Application of a sewage-based approach to assess the use of ten illicit drugs in four Chinese megacities

High-quality models for assessing the effects of environmental pollutants on the nervous system: 3D brain organoids

The prevalence of environmental problems and the increasing risk of human exposure to environmental pollutants have become a global concern. The increasing environmental pollution is one of the main reasons for the rising incidence of most neurological-related diseases in recent years. However, the ethical constraints of direct human research and the racial limitations of animal models have slowed the progress of research in this area. The purpose of this study is to review the neurotoxicity of different environmental pollutants on the brain using brain organoids as a new model and to conclude that brain organoids may play a key role in assessing the mechanisms by which environmental pollutants affect neurogenesis and cause neurological pathogenesis. To accurately determine the negative effects of environmental pollutants on the nervous system, self-organizing brain organoids that are highly similar to the developing brain have become a new model system for studying the effects of environmental pollutants on human brain development and disease. This study uses brain organoids as a model to summarize the neurotoxicity of different environmental pollutants on the nervous system, including structural changes in brain organoids, inhibition of neuronal differentiation and migration, impairment of mitochondrial function, damage to cellular cilia, and influence on signaling pathways. In conclusion, exposure to environmental pollutants may cause different neurotoxicity to the nervous system. Therefore, it is crucial to understand how to use brain organoids to ameliorate neurological disorders caused by environmental pollution.

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.

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.

Estimation of anti-diabetes drug metformin in Turkiye using wastewater-based epidemiology

Metformin is the most commonly used drug for the treatment of type 2 diabetes (T2D), which is dramatically increasing due to factors such as increasing obesity, physical inactivity, and aging of the population. Metformin analysis was carried out in composite wastewater samples seasonally collected from wastewater treatment plants in 10 cities in 2019 and 2020 30 cities in 2021 in Turkiye. Metformin was measured in all wastewater samples, with an average concentration of 97.81 μg/l in 2019, 75.19 μg/l in 2020, and 69.13 μg/l in 2021. This study was utilized to predict metformin usage in different sociodemographic regions in Turkiye using a wastewater-based epidemiology (WBE) approach. As a result of the analysis, the average metformin consumption in Turkiye was estimated to be 22.2 ± 9.6 [1.9-63.8] g/d/1,000 persons (mean ± SD [range]). Furthermore, these estimates were compared with data for time, sociodemographic characteristics, and patient numbers. Assessing the correlation with estimates and the socioeconomic classes of the cities in question revealed that cities with high-income levels had the lowest metformin use rate. Finally, the study provides supporting data aiding the development of public health strategies for decreasing the overall load of T2D across Turkiye.

Tracking methamphetamine and amphetamine consumption patterns in South Korea via enantiomeric analysis of wastewater

Wastewater-based epidemiology (WBE) has emerged as an effective method for monitoring a community's health status and lifestyle. In recent years, enantiomeric profiling has shown promise as a tool for tracing the sources of abused drugs through WBE. This study investigated amphetamine (AMP) and methamphetamine (METH) consumption in South Korea using enantiomeric analysis of untreated wastewater samples collected from 27 wastewater-treatment plants (WWTPs). Both AMP and METH were detected, with the predominant detection of S-(+)-METH indicating widespread illegal use of METH, which is primarily produced by a clandestine synthesis procedure that involves the reduction of ephedrine/pseudoephedrine. Most AMP/METH ratios in the samples were consistent with the expected METH excretion profile, indicating that the presence of AMP was primarily due to METH metabolism. However, R-(-) AMP was detected in 18.5 % and 25.9 % of wastewater samples in winter and spring, respectively, and the high AMP/METH ratio (>0.27) indicated potential AMP abuse. By differentiating between the sources of AMP and METH in wastewater, enantiomeric analysis could help authorities to target and address specific drug-abuse issues affecting the population more effectively.

Assessment of the excretion of oxidative stress biomarkers and anabolic steroids based on sewage: A case study of college students and the general population

The use of wastewater-based epidemiology to evaluate the health and lifestyle of the population is a novel research interest. However, studies concerning the excretion of endogenous metabolites due to oxidative stress and the consumption of anabolic steroids have rarely been involved. In this study, we compared the effects of events such as final examination and sports meeting on the levels of four oxidative stress biomarkers (8-isoPGF_2α, HNE-MA, 8-OHdG, and HCY) and four prohibited anabolic steroids (Testosterone, Androstenedione, Boldenone, and Metandienone) in sewage, using university students and urban populations as studying target. It was found that the per capita mass load of the four oxidative stress biomarkers 8-isoPGF_2α, HNE-MA, 8-OHdG, and HCY in the sewage of Guangzhou urban area and university town were 256.6 ± 76.1, 9.4 ± 3.8, 1.1 ± 0.5, and 0.9 ± 0.4 mg/d/1000, respectively. The mean mass load of 8-isoPGF_2α was significantly higher than that before the COVID-19 pandemic (74.9 ± 29.6 mg/d/1000 people, P < 0.05). The per capita load levels of oxidative stress biomarkers were significantly higher (P < 0.05) during the 2022 exam week relative to the pre-exam period, indicating that the exams caused transient stress to students. The per capita mass load of androgenic steroids was 77.7 mg/d/1000 people. There was an increase in the per capita load level of androgenic steroids during the provincial sports meeting. In this study, we quantified the concentration of oxidative stress biomarkers and androgenic steroids in the sewage and better realized the application of WBE on the health level and lifestyle of the population during special events.

Emerging contaminants in the northwest area of the Tai Lake Basin, China: Spatial autocorrelation analysis for source apportionment and wastewater-based epidemiological analysis

In the present study, 60 emerging contaminants (ECs) were detected from 88 target compounds in the district of Wujin, which is the northwest area of Tai Lake Basin, China. Among them, CF (caffeine), a type of PhAC (pharmaceutically active compound), was detected as the pollutant with the highest concentration. It was observed that the removal efficiencies of PFASs (per-/polyfluoroalkyl substances) in wastewater treatment plants were lower than those of pesticides; further, those of pesticides were lower than those of PhACs. Based on the spatial agglomeration estimated by the spatial autocorrelation model, the probable sources of 28 contaminants were identified. This model provided a new perspective that would help to clarify the location of sources with high accuracy. The point sources of 6 PFASs and 14 PhACs were successfully found; in contrast, the main source of pesticides was identified as an agricultural nonpoint source. Finally, the potential risks of the ECs were also assessed in this study, including their aquatic ecological risks and human exposure risks. It was concluded that pesticides generally had the highest ecological risk, followed by PFASs and PhACs. To evaluate the population risk of pesticides, the wastewater-based epidemiological model was extended to back-calculate the per capita pesticide consumption, which was 0.22 g d^-1 (10³capita)^-1.

Investigation on consumption of psychoactive substances and their ecological risks using wastewater-based epidemiology: a case study on Qinghai-Tibet Plateau

The Qinghai-Tibet Plateau is the third pole of the world, and information on the consumption of psychoactive substances (PSs) in this area is scarce. In this study, we selected Qinghai Province as the research area, and the per capita consumption and prevalence of PSs were investigated using wastewater-based epidemiology. Samples from 17 wastewater treatment plants (WWTPs) in 5 major cities in Qinghai Province were monitored, and 11 PSs were detected by ultra-high performance liquid chromatography-tandem mass spectrometry. Results showed that the target compounds were detected in all samples, with relatively high concentrations of ephedrine (2.1-4825.3 ng/L) and methamphetamine (1.5-295.7 ng/L). The consumption of methamphetamine in Xining City, Haidong City, and Haixi City was up to 78.4, 16.8, and 21.2 mg/1000 inh/d (the PS consumption per 1000 inhabitants in 1 day), respectively, higher than that in the other two cities, which was the result of the different consumption patterns and its relationship with the economic levels of each city. High consumption of methadone (47.9 mg/1000 inh/day) was found in Xining City, which might be related to the methadone maintenance therapy sites in the city. Methamphetamine was the most prevalent drug, with the prevalence ranging from 0.003 (Guoluo) to 0.197% (Xining), and the prevalence of other PSs was low. The ecological risk assessment of PSs in the effluent of WWTPs showed that methadone exerted a low risk to aquatic organisms in three sites, while other substances posed potential risk or no risk. However, the long-term effect of PSs cannot be ignored.

Occurrence of Z-drugs, benzodiazepines, and ketamine in wastewater in the United States and Mexico during the Covid-19 pandemic

Z-drugs, benzodiazepines and ketamine are classes of psychotropic drugs prescribed for treating anxiety, sleep disorders and depression with known side effects including an elevated risk of addiction and substance misuse. These drugs have a strong potential for misuse, which has escalated over the years and was hypothesized here to have been exacerbated during the COVID-19 pandemic. Wastewater-based epidemiology (WBE) constitutes a fast, easy, and relatively inexpensive approach to epidemiological surveys for understanding the incidence and frequency of uses of these drugs. In this study, we analyzed wastewater (n = 376) from 50 cities across the United States and Mexico from July to October 2020 to estimate drug use rates during a pandemic event. Both time and flow proportional composite and grab samples of untreated municipal wastewater were analyzed using solid-phase extraction followed by liquid chromatography-tandem mass spectrometry to determine loadings of alprazolam, clonazepam, diazepam, ketamine, lorazepam, nordiazepam, temazepam, zolpidem, and zaleplon in raw wastewater. Simultaneously, prescription data of the aforementioned drugs were extracted from the Medicaid database from 2019 to 2021. Results showed high detection frequencies of ketamine (90 %), lorazepam (87 %), clonazepam (76 %) and temazepam (73 %) across both Mexico and United States and comparatively lower detection frequencies for zaleplon (22 %), zolpidem (9 %), nordiazepam (<1 %), diazepam (<1 %), and alprazolam (<1 %) during the pandemic. Average mass consumption rates, estimated using WBE and reported in units of mg/day/1000 persons, ranged between 62 (temazepam) and 1100 (clonazepam) in the United States. Results obtained from the Medicaid database also showed a significant change (p < 0.05) in the prescription volume between the first quarter of 2019 (before the pandemic) and the first quarter of 2021 (pandemic event) for alprazolam, clonazepam and lorazepam. Study results include the first detections of zaleplon and zolpidem in wastewater from North America.

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.

A Framework for Public Health Authorities to Evaluate Health Determinants for Wastewater-Based Epidemiology

BACKGROUND

Wastewater-based epidemiology (WBE) is rapidly developing as a powerful public health tool. It can provide information about a wide range of health determinants (HDs), including community exposure to environmental hazards, trends in consumption of licit and illicit substances, spread of infectious diseases, and general community health. As such, the list of possible candidate HDs for WBE is almost limitless. Consequently, a means to evaluate and prioritize suitable candidates for WBE is useful, particularly for public health authorities, who often face resource constraints.

OBJECTIVES

We have developed a framework to assist public health authorities to decide what HDs may be appropriate for WBE and what biomarkers could be used. This commentary reflects the experience of the authors, who work at the interface of research and public health implementation.

DISCUSSION

To be suitable for WBE, a candidate HD should address a public health or scientific issue that would benefit from better understanding at the population level. For HDs where information on individual exposures or stratification by population subgroups is required, WBE is less suitable. Where other methodologies are already used to monitor the candidate HD, consideration must be given to whether WBE could provide better or complementary information to the current approach. An essential requirement of WBE is a biomarker specific for the candidate HD. A biomarker in this context refers to any human-excreted chemical or biological that could act as an indicator of consumption or exposure to an environmental hazard or of the human health state. Suitable biomarkers should meet several criteria outlined in this commentary, which requires background knowledge for both the biomarker and the HD. An evaluation tree summarizing key considerations for public health authorities when assessing the suitability of candidate HDs for WBE and an example evaluation are presented. https://doi.org/10.1289/EHP11115.

Monitoring of changes in illicit drugs, alcohol, and nicotine consumption during Ramadan via wastewater analysis

Illicit drug use is a global problem imposing social, economic, and health burdens on society. Wastewater-based epidemiology is an approach based on calculating the consumption of substances in the target population by analyzing the concentrations of human metabolic excretion products of licit and illicit substances in wastewater. This study estimated the changes in illicit drugs (cocaine, amphetamine, methamphetamine, ecstasy (3,4-Methylenedioxymethamphetamine), heroin, and marijuana (THC)), alcohol, and nicotine consumption in Adana Province during Ramadan compared to normal periods using wastewater-based epidemiology. An overall decrease was observed during the Ramadan Period, most strongly for ecstasy (29%) followed by heroin (19%). For cocaine, the variation was the slightest (8.6%). The differences were statistically significant for ecstasy, heroin, nicotine, and alcohol but not for cocaine, amphetamine, methamphetamine, and marijuana. This study is the first to show changes in the use of illicit drugs, alcohol, and nicotine under the influence of religious beliefs. In addition, there is limited data about illicit drugs, alcohol and nicotine abusers/users in Ramadan. This study provides information on the literature on this subject.

Competitive fluorescence immunoassay for the rapid qualitative screening and accurate quantitative analysis of ketamine

In this paper, a sensitive and specific competitive fluorescence immunoassay (CFIA) method was developed for the qualitative and quantitative analysis of ketamine (KET). A novel competitive model in which ketamine hapten (KET-BSA), coated on microporous plates, competed with ketamine antigen (KET-Ag) in actual samples to bind fluorescein isothiocyanate-labeled antibody (KET-Ab) could be used for rapid and indirect quantitative analysis of KET in human urine, blood, or sewage. In the CFIA method, KET concentration in the sample negatively correlated with the detected fluorescence intensity. The linear correlation coefficient of the competitive quantitative equation was 0.992, the linear range was 0.01-0.5 μg mL^-1, and the limit of detection (LOD) was 0.1 pg mL^-1. The specificity results showed that the cross-reaction rate of norketamine was less than 10%. Recoveries of spiked samples at low, medium, and high concentrations ranged from 96% to 117%. The CFIA method and classical gas chromatography-tandem mass spectrometry (GC-MS/MS) were used to detect the actual samples simultaneously. The relative deviation of the quantitative results was less than 10%. The LOD value of KET by CFIA was four orders of magnitude lower than that by GC-MS/MS. Additionally, CFIA had great advantages over GC-MS/MS in terms of sample pretreatment and economic investment. In conclusion, this study provided a targeting detection platform for KET, which achieved a rapid, portable, and sensitive analysis of trace KET in various materials.

Can wastewater surveillance assist China to cost-effectively prevent the nationwide outbreak of COVID-19?

China has controlled the nationwide spread of COVID-19 since April 2020, but it is still facing an enormous threat of disease resurgence originating from infected international travelers. Taking the rapid transmission and the mutation of SARS-CoV-2 into consideration, the current status would be easily jeopardized if sporadic locally-transmitted individuals are not identified at an early stage. Clinical diagnosis is the gold standard for COVID-19 surveillance, but it is hard to screen presymptomatic or asymptomatic cases in those who have not exhibited symptoms. Since presymptomatic or asymptomatic individuals are infectious, it is urgent to establish a surveillance system based on other tools that can profile the entire population. Infected people including those who are symptomatic, presymptomatic, and asymptomatic shed SARS-CoV-2 RNA in feces and thereby endow wastewater-based epidemiology (WBE) with an early-warning ability for mass COVID-19 surveillance. In the context of China's "COVID-zero" strategy, this work intends to discuss the practical feasibility of WBE applications as an early warning and disease surveillance system in hopes that WBE together with clinical testing would cost-effectively restrain sporadic COVID-19 outbreaks in China.

Exploring antibiotic consumption between urban and sub-urban catchments using both parent drugs and related metabolites in wastewater-based epidemiology

Consumption of antibiotics leads to the dissemination of antimicrobial resistance worldwide. Better knowledge of temporal and spatial consumption of antibiotics helps public health authorities to control their usage and combat antimicrobial resistance. However, measuring antibiotic consumption with population surveys, sales data, and production statistics remains challenging due to the complexity of prescription preference, patient compliance, and direct disposal of unused drugs. With the approach of wastewater-based epidemiology (WBE), this study aims to evaluate the consumption of eight commonly-used antibiotics between developed urban and developing sub-urban catchments in China and to characterise the ratios of parent drugs to metabolites in studying the consumption. Seven parent antibiotics were detected in all the wastewater samples (n = 56), whereas some metabolites were detected sporadically. The ratios of parent chemicals to metabolites varied among locations and were often higher than the ratios in pharmacokinetic studies. Estimated consumption of antibiotics ranged from 3.2 ± 2.0 mg/day/1000 inhabitants for trimethoprim to 28,400 ± 7800 mg/day/1000 inhabitants for roxithromycin in the studied catchments. Higher consumption of sulfapyridine, sulfadiazine and roxithromycin was observed in urban than suburban catchments, while consumption of sulfamethoxazole, norfloxacin, and trimethoprim was higher in suburban than in urban catchments. Using the literature data, we found more than 95% reduction of antibiotic use in an urban catchment. Our study revealed the geographical pattern in antibiotic use across different urban and suburban catchments via WBE, and the potential of monitoring parent-to-metabolite ratios for WBE in estimating antibiotic use. These results provide a basis for health authorities to plan different drug-specific control policies between urban and suburban catchments, and for future WBE studies to be aware of other sources, such as animal husbandry and disposals of unused drugs, that can influence the estimated consumption.

Wastewater-based monitoring of 2-fluoro-deschloroketamine abuse from 2019 to 2021 in a southern Chinese province

2-fluoro-deschloroketamine (FDCK) is a ketamine (KET) analog and new psychoactive substance that has appeared on the drug market in Europe and China in the past few years. The substance has been recently listed as a controlled drug by the narcotics control authority of China. In this work, FDCK and its metabolite nor-fluoro-deschloroketmaine (N-FDCK) in wastewater were analyzed for the first time to monitor FDCK abuse in a southern Chinese province that used to be a major producer and consumer of ketamine. For comparison, KET and its metabolite, nor-ketamine (N-KET) were monitored simultaneously. The concentration ratios between FDCK and N-FDCK were not statistically different from those of KET and N-KET. The average FDCK loads in the province in 2019 were higher than KET loads in most major cities in China in 2014 (when KET abuse hit its peak in the country). Rough estimation of FDCK and KET consumption revealed that FDCK was the predominant synthetic drug in the province in 2019, indicating rapid spread of the substance since its first appearance on the market. FDCK consumption decreased dramatically in 2020 and 2021, due to proactive actions by the local drug police before its listing as a controlled drug. Despite the dramatic decrease, FDCK was still the drug with greatest consumption by 2021, indicating that this substance persisted on the market even in the presence of forceful law enforcement. This finding also demonstrates that this substance may indeed have similar or even improved psychoactive effects relative to KET. Quick spread and persistence of FDCK demonstrated here indicates the urgent need to conduct wastewater-based monitoring of the abuse of the substance in other Chinese provinces and other countries.

Trends in Methamphetamine Use in the Mainland of China, 2006-2015

Background

Methamphetamine is the most prevalent drug in the mainland of China, yet few studies on the non-medical use of methamphetamine nationwide have been conducted. This study aimed to examine the trends in the prevalence of non-medical methamphetamine use and to explore the flow pattern of internal migrant methamphetamine users in the mainland of China.

Methods

Data were extracted from the National Dynamic Management and Control Database for Drug Users (NDMCD). Joinpoint regressions were used to examine trends in the prevalence and population size of methamphetamine use.

Results

A total of 1,821,468 methamphetamine use cases registered in NDMCD from 2006 to 2015 were identified. The number of methamphetamine use cases presented an increasing trend in all age subgroups, and among them, the elderly increased the fastest [annual percent change (APC_2006−2015), 122.9; 95% CI, 113.0–133.3; p < 0.001]. The prevalence of methamphetamine use increased from 4.69 per 100,000 population in 2008 to 45.38 per 100,000 population in 2015 (APC_2008−2015, 36.1; 95% CI, 31.9–40.6; p < 0.001). The regions of the Pearl River Delta, Yangtze River Delta, and Beijing-Tianjin-Hebei Urban Agglomeration absorbed over 96% of all internal migrant methamphetamine use cases, and the number of migrant methamphetamine use cases presented increased trends in these three regions.

Conclusions

The increasing trends in methamphetamine use have become a threat to all age groups in China. Substance use prevention programs should focus on internal migrant drug users, especially in economically developed regions.

Monitoring and ecological risk of illegal drugs before and after sewage treatment in an area

In this study, the occurrence of illicit drugs and their metabolites in the sewerage systems and in the influent and effluent of wastewater treatment plant (WWTP) in Konya, Turkey, was presented. The drug removal efficiencies of the central WWTP were investigated. Potential ecotoxicological risks for algae, fish, and Daphnia magna in the receiving environments were also evaluated. The highest estimated mean illicit drug use was obtained for cannabis (marijuana) at 280 ± 12 mg/day/1000 inhabitants and 430 ± 20 g/day/1000 inhabitants (15-64 years). Amphetamine was found to be the second most consumed drug of abuse. While cannabis and ecstasy consumption values were higher during the weekend, cocaine use dominated on weekdays. The removal efficiencies for THC-COOH and THC-OH were 100% in the WWTP. The average removal of cocaine, amphetamine, methamphetamine, MDMA, MDA, and methadone varied between 46 ± 7 and 87 ± 3%. The maximum concentration level of MDMA found can pose some low risk for Daphnia magna. The rest of the compounds detected in effluents did not show any toxic effects on fish, Daphnia magna, or algae. However, when the cumulative estimated risk quotient values were evaluated, there might be a low risk for Daphnia magna and algae in the receiving environment.

Cocaine esterase occurrence in global wastewater microbiomes and potential for biotransformation of novel psychoactive substances

The analysis of drugs in wastewater for forensic purposes has been constantly increasing and the investigation of the potential interaction between drugs or metabolites and sewage microbiota is important. The results demonstrated that cocaine esterase genes were widely distributed in 1142 global wastewater samples collected from 64 countries and linked to several bacterial species. In addition, in silico predictions indicated that carfentanil, 4F-MDMB-BINACA, 5F-MDMB-PICA, MDMB-4en-PINACA and mitragynine might also undergo microbial hydrolysis, in a similar fashion of cocaine degradation by cocaine esterase. In conclusion, it was demonstrated the microbial potential to hydrolyze drugs of abuse in wastewater environments, contributing to the critical evaluation of potential metabolites as biomarkers for microbial and human transformation of drugs in wastewater.

Automatic analytical approach for the determination of 12 illicit drugs and nicotine metabolites in wastewater using on-line SPE-UHPLC-MS/MS

In this study, we developed a novel on-line solid phase extraction (SPE)-ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS)-based analytical method for simultaneously quantifying 12 illicit drugs and metabolites (methamphetamine, amphetamine, morphine, codeine, 6-monoacetylmorphine, benzoylecgonine, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyamphetamine, cocaine, ketamine, norketamine, and methcathinone) and cotinine (COT) in wastewater samples. The analysis was performed by loading 2 mL of the sample onto an Oasis hydrophilic-lipophilic balance cartridge and using a cleanup step (5% methanol) to eliminate interference with a total run time of 13 min. The isotope-labeled internal standard method was used to quantify the target substances and correct for unavoidable losses and matrix effects during the on-line SPE process. Typical analytical characteristics used for method validation were sensitivity, linearity, precision, repeatability, recovery, and matrix effects. The limit of detection (LOD) and limit of quantification (LOQ) of each target were set at 0.20 ng/L and 0.50 ng/L, respectively. The linearity was between 0.5 ng/L and 250 ng/L, except for that of COT. The intra- and inter-day precisions were <10.45% and 25.64%, respectively, and the relative recovery ranged from 83.74% to 162.26%. The method was used to analyze various wastewater samples from 33 cities in China, and the results were compared with the experimental results of identical samples analyzed using off-line SPE. The difference rate was between 19.91% and −20.44%, and the error range could be considered acceptable. These findings showed that on-line SPE is a suitable alternative to off-line SPE for the analysis of illicit drugs in samples.

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A new wastewater analysis method based on on-line SPE UHPLC-MS/MS was established.

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The on-line SPE method showed excellent performance compared with off-line SPE.

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High sensitivity and short analysis time were achieved using the on-line SPE method.

Occurrence, mass loads, and ecological risks of amphetamine-like substances in a rural area of South China

The occurrence and levels of amphetamine like substances (ALSs) in various environments, as a group of illicit psychoactive substances, have attracted great attention due to their potential ecological risks. In this study, three ALSs (i.e., ephedrine (EPH), amphetamine (AMP) and methamphetamine (METH)) in the raw domestic wastewater (RDW) and surface river water (SRW) collected from the rural area in South China were analyzed. METH was identified as the prevalent and dominant ALS in the RDW, which was detected in approximately 99.0% of the samples with a mean concentration of 0.7 μg·L^-1, followed by AMP and EPH. Consistent trend was also found in the SRW collected from the same region. METH concentrations in the SRW were significantly and positively correlated with those in the RDW (p < 0.05), indicating that the discharge of RDW could be the important source of METH in the nearby rivers. The mean mass load of METH in the study rural area was about 65.8 mg·day^-1·1000 inhabitants^-1. Source apportionment showed that the abuse consumption was the main source of METH at most of sampling towns in the investigated rural area, and the mean mass load of METH at these towns (24.5 mg·day^-1·1000 inhabitants^-1) might reflect the abuse level of METH in this region. The disposal and illegal synthesis of METH could be important point sources, which led to the elevated METH level in the RDW. Risk assessment demonstrated that ALSs posed a minimal or medium risk to aquatic organisms. Our results provided valuable insights into the mass loads, source characteristics and ecological risks of ALSs in the rural area.

Monitoring geographical differences in illicit drugs, alcohol, and tobacco consumption via wastewater-based epidemiology: Six major cities in Turkey

A national wastewater-based epidemiology (WBE) monitoring campaign has been initiated to determine the trends in drug consumption in Turkey since 2019. This study aimed to present the wastewater monitoring results for four periods in 2019 for six major cities with 17 wastewater treatment plants. The study investigated heroin (HER), amphetamine (AMP), methamphetamine (METH), cocaine (COC), 3,4-methylenedioxymethamphetamine (MDMA), cannabis, alcohol, and tobacco to understand the temporal and geographical drug consumption trends. The results indicated a trend of regular cannabis use in all the cities. Considering geographical variations, the drug usage trends were not homogeneous within the country for any of the investigated drugs, except cannabis. HER consumption was predominant in Denizli (1042.48 mg/1000 inh/day), while İzmir and Antalya (154.10 and 79.56 mg/1000 inh/day, respectively) topped for COC consumption. Aydın had the highest consumption levels of AMP (90.03 mg/1000 inh/day) and METH (358.13 mg/1000 inh/day), while MDMA consumption was the highest in Samsun (157.64 mg/1000 inh/day). Tobacco consumption was high in Aydın (8791.69 mg/1000 inh/day) and Antalya (5375.17 mg/1000 inh/day), whereas alcohol consumption was higher in Bursa than in the other cities (53434.61 mL/1000 inh/day). There were no statistically significant differences in the weekend consumption levels of the investigated drugs among these six cities. Although this study included the results of 1 year of consumption monitoring, the data confirms internationally published information on the drug trafficking routes of conventional drugs in this region, especially the Heroin-Balkan route. Results from further sampling will enable accurate evaluation of global drug consumption and trafficking, in addition to alcohol and tobacco use.

Preparing for COVID-2x: Urban Planning Needs to Regard Urological Wastewater as an Invaluable Communal Public Health Asset and Not as a Burden

Prior to the COVID-19 pandemic, the analysis of urological wastewater had been a matter of academic curiosity and community-wide big-picture studies looking at drug use or the presence of select viruses such as Hepatitis. The COVID-19 pandemic saw systematic testing of urological wastewater emerge as a significant early detection tool for the presence of SARS-CoV-2 in a community. Even though the pandemic still rages in all continents, it is time to consider the post-pandemic world. This paper posits that urban planners should treat urological wastewater as a communal public health asset and that future sewer design should allow for stratified multi-order sampling.

Assessing patterns of illicit drug use in a Chinese city by analyzing daily wastewater samples over a one-year period

Wastewater-based epidemiology (WBE) has been used extensively around the globe to provide information on illicit drug consumption. In China, most WBE studies to date only include a limited number of samples per catchment, making it difficult to derive any temporal consumption patterns. This study addresses this knowledge gap by identifying the temporal consumption trends of nine drugs in a Chinese megacity using WBE over a one-year period. Daily influent samples (n = 279) were collected from a wastewater treatment plant serving ~500,000 residents. All target drugs showed similar levels of consumption throughout the week. These findings were different to previous WBE studies in developed countries, where amphetamine-type drugs have shown higher consumption on weekends than during the week. Such a difference could be due to the users' demographics and behaviors as reported in previous surveys and warrant more research to help formulate appropriate drug control policies in China. Our study also observed that declining methamphetamine and ketamine consumption between 2012 and 2018, while consumption of MDMA and methadone were stable over the same period.

Field evaluation of diffusive gradients in thin-film passive samplers for wastewater-based epidemiology

There is a need for a simple water sampling technique to enable routine monitoring of community drug consumption through wastewater-based epidemiology (WBE). This study investigates the potential use of diffusive gradients in thin films to sample organic compounds (o-DGT) for WBE. Three types of resin gels (HLB, XAD 18, and XDA-1) within o-DGT samplers each were deployed in triplicate at the inlets of two sewage treatment plants of Southern Asian cities. The target compounds included 15 illicit drugs and 18 antibiotics. A comprehensive evaluation was undertaken regarding each resin's ability to accumulate the target compounds and accuracy by comparing active samples. The organic compounds accumulated on each resin gel were characterised at the molecular level using Fourier transform ion-cyclotron-resonance mass spectrometry (FT-ICR MS). The results showed that the HLB resin performed better than the XAD 18 and XDA-1 resins. Based on calculations using the HLB-DGT data, methamphetamine and heroin were the two most popular illicit drugs consumed among the studied populations, and were followed by ketamine and codeine, which agreed well with the authoritative reports and reference data. The total drug consumption in Hanoi was one order of magnitude higher than that in Guangzhou, thus implying a probably more serious drug situation in the former. Overall, the findings of this study demonstrate that o-DGT passive samplers are a promising tool for WBE studies, particularly at WWTPs or in urban streams where an automatic sampler for taking composite water samples is absent.

Wastewater analysis reveals urban, suburban, and rural spatial patterns of illicit drug use in Dalian, China

Illicit drug use in rural and suburban areas of China has not been studied extensively, as most studies have focused on illicit drug use in urban areas. To compare the differences between urban, suburban, and rural drug use, we collected influent samples from 19 urban, 9 suburban, and 18 rural wastewater treatment plants in Dalian, respectively. A method using solid-phase extraction combined with derivatization for gas chromatography -mass spectrometry analysis was applied to detect biomarker concentrations. The concentrations of methamphetamine and morphine ranged from 3.12 to 605 ng/L and < 2.35 to 198 ng/L, respectively. Norketamine was found in only four samples (5.56 to 14.5 ng/L), while 3,4-methylenedioxymethamphetamine and benzoylecgonine were not detected in any samples. Methamphetamine use in rural areas (16.3 mg/day/1000 inhabitant (inh), prevalence: 0.06%) was significantly lower than those in urban (77.1 mg/day/1000 inh, prevalence: 0.23%) and suburban (234 mg/day/1000 inh, prevalence: 0.70%) areas. Heroin use in suburban areas (57.6 mg/day/1000 inh, prevalence: 0.10%) was significantly higher than that in urban (13.9 mg/day/1000 inh, prevalence: 0.02%) and rural (8.68 mg/day/1000 inh, prevalence: 0.02%) areas. The results indicate relatively low levels of illicit drug use in rural areas of Dalian, related to low incomes and outflow of the working-age population. Illicit drug use was most prevalent in suburban areas of Dalian, which may be influenced by large floating populations and few anti-drug efforts in suburban areas.

Occurrence, distribution, and potential health risks of psychoactive substances in Chinese surface waters

Ten psychoactive substances (PSs) and metabolites were identified and quantified in 217 surface water samples collected across China to reveal the occurrence, distribution, and potential health risks in Chinese surface waters. The results showed the ubiquitous occurrence of caffeine (CFI), paraxanthine (PXT) and cotinine (CTN) at all the monitored sites, the concentrations of which ranged from not detected to 3460 ng L^-1, while the remaining PSs were detected at trace levels (<50 ng L^-1). High concentrations of diet-related PSs (CTN, CFI, and PXT) typically occurred in areas with high population densities. Traditional drugs tended to occur in megacities and the illegal manufacturing bases of the illicit drugs. Emerging drugs were found to be very popular across the whole country, with no significant differences among the samples. The risk assessment results suggest that drinking water containing these PS residues posed no potential human health risk in any life stage. However, the age-dependent risk quotients (RQs) of the 5 assessed PSs for the 12 age intervals ranged from < 1.0 × 10^-7 to 0.005. In terms of the evaluated life stages, the RQs for early stages (from birth to <2 years) were significantly higher than the RQs for other stages.

Tracing consumption patterns of stimulants, opioids, and ketamine in China by wastewater-based epidemiology

Illicit drug use has long been a key issue of international concern, and the true situation is unknown to the relevant authorities. To develop a profile of comprehensive consumption patterns of illicit drugs in China, data from 34 wastewater treatment plants in 25 cities were collected to analyze four classes of drugs, including amphetamine-type stimulants, opioids, ketamine, and cocaine. They were identified and quantified in samples using methods based on gas chromatography coupled to mass spectrometry. According to the wastewater-based epidemiology (WBE) approach, an analysis of the consumption pattern was performed regarding per inhabitant consumption based on the revised metabolic rate. The consumption quantity of illicit drug and precursor was divided into four categories based on statistical difference analyses: methamphetamine and ephedrine (precursor) were the predominant drugs in the first category, followed by ketamine and heroin in the second category, methcathinone and 3,4-methylenedioxymethamphetamine (MDMA) in the third category, and cocaine and methadone in the fourth category. There were distinctive spatial patterns: heroin and cocaine consumption was higher in Southern China than in Northern China, heroin consumption was higher in Western China than in Eastern China, and the consumption of each drug differed across seven regions of China, especially with ephedrine and methcathinone consumption higher in North China; heroin consumption higher in Southwest, Central, and Northwest China; and ketamine and MDMA consumption higher in East, South, and Central China. Compared with findings in previous studies, there were temporal patterns, in which ketamine consumption presented a downward trend but heroin remained stable. Based on correlation analyses, there were the polydrug abuse patterns between heroin and cocaine, methcathinone and ketamine, and cocaine and MDMA. In general, this study based on WBE provides a comprehensive evaluation of drug consumption in China.

Comparison of community illicit drug use in 11 cities of Turkey through wastewater-based epidemiology

Wastewater-based epidemiology (WBE) is an ever-increasing discipline that enables researchers to track near-real-time data concerning the recreational use of illicit drugs. Community illicit drug use was estimated in eleven Turkish cities, using eighteen wastewater treatment plants, representing the metropolitan cities and rural areas with different socio-demographic characteristics. In this study, 24-h composite influent wastewater samples were collected for 1 week per season between March 2019 and December 2019. Heroin, amphetamine, methamphetamine, ecstasy, cocaine, and marijuana were covered as illicit drugs in this study. Solid-phase extraction, LC-MS/MS separation, identification, and quantification were used as the analytical methods. Overall results indicate that both cocaine and MDMA usage increased in all cities on weekends. More specifically, it was observed that the average amount of cocaine use regarding 11 cities was 14.7 mg/1000 person/day, while figures for other substances are as follows: 9.5 for amphetamine, 34.5 for methamphetamine, 38.4 for MDMA, 42.2 for heroin, and lastly 5412 mg/1000p/day for marijuana. This study holds the position of being the most comprehensive one conducted, considering spatial and temporal datasets on illicit drug consumption obtained via WBE in Turkey.

Investigation of temporal illicit drugs, alcohol and tobacco trends in Istanbul city: Wastewater analysis of 14 treatment plants

Wastewater-based drug monitoring is a complementary tool that has been used worldwide in recent years, and many cities have periodically reported monitoring results. However, this study is the first to analyze drugs in wastewater in a single city with a high population during four periods simultaneously from 14 treatment plants. The aim was to estimate the consumption of conventional illicit drugs [amphetamine (AMP), methamphetamine (METH), 3,4-methylenedioxymethamphetamine (MDMA), cannabis, cocaine, and heroin], tobacco, and alcohol in 2019 for quarterly periods in Istanbul city, which has a population of almost 20 million, to aid in implementing evidence-based measures. Additionally, the seasonal variations among the 14 wastewater treatment plants and their weekday/weekend comparison of drug use patterns and consumption per substance were examined. Solid phase extraction was followed by liquid chromatography-tandem mass spectrometry and a previously validated method was enhanced by adding new parameters (morphine, cotinine, and ethyl sulfate), and satisfactory results were obtained. In this study, alcohol, nicotine, and cannabis had the highest estimated per capita consumption with mean values of 29655.3 mL/1000 inh/day, 5507.6 mg/1000 inh/day and 3607.0 mg/1000 inh/day, respectively. These results were followed by heroin and cocaine consumption with mean values of 557.0 and 200.9 mg/1000 inh/day, respectively, whereas AMP-type stimulants had the lowest values among the targeted substances. METH and cannabis were also highly consumed drugs when compared with the results of other metropolitan cities, whereas heroin consumption was remarkably high owing to Turkey's location on a possible heroin trafficking route. Because Istanbul is the business center of the country and has the potential to attract tourists in all four seasons, meaningful seasonal consumption differences were not observed for all substances.

Spatial analysis of metformin use compared with nicotine and caffeine consumption through wastewater-based epidemiology in China

Monitoring the consumption of pharmaceuticals and licit drugs is important for assessing the needs of public health owing to the impact on individuals as well as society. The present work applied wastewater-based epidemiology to profile the spatial patterns of metformin, nicotine, and caffeine use and their correlations. Influent wastewater samples were collected from 27 wastewater treatment plants in 22 typical Chinese cities that covered all geographic regions of the country. The consumption of metformin ranged from 0.02 g/d/1000 inh to 8.92 g/d/1000 inh, whereas caffeine and nicotine consumption ranged from 4.33 g/d/1000 inh to 394 g/d/1000 inh and 0.17 g/d/1000 inh to 1.88 g/d/1000 inh, respectively. There were significant regional differences in the consumption of caffeine, with the highest consumption in East China and the lowest consumption in Northeast China. The consumption and concentration of caffeine were related to the gross domestic product and per capita disposable income of urban residents, respectively. There was a correlation between the concentrations of caffeine and cotinine (a nicotine metabolite), thereby indicating that individuals that use one of these substances are likely to use the other substance. A significant relationship was found between the concentration of metformin and cotinine, thereby implying that the use of tobacco may be correlated with type 2 diabetes. Co-analysis of these substances in wastewater may provide a more accurate picture of substance use situations within different communities and provide more information on human health, human behavior, and the economy. This report describes the newest study related to the consumption of metformin among the general population in China.

Simultaneous enantioselective analysis of illicit drugs in wastewater and surface water by chiral LC-MS/MS: A pilot study on a wastewater treatment plant and its receiving river

An enantioselective method for quantifying amphetamine-type chiral illicit drugs (CIDs) in wastewater and surface water was developed, validated, and applied to samples from a wastewater treatment plant (WWTP) and its effluent-receiving river in Beijing, China. Water samples were subjected to solid-phase extraction (SPE) and then quantified via liquid chromatography-tandem mass spectrometry. The enantioseparation of CIDs was performed with a CHIRALPAK CBH column. Chromatographic parameters, including mobile phase composition and flow rates, were tested to identify the satisfactory enantiomeric resolution. The SPE method was optimized by evaluating variables, including SPE cartridge types, extraction solvents, and solvent volumes. The Oasis HLB sorbent showed good performance with recoveries exceeding 60% and matrix effects ranging from -19.6% to 26.6% for most target enantiomers, except for norephedrine (NE), in three different aquatic matrixes. The established method was superior to previously reported methods and had a low limit of detection, low limit of quantification, and short runtime (<45 min). The repeatability and reproducibility of the method reached 19.1% and 17.8%, respectively. The method was successfully utilized to monitor the daily variations in CIDs in the influent, effluent, and effluent-receiving river of a WWTP in Beijing over 1 week. The common occurrence of 1 R,2 S-(-)-ephedrine (1 R,2 S-(-)-EPH), 1 S,2 S-(+)-pseudoephedrine (1 S,2 S-(+)-PEPH), R-(-)-methamphetamine (METH), and S-(+)-METH in wastewater samples was observed. Ephedrines (1 R,2 S-(-)-EPH and 1 S,2 S-(+)-PEPH) were the most abundant CIDs in the influent, effluent, upstream, and downstream samples with concentrations of 725.8 ± 181.2 ng/L, 22.9 ± 4.9 ng/L, 12.96 ± 0.79 ng/L, and 11.6 ± 6.7 ng/L, respectively. METH was detectable in most water samples and was present in excess in S-enantiomer form in the influent and in R-enantiomer form in the effluent and surface water. R-(-)-MDMA was detected at a concentration of up to 2.4 ng/L in the influent. The metabolites norketamine (NK), amphetamine(AMP), MDA, and NE were not detected in water samples given the low concentration of their parent drugs.

Simultaneous determination of 11 illicit drugs and metabolites in wastewater by UPLC-MS/MS

Assessing collective drug consumption based on the concentrations of illicit drugs and their metabolites in wastewater is a new technology. Currently, this technology is receiving attention in China, and methods for multiple illicit drug detection in wastewater are urgently needed. In our study, a method with a short runtime (7 min), a small solid-phase extraction (SPE) loading volume (50 mL) and high sensitivity (lower limits of quantitation (LLOQs) ranged from 0.2 to 5 ng/L) was developed for the simultaneous determination of amphetamines, ketamine, opiates, cocaine and their metabolites in wastewater. Samples were enriched by SPE on a mixed-mode sorbent (Oasis MCX) and analyzed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The limits of detection (LODs) ranged from 0.1 to 2 ng/L, and the LLOQs varied between 0.2 and 5 ng/L. Moreover, the method developed was applied to real wastewater samples collected from 15 different wastewater treatment plants (WWTPs). In the results, the most abundant compounds were morphine (1.8-46.6 ng/L) and codeine (3.7-24.9 ng/L), which were detected in 13 WWTPs. After successful optimization of the UPLC-MS/MS conditions and sample loading pH, the method developed is able to meet the needs of common illicit drug monitoring and high-throughput analysis requirements.

Assessment of metformin, nicotine, caffeine, and methamphetamine use during Chinese public holidays

Metformin, nicotine, caffeine, and methamphetamine are widely used in China. However, the consumption pattern of these substances among the general population during Chinese public holidays may be different. Influent wastewater samples were collected from a municipal wastewater treatment plant in Yingkou, China on public holidays (n = 6) and working days (n = 20) to examine the changes in metformin, nicotine, caffeine, and methamphetamine consumption. The consumption of metformin in the city ranged from 1.94 to 14.4 g d^-1 1000 people^-1, while that of nicotine, caffeine, and methamphetamine ranged from 0.46 to 2.18 g d^-1 1000 people^-1, 31.8-89.8 g d^-1 1000 people^-1, and 87.0-657 mg d^-1 1000 people^-1, respectively. The highest consumption of metformin, caffeine, and methamphetamine was observed during the Spring Festival. The results indicated that the consumption of these substances showed almost the same trend and was higher during the Spring Festival, which may be influenced by personal habits and traditional festival reunions. There is a correlation between the consumption of nicotine and caffeine. Moreover, there are correlations between the consumption of metformin and nicotine, caffeine, as well as methamphetamine. The information based on wastewater epidemiology and consumption behavior, suggests that drug use in the region requires more attention or monitoring during holidays.

A global systematic review and meta-analysis on illicit drug consumption rate through wastewater-based epidemiology

Wastewater-based epidemiology (WBE) is a complementary, well-established comprehensive, cost-effective, and rapid technique for monitoring of illicit drugs used in a general population. This systematic review and meta-analysis is the first to estimate the rank and consumption rate of illicit drugs through WBE studies. In the current study, the related investigations regarding the illicit drug consumption rate based on WBE were searched among the international databases including Scopus, PubMed, Science direct, Google scholar, and local database, Magiran from 2012 up to May 2019. The illicit drug consumption rate with 95% confidence intervals was pooled between studies by using random effect model. The heterogeneity was determined using I² statistics. Also, subgroup analyses were conducted to examine the possible effects of year and location of studies on observed heterogeneity. Meta-analysis of 37 articles indicates that the overall rank order of illicit drugs according to their pooled consumption rate can be summarized as tetrahydrocannabinol or cannabis (7417.9 mg/day/1000 people) > cocaine (655.7 mg/day/1000 people) > morphine (384.9 mg/day/1000 people) > methamphetamine (296.2 mg/day/1000 people) > codeine (222.7 mg/day/1000 people) > methadone (200.2 mg/day/1000 people) > 3,4-methylenedioxymethamphetamine (126.3 mg/day/1000 people) > amphetamine (118.2 mg/day/1000 people) > 2-ethylidene-1,5-dimethyl-3, 3-diphenylpyrrolidine (33.7 mg/day/1000 people). The pooled level rate was 190.16 mg/day/1000 people for benzoylecgonine (main urinary cocaine metabolite), 137.9 mg/day/1000 people for 11-nor-9-carboxy-delta9-tetrahydrocannabinol (main metabolite of cannabis), and 33.7 mg/day/1000 people for 2-ethylidene-1,5-dimethyl-3, 3-diphenylpyrrolidine (main metabolite of methadone). The I² values for all selected drugs were 100% (P value < 0.001). The results of year subgroup indicated that the changes of heterogeneity for all selected drugs were nearly negligible. The heterogeneity within studies based on continents subgroup just decreased in America for drugs like 11-nor-9-carboxy-delta9-tetrahydrocannabinol (I² = 24.4%) and benzoylecgonine (I² = 94.1%). The outcome of this meta-analysis can be used for finding the illicit drugs with global serious problem in view of consumption rate (i.e., cannabis and cocaine) and helping authorities to combat them.

Occurrence and risk assessment of psychoactive substances in tap water from China

Psychoactive substances are becoming a new concern in aquatic environment along with the increase in use of these substances. In this study, 23 psychoactive substances were investigated in the tap water collected in 63 sites in China. Eighteen out of 23 psychoactive substances were detected at the range of < method detection limits (MDLs) to 24.9 ng L-1. It was found that diazepam and temazepam were the major psychoactive substances in the tap water with the median concentration of 1.0 and 0.06 ng L^-1, respectively. The high exposure dose for each psychoactive substance was calculated from 0.6 to 855 pg kg^-1 bw d^-1 and showed an order of men ≥ boys ≥ girls ≥ women. Risk assessment revealed there was little risk of psychoactive substances on human health at current residual levels.

A revised excretion factor for estimating ketamine consumption by wastewater-based epidemiology - Utilising wastewater and seizure data

The rate of drug excretion (excretion factor) is a critical parameter for monitoring drug consumption in the population by wastewater-based epidemiology (WBE). Previous studies have refined excretion factors for common illicit drugs, such as cocaine, amphetamine, methamphetamine, heroin, to improve the accuracy and reduce uncertainty in back-calculating consumption. Nevertheless, for ketamine, one of the most prevalent psychoactive substances, a careful review of its excretion factors has not been performed due to limited pharmacokinetic data. Here we review WBE studies and seizure data to refine and validate the excretion factors for ketamine and norketamine. The average ketamine/norketamine ratio in wastewater (5.36) was much higher than that found in urine (0.64), which means that the excretion factors derived only from pharmacokinetics data are not appropriate. Based on the comparison of the ratio between estimated consumptions of ketamine and methamphetamine by WBE with their corresponding ratio in official seizure data, a revised WBE excretion factor of 20% was proposed for ketamine following this review and applied to estimate the ketamine consumption in China. The revised estimates of ketamine consumption corresponded well with drug statistics. This suggests that the revised ketamine excretion factor is appropriate for estimating ketamine consumption by WBE. Systematic review of WBE studies is a suitable approach to refine the excretion factors for substances with inadequate pharmacokinetic data.

Urban wastewater analysis as an effective tool for monitoring illegal drugs, including new psychoactive substances, in the Eastern European region

The use of illicit drugs causes unquestionable societal and economic damage. To implement actions aimed at combating drug abuse, it is necessary to assess illicit drug consumption patterns. The purpose of this paper was to develop, optimize, validate and apply a procedure for determining new psychoactive substances (NPSs) and classic drugs of abuse and their main metabolites in wastewater samples by using solid phase extraction (SPE) and high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS). Moreover, detailed validation of the procedure was conducted. The developed SPE–HPLC-MS/MS procedure (within the sewage-based epidemiology strategy) allowed for the simultaneous, selective, very sensitive, accurate (recoveries ≥ 80.1%) and precise (CV ≤ 8.1%) determination of new and classic psychoactive substances in wastewater samples. This study is characterized by new scientific elements, especially in terms of the freeze-thaw and post-preparative stability of the selected psychoactive substances. This is the first time that NPSs (mephedrone and ketamine), the main metabolites of heroin (6-acetylmorphine, 6-AM) and marijuana (11-nor-9-carboxy-Δ9-tetrahydrocannabinol, THC-COOH) have been detected and monitored in Poland. This study is also the first to corroborate the data available from the EMCDDA and EUROPOL report and indicates that the retail market for cocaine is expanding in Eastern Europe.

Methamphetamine use in typical Chinese cities evaluated by wastewater-based epidemiology

Methamphetamine has become one of the most widely used illicit drugs in China. To understand the current situation in China, the prevalence and consumption of methamphetamine were estimated through wastewater-based epidemiology (WBE) in the present study. Methamphetamine concentrations ranged from 42.6 ng/L (Harbin) to 700 ng/L (Xi'an) in influent wastewater samples collected from 27 wastewater treatment plants (WWTPs) in 22 Chinese cities. The estimated consumption of methamphetamine was 23.0 (Dingxi) to 376 (Xi'an) mg/day/1000 inhabitants with a mean value of 157 mg/day/1000 inhabitants. The annual consumption in 2018 was estimated to be 84 tons (95% confidence interval, 44-136), which was 26% lower than that in 2014. The prevalence of methamphetamine use was 0.64% (95% confidence interval, 0.18-1.25), indicating that more than five million people used methamphetamine in 2018. Although drug abuse is common in the country, the consumption showed a different spatial pattern, with the highest values in Central China and the lowest use in Northeast China, so drug use is still considered a geographic and culture-dependent behaviour. The results indicated that WBE can not only be used to assess the trends of illicit drug use, but also to analyse the spatial differences in the whole country, which will provide complementary evidence for the prevention and control of methamphetamine use.

Use of legal and illegal substances in Malé (Republic of Maldives) assessed by wastewater analysis

This study used wastewater-based epidemiology (WBE) to investigate the lifestyle of the inhabitants of Malé, the capital of the Republic of Maldives. Raw wastewater 12-h composite samples were collected from nine pumping stations serving the city area - thus representative of the whole Malé population. Samples were analysed by liquid chromatography coupled to mass spectrometry for estimating the profile of use of a large number of substances including illicit drugs, alcohol, caffeine, tobacco and pharmaceuticals. The illicit drugs most used were cannabis (THC) and heroin (700 and 18 g/day), with lower consumption of cocaine and amphetamines (0.1-1.2 g/day). It is important to note that the consumption of cannabis in Malé was comparable to that measured in other countries, while the consumption of heroin was higher. Among cathinones, mephedrone was detected at the highest levels similar to other countries. Consumption of alcohol, which is not allowed in Maldives, was found (1.3 L/day/1000 inhabitants), but at a low level compared with other countries (6-44 L/day/1000 inhabitants), while the consumption of caffeine and tobacco was generally in line with reports from other countries. Unique information on pharmaceuticals use was also provided, since no official data were available. Human lifestyle was evaluated by applying for the first time the full set of WBE methodologies available in our laboratory. Results provided valuable epidemiological information, which may be useful for national and international agencies to understand population lifestyles better, including illicit drug issues, and for planning and evaluation of drug prevention programs in Malé.

Monitoring consumption of methadone and heroin in major Chinese cities by wastewater-based epidemiology

BACKGROUND

Methadone maintenance treatment (MMT) services have been used in China for treatment of heroin dependence. But no study has been conducted to assess the appropriateness of MMT distribution and the potential abuse of methadone in China. This study aims to do that through a nationwide estimation of methadone consumption in China via wastewater-based epidemiology and subsequently compare it with MMT data and level of heroin abuse.

METHODS

Wastewater samples were collected from 53 wastewater treatment plants in 27 major cities that cover all geographic regions of China. Methadone and pure heroin consumptions were estimated based on influent concentrations of methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), morphine and codeine.

RESULTS

Drug residues were detected in most samples. The ratio of EDDP/methadone was around 2 in influents and methadone and EDDP loads were strongly correlated, indicating that they originated from human consumption. Both influent methadone and EDDP loads in Southwest and Northwest China were significantly higher than those in other regions. The highest estimated consumptions of methadone and heroin in China were 22.0 ± 2.1 mg/1000 in./d and 263.9 ± 115.9 mg/1000 in./d, respectively. There was a significant positive correlation between methadone and heroin consumptions.

CONCLUSIONS

Consumption of methadone in China was primarily from MMT services. The use of methadone and heroin displayed a clear geographical pattern: it is higher in the western inland regions than in the eastern regions. This study has shown that the distribution of MMT services is reflective of the level of heroin abuse in different regions of China.

Temporal profile of illicit drug consumption in Guangzhou, China monitored by wastewater-based epidemiology

Wastewater-based epidemiology (WBE) has been widely used as a complementary method for estimating consumption of illicit drugs in the population. Temporal drug consumption estimates derived from WBE can provide important information for law enforcement and public health authorities in understanding changes in supply and demand of illicit drugs, but currently lacking in China. In this study, influent wastewater samples from a municipal sewage treatment plant in Guangzhou, China were collected for 8 weeks to investigate the temporal change in consumption of six illicit drugs in the catchment. The results indicated that methamphetamine and ketamine were the dominant illicit drugs in Guangzhou with the per capita use of 14.7-470.7 mg/day/1000 people and 64.9-673.7 mg/day/1000 people, respectively. No distinct weekly patterns were observed for illicit drug consumption in Guangzhou, indicating that drug users are likely to be regular ones. Further assessment about the impact of public holidays on the consumption behavior of drugs showed little impact for ketamine (p = 0.689), but higher consumptions of methamphetamine (p = 0.003) and cocaine (p = 0.027) were observed during public holidays than the control period. The considerable decrease in drug consumption observed in October 2017 compared with January and May 2017 was possibly the consequence of law enforcement action.

Applying a population model based on hydrochemical parameters in wastewater-based epidemiology

Wastewater-based epidemiology combining with a population model based on hydrochemical parameters was applied in 10 wastewater treatment plants (WWTPs) in Jilin province, China. Population of WWTPs served was calculated by the model including three hydrochemical parameters ammonia nitrogen, chemical oxygen demand, and total phosphorus. The population model was constructed by using analytic hierarchy process to calculate weight factors of each hydrochemical parameters equivalent population. The size of population estimated by the model showed the highest correlations with cotinine mass load (r²=0.91, p<0.001), demonstrating better population estimation. Meanwhile daily excretion of cotinine per capita was first estimated about 0.68mg in China through liner regression analysis. In accessing the viability of the population model, the abuse of methamphetamine (METH) was calculated. Prevalence of METH use in Jilin province was calculated with an average of 0.72% based on the population model, which was similar with the result reported by United Nations World Drug Report in 2018. In assessing uncertainty of different population estimations, population model showed lower uncertainty than single hydrochemical equivalent population. These results indicate the population model based on hydrochemical parameters reduces uncertainty in population estimation and is a useful tool in monitoring illicit drug abuse.

Long-term monitoring of drug consumption patterns in a large-sized European city using wastewater-based epidemiology: Comparison of two sampling schemes for the assessment of multiannual trends

A comprehensive study aimed at monitoring of temporal variability of illicit drugs (heroin, cocaine, amphetamine, MDMA, methamphetamine and cannabis) and therapeutic opiate methadone in a large-sized European city using wastewater-based epidemiology (WBE) was conducted in the city of Zagreb, Croatia, during an 8-year period (2009-2016). The study addressed the impact of different sampling schemes on the assessment of temporal drug consumption patterns, in particular multiannual consumption trends and documented the possible errors associated with the one-week sampling scheme. The highest drug consumption prevalence was determined for cannabis (from 59 ± 18 to 156 ± 37 doses/day/1000 inhabitants 15-64 years), followed by heroin (from 11 ± 10 to 71 ± 19 doses/day/1000 inhabitants 15-64 years), cocaine (from 8.3 ± 0.9 to 23 ± 4.0 doses/day/1000 inhabitants 15-64 years) and amphetamine (from 1.3 ± 0.9 to 21 ± 6.1 doses/day/1000 inhabitants 15-64 years) whereas the consumption of MDMA was comparatively lower (from 0.18 ± 0.08 to 2.7 doses ±0.7 doses/day/1000 inhabitants 15-64 years). The drug consumption patterns were characterized by clearly enhanced weekend and Christmas season consumption of stimulating drugs (cocaine, MDMA and amphetamine) and somewhat lower summer consumption of almost all drugs. Pronounced multiannual consumption trends were determined for most of the illicit drugs. The investigated 8-year period was characterized by a marked increase of the consumption of pure cocaine (1.6-fold), THC (2.7-fold), amphetamine (16-fold) and MDMA (15-fold) and a concomitant decrease (2.3-fold) of the consumption of pure heroin. The heroin consumption decrease was associated with an increase of methadone consumption (1.4-fold), which can be linked to its use in the heroin substitution therapy. The estimated number of average methadone doses consumed in the city of Zagreb was in a good agreement with the prescription data on treated opioid addicts in Croatia.

Reduction in methamphetamine consumption trends from 2015 to 2018 detected by wastewater-based epidemiology in Dalian, China

BACKGROUND

Wastewater-based epidemiology (WBE) has become a useful tool in long-term or short-term continuous monitoring of illicit drugs consumption over the world.

METHODS

We investigated the trend of methamphetamine (METH) use between 2015 and 2018 through WBE in Dalian, a typical Chinese city. Samples were collected in 11 municipal wastewater treatment plants (WWTPs). An analytical method, solid-phase extraction combined with trifluoroacetic anhydride derivatization prior to gas chromatography-mass spectrometry (GC-MS) analysis was applied to detect METH concentrations.

RESULTS

During the sampling period, the METH concentrations increased slowly from 315 ± 243 ng/L in 2015 to 523 ± 549 ng/L in 2016, followed by a significant decrease with the concentrations 188 ± 187 ng/L in 2017 and 54.6 ± 42.9 ng/L in 2018. Ammonium nitrogen (NH₄-N) was applied to estimate population size. The average coefficient of variation for population in 11 WWTPs was 35.3 ± 8.9%, reflecting the dynamic variations of population effectively. For METH consumption, there was a gradual increase from 2015 (231 mg/day/1000 people) to 2016 (414 mg/day/1000 people) and a significant linear decrease to 2017 (206 mg/day/1000 people) and 2018 (53.9 mg/day/1000 people). The prevalence of METH increased from 2015 (0.78%) to 2016 (1.06%), then decreased to 2017 (0.55%) and 2018 (0.17%), showed similar trends with the consumption.

CONCLUSIONS

The obvious reduction trends of METH consumption via WBE over the period in Dalian provides objective evidence for declined METH consumption in local population. The reduction is probably due to the severe crack-down of illicit drugs by the government.