The first application of wastewater-based drug epidemiology in five South Korean cities

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.

Illicit Drugs in Surface Waters: How to Get Fish off the Addictive Hook

The United Nations World Drug Report published in 2022 alarmed that the global market of illicit drugs is steadily expanding in space and scale. Substances of abuse are usually perceived in the light of threats to human health and public security, while the environmental aspects of their use and subsequent emissions usually remain less explored. However, as with other human activities, drug production, trade, and consumption of drugs may leave their environmental mark. Therefore, this paper aims to review the occurrence of illicit drugs in surface waters and their bioaccumulation and toxicity in fish. Illicit drugs of different groups, i.e., psychostimulants (methamphetamines/amphetamines, cocaine, and its metabolite benzoylecgonine) and depressants (opioids: morphine, heroin, methadone, fentanyl), can reach the aquatic environment through wastewater discharge as they are often not entirely removed during wastewater treatment processes, resulting in their subsequent circulation in nanomolar concentrations, potentially affecting aquatic biota, including fish. Exposure to such xenobiotics can induce oxidative stress and dysfunction to mitochondrial and lysosomal function, distort locomotion activity by regulating the dopaminergic and glutamatergic systems, increase the predation risk, instigate neurological disorders, disbalance neurotransmission, and produce histopathological alterations in the brain and liver tissues, similar to those described in mammals. Hence, this drugs-related multidimensional harm to fish should be thoroughly investigated in line with environmental protection policies before it is too late. At the same time, selected fish species (e.g., Danio rerio, zebrafish) can be employed as models to study toxic and binge-like effects of psychoactive, illicit compounds.

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.

Target and suspect screening of (new) psychoactive substances in South Korean wastewater by LC-HRMS

New psychoactive substances (NPS) are a type of abused drug designed to mimic the effects of the currently known illicit drugs, whose structures are constantly changing to escape surveillance. The quick identification of NPS use in the community therefore demands immediate action. This study aimed to develop a target and suspect screening method using LC-HRMS to identify NPS in wastewater samples. An in-house database of 95 traditional and NPS was built using the reference standards, and an analytical method was developed. Wastewater samples were collected from 29 wastewater treatment plants (WWTP) across South Korea, representing 50 % of the total population. The psychoactive substances in waste water samples were screened using in-house database and developed analytical methods. A total of 14 substances were detected in the target analysis, including three NPS (N-methyl-2-AI, 25E-NBOMe, and 25D-NBOMe) and 11 traditional psychoactive substances and their metabolites (zolpidem phenyl-4-COOH, ephedrine, ritalinic acid, tramadol, phenmetrazine, phendimetrazine, phentermine, methamphetamine, codeine, morphine, and ketamine). Out of these, N-methyl-2-AI, zolpidem phenyl-4-COOH, ephedrine, ritalinic acid, tramadol, phenmetrazine, and phendimetrazine were detected with a detection frequency of over 50 %. Primarily, N-methyl-2-Al was detected in all the wastewater samples. Additionally, four NPSs (amphetamine-N-propyl, benzydamine, isoethcathinone, methoxyphenamine) were tentatively identified at level 2b in a suspect screening analysis. This is the most comprehensive study to investigate NPS using target and suspect analysis methods at the national level. This study raises a need for continuous monitoring of NPS in South Korea.

Estimation of legal and illegal drugs consumption in Valencia City (Spain): 10 years of monitoring

Wastewater-based epidemiology (WBE) approach provides objective, quantitative, near real-time profiles of illicit drug consumption by monitoring the concentration of unchanged parent drugs or their metabolites entering the municipal sewage system. Valencia is the third most populous city in Spain (an important country for the use and transit of several of these drugs). Estimations of consumption over long periods of time will help get better understanding of spatial and temporal trends in the use of licit and illicit drugs. Accordingly, applying the "best practice" protocol, 16 drugs of abuse and metabolites were monitored in this study, and 8 were daily measured during one-two weeks between 2011 and 2020 at the inlet of three wastewater treatment plants of Valencia City. Analysis of the selected compounds was performed by liquid chromatography-triple quadrupole mass spectrometry, and the concentrations obtained were used to back-calculate the consumption data. Cannabis, tobacco, and cocaine were the most consumed drugs whereas opioids were less used. Cannabis and cocaine consumption are on average 2.7-23.4 and 1.1-2.3 g/day/1000inh, respectively, and their use tended to increase since 2018. Weekly profiles were characterized by higher consumption of cocaine, ecstasy, and heroin during weekends compared to weekdays. Similarly, during "Las Fallas" (main local festivity), increased use of cocaine and amphetamine-type stimulants, mainly MDMA, was measured. WBE proved to be an objective and useful methodology to get more insight on temporal drugs of abuse consumption, and the changes derived from local festivities.

Long-term wastewater-based surveillance and impacts of the COVID-19 pandemic on drug use trends in a U.S. Northeast rural town

Herein we discuss the findings of a two-year wastewater-based drug use surveillance from September 2018 to August 2020 and present objective evidence on the impacts of the COVID-19 pandemic on drug use in a rural community. 24-h composite wastewater samples were collected twice each month from a university town in Northeastern United States and were analyzed for ten priority opioids and stimulants: morphine, codeine, hydrocodone, methadone, fentanyl cocaine, methamphetamine, amphetamine, 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxy-N-ethylamphetamine (MDEA). All target drugs were detected at 100 % frequency in wastewater samples. On a mass basis, the average estimated per capita drug consumption were highest for cocaine, morphine, and amphetamine, and lowest for MDMA, MDEA, and hydrocodone. Furthermore, the estimated per capita consumption of fentanyl was higher than previous reports from rural and university settings in the U.S. Generally, drug consumption was higher during the spring semesters, with year-on-year semester increases also noted over the 2-y study period. Except for methadone and cocaine, the estimated average per capita consumption of drugs increased over the pandemic period, with the highest increase noted for MDMA (286 % increase compared to baseline, p = 0.016). Estimated average consumption of methadone and cocaine decreased slightly by 6 % and 7 %, respectively. These results demonstrate the utility and strength of wastewater-based approaches in capturing long-term and evolving trends in drug use within communities. Our study findings reflect the regionwide problem with opioid-related overdoses and increasing stimulant prescription rates. Our findings also provide objective data and insights for health policymakers on the effects of the pandemic period on community drug use in a rural U.S. town.

Selective enrichment, identification, and isolation of diclofenac, ibuprofen, and carbamazepine degrading bacteria from a groundwater biofilm

Diclofenac, ibuprofen, and carbamazepine are three of the most widely detected and most concerning pharmaceutical residues in aquatic ecosystems. The aim of this study was to identify bacteria that may be involved in their degradation from a bacterial biofilm. Selective enrichment cultures in mineral salt solution containing pharmaceutical compounds as sole source of carbon and energy were set up, and population dynamics were monitored using shotgun metagenome sequencing. Bacterial genomes were reconstructed using genome-resolved metagenomics. Thirty bacterial isolates were obtained, identified at species level, and tested regarding pharmaceutical biodegradation at an initial concentration of 1.5 mg l-1. The results indicated that most probably diclofenac biodegrading cultures consisted of members of genera Ferrovibrio, Hydrocarboniphaga, Zavarzinia, and Sphingopyxis, while in ibuprofen biodegradation Nocardioides and Starkeya, and in carbamazepine biodegradation Nocardioides, Pseudonocardia, and Sphingopyxis might be involved. During the enrichments, compared to the initial state the percentage relative abundance of these genera increased up to three orders of magnitude. Except Starkeya, the genomes of these bacteria were reconstructed and annotated. Metabolic analyses of the annotated genomes indicated that these bacteria harbored genes associated with pharmaceutical biodegradation. Stenotrophomonas humi DIC_5 and Rhizobium daejeonense IBU_18 isolates eliminated diclofenac and ibuprofen during the tests in the presence of either glucose (3 g l-1) or in R2A broth. Higher than 90% concentration reduction was observed in the case of both compounds.

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.

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.

Optimal allocation and operation of sewer monitoring sites for wastewater-based disease surveillance: A methodological proposal

Wastewater-based epidemiology (WBE) is drawing increasing attention as a promising tool for an early warning of emerging infectious diseases such as COVID-19. This study demonstrated the utility of a spatial bisection method (SBM) and a global optimization algorithm (i.e., genetic algorithm, GA), to support better designing and operating a WBE program for disease surveillance and source identification. The performances of SBM and GA were compared in determining the optimal locations of sewer monitoring manholes to minimize the difference among the effective spatial monitoring scales of the selected manholes. While GA was more flexible in determining the spatial resolution of the monitoring areas, SBM allows stepwise selection of optimal sampling manholes with equiareal subcatchments and lowers computational cost. Upon detecting disease outbreaks at a regular sewer monitoring site, additional manholes within the catchment can be selected and monitored to identify source areas with a required spatial resolution. SBM offered an efficient method for rapidly searching for the optimal locations of additional sampling manholes to identify the source areas. This study provides strategic and technical elements of WBE including sampling site selection with required spatial resolution and a source identification method.

Pharmaceuticals in the Aquatic Environment: A Review on Eco-Toxicology and the Remediation Potential of Algae

The pollution of the aquatic environment has become a worldwide problem. The widespread use of pesticides, heavy metals and pharmaceuticals through anthropogenic activities has increased the emission of such contaminants into wastewater. Pharmaceuticals constitute a significant class of aquatic contaminants and can seriously threaten the health of non-target organisms. No strict legal regulations on the consumption and release of pharmaceuticals into water bodies have been implemented on a global scale. Different conventional wastewater treatments are not well-designed to remove emerging contaminants from wastewater with high efficiency. Therefore, particular attention has been paid to the phycoremediation technique, which seems to be a promising choice as a low-cost and environment-friendly wastewater treatment. This technique uses macro- or micro-algae for the removal or biotransformation of pollutants and is constantly being developed to cope with the issue of wastewater contamination. The aims of this review are: (i) to examine the occurrence of pharmaceuticals in water, and their toxicity on non-target organisms and to describe the inefficient conventional wastewater treatments; (ii) present cost-efficient algal-based techniques of contamination removal; (iii) to characterize types of algae cultivation systems; and (iv) to describe the challenges and advantages of phycoremediation.

Contribution of Illicit Drug Use to Pharmaceutical Load in the Environment: A Focus on Sub-Saharan Africa

Illicit drug abuse and addiction are universal issues requiring international cooperation and interdisciplinary and multisectoral solutions. These addictive substances are utilized for recreational purposes worldwide, including in sub-Saharan Africa. On the other hand, conventional wastewater treatment facilities such as waste stabilization ponds lack the design to remove the most recent classes of pollutants such as illicit drug abuse. As a result, effluents from these treatment schemes contaminate the entire ecosystem. Public health officials are concerned about detecting these pollutants at alarming levels in some countries, with potential undesirable effects on aquatic species and increased health hazards through exposure to contaminated waters or recycling treated or untreated effluents in agriculture. Contaminants including illicit substances enter the environment by human excreta following illegal intake, spills, or through direct dumping, such as from clandestine laboratories, when their manufacturer does not follow accepted production processes. These substances, like other pharmaceuticals, have biological activity and range from pseudopersistent to highly persistent compounds; hence, they persist in the environment while causing harm to the ecosystem. The presence of powerful pharmacological agents such as cocaine, morphine, and amphetamine in water as complex combinations can impair aquatic organisms and human health. These compounds can harm human beings and ecosystem health apart from their low environmental levels. Therefore, this article examines the presence and levels of illicit substances in ecological compartments such as wastewater, surface and ground waters in sub-Saharan Africa, and their latent impact on the ecosystem. The information on the occurrences of illicit drugs and their metabolic products in the sub-Saharan Africa environment and their contribution to pharmaceutical load is missing. In this case, it is important to research further the presence, levels, distribution, and environmental risks of exposure to human beings and the entire ecosystem.

Removal of METH through Tertiary or Advanced Treatment in a WWTP

METHs are drugs that enter wastewater through the feces and urine of users. Conventional wastewater treatment plants are not capable of removing this type of emerging contaminant, but, in recent years, techniques have been developed to abate drugs of abuse. The present investigation focused on obtaining the technique that keeps the best balance between the comparison criteria considered: efficiency; costs; development stage; and waste generation. That is why a bibliographic review was carried out in the scientific databases of the last eight years, concluding that the six most popular techniques are: SBR, Fenton reaction, mixed-flow bioreactor, ozonation, photocatalysis, and UV disinfection. Subsequently, the Saaty and Modified Saaty methods were applied, obtaining a polynomial equation containing the four comparison criteria for the evaluation of the techniques. It is concluded that the UV disinfection method is the one with the best relationship between the analyzed criteria, reaching a score of 0.8591/1, followed by the Fenton method with a score of 0.6925/1. This research work constitutes a practical and easy-to-use tool for decision-makers, since it allows finding an optimal treatment for the abatement of METHs.

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.

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.

Analysis of 39 drugs and metabolites, including 8 glucuronide conjugates, in an upstream wastewater network via HPLC-MS/MS

Pharmaceutical compounds ingested by humans are metabolized and excreted in urine and feces. These metabolites can be quantified in wastewater networks using wastewater-based epidemiology (WBE) methods. Standard WBE methods focus on samples collected at wastewater treatment plants (WWTPs). However, these methods do not capture more labile classes of metabolites such as glucuronide conjugates, products of the major phase II metabolic pathway for drug elimination. By shifting sample collection more upstream, these unambiguous markers of human exposure are captured before hydrolysis in the wastewater network. In this paper, we present an HPLC-MS/MS method that quantifies 8 glucuronide conjugates in addition to 31 parent and other metabolites of prescription and synthetic opioids, overdose treatment drugs, illicit drugs, and population markers. Calibration curves for all analytes are linear (r2 > 0.98), except THC (r2 = 0.97), and in the targeted range (0.1-1,000 ng mL-1) with lower limits of quantification (S/N = 9) ranging from 0.098 to 48.75 ng mL-1. This method is fast with an injection-to-injection time of 7.5 min. We demonstrate the application of the method to five wastewater samples collected from a manhole in a city in eastern Massachusetts. Collected wastewater samples were filtered and extracted via solid-phase extraction (SPE). The SPE cartridges are eluted and concentrated in the laboratory via nitrogen-drying. The method and case study presented here demonstrate the potential and application of expanding WBE to monitoring labile metabolites in upstream wastewater networks.

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.

The embodiment of wastewater data for the estimation of illicit drug consumption in Spain

Data obtained from wastewater analysis can provide rapid and complementary insights in illicit drug consumption at community level. Within Europe, Spain is an important country of transit of both cocaine and cannabis. The quantity of seized drugs and prevalence of their use rank Spain at the top of Europe. Hence, the implementation of a wastewater monitoring program at national level would help to get better understanding of spatial differences and trends in use of illicit drugs. In this study, a national wastewater campaign was performed for the first time to get more insight on the consumption of illicit drugs within Spain. The 13 Spanish cities monitored cover approximately 6 million inhabitants (12.8% of the Spanish population). Untreated wastewater samples were analyzed for urinary biomarkers of amphetamine, methamphetamine, MDMA, cocaine, and cannabis. In addition, weekend samples were monitored for 17 new psychoactive substances. Cannabis and cocaine are the most consumed drugs in Spain, but geographical variations showed, for instance, comparatively higher levels of methamphetamine in Barcelona and amphetamine in Bilbao, with about 1-fold higher consumption of these two substances in such metropolitan areas. For amphetamine, an enantiomeric profiling was performed in order to assure the results were due to consumption and not to illegal dumping of production residues. Furthermore, different correction factors for the excretion of cannabis were used to compare consumption estimations. All wastewater results were compared with previously reported data, national seizure data and general population survey data, were a reasonable agreement was found. Daily and yearly drug consumption were extrapolated to the entire Spanish population with due precautions because of the uncertainty associated. These data was further used to estimate the retail drug market, where for instance cocaine illicit consumption alone was calculated to contribute to 0.2-0.5% of the Spanish gross domestic product (ca. 3000-6000 million Euro/year).

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.

A review of the presence of SARS-CoV-2 RNA in wastewater and airborne particulates and its use for virus spreading surveillance

According to the WHO, on October 16, 2020, the spreading of the SARS-CoV-2, responsible for the COVID-19 pandemic, reached 235 countries and territories, and resulting in more than 39 million confirmed cases and 1.09 million deaths globally. Monitoring of the virus outbreak is one of the main activities pursued to limiting the number of infected people and decreasing the number of deaths that have caused high pressure on the health care, social, and economic systems of different countries. Wastewater based epidemiology (WBE), already adopted for the surveillance of life style and health conditions of communities, shows interesting features for the monitoring of the COVID-19 diffusion. Together with wastewater, the analysis of airborne particles has been recently suggested as another useful tool for detecting the presence of SARS-CoV-2 in given areas. The present review reports the status of research currently performed concerning the monitoring of SARS-CoV-2 spreading by WBE and airborne particles. The former have been more investigated, whereas the latter is still at a very early stage, with a limited number of very recent studies. Nevertheless, the main results highlights in both cases necessitate more research activity for better understating and defining the biomarkers and the related sampling and analysis procedures to be used for this important aim.

Input-output balance of cadmium in typical agriculture soils with historical sewage irrigation in China

The gradual increase of cadmium (Cd) in soils has caused environmental and health risk, and it's important to study the accumulation trend to evoke the awareness of farmland safety management. This research during the period of March in 2017-2018 evaluated the input (irrigation, atmospheric deposition, fertilizer and pesticide application) and the output (runoff and seepage, grain and straw uptake) of Cd in contaminated farmland irrigated with sewage water in Hebei Province. The experimental results indicated sewage irrigation (51.03%), and atmospheric deposition (46.35%) were the main input pathways; Grain uptake (42.72%) and straw removal (50.71%) played a major role in output fluxes. The input-output balance (net transport fluxes) of Cd in the farmland were estimated to be +3621.68 ~ +8899.78 mg·(ha·yr)^-1 under different conditions (sewage irrigation with straw returning/straw removal, clean water irrigation with straw returning/straw removal), representing there was a Cd inputting in the farmland during the study. Even in the case of the lowest net transport fluxes, the annual increase of Cd concentration in soils reached to 0.0014 mg/kg. Therefore, it's necessary to take action that cutting off those pathway inputs into farmland ecosystems, such as monitoring the water quality of irrigation water sources, applying fertilizer and pesticide properly. Furthermore, attentions need to be paid to the Cd input into the farmland and environmental risks that may arise while returning straw to the field for improving soil fertility and crop production.

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.

Evaluation of pharmaceutical abuse and illicit drug use in South Korea by wastewater-based epidemiology

Drug abuse trends in South Korea were assessed by estimating the consumption rates of drugs that may be abused or misused by performing wastewater-based drug epidemiology. Of the 29 target compounds, 10 were found in samples from three wastewater treatment plants. Ephedrine had the highest mean estimated consumption rate, 574.1 mg d^-1 (1000 people)^-1. The anti-obesity drugs phendimetrazine and phentermine had the second and fifth highest mean estimated consumption rates, 182.9 and 113.1 mg d^-1 (1000 people)^-1, respectively. The zolpidem consumption rate was 65.8 mg d^-1 (1000 people)^-1. Methamphetamine was the only illicit drug detected in wastewater, and the estimated consumption rates (14.9-28.6 mg d^-1 (1000 people)^-1) were similar to consumption rates found in previous Korean studies (not detected to 45.8 mg d^-1 (1000 people)^-1). The mean estimated meperidine and cis-tramadol (opioid) consumption rates were 120 and 27.5 mg d^-1 (1000 people)^-1, respectively, and were 8.2 and 1.7 times higher, respectively, than the consumption rates found in 2013. Methylphenidate was detected in the influent and effluent samples at mean concentrations of 2.7 and 2.6 ng L^-1, respectively, but the methylphenidate consumption rate could not be estimated because of the low excretion rate for humans (<1%).

Can wastewater analysis be used as a tool to assess the burden of pain treatment within a population?

Pain is a global health priority that is challenging to asses. Here we propose a new approach to estimating the burden of pain treatment in a population using wastewater-based epidemiology (WBE). WBE is able to quantify multiple pharmaceutical compounds in order to estimate consumption by a population. Wastewater samples collected from areas representing whole communities can be analysed to estimate the consumption of drugs used to treat pain, such as nonsteroidal anti-inflammatory drugs (NSAIDs) and opioids. The collection and analysis of wastewater can be conducted systematically to estimate the total consumption of NSAIDs and/or opioids in the population of a catchment area and to compare changes over time within the catchment or between different catchment populations. Consumption estimates can be combined by standardising the mass consumed to Defined Daily Doses (DDD) or morphine equivalents in order to assess, the population burden of pain treatment from mild to moderate (for NSAIDs) and for strong and severe pain (for opioids). We propose this method could be used to evaluate the total pain treatment burden between locations and over time. While this concept shows promise, future studies should evaluate the applicability as a tool to measure the burden of pain receiving treatment in a community.

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.

Modeling wastewater temperature and attenuation of sewage-borne biomarkers globally

Accurate modeling of in-sewer degradation of sewage-borne epidemiological biomarkers requires information on local wastewater temperature. We applied a deterministic, physical model to map theoretical wastewater temperature on a monthly scale worldwide and incorporated in the model estimated changes in the decay rate of 31 biomarkers of public health relevance frequently used in wastewater-based epidemiology (WBE). Over the course of a year, 75% of the world's global wastewater temperatures were estimated to fall into the temperature range of 6.9-34.4 °C. These non-fitted results obtained purely a priori were in good agreement with empirical observations (n = 400), as indicated by coefficients for Pearson (0.81; 0.76) and Spearman (0.86; 0.78) correlations for annual minima and maxima, respectively. Application of the Q₁₀ rule for biochemical reaction rates showed that, depending on wastewater temperature, half-lives of sewage-borne biomarkers will change significantly (range: 27%-7,010%) from the baseline at ambient conditions (21 ± 1 °C; 100%). Importantly, these temperature-related modulations of in-sewer biomarker decay changed the size of the area observable by WBE; in the extreme, changes in the distal reach observable by WBE were predicted to be as large as 49-fold over the course of a year at a given location. This first model of spatial and temporal variability in wastewater temperature has multiple suggested applications, including (i) utility for explaining literature-reported discrepancies in the detectability and levels of sewage-borne biomarkers, (ii) identification of optimal and sub-optimal wastewater-borne biomarkers depending on their varying half-lives over the course of the year at the sampling location of interest, and (iii) estimating the effective size of the sewershed capture zone in WBE studies.

Cluster analysis of child homicide in South Korea

BACKGROUND

There has been an insufficient in-depth analysis of the nature and prevalence of the typologies of child homicide in Asia, particularly in South Korea.

OBJECTIVE

In the current study, we sought to determine the prevalence and identify the heterogeneity of the child homicide phenomenon in South Korea.

PARTICIPANT AND SETTINGS

All 341 original case files (i.e., hospital, police, and autopsy reports) of homicide incidents involving children aged 0-18 in 2016 were obtained from the forensic autopsy archives of the National Forensic Service (NFS), which handles 100 % of the medico-legal autopsies in South Korea. These were examined and reclassified based on our definition.

METHOD

A cluster analysis using Gower's distance was applied, which has rarely been utilized in this field of research. By performing a qualitative analysis, we first extracted 70 (numerical, logical, categorical) crime, victim, perpetrator, and household relevant variables, which were later utilized in the cluster analysis.

RESULTS

Among the 341 cases from 2016, 95 were judged to be at least suspicious child homicide cases. When applying the cluster analysis, eight sub-clusters were extracted: child torture, maternal filicide, neonaticide, death not related to previous abuse, paternal filicide, paternal infanticide, maternal infanticide, and psychotic killings.

CONCLUSIONS

The commonality and the unique aspect of the child homicide phenomenon in South Korea, in comparison with the results from previous research from other countries, are discussed.

Monitoring Consumption of Common Illicit Drugs in Kuala Lumpur, Malaysia, by Wastewater-Cased Epidemiology

Southeast Asian countries including Malaysia play a major role in global drug trade and abuse. Use of amphetamine-type stimulants has increased in the past decade in Malaysia. This study aimed to apply wastewater-based epidemiology for the first time in Kuala Lumpur, Malaysia, to estimate the consumption of common illicit drugs in urban population. Influent wastewater samples were collected from two wastewater treatment plants in Kuala Lumpur in the summer of 2017. Concentrations of twenty-four drug biomarkers were analyzed for estimating drug consumption. Fourteen drug residues were detected with concentrations of up to 1640 ng/L. Among the monitored illicit drugs, 3,4-methylenedioxy-methamphetamine (MDMA) or ecstasy had the highest estimated per capita consumptions. Consumption and dose of amphetamine-type stimulants (methamphetamine and MDMA) were both an order of magnitude higher than those of opioids (heroin and codeine, methadone and tramadol). Amphetamine-type stimulants were the most prevalent drugs, replacing opioids in the drug market. The prevalence trend measured by wastewater-based epidemiology data reflected the shift to amphetamine-type stimulants as reported by the Association of Southeast Asian Nations Narcotics Cooperation Center. Most of the undetected drug residues were new psychoactive substances (NPSs), suggesting a low prevalence of NPSs in the drug market.

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.

Long-term tracking of opioid consumption in two United States cities using wastewater-based epidemiology approach

Access to near-real time opioid use data is essential to the effective management of the U.S. opioid crisis. Current narcotic data collection methods are limited by time delay and would be complimented by a rapid data acquisition technique. Use of wastewater-based epidemiology (WBE) analysis may offer access to near real-time data on opioid consumption but application in the United States has been limited. From 2015 to 2017, monthly 24-h time-weighted composite samples of municipal raw wastewater from two Midwestern U.S. cities were routinely analyzed using liquid chromatography-tandem mass spectrometry for morphine, codeine, oxycodone, heroin, fentanyl, and select opioid metabolites. Concentrations of opioids (ng/L) in raw wastewater from City 1 and 2, respectively, were: morphine (713 ± 38; 306 ± 29; detection frequency (DF): 100%), oxycodone (17.8 ± 1.1; 78 ± 6; DF: 100%), codeine (332 ± 37; 100 ± 27; DF: 93%), heroin (41 ± 16; 9 ± 11; DF: 81%), and fentanyl (1.7 ± 0.2; 1.0 ± 0.5; DF: 62%). Average opioid consumption rates estimated using WBE ranged between 9 and 2590 mg/day/1000 persons. Anticipated overdoses and overdose-deaths calculated from analyte concentrations in wastewater forecasted 200 opioid-related overdoses/year and 39 opioid related overdose-deaths/year across the two cities during the year 2016, which aligned well with observed coroner-reported opioid deaths. This long-term U.S. screening study of opioids in wastewater was the first to utilize wastewater epidemiological data to estimate the number of expected overdose and overdose-deaths, and to identify detectable levels of the powerful synthetic opioid fentanyl in community wastewater consistently over the course of one whole year.

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.

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.

Tracking narcotics consumption at a Southwestern U.S. university campus by wastewater-based epidemiology

Wastewater-based epidemiology (WBE) was applied to estimate the consumption of twelve narcotics within a Southwestern U.S. university campus. Seven consecutive 24-hour composite raw wastewater samples (n = 80) were obtained once per month from sampling locations capturing >95% of campus-generated wastewater. Samples were analyzed for indicators of consumption of morphine, codeine, oxycodone, heroin, fentanyl, methadone, buprenorphine, amphetamine, methylphenidate, alprazolam, cocaine, and MDMA using LC-MS/MS. Eleven indicator compounds (oxycodone, codeine, norcodeine, 6-acetylmorphine, EDDP, amphetamine, alprazolam, alpha-hydroxyalprazolam, cocaine, benzoylecgonine, and MDMA) occurred at 100% detection frequency across the study, followed by morphine-3-glucuronide (98%), noroxycodone (95%), methylphenidate (90%), heroin (7%), norfentanyl (7%), and fentanyl (5%). Estimates of average narcotics consumption ranked as follows in units of mg/day/1000 persons: heroin (474 ± 32), cocaine (551 ± 49), amphetamine (256 ± 12), methylphenidate (236 ± 28), methadone (72 ± 8), oxycodone (80 ± 6), alprazolam (60 ± 2), MDMA (88 ± 35), codeine (50 ± 4), and morphine (18 ± 3). This campus-based WBE study yielded baseline data on 12 narcotics for a U.S. campus and demonstrated for the first time the feasibility of detecting the fentanyl metabolite norfentanyl in this setting.

Association between purity of drug seizures and illicit drug loads measured in wastewater in a South East Queensland catchment over a six year period

This study aimed to examine associations between the annual average purity of seized illicit drugs and their corresponding load measured in wastewater. Daily loads (averaging 81 samples/year) and purity of seized methamphetamine (average 287 samples/year), cocaine (50/year) and MDMA (70/year) were collected from a catchment that serviced approximately 220,000 persons in Queensland, Australia during 2010-2015. Using regression models for mass load and purity data, we found a strong linear increase in the mass load of methamphetamine detected across study years (363-1126 mg/1000 people/day, R² = 0.89). Strong linear increases in methamphetamine purity were also apparent (19-69%), and were closely correlated with detected mass load (r > 0.9). When differences in purity were controlled for, the linear trend in mass load over time was no longer significant (p > 0.27). For cocaine and MDMA there were no statistically significant trends in either mass load or drug purity over the study period. Our study demonstrates that purity changes may have accounted for a substantial proportion of increases of methamphetamine load measured in wastewater of the studied catchment. Wherever possible, when examining temporal trends in drug loads, or when making comparisons between geographic regions, purity trends should also be examined, as this can aid appropriate interpretation of findings by stakeholders and policy makers.

Mass spectrometric strategies for the investigation of biomarkers of illicit drug use in wastewater

The analysis of illicit drugs in urban wastewater is the basis of wastewater-based epidemiology (WBE), and has received much scientific attention because the concentrations measured can be used as a new non-intrusive tool to provide evidence-based and real-time estimates of community-wide drug consumption. Moreover, WBE allows monitoring patterns and spatial and temporal trends of drug use. Although information and expertise from other disciplines is required to refine and effectively apply WBE, analytical chemistry is the fundamental driver in this field. The use of advanced analytical techniques, commonly based on combined chromatography-mass spectrometry, is mandatory because the very low analyte concentration and the complexity of samples (raw wastewater) make quantification and identification/confirmation of illicit drug biomarkers (IDBs) troublesome. We review the most-recent literature available (mostly from the last 5 years) on the determination of IDBs in wastewater with particular emphasis on the different analytical strategies applied. The predominance of liquid chromatography coupled to tandem mass spectrometry to quantify target IDBs and the essence to produce reliable and comparable results is illustrated. Accordingly, the importance to perform inter-laboratory exercises and the need to analyze appropriate quality controls in each sample sequence is highlighted. Other crucial steps in WBE, such as sample collection and sample pre-treatment, are briefly and carefully discussed. The article further focuses on the potential of high-resolution mass spectrometry. Different approaches for target and non-target analysis are discussed, and the interest to perform experiments under laboratory-controlled conditions, as a complementary tool to investigate related compounds (e.g., minor metabolites and/or transformation products in wastewater) is treated. The article ends up with the trends and future perspectives in this field from the authors' point of view. © 2016 Wiley Periodicals, Inc. Mass Spec Rev 37:258-280, 2018.

Municipal Wastewater as a Microbial Surveillance Platform for Enteric Diseases: A Case Study for Salmonella and Salmonellosis

Municipal wastewater (MW) contains a conglomeration of human enteric microbiota from a community and, hence, represents a potential surveillance tool for gastrointestinal infectious disease burden at the community level. To evaluate this, the concentration of Salmonella in MW samples from Honolulu, Hawaii, was monitored over a 54-week period, which showed positive and significant linear and rank correlation with clinical salmonellosis case numbers over the same period. Salmonella isolates were obtained from the MW samples and then compared with clinical isolates obtained by the Hawaii Department of Health State Laboratories over the same period. The MW isolate collection contained 34 serotypes, and the clinical isolate collection contained 47 serotypes, 21 of which were shared between the two isolate collections, including nine of the 12 most commonly detected clinical serotypes. Most notably, nine Salmonella strains, including one outbreak-associated Paratyphi B strain and eight other clinically rare strains, were shared and concurrently detected between the MW and the clinical isolate collections, indicating the feasibility of using enteric pathogens in the MW as a timely indication of community enteric disease activity.

Five-year monitoring of 19 illicit and legal substances of abuse at the inlet of a wastewater treatment plant in Barcelona (NE Spain) and estimation of drug consumption patterns and trends

Illicit and legal drugs of abuse, including alcohol, continue to be in the focus of many governmental national and international studies due to the important consequences of their consumption at both individual and social level. Estimation of drug use at the community level from the concentrations of the drugs themselves or their major metabolites measured in wastewater has become an increasingly accepted and extended tool, complementary to the methods traditionally used for this purpose. The present work describes the application of this approach, generally known as wastewater epidemiology, to investigate the latest drug consumption patterns and trends in the European city of Barcelona. To this end, a total of 19 selected drugs of abuse and metabolites were monitored at the inlet of one of the main wastewater treatment plants of Barcelona every day during one week in March between 2011 and 2015. Analysis of the selected drugs and metabolites in the wastewater samples was performed by means of two methodologies based on liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the concentrations obtained were translated into consumption data. In agreement with official records, alcohol, followed by cannabis, cocaine, amphetamine-like compounds, and methadone were the most consumed drugs. Alcohol, cannabis, and cocaine consumption were on average 18mL(14g)/day/inhabitant (>15), 38g/day/1000 inhabitants aging 15-64, and 2.4g/day/1000 inhabitants aging 15-64, respectively. As for drug use trends, consumption increased over the 5years monitored for all drugs, but for heroin and diazepam. Weekly profiles characterized by higher consumption over the weekend as compared to weekdays were observed only for alcohol, cocaine, and MDMA. Extrapolation of the data obtained for the area under study to the national Spanish territory yields consumption figures of 142t of illicit drugs per year and >2500 million euro turnover per year in the black market.

Estimating heroin abuse in major Chinese cities through wastewater-based epidemiology

Heroin consumption in major cities across China was estimated for the first time via wastewater-based epidemiology. Influent and effluent wastewater samples were collected from 49 wastewater treatment plants (WWTPs) in 24 major cities that cover all the geographic regions of the country. Concentrations of morphine, 6-acetylmorphine, and codeine were measured. Near complete removal of morphine by wastewater treatment processes was observed, whereas removal rates of codeine were slightly lower. Morphine loads were much higher than codeine loads at most WWTPs in China, a trend opposite to that in many European countries. In addition, morphine and codeine loads were strongly correlated at most WWTPs, indicating morphine and codeine in wastewater were predominantly from the same source, street heroin. At WWTPs in Guangzhou and Shenzhen, codeine loads were considerably higher than morphine loads, consistent with previous reports of codeine abuse (e.g., as cough syrup) among middle and high school students in Guangdong province. Heroin consumption was derived based on morphine loads and taking into account therapeutic use of morphine and codeine, as well as contribution of codeine and acetylcodeine in street heroin. Highest heroin consumption was observed in northwestern and southwestern China. The average heroin consumption of the sampled cities was 64.6±78.7mg/1000inh/d. The nation-wide average heroin consumption was much lower than that of methamphetamine, consistent with seizure data and numbers of registered heroin and methamphetamine users in China.

Occurrence and fate of illicit drugs and pharmaceuticals in wastewater from two wastewater treatment plants in Costa Rica

Chemical analysis of raw wastewater in order to assess the presence of biological markers entering a wastewater treatment plant can provide objective information about the health and lifestyle of the population connected to the sewer system. This work was performed in a tropical country of Central America, Costa Rica, with the aim of extending this knowledge to new world regions. This work is the first to report wastewater-based epidemiological data on the use of illicit drugs in this region of the world. Composite wastewater samples from the influents of two different wastewater treatment facilities and surface water samples from surrounding areas were collected applying the best practice protocol and analysed to investigate the occurrence and fate of selected illicit drugs of abuse and pharmaceuticals. Results showed the presence of chemical indicators of the classic drugs cocaine and cannabis at high concentration levels, besides the moderate presence of the opiates codeine and morphine. Neither the worldwide commonly used psychoactive substances of abuse such as synthetic phenethylamines, nor pharmaceuticals from the family of benzodiazepines were detected, demonstrating the spatial differences in drug use among different world regions. In addition, effluent wastewater samples were analysed and compared to influent concentrations in order to evaluate the decrease in concentration of the targeted analytes through two treatment technologies. As a final step, a wide-scope qualitative screening, including hundreds of suspect compounds, was applied in order to have a better knowledge on the presence of pharmaceuticals in waters and to assess the potential impact of the treated wastewater into the receiving aquatic ecosystems.

Tracing methamphetamine and amphetamine sources in wastewater and receiving waters via concentration and enantiomeric profiling

Wastewater analysis is a promising approach to monitor illicit drug abuse of a community. However, drug use estimation via wastewater analysis may be biased by sources other than abuse. This is especially true for methamphetamine and amphetamine as their presence in wastewater may come from many sources, such as direct disposal or excretion following administration of prescription drugs. Here we traced methamphetamine and amphetamine sources via concentration and enantiomeric profiling of the two compounds from black market to receiving waters. Methamphetamine in wastewater was found to predominantly arise from abuse, proving the feasibility of using wastewater analysis for estimating its consumption in China. Amphetamine abuse was previously considered negligible in East and Southeast Asia. However, we found that amphetamine was abused considerably (up to 90.7mg/1000inh/day) in a significant number (>20%) of major cities in China. Combined concentration and enantiomeric profiling also revealed direct disposal into receiving waters of methamphetamine manufactured by different processes. These findings have important implications for monitoring of and law enforcement against methamphetamine/amphetamine abuse and related crimes in China and abroad.

Occurrence of illicit drugs in water and wastewater and their removal during wastewater treatment

This review critically evaluates the types and concentrations of key illicit drugs (cocaine, amphetamines, cannabinoids, opioids and their metabolites) found in wastewater, surface water and drinking water sources worldwide and what is known on the effectiveness of wastewater treatment in removing such compounds. It is also important to amass information on the trends in specific drug use as well as the sources of such compounds that enter the environment and we review current international knowledge on this. There are regional differences in the types and quantities of illicit drug consumption and this is reflected in the quantities detected in water. Generally, the levels of illicit drugs in wastewater effluents are lower than in raw influent, indicating that the majority of compounds can be at least partially removed by conventional treatment processes such as activated sludge or trickling filters. However, the literature also indicates that it is too simplistic to assume non-detection equates to drug removal and/or mitigation of associated risks, as there is evidence that some compounds may avoid detection via inadequate sampling and/or analysis protocols, or through conversion to transformation products. Partitioning of drugs from the water to the solids fraction (sludge/biosolids) may also simply shift the potential risk burden to a different environmental compartment and the review found no information on drug stability and persistence in biosolids. Generally speaking, activated sludge-type processes appear to offer better removal efficacy across a range of substances, but the lack of detail in many studies makes it difficult to comment on the most effective process configurations and operations. There is also a paucity of information on the removal effectiveness of alternative treatment processes. Research is also required on natural removal processes in both water and sediments that may over time facilitate further removal of these compounds in receiving environments.