Population drug use in Australia: a wastewater analysis

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.

Occurrence, ecotoxicity and ecological risks of psychoactive substances in surface waters

Psychoactive substances (PSs) represent a subset of emerging contaminants. Their widespread production and utilization contribute to a growing ecological burden and risk on a global scale. Conventional wastewater treatment methods have proven insufficient in adequately removing psychoactive substances, leading to their occurrence in surface water ecosystems worldwide. As of present, however, a thorough understanding of their geographical prevalence and distribution patterns remains elusive. Further, in the existing literature, there is a scarcity of comprehensive overviews that systematically summarize the toxicity of various psychoactive substances towards aquatic organisms. Through summarizing almost 140 articles, the present study provides an overview of the sources, pollution status, and biotoxicity of psychoactive substances in surface waters, as well as an assessment of their ecological risks. Concentrations of several psychoactive substances in surface waters were found to be as high as hundreds or even thousands of ng·L-1. In parallel, accumulation of psychoactive substances in the tissues or organs of aquatic organisms was found to potentially cause certain adverse effects, including behavioral disorders, organ damage, and DNA changes. Oxidative stress was found to be a significant factor in the toxic effects of psychoactive substances on organisms. The application of the risk quotient approach indicated that psychoactive substances posed a medium to high risk in certain surface water bodies, as well as the need for sustained long-term attention and management strategies.

To sample or not to sample: A governance-focused decision tree for wastewater service providers considering participation in wastewater-based epidemiology (WBE) in support of public health programs

Wastewater-based epidemiology (WBE) provides value to public health monitoring and protection. Participation of public and private wastewater system operators in WBE efforts is critical to public health surveillance program success and sustainability. However, given the number of WBE solicitations wastewater service providers receive, the limitation of service provider resources, the concerns around privacy, ethics, and equity, and the fatigue associated with responding to COVID-19, operators are becoming more hesitant to participate in WBE efforts. While various ethical concerns and sustainability challenges associated with WBE have been documented, no efforts to date have investigated what factors should systematically influence the decision to provide samples to a WBE effort. Therefore, this study develops a decision-making tool for WBE teams to proactively monitor, manage, and avoid wastewater system operators' operational risks and potential liabilities. Ultimately, using this tool allows WBE program partners in academia, government, and industry to better understand wastewater system operators' needs and challenges surrounding data quality and use, public health ethics, and daily wastewater infrastructure operation.

Wastewater-based monitoring of illicit drugs in Cyprus by UPLC-MS/MS: The impact of the COVID-19 pandemic

The outbreak and spread of COVID-19 impacted through various ways the lives of millions of humans globally. In this work, wastewater-based epidemiology (WBE) was applied to investigate the effect of the actions taken by the Republic of Cyprus to confine COVID-19 on the use of illicit stimulant drugs. Daily influent samples were collected from the six main wastewater treatment plants (WWTPs) of the country i) before lockdown (3-9 April 2019), ii) during lockdown (21-27 April 2020), iii) during the post-lockdown period (14-20 July 2020), and, iv) during each season of the following year (20-26 April 2021, 19-25 July 2021, 11-17 October 2021, 25 December 2021-2 January 2022), and analyzed for amphetamine, methamphetamine, MDMA and cocaine. In most areas, amphetamine and methamphetamine use was not affected during the confinement period, but as availability of the substances decreased with time, a drop in their use was observed when most restriction measures were eased (up to 9- and 22-fold decrease, respectively). The limitations on social interactions and events during the quarantine period seem to have led to the reduction of MDMA and cocaine and driven a sharp decrease of their use in most areas studied (up to 11 and 6 times lower, respectively). However, the re-opening of activities led to a pronounced consumption increase, reaching maximum daily values of 800 and 2691 mg/1000 inhabitants/day, respectively. In 2021, drug use was re-established to lower levels. The examination of weekly patterns during this year revealed higher weekend use of methamphetamine, MDMA and cocaine. Our results suggest that both the implementation and the easing of COVID-19 related measures affected the availability and the use of drugs. This study also provides the first insight on the consumption of illicit drugs in the Republic of Cyprus during pre-, post- and pandemic times and demonstrates the importance of WBE.

Occurrence and Transformation of Ephedrine/Pseudoephedrine and Methcathinone in Wastewater in China

Previous wastewater-based epidemiology studies on methcathinone (MC), a controlled substance in many countries, attributed its occurrence in wastewater to its misuse. However, such attribution did not consider the possibility that MC may also come from the transformation of ephedrine (EPH) and pseudo-ephedrine (PEPH). In this work, EPH/PEPH and MC in wastewater of six major Chinese cities were systematically examined. EPH/PEPH concentrations in all the cities showed clear seasonal variations, with maximum and minimum concentrations observed in winter and summer, respectively. In contrast, MC concentrations were the lowest in winter, leading to minimum concentration ratios between MC and EPH/PEPH in winter. Lack of MC seizure in the cities suggests that MC abuse could not account for the ubiquitous detection of the substance in the wastewater of these cities. Batch experiments confirmed EPH/PEPH transformation into MC in wastewater. The significantly lower transformation rate at a lower temperature was consistent with low MC concentrations in winter. These results indicate that when monitoring MC through wastewater, EPH/PEPH concentrations must be determined simultaneously to avoid false identification of MC abuse. The observed ratios of MC to EPH/PEPH concentrations in this work may be used to determine MC abuse. Alternatively, other biomarkers (e.g., cathinone) may be considered to avoid interference from EPH/PEPH transformation.

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.

Detection of Eight Cannabinoids and One Tracer in Wastewater and River Water by SPE-UPLC–ESI-MS/MS

The consumption of illicit drugs represents a global social and economic problem. Using suitable analytical methods, monitoring, and detection of different illegal drugs residues and their metabolites in wastewater samples can help combat this problem. Our article defines a method to develop, validate, and practically applicate a rapid and robust analytical process for the evaluation of six naturally occurring cannabinoids (CBG, CBD, CBDV, CBN, THC, THCV), two cannabinoids in acidic form (CBDA, THCA-A), and the major cannabis-related human metabolite (THC-COOH). After SPE offline enrichment, we used a UPLC–ESI-MS/MS system, which permitted the determination of several by-products. Studied matrices were samples of different origins: (i) effluent water from a wastewater treatment plant in the Porto urban area; (ii) environmental water from Febros River, the last left-bank tributary of the Douro River. The multi-residue approach was substantiated and successfully employed to analyze the water samples collected in the above locations. The rapid and precise quantification of nine different cannabinoids in different water samples occurred within nine minutes at the ng L−1 level. The appearance of dozens of ng L−1 of some cannabis secondary metabolites, such as CBD, CBDA, CBN, THCA-A, indicates this plant species’ widespread usage among the general population in the considered area.

Environmental occurrence and ecological risks of psychoactive substances

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

Wastewater-based epidemiology for illicit drugs: A critical review on global data

Illicit drug use is complex, hidden and often highly stigmatized behaviour, which brings a vast challenge for drug surveillance systems. Drug consumption can be estimated by measuring human excretion products in untreated wastewater, known as wastewater-based epidemiology (WBE). Over the last decade, the application of wastewater-based epidemiology to monitor illicit drug loads increased and WBE is currently applied on a global scale. Studies from over the globe are evaluated with regard to their sampling method, analytical accuracy and consumption calculation, aiming to further reduce relevant uncertainties in order to make reliable comparisons on a global level. Only a limited number is identified as high-quality studies, so further standardization of the WBE approach for illicit drugs is desired especially with regard to the sampling methodology. Only a fraction of the reviewed papers explicitly reports uncertainty ranges for their consumption data. Studies which had the highest reliability are recently published, indicating an improvement in reporting WBE data. Until now, WBE has not been used in large parts of Africa, nor in the Middle East and Russia. An overview of consumption data across the continents on commonly studied drugs (cocaine, MDMA, amphetamine and methamphetamine) is provided. Overall, high consumption rates are confirmed in the US, especially for cocaine and methamphetamine, while relatively low illicit drug consumption is reported in Asia.

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.

Wastewater analysis of psychoactive drugs: Non-enantioselective vs enantioselective methods for estimation of consumption

The consumption of licit and illicit psychoactive drugs (PAD) is ubiquitous in all communities and a serious public health problem. Measuring drug consumption is difficult but essential for health-care professionals, risk assessment and policymakers. Different sources of information have been used for a comprehensive analysis of drug consumption. Among them, Wastewater based epidemiology (WBE) emerged as an essential and complementary methodology for estimating licit and illicit drugs consumption. This methodology can be used for quantification of unchanged drugs or their human-specific metabolites in wastewater for estimation of consumption or screening of new PAD. Although some limitations are still being pointed out (e.g., estimation of the population size, use of suitable biomarkers or pharmacokinetics studies), the non-invasive and potential for monitoring real-time data on geographical and temporal trends in drug use have been showing its capacity as a routine and complementary tool. Chromatographic methods, both non-enantioselective and enantioselective are the analytical tools used for quantification of PAD in wastewaters and further estimation of consumption. Therefore, this manuscript aims to summarize and critically discuss the works used for wastewater analysis of PAD based on WBE using non-enantioselective and enantioselective methods for estimation of consumption. Non-enantioselective methods are among the most reported including for chiral PAD. Nevertheless, a trend has been seen towards the development of enantioselective methods as most PAD are chiral and determination of the enantiomeric fraction can provide additional information (e.g., distinction between consumption or direct disposal, or manufacture processes) and fulfill some WBE gaps.

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).

A Narrative Review of the Recent 'Ice' Epidemic: An Australian Perspective

Background:

The use of methamphetamine or amphetamine stimulant drugs has been identified by authoritative public health bodies as a global health issue, with a worrying trend towards production and consumption of a higher purity crystalline form methamphetamine (ice) over the past decade. This trend has been well documented within Australia, resulting in a public perception of there being an ‘ice’ epidemic in regional/rural areas. Considering the illicit nature of ice, monitoring it is challenging and as such little information is available regarding the actual extent of methamphetamine use, harms and patterns in regional/remote Australia.

Aim:

To collate the available literature regarding methamphetamine use in regional/rural Australia and identify gaps in the literature.

Methods:

A literature search was conducted by searching 6 databases (PUBMED, Medline, CINAHL, EMBASE, PsycINFO and SCOPUS) following which exclusion/inclusion criteria were applied. Included papers were appraised with the Joanna Briggs Institute Critical appraisal tools and synthesised in light of the sociocultural, ethnic and geographic differences in methamphetamine use in Australia.

Results:

Regarding rural/regional Australia there is a significant lack of research into methamphetamine use, patterns and epidemiology since the rise of crystalline methamphetamine in 2013. The existing literature available suggests great variability in methamphetamine harms in rural communities. This can be a double-edged sword however, as the introduction of ice into a remote/rural community may result in greater harms if it becomes ingrained in local customs. Similarly, there is a lack of research into the specific factors within Indigenous communities leading to an increased rate of methamphetamine use amongst members.

Recommendation:

Future research should address the causes of variance in methamphetamine harms in rural/remote regions. Although the scope of this paper was the Australian context, a wider international approach may yield useful information.

Evaluating the stability of prescription drugs in municipal wastewater and sewers based on wastewater-based epidemiology

Wastewater-based epidemiology (WBE) is considered as an effective tool for monitoring drug consumption, which is often obtained by back-calculation using the influent concentration and other parameters of wastewater treatment plants. Lack of information on the transformation of drugs in municipal wastewater and sewers may lead to inaccurate consumption estimation. Fourteen prescription drugs in four major categories of diseases (cardiovascular, diabetes, depression, and asthma) were selected to study their adsorption and biodegradation in wastewater and biofilm sewers under different temperatures, pH and biofilms conditions. The result demonstrated that the decay percentage of drugs in wastewater is increased with temperature. Within 72 h, eleven of these 14 drugs, such as metformin, metoprolol, bezafibrate, etc., have decay percentages below 20% in wastewater, which are considered as stable drugs; and the decay percentages of the other three, monluster, paroxetine, and sertraline, are greater than 20%, which are the most unstable drugs. In lab-scale aerobic and anaerobic sewers, the decay percentages of metformin, glipizide, metoprolol, gemfibrozil, and atorvastatin are less than 20% within 24 h. The decay percentages of venlafaxine, citalopram, fluoxetine, salmeterol, and salbutamol within 24 h are 20%-60% and paroxetine and sertraline are close to or even exceed 80% within 6 h. Biodegradation of drugs in sewers with aerobic or anaerobic biofilms is higher than that in wastewater systems without biofilms. The results showed that when the per capita consumption of drugs is estimated by using the WBE method, the stability of drugs in wastewater and different types of sewers will significantly affect their residual concentrations.

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.

Psychoactive compounds at environmental concentration alter burrowing behavior in the freshwater crayfish

Pharmaceutically active compounds (PhAC) have been increasingly detected in freshwater and marine waterbodies worldwide and are recognized as major emerging micropollutant threat to the aquatic environment. Despite their low concentrations in the environment, there is evidence of effects on non-target aquatic organisms in natural habitats. To assess the potential effects of PhACs on its burrowing behavior, we exposed the red swamp crayfish Procambarus clarkii to methamphetamine or tramadol at the environmentally relevant concentration of 1 μg/L. Methamphetamine-exposed females constructed burrows of lower depth and volume relative to individual weight than did controls. Tramadol-exposed females consistently exhibited a tendency for smaller burrows, but this difference was not significant. Exposed males showed a non-significant tendency to excavate larger burrows compared with the control. Control and tramadol-treated females maintained the natural tendency of constructing relatively deeper and/or larger-volume burrows compared with males. This sex-related pattern was not detected in the methamphetamine group. The rate of human therapeutic PhAC usage is relatively stable year-round, and impacts on crayfish burrowing can be particularly damaging during periods of drought, when the dilution of waste waters is reduced, and burrowing becomes a critical survival strategy. Our results suggest that an increasingly broad range of environmental impacts of PhACs on non-target organisms can be expected in natural ecosystems.

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.

Rapid Assessment of Opioid Exposure and Treatment in Cities Through Robotic Collection and Chemical Analysis of Wastewater

INTRODUCTION

Accurate data regarding opioid use, overdose, and treatment is important in guiding community efforts at combating the opioid epidemic. Wastewater-based epidemiology (WBE) is a potential method to quantify community-level trends of opioid exposure beyond overdose data, which is the basis of most existing response efforts. However, most WBE efforts collect parent opioid compounds (e.g., morphine) at wastewater treatment facilities, measuring opioid concentrations across large catchment zones which typically represent an entire municipality. We sought to deploy a robotic sampling device at targeted manholes within a city to semi-quantitatively detect opioid metabolites (e.g., morphine glucuronide) at a sub-city community resolution.

METHODS

We deployed a robotic wastewater sampling platform at ten residential manholes in an urban municipality in North Carolina, accounting for 44.5% of the total municipal population. Sampling devices comprised a robotic sampling arm with in situ solid phase extraction, and collected hourly samples over 24-hour periods. We used targeted mass spectrometry to detect the presence of a custom panel of opioids, naloxone, and buprenorphine.

RESULTS

Ten sampling sites were selected to be a representative survey of the entire municipality by integrating sewer network and demographic GIS data. All eleven metabolites targeted were detected during the program. The average morphine milligram equivalent (MME) across the nine illicit and prescription opioids, as excreted and detected in wastewater, was 49.1 (standard deviation of 31.9) MME/day/1000-people. Codeine was detected most frequently (detection rate of 100%), and buprenorphine was detected least frequently (12%). The presence of naloxone correlated with city data of known overdoses reversed by emergency medical services in the prehospital setting.

CONCLUSION

Wastewater-based epidemiology with smart sewer selection and robotic wastewater collection is feasible to detect the presence of specific opioids, naloxone, methadone, and buprenorphine within a city. These results suggest that wastewater epidemiology could be used to detect patterns of opioid exposure and may ultimately provide information for opioid use disorder (OUD) treatment and harm reduction programs.

Occurrence, removal and environmental risk of markers of five drugs of abuse in urban wastewater systems in South Australia

The occurrence and fate of five drugs of abuse in raw influent and treated effluent wastewater were investigated over a period of 1 year in the Adelaide region of South Australia. Four wastewater treatment plants were chosen for this study and monitored for five drugs which included cocaine in the form of its metabolite benzoylecgonine (BE), methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA) and two opioids (codeine and morphine) during the period April 2016 to February 2017. Alongside concentrations in raw sewage, the levels of drugs in the treated effluent were assessed and removal efficiencies were calculated. Drug concentrations were measured by mixed-mode solid phase extraction and liquid chromatography coupled to a quadrupole mass spectrometer. Drug concentrations detected in the raw wastewater ranged from 7 to 6510 ng/L and < LOD to 4264 ng/L in treated effluent samples. Drug removal rates varied seasonally and spatially. The mass loads of drugs discharged into the environment were in descending order: codeine > methamphetamine > morphine > MDMA > BE. Results showed that all the targeted drugs were on average incompletely removed by wastewater treatment, with removal performance highest for morphine (94%) and lowest for MDMA (58%). A screening-level environmental risk assessment was subsequently performed for the drugs based on effluent wastewater concentrations. Based on calculated risk quotients, overall environmental risk for these compounds appears low, with codeine and methamphetamine likely to pose the greatest potential risk to receiving environments. Given the recognised limitations of current ecotoxicological models and risk assessment methods for these and other pharmaceutical drugs, the potential for environmental impacts associated with the continuous discharge of these compounds in wastewater effluents should not be overlooked.

Aquatic Phytotoxicity to Lemna minor of Three Commonly Used Drugs of Addiction in Australia

The manufacturing and consumption of drugs of addiction has increased globally and their widespread occurrence in the environment is an emerging concern. This study evaluated the phytotoxicity of three compounds: methamphetamine, codeine and morphine; commonly reported in Australian urban water, to the aquatic plant Lemna minor under controlled conditions. L. minor was sensitive to lower drug concentrations when administered in multi-compound mixtures (100-500 µg L^-1) than when applied individually (range 600-2500 µg L^-1), while no adverse effects were observed at environmentally-relevant concentrations (1-5 µg L^-1) detected in wastewater effluent. In conclusion, the results show that the concentrations of these compounds discharged into the environment are unlikely to pose adverse phytotoxic effects. These three compounds are known to be the most stable of their group under such conditions indicating that with this respect it is safe to use recycled water for existing regulated reclaimed purposes including agricultural or parklands irrigation or replenishing surface and groundwater. However, more research on the analysis of methamphetamines and opiates in municipal effluents is needed to reassure the likely environmental hazard of these neuroactive drug classes to aquatic organisms. Given the ever-growing production and aquatic disposal of discharge wastewater globally, this study provides timely and valuable insights into the likely drug-related impacts of effluent disposal on aquatic plants in receiving environments.

Removal of emerging drugs of addiction by wastewater treatment and water recycling processes and impacts on effluent-associated environmental risk

Drugs of addiction, have been recognized as potential contaminants of concern to the environment. Effluent wastewater discharge is a major source of contamination to aquatic receiving environments. A year-long monitoring program was undertaken in Australia to characterise the fate of four emerging drugs of addiction: methamphetamine; MDMA; pharmaceutical opioids: codeine and morphine and a metabolite: benzoylecgonine in four wastewater treatment plants operating with different secondary treatment technologies: conventional activated sludge (CAS), membrane bioreactors (MBR), integrated fixed-film AS (IFAS) and sequencing batch reactor (SBR). The effect of subsequent tertiary treatment (coagulation/flocculation) on the removal efficiency was also assessed. Drugs were detected in influent and effluent samples (mean concentration ranged from 43-4777 and 17-1721 ng/L, respectively). Treated effluents had noticeably lower levels compared to raw influents. Removal efficiency of compounds depended on the secondary treatment employed, with IFAS and MBR performing the best with significant removal of compounds (≈90%) followed by CAS (54-96%) and lastly SBR (42-83%). Despite the low levels of drugs measured after the secondary treatment, near complete removal after tertiary treatment (≈99%) was recorded, which demonstrated the effectiveness of using the coagulation/flocculation process as an effective step for enhancing the removal efficiency. The levels of drugs were at a low level in the effluents released into the environment and used for recycling and all posed a low environmental risk in urban water courses based on the risk assessment. The information given here provides new and useful information to the water industry and regulators on the efficiency of drug removal in a range of wastewater treatment configurations.

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.

Simultaneous determination of 24 opioids, stimulants and new psychoactive substances in wastewater

Wastewater-based epidemiology has become a reputable means to estimate drug consumption within a community. However, these methods typically focus solely on illicit drugs or a single chemical family, with multi-class methods out of favour due to the increased analytical challenges. •A sensitive liquid chromatography - mass spectrometry method was developed for the simultaneous determination of 24 opioids, stimulants and new psychoactive substances in influent wastewater.•Filtered wastewater samples, preserved with sodium metabisulfite, were pretreated and 1000 times concentrated using off-line solid phase extraction.•The method was optimised and fully validated for all compounds, with limits of quantification between 0.2 and 300 ng/L.

Music festivals and drugs: Wastewater analysis

Drug consumption in individual cities, regions, and at various music events and festivals across the EU has generally been monitored via questionnaires, patients' medical data, and police reports. However, an overview of drug consumption obtained from these methods can be negatively affected by various subjective factors. We aimed to investigate an association between levels of target drugs in wastewater, music genres, and festival courses. The occurrence of illicit drugs, their metabolites, and psychoactive compounds was investigated in the influent of six wastewater treatment plants in the Czech and Slovak Republic during seven large-scale music festivals from different music genres: metal, rock, pop, country and folk, ethnic, multi-genre, dance, and trance. The total number of participants included >130,000 active festival attendees. The association between music genre and illicit drug and/or psychoactive pharmaceutical consumptions is discussed on the basis of the results obtained through wastewater analyses. The observed trend was similar to worldwide published data with a specific local phenomenon of methamphetamine prevalence that did not significantly change between music events. Increased specific loads of cocaine (measured as its metabolite benzoylecgonine) and Ecstasy, along with some cannabis, were mainly observed during pop/rock and dance music festivals. However, there was no significant increase observed in the specific loads of all monitored psychoactive pharmaceuticals. This study demonstrates that the abuse of some illicit drugs is closely associated with specific music preferences.

Wastewater-Based Epidemiology for Early Detection of Viral Outbreaks

The immense global burden of infectious disease outbreaks and the need to establish prediction and prevention systems have been recognized by the World Health Organization (WHO), the National Institutes of Health (NIH), the United States Agency of International Development (USAID), the Bill and Melinda Gates Foundation, and the international scientific community. Despite multiple efforts, this infectious burden is still increasing. For example, it has been reported that between 1.5 and 12 million people die each year from waterborne diseases and diarrheal diseases are listed within the top 15 leading causes of death worldwide. Rapid population growth, climate change, natural disasters, immigration, globalization, and the corresponding sanitation and waste management challenges are expected to intensify the problem in the years to come.

Assessment of drugs of abuse in a wastewater treatment plant with parallel secondary wastewater treatment train

In this study, 24-hour composite wastewater samples were collected from a wastewater treatment plant of New Zealand with parallel secondary treatment units. The aim was to investigate the occurrence, removal, and consumption of 13 drugs of abuse (DOAs) including illicit drugs, alcohol, nicotine, and their metabolites. The filtered samples were analysed through direct injection on LC-MS/MS. Ethyl sulfate, one of the major metabolites of alcohol, was detected at the highest concentration (mean = 8300 ng/L) in wastewater influent. The mean concentrations of methamphetamine and hydroxycotinine in the influent were found to be 935 ng/L and 5000 ng/L, respectively. Amphetamine (383 ng/L) and cocaine (286 ng/L) were detected at the highest concentrations in the effluent. The removal efficiency of the treatment plant varied for DOAs: >99% for morphine, ethyl sulfate, and hydroxycotinine and <50% for methadone and 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP). Primary treatment did not show any significant removal of DOAs while the removal efficiencies of total monitored DOAs by Membrane Bioreactor (MBR) and Bardenpho processes were found to be similar (~95% removal). The population was estimated using hydrochemical parameters and human urine biomarkers and showed good agreement with wastewater treatment plant's estimates. Weekday-weekend variation in the consumption of alcohol and methamphetamine was found to be significant, with a higher estimated consumption during the weekends. Monitored DOAs in influent were present at highest concentrations during summer (23 μg/L), at low concentrations during winter (17 μg/L), and at lowest concentrations during heavy rainfall event (11 μg/L), possibly due to dilution. The population normalised mass loads of DOAs were found to correlate with their metabolites, and morphine was found to correlate with nicotine metabolites.

Fluorescence Excitation-Emission Spectroscopy: An Analytical Technique to Monitor Drugs of Addiction in Wastewater

Emerging contaminants of concern have become a serious issue for the scientific community and society more broadly in recent years due to their increasingly widespread environmental distribution and largely unknown environmental and human health impacts. This study aimed to explore the use of fluorescence excitation-emission (F-EEM) spectroscopy as an alternative analytical method to evaluate the presence of key drugs of addiction (benzoylecgonine, methamphetamine, MDMA, codeine and morphine) in wastewater treatment plants. The chemicals of interest from wastewater were extracted by mixed-mode solid phase extraction and quantified using liquid chromatography tandem mass spectrometry. The same wastewater samples were also analysed by a fluorescence spectrophotometer for fluorescence spectra at wavelengths 280–600 nm (emission) and 200–600 nm (excitation). The study also investigated the relevance of different methods for interpreting F-EEM matrices data including parallel factor analysis (PARAFAC) modelling and fluorescence regional integration technique. PARAFAC identified four components, and among them, component C2, identified at the λex/λem = 275/340 nm wavelength associated with proteinaceous compounds most likely related to tryptophan amino acid, showed significant correlation with codeine removal. MDMA and morphine were not correlated to any of the fluorescence regions. The fluorescence regions related to aromatic protein-like fluorescence were correlated significantly with drug concentration and so may offer a suitable alternative approach for monitoring drugs including benzoylecgonine, methamphetamine and codeine.

The use of wastewater analysis in forensic intelligence: drug consumption comparison between Sydney and different European cities

Wastewater analysis offers objective and complementary information to illicit drug agencies by monitoring patterns of illicit drug consumption. In this study, wastewater samples from three different wastewater treatment plants in Sydney, Australia were collected in March 2016. Ten targeted drugs were analysed and temporal and geographical analyses were performed to obtain a better understanding of the type and amount of illicit drugs consumed in Sydney in comparison with similar studies conducted around Australia and in Europe. Among the targeted drugs, methamphetamine was consumed the most, followed by cocaine and 3,4-methylenedioxymethamphetamine (MDMA). Weekly patterns were observed where a peak during the weekend was present. The geographical analysis showed differences between the regions targeted. This observation may be related to socio-demographic aspects. The comparison of our study to other data sources from Australia showed a high consumption of methamphetamine in Sydney and Western Australia. The comparison between Sydney and different European cities revealed a difference in consumption, which is in line with traditional market indicators. The information obtained through wastewater analysis provides complementary information regarding illicit drug consumption, the size, and the evolution of the illicit drug market. This, ultimately, will assist authorities in making informed decisions.

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.

A multi-laboratory investigation of drug background levels

Identifying and quantifying the drug background in operational environments such as forensic laboratories is an emerging body of research. Knowing these levels is crucial to addressing issues like occupational exposure risk - due to the emergence of potent novel psychoactive substances and synthetic opioids - and data integrity - due to improvements in instrument sensitivity. The work presented here builds upon a prior study to provide a broader representation of the average drug background levels found on surfaces in forensic laboratories. Over 700 samples from 20 laboratories were collected, extracted, and analyzed quantitatively using LC-MS/MS, and qualitatively using TD-DART-MS. Quantitative analysis by LC-MS/MS included a panel of 18 drugs while the non-targeted qualitative analysis by TD-DART-MS screened for over three hundred drugs and excipients. The study focused primarily on surfaces within the drug unit and evidence receiving area of the laboratories, but also investigated other operational units (crime scene, drug interdiction, latent prints, and toxicology) as well as report writing. Background levels were highest within the drug unit of the laboratory, though detectable (tens of nanograms) levels were observed in nearly all sampled areas. The data from this expanded study plays a critical role in addressing laboratory concerns such as establishing drug identification reporting limits for new instrumentation and establishing new workflow or cleaning protocols while also providing a more comprehensive dataset for general environmental background studies.

A study through batch tests on the analytical determination and the fate and removal of methamphetamine in the biological treatment of domestic wastewater

Methamphetamine (MET) is one of the most used illicit drugs in Europe and is recognized as one of the Emerging Organic Micropollutants. It is discharged into the sewerage system from different sources and then enters the wastewater treatment plants. The present study aimed at providing a better knowledge of the fate of MET through the wastewater treatment plants. The study addressed two different issues: (1) optimization of the analytical methods for MET determination in both liquid and sludge phases, focusing on the effects of potentially interfering substances and (2) investigation on the behaviour of MET in the biological treatment process, with specific concern for the biomass activity at different drug concentrations. Results of the study on issue 1 highlighted that the applied analytical method for MET determination (UPLC-MS/MS) is affected by the main components of wastewater for about 9-23%, which is comparable with the uncertainties of the method (about ± 28%). The method showed also to be repeatable and reliable (recovery > 75%; repeatability < 10-15%; bias uncertainty < 30%), and relatively easy-to-use. Therefore, it can be considered suitable for measurements on routine base in the WWTPs. Batch tests conducted to address issue 2 showed total removal of 84, 90, and 96% at 50, 100, and 200 ng/L initial MET concentration, respectively, for a contact time of 6 h. The removal process was mainly ascribed to the biological activity of both heterotrophic and autotrophic bacteria. The pseudo first-order kinetic model provided the best fitting of the experimental data of the overall biological processes at all the tested concentrations. Furthermore, the respirometric tests showed that MET does not induce any inhibition. Adsorption of MET on activated sludge was always very low.

Environmentally relevant concentrations of tramadol and citalopram alter behaviour of an aquatic invertebrate

Environmental pollution by pharmaceutically active compounds, used in quantities similar to those of pesticides and other organic micropollutants, is increasingly recognized as a major threat to the aquatic environment. These compounds are only partly removed from wastewaters and, despite their low concentrations, directly and indirectly affect behaviour of freshwater organisms in natural habitats. The aim of this study was to behaviourally assess the effects of an opioid painkiller (tramadol) and antidepressant drug (citalopram) on behaviour patterns of a clonal model species, marbled crayfish. Animals exposed to environmentally relevant concentrations of both tested compounds (∼1 μg l^-1) exhibited significantly lower velocity and shorter distance moved than controls. Crayfish exposed to tramadol spent more time in shelters. Results were obtained by a simple and rapid method recommended as suitable for assessment of behaviour in aquatic organisms exposed to single pollutants and combinations.

Investigating the correlation between wastewater analysis and roadside drug testing in South Australia

BACKGROUND

The societal impact of drug use is well known. An example is when drug-intoxicated drivers increase the burden on policing and healthcare services.

METHODS

This work presents the correlation of wastewater analysis (using UHPLC-MS/MS) and positive roadside drug testing results for methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA) and cannabis from December 2011-December 2016 in South Australia.

RESULTS

Methamphetamine and MDMA showed similar trends between the data sources with matching increases and decreases, respectively. Cannabis was relatively steady based on wastewater analysis, but the roadside drug testing data started to diverge in the final part of the measurement period.

CONCLUSIONS

The ability to triangulate data as shown here validates both wastewater analysis and roadside drug testing. This suggests that changes in overall population drug use revealed by WWA is consistent and proportional with changes in drug-driving behaviours. The results show that, at higher levels of drug use as measured by wastewater analysis, there is an increase in drug driving in the community and therefore more strain on health services and police.

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.

A new approach towards biomarker selection in estimation of human exposure to chiral chemicals: a case study of mephedrone

Wastewater-based epidemiology is an innovative approach to estimate public health status using biomarker analysis in wastewater. A new compound detected in wastewater can be a potential biomarker of an emerging trend in public health. However, it is currently difficult to select new biomarkers mainly due to limited human metabolism data. This manuscript presents a new framework, which enables the identification and selection of new biomarkers of human exposure to drugs with scarce or unknown human metabolism data. Mephedrone was targeted to elucidate the assessment of biomarkers for emerging drugs of abuse using a four-step analytical procedure. This framework consists of: (i) identification of possible metabolic biomarkers present in wastewater using an in-vivo study; (ii) verification of chiral signature of the target compound; (iii) confirmation of human metabolic residues in in-vivo/vitro studies and (iv) verification of stability of biomarkers in wastewater. Mephedrone was selected as a suitable biomarker due to its high stability profile in wastewater. Its enantiomeric profiling was studied for the first time in biological and environmental matrices, showing stereoselective metabolism of mephedrone in humans. Further biomarker candidates were also proposed for future investigation: 4′-carboxy-mephedrone, 4′-carboxy-normephedrone, 1-dihydro-mephedrone, 1-dihydro-normephedrone and 4′-hydroxy-normephedrone.

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.

The presence of licit and illicit drugs in police stations and their implications for workplace drug testing

The presence of licit and illicit drug residues on surfaces was studied in 10 police stations and a central drug evidence store in New South Wales, Australia, with the results compared to similar surfaces in four public buildings (to establish a community baseline). The results of almost 850 workplace surface swabs were also compared to the outcome of drug analysis in urine and hair samples volunteered by police officers. Surfaces were swabbed with alcohol and the swabs were extracted and analysed by LC-MS/MS. Low level concentrations of the more commonly used drugs were detected at four public sites and one restricted access police office facility. Surface swabs taken in 10 city and country police stations yielded positive results for a broader suite of drugs than at background sites however 75-93% of the positive drug results detected in police stations were below 40ng, which is only slightly greater than the largest background result measured in the current study. This study indicates that contamination issues are more likely to be focussed in higher risk areas in police stations, such as counters and balances in charge areas, and surfaces within drug safes although front reception counters also returned surface contamination. All 64 urine samples collected in this study were negative, while only 2 of the 11 hair samples collected from donors resulted in trace concentrations for cocaine, but not its metabolite benzoylecgonine. Positive hair samples were only obtained from police donors in very high risk jobs, indicating that the exposure risk is low. Minor changes to the materials used as work surfaces, and some procedural changes in police stations and large evidence stores are suggested to decrease the likelihood of drugs contaminating work surfaces, thereby reducing the potential exposure of police officers to drugs in the workplace.

Occurrence of diazepam and its metabolites in wastewater and surface waters in Beijing

Occurrence of diazepam and its metabolites, nordiazepam, temazepam, and oxazepam in the water environment in Beijing was investigated. Samples were collected from four rivers flowing through the city and from all the thirteen sewage treatment plants in the urban area. Average influent concentrations of diazepman, temazepam, and oxazepam in 2013 summer ranged from 0.9 to 7.1, 1.5 to 3.4, and 2.9 to 12.4 ng L^-1, respectively, whereas nordiazepam concentrations were below quantification limit on the majority of sampling dates. No significant seasonal variation in influent concentrations was observed. Removal during treatment was low for diazepman (<50%), temazepam (<20%), and oxazepam (<20%), consistent with previous findings reported in the literature. Wastewater-based epidemiology approach was applied to back-calculate population size-normalized diazepam consumption (using temazepam as biomarker) in Beijing, which was found to be at least 3.8 times more of the national average. Diazepam, temazepam, and oxazepam were widely detected in surface waters, with concentrations greater than concentrations in sewage influents at many sampling points, strongly indicating direct discharge of wastewater of high diazepam concentrations into the surface waters in the city.

Monitoring MDMA metabolites in urban wastewater as novel biomarkers of consumption

Consumption of 3,4-methylendioxymethamphetamine (MDMA) has been always estimated by measuring the parent substance through chemical analysis of wastewater. However, this may result in an overestimation of the use if the substance is directly disposed in sinks or toilets. Using specific urinary metabolites may overcome this limitation. This study investigated for the first time the suitability of a panel of MDMA metabolites as biomarkers of consumption, considering the specific criteria recently proposed, i.e. being detectable and stable in wastewater, being excreted in a known percentage in urine, and having human excretion as the sole source. A new analytical method was developed and validated for the extraction and analysis of MDMA and three of its main metabolites in wastewater. 24-h composite raw wastewater samples from three European cities were analysed and MDMA use was back-calculated. Results from single MDMA loads, 4-hydroxy-3-methoxymethamphetamine (HMMA) loads and from the sum of MDMA, HMMA and 4-hydroxy-3-methoxyamphetamine (HMA) loads were in line with the well-known recreational use of this drug: consumption was higher during the weekend in all cities. HMMA and HMA turned out to be suitable biomarkers of consumption; however, concentrations measured in wastewater did not resemble the expected pharmacokinetic profiles, quite likely due to the very limited information available on excretion profiles. Different options were tested to back-calculate MDMA use, including the sum of MDMA and its metabolites, to balance the biases associated with each single substance. Nevertheless, additional pharmacokinetic studies are urgently needed in order to get more accurate excretion rates and, therefore, improve the estimates of MDMA use.

Drugs of abuse and their metabolites in the urban rivers of Beijing, China: Occurrence, distribution, and potential environmental risk

The occurrence and distribution of five drugs of abuse and their metabolites, namely, methamphetamine (METH), amphetamine (AMP), ketamine (KET), ephedrine (EPH), and hydroxylimine (HY), were investigated in the surface water in urban rivers in Beijing, China. A total of 117 surface water samples were collected from the seven rivers in the Beijing urban areas during four different seasons. Laboratory analyses revealed that EPH and METH were the most predominant drugs, with detection frequency ranging from 94% to 100% and from 65% to 100%, respectively. High levels of METH and KET were observed in the center part of the urban areas, which was likely associated with the drug abuse and the entertainment activities. Seasonal variation of the drug occurrence showed that the highest concentration of drugs of abuse was found during winter, which was likely due to the high consumption, low temperature, and low water flows during the cold weather. By contrast, the concentration and detection frequency of AMP and HY were relatively low. Risk assessment by the risk quotient method indicated that the five drugs of abuse and their metabolites were not likely to exert biological effects on the aquatic ecosystems at current levels in the surface water. However, the potential adverse effect of drugs of abuse and their metabolites on ecosystem functioning and human health should not be neglected.

Occurrence of new psychoactive substances in wastewater of major Chinese cities

New psychoactive substances have become increasingly popular across the globe in recent years, which may cause certain public health issues. In this work, sewage-based epidemiology was applied to examine the use of two synthetic cathinones, mephedrone and methylenedioxypyrovalerone (MDPV), and three piperazines, benzylpiperazine (BZP), trifluoromethylphenylpiperazine (TFMPP), and 1-(3-Chlorophenyl)piperazine (mCPP), across China. Influent wastewater samples were collected from 36 sewage treatment plants (STPs) in 18 major cities that cover all the geographic regions of the country. Effluent samples were also collected from selected STPs to determine removal rates. Mephedrone, TFMPP, and mCPP were below detection limits in all the wastewater samples collected, indicating negligible use of these substances in China. MDPV was detected in wastewater at 13 STPs. However, its loads were <1mg/1000inh/d at most of these STPs, indicating low use of this substance. BZP was detected at all the STPs examined, with loads typically falling within the range of 3-10mg/1000inh/d. No clear geographic pattern in BZP occurrence in wastewater was identified. Since BZP in wastewater may also come from its legal sources, whether widespread occurrence of BZP means widespread abuse is yet to be confirmed. Apparent removal of MDPV by wastewater treatment was low (<25%), whereas removal of BZP was nearly complete (typically>95%).

Refining correction factors for back-calculation of illicit drug use

The estimation of illicit drugs use through wastewater analysis has become an important issue in the last few years due to their large worldwide consumption, which results in economic, social and health costs. The amounts of urinary biomarkers of illicit drugs (selected drugs or their metabolites) measured in wastewater are used to back-calculate the consumption of a particular drug by the population and to monitor temporal and spatial trends of illicit drug use in a community. The reliability of back-calculation depends on different factors, one being the accuracy of correction factors. A wide range of correction factors have been used in different studies and some biases must be expected when comparing results. Most of the correction factors were developed several years ago, so they need to be updated to include the latest information on pharmacokinetics. Moreover, new comprehensive methods to treat data should be adopted. The goal of this study is to refine current correction factors for back-calculation of the most widely used illicit drugs: amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA) and tetrahydrocannabinol (THC). The mean percentages of excretion of the parent drugs and their metabolites were calculated for each route of administration, utilizing all accessible pharmacokinetic studies in the literature. This allowed to select the most suitable drug target residue and a refined correction factor was obtained for each substance considering the most frequent route of administration. The refined correction factors we propose can be used in wastewater based epidemiology to standardize the back-calculation of these drugs. These results can be included in the best practice protocol currently adopted in EU studies in order to reduce uncertainty and improve the comparability of results.

Removal of benzoylecgonine from water matrices through UV254/H2O2 process: Reaction kinetic modeling, ecotoxicity and genotoxicity assessment

Benzoylecgonine (BE), the main cocaine metabolite, has been detected in numerous surface water and treatment plants effluents in Europe and there is urgent need for effective treatment methods. In this study, the removal of BE by the UV254/H2O2 process from different water matrices was investigated. By means of competition kinetics method, the kinetic constant of reaction between BE and the photogenerated hydroxyl radicals (OH) was estimated resulting in kOH/BE=5.13×10(9)M(-1)s(-1). By-products and water matrices scavengers effects were estimated by numerical modeling of the reaction kinetics for the UV254/H2O2 process and validated in an innovative microcapillary film (MCF) array photoreactor and in a conventional batch photoreactor. The ecotoxicity of the water before and after treatment was evaluated with four organisms Raphidocelis subcapitata, Daphnia magna, Caenorhabditis elegans, and Vicia faba. The results provided evidence that BE and its transformation by-products do not have significant adverse effects on R. subcapitata, while D. magna underwent an increase of lipid droplets. C. elegans was the most sensitive to BE and its by-products. Furthermore, a genotoxicity assay, using V. faba, showed cytogenic damages during the cell mitosis of primary roots.