Prevalence of illicit drug consumption in a population of Hanoi: an estimation using wastewater-based epidemiology

Illicit drug use derived from wastewater-based epidemiology in Iran, their removal during wastewater treatment, and occurrence in receiving waters

This study aimed to measure the licit and illicit drug concentrations in wastewater treatment plants (WWTPs), their removal efficiency, and their consumption rate by wastewater-based epidemiology (WBE) approach. A 2-season monitoring program was undertaken for the first time in Iran. Residues of licit and illicit drugs (amphetamine, 3,4-methylenedioxyamphetamine, methamphetamine, codeine, 3,4-methylenedioxymethamphetamine, heroin, cocaine, and methadone) and major metabolites (benzoylecgonine, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine and 6-monoacetylmorphine) were analyzed by LC-MS/MS in composite sampling after solid phase extraction method. These analytes were also measured in rivers vicinity to selected cities. The detected concentration in raw wastewater was converted into the quantity of illicit drugs per capita using back-calculation. There was no detection of cocaine, its metabolite benzoylecgonine, or 3,4-methylenedioxymethamphetamine in any of the samples. Among the analytes measured, morphine and codeine exhibited the most prevalent occurrence and highest concentration levels in all the samples. Heroin was the main illicit drugs used in the studied population with a mean consumption rate of 6108 and 158 mg/day/1000 inh. in cold and warm seasons, respectively. The removal efficiencies of drugs during wastewater treatment ranged from 3.5 % (3,4-methylenedioxyamphetamine) to >99 % (amphetamine, methamphetamine, and codeine); however, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine demonstrated a negative removal within WWTPs. This study provides crucial insights into the consumption of illicit drugs in Iran, as well as the release of illicit drugs and their metabolites through WWTPs.

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.

International Workers' Day: Consumption Patterns of Morphine, Codeine, and Methamphetamine in Urban and Rural Areas Based on Wastewater-Based Epidemiology

Wastewater-based epidemiology (WBE) is a reliable means to estimate drug consumption in a specific population. By measuring the concentration of drug residues or metabolites in wastewater, the consumption behavior pattern of a specific population can be deduced. Using the WBE method, the present study, for the first time, continuously monitored the differences in the consumption of morphine (MOR), codeine (CODE), and methamphetamine (METH) in three wastewater-treatment plants in a city and two surrounding villages in Xinjiang, China during International Workers' Day and the following week. The wastewater samples were pretreated by solid-phase extraction and then analyzed by high-performance liquid chromatography-tandem mass spectrometry. Methamphetamine was not detected in rural areas and was detected only on International Workers' Day in urban areas. According to the estimation of per capita consumption, the per capita consumption of MOR, CODE, and METH in urban inhabitants was 12.04 to 23.39, 10.44 to 16.39, and 1.31 mg/day/1000 inhabitants. The per capita consumption of MOR and CODE in rural areas was 5.19 to 8.35 and 2.56 to 3.52 mg/day/1000 inhabitants. The consumption of MOR in urban and rural areas was significantly higher than that of CODE and METH. During International Workers' Day, workdays, and weekends, the consumption of MOR and CODE in urban areas is significantly higher than that in rural areas. Compared with those on weekends, the consumption of urban MOR and CODE increased more during International Workers' Day. The consumption of MOR in urban areas showed a weekend effect. The present study can provide information for subsequent research and government departments. Environ Toxicol Chem 2024;43:2569-2577. © 2024 SETAC.

Assessment of illicit drug use in Seoul, the capital of South Korea for 21 days by wastewater-based epidemiology

22 illicit drugs were monitored in Seoul, the capital of South Korea for 21 days using wastewater-based epidemiology to assess the drug usage patterns for the first time by region and social status. Among the targeted compounds, 10 were detected, with consistent detection of methamphetamine in samples over the entire sampling period. In addition, ketamine had the highest estimated consumption rate at 47.5 mg/day/1000 people, followed by methamphetamine at 12.5 mg/day/1000 people. Methamphetamine and MDMA(3,4-methylenedioxymethamphetamine) exhibited relatively stable daily patterns, with coefficients of variation of 7.03 %, and 13.4 % respectively. Furthermore, no statistically significant differences were observed between weekends and weekdays for all compounds (Mann-Whitney Rank Sum test, p > 0.05). Statistically significant regional differences in drug consumption were observed for methamphetamine, MDMA, and ketamine (Mann-Whitney Rank Sum test, p < 0.05). These differences were found to be related to average annual income and educational levels.

Investigating illicit drug hotspots and daily variations using sewer-network wastewater analysis

Previous wastewater-based epidemiology (WBE) research on illicit drug use has predominantly focused on wastewater treatment plant (WWTP) influents, but information on sewer-network wastewater is very limited. This study represents a pioneering small-scale WBE investigation based on the analysis of sewer-network wastewater samples from different sewer manholes in suburban (Tamsui region) and urban areas (Zhongshan and Wanhua regions) and a comparison of the results with those obtained from corresponding WWTP influents. Among sixteen illicit drugs, methamphetamine exhibited the highest concentration in sewer-network wastewater across both areas. Suburban-urban variations were observed, with more types of illicit drugs detected in the suburban area. Back-calculation indicated that methamphetamine and ketamine were the most-consumed illicit drugs in both sewer-network wastewaters and WWTP influents. Similar types of illicit drugs were detected in the sewer-network wastewaters and WWTP influents, indicating the representativeness of WWTP influents in assessing regional illicit drug abuse. Nevertheless, the sewer-network wastewater results offered additional information making it possible to pinpoint potential hotspots of illicit drug and identify peak usage periods throughout the day, in contrast to the WWTP influent results. In the non-suspected suburban area of Tamsui, high potential hotspots of methamphetamine (sampling points 3 and 6) and ketamine (sampling points 1 and 8) were identified. Although the Zhongshan and Wanhua regions were chosen as suspected hotspots of illicit drug abuse, more severe illicit drug use was observed in Wanhua. Moreover, a trend toward higher illicit drug use from early morning to morning was observed. Despite sampling challenges and higher costs, small-scale WBE via sewer-network wastewater analysis provides superior identification of drug abuse hotspots and peak usage periods. Therefore, this study provides valuable insights for law enforcement and can help prevent and combat illicit drug abuse by targeting potential hotspots and understanding daily illicit drug use dynamics.

Monitoring of ketamine-based emerging contaminants in wastewater: a direct-injection method and fragmentation pathway study

The ketamine (KET) and its analogs consumed by humans are becoming emerging contaminants (ECs), as they at present in surface waters after being carried through wastewater systems. Drugs in wastewater can be analyzed using the direct-injection method, a simple wastewater analysis (WWA) method that can provide objective, continuous and nearly to real-time findings. This article describes an ultra-high-pressure liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous quantification and confirmation of seven KET-based ECs in wastewater by direct injection. After optimization of the UPLC-MS/MS and sample pretreatment conditions, the method was validated and applied to samples (n = 157) collected from several wastewater treatment plants (WWTPs) in southern China in which KET had the highest detection rate. The established direct-injection method was not only simple to perform but also had better sensitivity, shorter detection times, and analyzed more KET-based ECs than currently published methods, meeting the requirements for the monitoring and high-throughput analysis of common KET-based ECs. We also analyzed the fragmentation pathway of KET-based ECs to obtain product ion information on other unknown substances. Additional studies are needed to establish a comprehensive direct-injection screening method of ECs in wastewater on model-based assessment.

Evaluation of spatial and temporal changes in illicit drug use in the Taipei metropolitan area via wastewater-based epidemiology

Taiwan, identified as pivotal in the Asian drug trafficking chain, has been experiencing a surge in illicit drug-related issues. Wastewater-based epidemiology (WBE) has emerged as a promising approach for comprehensive evaluation of actual illicit drug usage. This study presents the first WBE investigation of illicit drug consumption in Taiwan based on the analysis of wastewater from four wastewater treatment plants (WWTPs) in the Taipei metropolitan area. Additionally, it demonstrates a high correlation between the amounts of illicit drugs seized and influent concentrations over an extended period of time. The reliability of solid-phase extraction and analysis via high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was validated for 16 illicit drugs (methamphetamine, ketamine, cocaine, codeine, methadone, morphine, meperidine, fentanyl, sufentanil, para-methoxyamphetamine (PMA), para-methoxymethamphetamine (PMMA), 3,4-methylenedioxymethamphetamine (MDMA), cathinone, methcathinone, mephedrone (MEPH), and 4-methylethcathinone (4-MEC)). Methamphetamine, ketamine, and 4-MEC were consistently detected in all wastewater samples, underscoring their prevalence in the Taipei metropolitan area. Biochemical oxygen demand (BOD) and ammonia nitrogen (ammonia N) were employed to reduce uncertainty in estimations of population size during back-calculation of illicit drug consumption. The results indicate that methamphetamine was the most consumed drug (175-740 mg day-1 1000 people-1), followed by ketamine (22-280 mg day-1 1000 people-1). In addition, urban-related WWTPs exhibited higher consumption of methamphetamine and ketamine than did the suburban-related WWTP, indicating distinct illicit drug usage patterns between suburban and urban regions. Moreover, an examination of temporal trends in wastewater from the Dihua WWTP revealed a persistent predominance of ketamine and methamphetamine, consistent with statistical data pertaining to seizure quantities and urine test results. The study provides encouraging insight into spatial and temporal variations in illicit drug usage in the Taipei metropolitan area, emphasizing the complementary role of WBE in understanding trends in illicit drug abuse.

Nationwide assessment of illicit drug consumption patterns in South Korea using wastewater-based epidemiology during the COVID-19 pandemic (2020-2022)

Illicit drugs have become a crucial global social issue, with South Korea experiencing a continuous increase in the number of offenders and drug smuggling. This study employed wastewater-based epidemiology to investigate consumption patterns of 8 illicit drugs and their 7 metabolites during the COVID-19 pandemic (2020-2022) in South Korea. Ten compouds were detected in the wastewater influent. Methamphetamine (METH) was prevalent in samples, followed by amphetamine and ecstasy (MDMA). Interestingly, MDMA and ketamine (KET), which were not detected in previous Korean studies conducted before COVID-19 pandemic, were detected in this study. METH exhibited the highest consumption rates, decreasing from 16.6 to 12.4 mg/day/1000 people between 2020 and 2022, while MDMA increased over the three years (mean: 1.16, 1.24, and 1.62 mg/day/1000 people in 2020, 2021, and 2022, respectively) (p < 0.05). Significant correlations were identified between regional income levels and the consumption rates of METH (p < 0.01), MDMA (p < 0.01), and KET (p < 0.05). Furthermore, METH and MDMA consumption rates in cities were positively correlated with the number of drug offenders arrested and local clubs in those cities. The findings of this study provide valuable insights into shaping regulatory policies related to illicit drugs and future studies.

Model-based and model-free mechanisms in methamphetamine use disorder

People with methamphetamine use disorder (MUD) struggle to shift their behaviour from methamphetamine-orientated habits to goal-oriented choices. The model-based/model-free framework is well suited to understand this difficulty by unpacking the computational mechanisms that support experienced-based (model-free) and goal-directed (model-based) choices. We aimed to examine whether 1) participants with MUD differed from controls on behavioural proxies and/or computational mechanisms of model-based/model-free choices; 2) model-based/model-free decision-making correlated with MUD symptoms; and 3) model-based/model-free deficits improved over six weeks in the group with MUD. Participants with MUD and controls with similar age, IQ and socioeconomic status completed the Two-Step Task at treatment commencement (MUD n = 30, Controls n = 31) and six weeks later (MUD n = 23, Controls n = 26). We examined behavioural proxies of model-based/model-free decisions using mixed logistic regression, and their underlying mechanisms using computational modelling. At a behavioural level, participants with MUD were more likely to switch their choices following rewarded actions, although this pattern improved at follow up. At a computational level, groups were similar in their use of model-based mechanisms, but participants with MUD were less likely to apply model-free mechanisms and less likely to repeat rewarded actions. We did not find evidence that individual differences in model-based or model-free parameters were associated with greater severity of methamphetamine dependence, nor did we find that group differences in computational parameters changed between baseline and follow-up assessment. Decision-making challenges in people with MUD are likely related to difficulties in pursuing choices previously associated with positive outcomes.

Chronic exposure to (2 R,6 R)-hydroxynorketamine induces developmental neurotoxicity in hESC-derived cerebral organoids

(R,S)-ketamine (ketamine) has been increasingly used recreationally and medicinally worldwide; however, it cannot be removed by conventional wastewater treatment plants. Both ketamine and its metabolite norketamine have been frequently detected to a significant degree in effluents, aquatic, and even atmospheric environments, which may pose risks to organisms and humans via drinking water and aerosols. Ketamine has been shown to affect the brain development of unborn babies, while it is still elusive whether (2 R,6 R)-hydroxynorketamine (HNK) induces similar neurotoxicity. Here, we investigated the neurotoxic effect of (2 R,6 R)-HNK exposure at the early stages of gestation by applying human cerebral organoids derived from human embryonic stem cells (hESCs). Short-term (2 R,6 R)-HNK exposure did not significantly affect the development of cerebral organoids, but chronic high-concentration (2 R,6 R)-HNK exposure at day 16 inhibited the expansion of organoids by suppressing the proliferation and augmentation of neural precursor cells (NPCs). Notably, the division mode of apical radial glia was unexpectedly switched from vertical to horizontal division planes following chronic (2 R,6 R)-HNK exposure in cerebral organoids. Chronic (2 R,6 R)-HNK exposure at day 44 mainly inhibited the differentiation but not the proliferation of NPCs. Overall, our findings indicate that (2 R,6 R)-HNK administration leads to the abnormal development of cortical organoids, which may be mediated by inhibiting HDAC2. Future clinical studies are needed to explore the neurotoxic effects of (2 R,6 R)-HNK on the early development of the human brain.

Trends and challenges in analytical chemistry for multi-analysis of illicit drugs employing wastewater-based epidemiology

Wastewater-based epidemiology (WBE) for quantification of illicit drug biomarkers (IDBs) in wastewater samples is an effective tool that can provide information about drug consumption. The most commonly quantified IDBs belong to different chemical classes, including cocaine, amphetamine-type stimulants, opioids, and cannabinoids, so the different chemical properties of these molecules pose a challenge in the development of analytical methods for multi-analyte analysis. Recent workflows include the steps of sampling and storage, sample preparation using solid-phase extraction (SPE) or without extraction, and quantification of analytes employing gas or liquid chromatography coupled with mass spectrometry. The greatest difficulty is due to the fact that wastewater samples are complex chemical mixtures containing analytes with different chemical properties, often present at low concentrations. Therefore, in the development of analytical methods, there is the need to simplify and optimize the analytical workflows, reducing associated uncertainties, analysis times, and costs. The present work provides a critical bibliographic survey of studies published from the year 2020 until now, highlighting the challenges and trends of published analytical workflows for the multi-analysis of IDBs in wastewater samples, considering sampling and sample preparation, method validation, and analytical techniques.

High resolution mass spectrometry (HRMS) determination of drugs in wastewater and wastewater based epidemiology in Cadiz Bay (Spain)

Multi-residue methods for the determination of the myriad of compounds of emerging concern (CECs) entering in the environment are key elements for further assessment on their distribution and fate. Here, we have developed an analytical protocol for the simultaneous analysis of 195 prescription, over-the-counter, and illicit drugs by using a combination of solid phase extraction (SPE) and determination by liquid chromatography coupled to high resolution mass spectrometry (LC-HRMS). The method was applied to the analysis of influent sewage samples from 3 wastewater treatment plants (WWTPs) from Cadiz Bay (SW Spain), enabling the quantification of more than 100 pharmaceuticals, 19 of them at average concentrations higher than 1 μg L^-1, including caffeine (92 μg L^-1), paracetamol (72 μg L^-1), and ibuprofen (56 μg L^-1), as well as several illicit drugs (e.g., cocaine). Wastewater based epidemiology (WBE) was applied for 27 of the detected compounds to establish their consumption in the sampling area, which has been never attempted before. Caffeine, naproxen, and salicylic acid stood out because of their high consumption (638, 51, and 20 g d^-1·1000pop^-1, respectively). Regarding illicit drugs, cocaine showed the highest frequency of detection and we estimated an average consumption of 3683 mg d^-1·1000pop^-1 in Cadiz Bay. The combination of new HRMS methods, capable of discriminating thousands of chemicals, and WBE will allow for a more comprehensive characterization of chemical substances and their consumption in urban environments in the near future.

Origin, transport and ecological risk assessment of illicit drugs in the environment - A review

Illicit drugs are a novel group of emerging pollutants. A growing global environmental load and ecological risk is created by the ongoing release of these toxins into the environment. Conventional water processing plants fail to completely remove drugs of abuse from both surface water and wastewater. The origin, environmental fate and ecological repercussions of illicit drugs, despite their detection in surface waterways around the world, are not well understood. In this review, illicit drug detections in potable water, surface water and wastewater globally have been studied during the past 15 years in order to establish a baseline for future years. The most common drugs with abuse potential detected in different sources of potable and surface water were methadone (0.12-22.7 ng/L), cocaine (0.05-506.6 ng/L), benzoylecgonine (0.07-1019 ng/L), amphetamine (1.4-342.6 ng/L), and codeine (0.002-42 ng/L). The bulk of research only looked at a small number of drugs of abuse, indicating that despite widespread use, a large spectrum of these intoxicants has yet to be detected. This review focuses on the origin of illicit drug contaminants in water bodies, air, and soil, their persistence in the environment, and the typical concentrations at which they occur in the environment. The impact of these drugs on aquatic organisms like Elliptio complanata mussels, crayfish and zebrafish has also been reviewed.

Consumption of common illicit drugs in twenty-one cities in southwest China through wastewater analysis

Wastewater-based epidemiology (WBE) was applied to estimate illicit drugs consumption at a provincial scale in southwest China. A large-scale wastewater sampling campaign was carried out from October to November in 2021 in 156 different wastewater treatment plants (WWTPs). Two 24-h composite influent wastewater samples were collected in each WWTP. Concentrations of 11 illicit drugs or their metabolites were determined using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Benzoylecgonine, cocaine, 6-monoacetylmorphine, norketamine, 3,4-methylenedioxymethamphetamine (MDMA), and MDA were not detected in any of the wastewater samples. Methamphetamine and morphine were detected in >84% of samples, while ketamine was found in about 6% of the samples. The city-specific population-weighted consumption of methamphetamine and ketamine were in the range of 0.6-49.7 and N.D.-7.0 mg 1000 inh^-1 day^-1, respectively, with provincial population-weighted values of 22.6 and 2.4 mg 1000 inh^-1 day^-1 in southwest China. The city-specific load of morphine varied from 3.2 to 10.2 mg 1000 inh^-1 day^-1, with provincial population-weighted load of 6.7 mg 1000 inh^-1 day^-1. Taking into account therapeutic use of morphine and codeine, the provincial heroin consumption was estimated to be 10.3 mg 1000 inh^-1 day^-1, ranging from 1.7 to 18.5 mg 1000 inh^-1 day^-1 in 21 cities. Overall, the patterns of illicit drugs use were similar across southwest China, with high prevalence of methamphetamine and heroin, but relatively low use of ketamine. These findings could provide accurate drugs consumption information for timely identifying potential hotspots of illicit drugs use in southwest China.

Refining the estimation of amphetamine consumption by wastewater-based epidemiology

Consumption of amphetamine and methamphetamine, two common illicit drugs, has been monitored by wastewater-based epidemiology (WBE) in many countries over the past decade. There is potential for the estimated amount of amphetamine used to be skewed at locations where methamphetamine is also consumed, because amphetamine is also excreted to wastewater following methamphetamine consumption. The present study aims to review the available data in the literature to identify an average ratio of amphetamine/methamphetamine (AMP/METH) that is excreted to wastewater after methamphetamine consumption. This ratio could then be used to refine the estimation of amphetamine consumption in catchments where there is both amphetamine and methamphetamine use. Using data from more than 6000 wastewater samples from Australia where methamphetamine is the dominant illicit amphetamine-type substance on the market, we were able to subtract the contribution of legal sources of amphetamine contribution and obtain the median AMP/METH ratio in wastewater of 0.09. Using this value, the amphetamine derived from methamphetamine consumption can be calculated and subtracted from the total amphetamine mass loads in wastewater samples. Without considering the contribution of amphetamine from methamphetamine use, selected European catchments with comparable consumption of amphetamine and methamphetamine showed up to 83% overestimation of amphetamine use. For catchments with AMP/METH ratio greater than 1.00, the impact of amphetamine from methamphetamine would be negligible; for catchments with AMP/METH ratio in the range of 0.04-0.19, it will be difficult to accurately estimate amphetamine consumption.

Rapid detection and speciation of illicit drugs via a thin-film microextraction approach for wastewater-based epidemiology study

High detection frequency of illicit drugs in water samples urges the development of rapid detection method for wastewater-based epidemiology (WBE) study. Here, we first developed a fast, convenient, and cost-effective method by combining thin-film microextraction (TFME) with gas chromatography-mass spectrometry (GC-MS) for sensing illicit drugs in wastewater sample. A divinylbenzene particle-loaded membrane was prepared by dip coating on a copper mesh. The sampling conditions of three illicit drugs were optimized and the performance of the proposed method was evaluated. The limit of detection was 5.5 2.0, and 1.1 ng L^-1 for methamphetamine (MAMP), ketamine (KET), and methaqualone (MEQA), respectively, with acceptable precision (< 6.1 % for membrane to membrane reproducibility) and recovery from influent water (95 % - 111 %). Then, the proposed method was applied to study the occurrence and distribution of the target compounds in a wastewater treatment plant. The presence of methamphetamine, ketamine, and methaqualone was confirmed and their concentrations in the influent sample were 57 ± 8, 40 ± 4, and 75 ± 2 ng L^-1, respectively. The speciation of the target compounds in different ponds was also investigated. Results showed that the content of organic matter and the pH of the sample significantly affected the binding state of the compounds. This work provides an efficient and accurate analytical protocol for WBE investigation of illicit drugs.