specifically validated for WBE purposes. This study aimed to fill this knowledge gap by calibrating and validating the CFs for 5 commonly prescribed antidepressants. CFs were calibrated by dividing corresponding geo-located sales data by wastewater mass loads from 18 wastewater treatment plants in Australia for the same 3.5-year period. The refined CFs were 9.0 for fluoxetine, 6.4 for venlafaxine, and 25 for quetiapine. For the case of racemic citalopram and the pure S-enantiomer (escitalopram), individual CFs were proposed as 2.0 and 11, respectively. To validate their applicability, the new CFs were applied to independent datasets of wastewater samples collected in Belgium (2019 to 2022) and Australia (2020) and compared with sales data. The new calibrated CFs produced more accurate wastewater-based estimates of consumption for citalopram, escitalopram, fluoxetine, venlafaxine, and quetiapine, enhancing the capability of WBE in public health surveillance.

Exposure to smoking and greenspace are associated with allergy medicine use - A study of wastewaterin 28 cities of China

Allergies have become an important public health issue as their occurrence is reportedly on the rise around the world. Exposure to environmental factors is considered as trigger for allergic diseases. However, there was limited data on the importance of each factor, particularly in China. In this study, we aimed to investigate the association between occurrence of allergic diseases with exposure to multiple environmental factors via wastewater surveillance across 28 cities in China. The surveillance was conducted by measuring biomarkers of proxies of allergic diseases, i.e. antihistamines, asthma drug, and of smoking, i.e. cotinine in wastewater. Data of green space and air quality were also collected. We observed the level of antihistamine use were significantly associated with smoking, green space and pollen but not significant with air pollution. People in Northern China used more antihistamines than their compatriots in Southern China, an observation aligning with previous reporting of more allergy prevalence in the North than the South of China. Our study affirmed that in China smoking is responsible for a rise in allergy and asthma in the population. Meanwhile, selected sensitizing pollens (occurring during summer) could have stronger impact to trigger allergies than other pollens (occurring in winter).

Direct injection UPLC-MS/MS method for analysing 77 compounds including human biomarkers, illicit drugs, new psychoactive substances and metabolites in wastewater

Wastewater analysis technology has emerged as a promising tool for monitoring illicit drug consumption. However, the current reliance on the solid-phase extraction (SPE) pre-treatment method presents significant challenges for widespread adoption and high-throughput monitoring, as it consumes a large amount of time and labor as well as requires specialized instruments. This study has developed a direct injection (DI) technique for UPLC-MS/MS, enabling the detection of 77 compounds encompassing metabolites of human biomarkers, illicit drugs, and new psychoactive substances. The DI method underwent rigorous optimization and validation, demonstrating a lower limit of quantitation (LLOQ) ranging from 1 ng L-1 to 100 ng L-1 and a limit of detection (LOD) ranging from 0.5 ng L-1 to 80 ng L-1. The SPE method comprising two common SPE cartridges and the DI method were compared in terms of matrix effects, recoveries, and accuracies through analyzing spiked wastewater samples. The DI method exhibited superior capability in detecting a wider range of compounds while being more time-efficient, and it also significantly demonstrated a better recovery, lower matrix effect, and lower relative error in spiked samples. Real wastewater samples from 25 wastewater treatment plants (WWTPs) were analyzed using this method. This study expanded the targets species of wastewater analysis by DI method and provided practical strategies for conducting large-scale drug monitoring.

Improved entropy-CRITIC population model based on temporal and spatial variability: Construction and application in wastewater epidemiology

Numerous factors contribute to the uncertainty inherent in conducting wastewater-based epidemiology (WBE), with shifting populations exerting a significant influence. However, traditional single- and multi-parameter population models suffer from certain limitations. This study employs an evaluation model framework to construct a model (EC model) based on data characteristics. Weight coefficients derived from 16 cities across seven regions of China are aggregated into a national model. In contrast to alternative models, the EC model exhibits a robust correlation (r2 = 0.98) with census population data, suggesting a potentially more precise depiction of population dynamics. The low variability (RSD = 9.73 %) indicates effective constraint of anomalous parameter fluctuations, yielding minimal Bias (-1.12 %) and SRMSE (14.75 %), thus ensuring reliable population estimation. The model is applied to estimate the consumption of lifestyle-related compounds and the prevalence of hypertension in China. Northern regions demonstrate higher consumption levels, alongside a significant disparity in hypertension prevalence (26.96 %) compared to the south (16.01 %). Hypertension exhibits positive correlations with lifestyle-related compounds such as alcohol and nicotine (r = 0.52, r = 0.55). Sensitivity analysis reveals that the EC model introduces an uncertainty of 24.48 % in population estimates. Through the incorporation of representative datasets and novel algorithms, this model has the potential to enhance the reliability of outcomes in WBE strategy implementation.

Screening potential biomarkers for acute respiratory infectious diseases from antipyretics, antiviral, and antibiotics in wastewater

Since the onset of COVID-19, respiratory diseases have emerged as a focal concern within the field of public health. This study aims to reveal the prevalence of acute respiratory infectious diseases by screening antipyretic, antiviral, and antibiotic biomarkers through wastewater analysis. Samples were collected over a seven-day period each year in 2022, 2023, and 2024 from a northern city in China, assessing the concentrations of two antipyretics (paracetamol and ibuprofen), one antiviral drug (oseltamivir), eleven antibiotics, and three pathogens (influenza A, influenza B, and Mycoplasma pneumoniae). The usage of most antipyretics and antibiotics was higher in 2023 and 2024, primarily due to the outbreak of COVID-19 in 2023 and the prevalence of influenza A, influenza B, and Mycoplasma pneumoniae in 2024. The prevalence assessed using antipyretics (2.68 %) and pathogens (2.70 %) demonstrated a high degree of consistency, whereas the prevalence estimated using antibiotics and antiviral drugs was only 0.53 % and 0.36 %, respectively. Antibiotics are generally used to treat a broad spectrum of bacterial infections rather than targeting a specific pathogen, so their presence in wastewater may not directly reflect the prevalence of a particular disease. In contrast, antipyretics and specific pathogens exhibit a stronger correlation, suggesting that they may serve as more reliable biomarkers than antiviral and antibiotic drugs. The research findings offer alternative biomarkers, such as antipyretics, aside from pathogens, for the assessment of acute respiratory infectious diseases.

Occurrence and distribution of emerging contaminants in wastewater treatment plants: A globally review over the past two decades

Emerging contaminants are pervasive in aquatic environments globally, encompassing pharmaceuticals, personal care products, steroid hormones, phenols, biocides, disinfectants and various other compounds. Concentrations of these contaminants are detected ranging from ng/L to μg/L. Even at trace levels, these contaminants can pose significant risks to ecosystems and human health. This article systematically summarises and categorizes data on the concentrations of 54 common emerging contaminants found in the influent and effluent of wastewater treatment plants across various geographical regions: North America, Europe, Oceania, Africa, and Asia. It reviews the occurrence and distribution of these contaminants, providing spatial and causal analyses based on data from these regions. Notably, the maximum concentrations of the pollutants observed vary significantly across different regions. The data from Africa, in particular, show more frequent detection of pharmaceutical maxima in wastewater treatment plants.

Ferroptosis involvement in the neurotoxicity of flunitrazepam in zebrafish

In recent years, psychoactive drugs such as benzodiazepines (BZDs) have been frequently detected in water environments, however, there is still limited understanding regarding their potential impact on neurological health and underlying mechanisms. This study evaluated the neurotoxicity of the typical BZD drug flunitrazepam (FLZ, 0.2 and 5 μg/L) in zebrafish embryos and adults, and investigated the relationship between ferroptosis and FLZ-induced neurotoxicity. The results indicated that acute exposure to FLZ significantly inhibited zebrafish embryo hatching and promotes death, induced larval deformities, and led to abnormal neurobehavioral responses in larvae, likely due to ferroptosis induction. Results from a 30-day subacute exposure to FLZ showed that it decreased motor function and induced cognitive impairment in adult zebrafish. Immunofluorescence of brain tissues revealed a reduction in neurons in the telencephalon and an increase in microglia in the mesencephalon of the zebrafish exposed to FLZ. The ultrastructure of brain mitochondria showed serious damage. Besides, FLZ exposure increased iron levels, reduced GSH/GSSG and increased LPO in brain tissue, which is related to the abnormal expression of genes associated with ferroptosis. In the rescue experiments with co-exposure to deferoxamine (DFO), the motor-related parameters and biochemical indexes related to ferroptosis were restored, suggesting that FLZ can induce ferroptosis. The molecular docking results indicated that FLZ had a higher affinity with transferrin. This study elucidates the close relationship between ferroptosis and FLZ-induced neurotoxicity, which is significant for understanding the physiological damage caused by psychoactive substances and assessing environmental risks.

Occurrence of emerging contaminants in three river basins impacted by wastewater treatment plant effluents: Spatio-seasonal patterns and environmental risk assessment

The concern on the fate and distribution of contaminants of emerging concern (CECs) is a burning topic due to their widespread occurrence and potential harmful effects. Particularly, antibiotics have received great attention due to their implications in antimicrobial resistance occurrence. The impact of wastewater treatment plants (WWTP) is remarkable, being one of the main pathways for the introduction of CECs into aquatic systems. The combination of novel analytical methodologies and risk assessment strategies is a promising tool to find out environmentally relevant compounds posing major concerns in freshwater ecosystems impacted by those wastewater effluents. Within this context, a multi-target approach was applied in three Spanish river basins affected by different WWTP treated effluents for spatio-temporal monitoring of their chemical status. Solid phase extraction followed by ultra-high-performance liquid chromatography were used for the quantification of a large panel of compounds (n = 270), including pharmaceuticals and other consumer products, pesticides and industrial chemicals. To this end, water samples were collected in four sampling campaigns at three locations in each basin: (i) upstream from the WWTPs; (ii) WWTP effluent discharge points (effluent outfall); and (iii) downstream from the WWTPs (500 m downriver from the effluent outfall). Likewise, 24-h composite effluent samples from each of the WWTPs were provided in all sampling periods. First the occurrence and distribution of these compounds were assessed. Diverse seasonal trends were observed depending on the group of emerging compounds, though COVID-19 outbreak affected variations of certain pharmaceuticals. Detection frequencies and concentrations in effluents generally exceeded those in river samples and concentrations measured upstream WWTPs were generally low or non-quantifiable. Finally, risks associated with maximum contamination levels were evaluated using two different approaches to account for antibiotic resistance selection as well. From all studied compounds, 89 evidenced environmental risk on at least one occasion in this study.

Preparation of amphiphilic poly(divinylbenzene-co-N-vinylpyrrolidone)-functionalized polydopamine magnetic nanoadsorbents for enrichment of synthetic cannabinoids in wastewater

Concerns have been raised about synthetic cannabinoids (SCs), which are among the most often trafficked and used illegal substances. An analytical method that holds promise for determining illicit drug use in the general population is wastewater-based epidemiology (WBE). Unfortunately, the concentration of SCs in wastewater is often extremely low on account of their hydrophobic nature, thus presenting a significant obstacle to the accurate detection and quantification of SCs using WBE. In this study, we present novel magnetic nanomaterials as amphiphilic adsorbents for pretreatment of wastewater using magnetic solid phase extraction (MSPE). Polydopamine-modified Fe3O4 nanoparticles were used as the magnetic core and further functionalized with poly(divinylbenzene-N-vinylpyrrolidone). Coupled with UHPLC-MS/MS analysis, an analytical method to simultaneously detect nine SCs at trace-levels in wastewater was developed and validated, enriching 50 mL wastewater to 100 μL with limits of detection (LOD) being 0.005-0.5 ng L-1, limits of quantification (LOQ) being 0.01-1.0 ng L-1, recoveries ranging from 73.99 to 110.72%, and the intra- and inter-day precision's relative standard deviations less than 15%. In comparison to the time-consuming conventional column-based solid phase extraction, the entire MSPE procedure from sample pre-treatment to data acquisition could be finished in one hour, thus largely facilitating the WBE method for drug surveillance and control.

Evaluation of pharmaceutical consumption between urban and suburban catchments in China by wastewater-based epidemiology

Wastewater-based epidemiology (WBE) is amply used for estimating human consumption of chemicals, yet information on regional variation of pharmaceuticals and their environmental fate are scarce. Thus, this study aims to estimate the consumption of three cardiovascular, four non-steroidal anti-inflammatory pharmaceuticals (NSAIDs), and four psychoactive pharmaceuticals between urban and suburban catchments in China by WBE, and to explore their removal efficiencies and ecological risks. Eleven analytes were detected in both influent and effluent samples. The estimated consumptions ranged from Collapse

Key Words

• Ecological risks
• Pharmaceutical usage
• Regional variation
• Removal efficiency
• Wastewater treatment plant

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MESH Headings

• China
• Water Pollutants, Chemical/analysis
• Wastewater/analysis
• Wastewater/chemistry
• Pharmaceutical Preparations/analysis
• Cities
• Humans
• Risk Assessment
• Anti-Inflammatory Agents, Non-Steroidal/analysis
• Environmental Monitoring
• Wastewater-Based Epidemiological Monitoring
• Psychotropic Drugs/analysis

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Affiliation(s)

Zongrui Li State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China
Jincheng Li State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China
Yongxia Hu West Center, Guangzhou Institute of Chemistry, Chinese Academy of Sciences, Chongqing, 400714, China
Yile Yan State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China
Shaoyu Tang Research Center for Eco-Environmental Engineering, School of Environment and Civil Engineering, Dongguan University of Technology, Dongguan, 523808, China
Ruixue Ma State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China
Liangzhong Li State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China; CAS Key Laboratory of Renewable Energy, Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou, 510640, China.

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Magnetic solid-phase extraction based on polydopamine-coated magnetic nanoparticles for rapid and sensitive analysis of eleven illicit drugs and metabolites in wastewater with the aid of UHPLC-MS/MS

The quantification of illicit drugs in wastewater has become a valuable tool for monitoring illicit drug abuse. The commonly utilized methods for detecting drugs in wastewater require a substantial sample volume, extended pretreatment durations, and intricate procedures. This study first employed polydopamine-coated magnetic nanocomposites as adsorbents for magnetic solid-phase extraction, combined with UPLC-MS/MS, to simultaneously determine the concentrations of eleven common illicit drugs in wastewater. The synthesis process for Fe3O4@PDA is straightforward and high-yield. Benefiting from the strong magnetic response, good dispersibility, and abundant binding sites of the prepared nanocomposites, the extraction of illicit drugs from wastewater could be achieved in just 15 min. The method exhibited satisfactory limits of quantitation (ranging from 5 to 10 ng/L), commendable accuracy (ranging from 90.59 % to 106.80 %), good precision (with RSDs below 10 %), and less sample consumption (only 1 mL). The efficacy of this method was successfully validated through its application to actual wastewater samples collected from ten wastewater treatment plants. The results indicated that morphine, codeine, methamphetamine, and ketamine were the predominant illicit drugs present in the samples. The method developed is able to meet the needs of common illicit drug monitoring and high-throughput analysis requirements.

Flunitrazepam and its metabolites induced brain toxicity: Insights from molecular dynamics simulation and transcriptomic analysis

Psychoactive drugs frequently contaminate aquatic environments after human consumption, raising concerns about their residues and ecological harm. This study investigates the effects of flunitrazepam (FLZ) and its metabolite 7-aminoflunitrazepam (7-FLZ), benzodiazepine-class psychoactive drugs, on brain accumulation, blood-brain barrier (BBB), and neuroinflammation of the model organism zebrafish. Molecular dynamics simulation and transcriptome sequencing were used to uncover their toxic mechanisms. Results demonstrate that both FLZ and 7-FLZ can accumulate in the brain, increasing Evans blue levels by 3.4 and 0.8 times, respectively. This increase results from abnormal expression of tight junction proteins, particularly ZO-1 and Occludin, leading to elevated BBB permeability. Furthermore, FLZ and 7-FLZ can also induce neuroinflammation, upregulating TNFα by 91% and 39%, respectively, leading to pathological changes and disrupted intracellular ion balance. Molecular dynamics simulation reveals conformational changes in ZO-1 and Occludin proteins, with FLZ exhibiting stronger binding forces and greater toxicity. Weighted gene co-expression network analysis identifies four modules correlated with BBB permeability and neuroinflammation. KEGG enrichment analysis of genes within these modules reveals pathways like protein processing in the endoplasmic reticulum, NOD-like receptor signaling pathway, and arginine and proline metabolism. This study enhances understanding of FLZ and 7-FLZ neurotoxicity and assesses environmental risks of psychoactive substances. ENVIRONMENTAL IMPLICATION: With the increasing prevalence of mental disorders and the discharge of psychoactive drugs into water, even low drug concentrations (ng/L-μg/L) can pose neurological risks. This study, utilizing molecular dynamic (MD) simulations and transcriptome sequencing, investigate the neurotoxicity and mechanisms of flunitrazepam and 7-aminoflunitrazepam. It reveals that they disrupt the blood-brain barrier in zebrafish and induce neuroinflammation primarily by inducing conformational changes in tight junction proteins. MD simulations are valuable for understanding pollutant-protein interactions. This research offers invaluable insights for the environmental risk assessment of psychoactive drugs and informs the development of strategies aimed at prevention and mitigation.

Flunitrazepam induces neurotoxicity in zebrafish through microbiota-gut-brain axis

The abuse of psychoactive substances has led to their frequent detection in the environment, with unknown effects on the nervous system. In this study, zebrafish were exposed to benzodiazepine drug flunitrazepam (FLZ, 0.2 and 5 μg/L) for 30 days to assess its neurotoxicity. Results revealed that FLZ disrupted the balance of gut microbiota and caused an increase in pathogenic bacteria, such as Paracoccus and Aeromonas, leading to pathological damage to the intestine. The upregulation of intestinal pro-inflammatory factors, IL-1β and TNF-α, by 2.4 and 6.3 times, respectively, along with the downregulation of tight junction proteins, Occludin and zonula occludens 1 (ZO-1), by 80 % and 50 %, increased in intestinal permeability. Moreover, untargeted metabolomics demonstrated that FLZ interfered with intestinal nucleotide metabolism and amino acid biosynthesis. FLZ could also increase the levels of lipopolysaccharide (LPS) and malondialdehyde (MDA) in the brain by 0.9 and 3.4 times, respectively, leading to pathological changes in brain tissue. Furthermore, FLZ significantly disturbed nucleotide metabolism and amino acid biosynthesis and metabolism pathways in the brain. Correlation analysis between gut microbiota and neurochemicals confirmed that FLZ can induce neurotoxicity through the microbiota-gut-brain axis. These findings elucidate the molecular mechanisms of psychoactive drugs on microbiota-gut-brain axis and provide a theoretical basis for the ecological environmental risk assessment of various psychoactive substances.

Wastewater analysis for new psychoactive substances and cocaine and cannabis in a Northern Ireland Prison

The global drug market has been significantly impacted by the emergence of new psychoactive substances, leading to challenges in creating effective legislative controls and their use within recreational drug consumption. This research explores the prevalence of new psychoactive substances and non-medicinal and medicinal compounds within a prison facility in Northern Ireland. Wastewater samples collected from seven different manholes within the prison were analysed for 37 target compounds including the two most found illicit substances: benzoylecgonine (primary metabolite of cocaine) and cannabis. Using solid phase extraction with Oasis HLB and liquid-chromatography-time-of-flight-mass spectrometry across a gradient of 9 min, our analysis revealed that benzoylecgonine was the sole compound consistently present in all collected samples. Following this finding, our target compound selection was broadened to encompass medicinal compounds and employing qualitative analysis we re-evaluated the samples and discovered the presence of buprenorphine, benzodiazepines, methadone, morphine, and codeine. Finally, the study explored the application of enzymatic beta-glucuronidase hydrolysis to the samples. This final phase yielded significant findings, indicating the presence of codeine and nordiazepam at higher peak intensities, thereby shedding light on the potential implications of this enzymatic process.

In five wastewater treatment plants in Xinjiang, China: Removal processes for illicit drugs, their occurrence in receiving river waters, and ecological risk assessment

Residues of illicit drugs are frequently detected in wastewater, but data on their removal efficiency by wastewater treatment plants (WWTPs) and the ecological risks to the aquatic environment are lacking in this study. The research evaluates the residues, mass load, drug removal efficiency, and risk assessment of illicit drugs in WWTPs and aquatic environments (lakes) in Xinjiang, China. Initially, the concentration (incidence) and mass load of 10 selected illicit drugs were analyzed through wastewater analysis. The detected substances included methamphetamine (METH), morphine (MOR), 3,4-methylenedioxy methamphetamine (MDMA), methadone (MTD), cocaine (COC), benzoylecgonine (BE), ketamine (KET), and codeine (COD), with concentrations ranging from 0.11 ± 0.01 ng/L (methadone) to 48.26 ± 25.05 ng/L (morphine). Notably, morphine (59.74 ± 5.82 g/day) and methamphetamine (41.81 ± 4.91 g/day) contributed significantly to the WWTPs. Next, the drug removal efficiency by different sewage treatment processes was ranked as follows: Anaerobic-Oxic (A/O) combined Membrane Bio-Reactor (MBR) treatment process > Oxidation ditch treatment process > Anaerobic-Anoxic-Oxic (A2/O) treatment process > Anaerobic-Anoxic-Oxic combined Membrane Bio-Reactor treatment process. Finally, the research reviewed the concentration and toxicity assessments of these substances in the aquatic environment (lakes). The results indicated that Lake1 presented a medium risk level concerning the impact of illicit drugs on the aquatic environment, whereas the other lakes exhibited a low risk level. As a result, it is recommended to conduct long-term monitoring and source analysis of illicit drugs, specifically in Lake1, for further investigation. In conclusion, to enhance the understanding of the effects of illicit drugs on the environment, future research should expand the list of target analytes.