What else can the analysis of sewage for urinary biomarkers reveal about communities?

Wastewater-based monitoring reveals geospatial-temporal trends for antibiotic-resistant pathogens in a large urban community

Antimicrobial resistance (AMR) is one of the top ten global health threats, and current surveillance programs rarely monitor it outside healthcare settings. This limits our ability to understand and manage the spread of AMR. Wastewater testing has the potential to simply, reliably and continuously survey trends in AMR outside the healthcare settings, as it captures biological material from the entire community. To establish and evaluate such a surveillance, we monitored wastewater for four clinically significant pathogens across the urban area of Greater Sydney, Australia. Untreated wastewater from 25 wastewater treatment plants (WWTPs) covering distinct catchment regions of 5.2 million residents was sampled between 2017 and 2019. Isolates for extended-spectrum β-lactamases-producing Enterobacteriaceae (ESBL-E) were consistently detected, suggesting its endemicity in the community. Isolates for carbapenem-resistant Enterobacteriaceae (CRE), vancomycin-resistant enterococci (VRE), and methicillin-resistant Staphylococcus aureus (MRSA) were only occasionally detected. The flow normalized relative (FNR) ESBL-E load was positively correlated with the proportion of the population between 19 and 50 years of age, completion of vocational education and the average length of hospital stay. Collectively, these variables explained only a third of the variance of the FNR ESBL-E load, indicating further, yet-unidentified factors as a contributor to the distribution. About half of the variation in the FNR CRE load was explained by the average length of hospital stay, showing healthcare-related drivers. Interestingly, variation in the FNR VRE load was not correlated to healthcare-related parameters but to the number of schools per 10,000 population. Our study provides insight into how routine wastewater surveillance can be used to understand the factors driving the distribution of AMR in an urban community. Such information can help to manage and mitigate the emergence and spread of AMR in important human pathogens.

Research needs for optimising wastewater-based epidemiology monitoring for public health protection

Wastewater-based epidemiology (WBE) is an unobtrusive method used to observe patterns in illicit drug use, poliovirus, and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The pandemic and need for surveillance measures have led to the rapid acceleration of WBE research and development globally. With the infrastructure available to monitor SARS-CoV-2 from wastewater in 58 countries globally, there is potential to expand targets and applications for public health protection, such as other viral pathogens, antimicrobial resistance (AMR), pharmaceutical consumption, or exposure to chemical pollutants. Some applications have been explored in academic research but are not used to inform public health decision-making. We reflect on the current knowledge of WBE for these applications and identify barriers and opportunities for expanding beyond SARS-CoV-2. This paper critically reviews the applications of WBE for public health and identifies the important research gaps for WBE to be a useful tool in public health. It considers possible uses for pathogenic viruses, AMR, and chemicals. It summarises the current evidence on the following: (1) the presence of markers in stool and urine; (2) environmental factors influencing persistence of markers in wastewater; (3) methods for sample collection and storage; (4) prospective methods for detection and quantification; (5) reducing uncertainties; and (6) further considerations for public health use.

Basic influent sewage quality reflects sewershed characteristics in Tokyo city

Sewage comprises multifarious information on sewershed characteristics. For instance, influent sewage quality parameters (ISQPs) (e.g., total nitrogen (TN)) are being monitored regularly at all treatment plants. However, the relationship between ISQPs and sewershed characteristics is rarely investigated. Therefore, this study statistically investigated relationships between ISQPs and sewershed characteristics, covering demographic, social, and economic properties in Tokyo city as an example of a megacity. To this end, we collected ISQPs and sewershed characteristic data from 2015 to 2020 in 10 sewersheds in Tokyo city. By principal component analysis, spatial variability of ISQPs was aggregated into two principal components (89.8% contribution in total), indicating organics/nutrients and inorganic salts, respectively. Concentrations of organics/nutrients were significantly correlated with the population in sewersheds (daytime population density, family size, age distribution, etc.). Inorganic salts are significantly correlated with land cover ratios. Finally, a multiple regression model was developed for estimating the concentration of TN based on sewershed characteristics (R²=0.97). Scenario analysis using the regression model revealed that possible population movements in response to the coronavirus pandemic would substantially reduce the concentration of TN. These results indicate close relationships between ISQPs and sewershed characteristics and the potential applicability of big data of ISQPs to estimate sewershed characteristics and vice versa.

Proposed approaches for coronaviruses elimination from wastewater: Membrane techniques and nanotechnology solutions

Since the beginning of the third Millennium, specifically during the last 18 years, three outbreaks of diseases have been recorded caused by coronaviruses (CoVs). The latest outbreak of these diseases was Coronavirus Disease 2019 (COVID-19), which has been declared by the World Health Organization (WHO) as a pandemic. For this reason, current efforts of the environmental, epidemiology scientists, engineers, and water sector professionals are ongoing to detect CoV in environmental components, especially water, and assess the relative risk of exposure to these systems and any measures needed to protect the public health, workers, and public, in general. This review presents a brief overview of CoV in water, wastewater, and surface water based on a literature search providing different solutions to keep water protected from CoV. Membrane techniques are very attractive solutions for virus elimination in water. In addition, another essential solution is nanotechnology and its applications in the detection and protection of human and water systems.

Wastewater-based epidemiology as a novel tool to evaluate human exposure to pesticides: Triazines and organophosphates as case studies

Production and application of pesticides have risen remarkably in the last few decades. Even if they provide many benefits, they can be hazardous for humans and ecosystems when they are not used cautiously. Human exposure to pesticides is well documented, but new approaches are needed to boost the available information. This work proposes a new application of wastewater-based epidemiology (WBE) to assess the exposure of the general population to organophosphate and triazine pesticides (pyrethroid pesticides have already been validated). Several human urinary metabolites tested as WBE biomarkers, were suitable. Untreated wastewater samples from different European countries were analyzed by liquid chromatography-tandem mass spectrometry. Biomarker concentrations were converted to mass loads and used to back-calculate the local population's exposure to the parent pesticides, using specific correction factors developed in this study. Exposure to organophosphates and pyrethroids showed spatial and seasonal variations. Finally, pesticide exposure was estimated in twenty cities of ten European countries and compared with the acceptable daily intake, concluding that some populations might face health risks. The study confirms WBE as a suitable approach for assessing the average community exposure to pesticides and is a valuable complementary biomonitoring tool. WBE can provide valuable data for public health.

Exploring the integrity of targeted PFASs in extracted wastewater samples during transport and storage stages

Little information exists on the effects of shipping and handling on per- and polyfluoroalkyl substances (PFASs) in environmental samples. Thus, we evaluated the integrity of dried wastewater extracts and the sensitivity of our high-resolution mass spectrometry (HRMS) instrument to perform such analyses by monitoring 13 representative PFASs in samples extracted, evaporated, and stored at room temperature up to one month. Relative to zero-day recoveries of six detected PFASs ranged between 94 and 124% (RSD <38%) for influents, between 88 and 126% (RSD <18%) for effluents after 28 days. Larger variabilities are tentatively associated with the lack of specific mass-labeled standards and the interactions between analytes and remaining matrix components over time. In a second stage, a mix of local and international dry-shipped wastewater samples were analyzed and the same PFASs were quantified. Up to six PFASs were identified, with median concentrations ranging from 1.3 (perfluoro butyl sulfonate (PFBS)) to 7.7 ng/L (perfluoro hexanoic acid (PFHxA)) and from 1.5 (PFBS) to 13.8 ng/L (PFHxA) in local influents and effluents respectively; and from 0.7 (perfluoro hexyl sulfonate (PFHxS)) to 52.8 ng/L (PFHxA) and from 0.5 (PFHxS) to 21.4 ng/L (PFHxA) in Greek influents and effluents, respectively. The importance of this study lies on the need to consider the wider recovery shifts and expanded variability ranges of PFASs derived from the transport and storage times of dried extracts, particularly when applied to HRMS and wide-scope screening approaches.

Current and future perspectives for wastewater-based epidemiology as a monitoring tool for pharmaceutical use

The medical and societal consequences of the misuse of pharmaceuticals clearly justify the need for comprehensive drug utilization research (DUR). Wastewater-based epidemiology (WBE) employs the analysis of human metabolic excretion products in wastewater to monitor consumption patterns of xenobiotics at the population level. Recently, WBE has demonstrated its potential to evaluate lifestyle factors such as illicit drug, alcohol and tobacco consumption at the population level, in near real-time and with high spatial and temporal resolution. Up until now there have been fewer WBE studies investigating health biomarkers such as pharmaceuticals. WBE publications monitoring the consumption of pharmaceuticals were systematically reviewed from three databases (PubMed, Web of Science and Google Scholar). 64 publications that reported population-normalised mass loads or defined daily doses of pharmaceuticals were selected. We document that WBE could be employed as a complementary information source for DUR. Interest in using WBE approaches for monitoring pharmaceutical use is growing but more foundation research (e.g. compound-specific uncertainties) is required to link WBE data to routine pharmacoepidemiologic information sources and workflows. WBE offers the possibility of i) estimating consumption of pharmaceuticals through the analysis of human metabolic excretion products in wastewater; ii) monitoring spatial and temporal consumption patterns of pharmaceuticals continuously and in near real-time; and iii) triangulating data with other DUR information sources to assess the impacts of strategies or interventions to reduce inappropriate use of pharmaceuticals.

Do food and stress biomarkers work for wastewater-based epidemiology? A critical evaluation

Dietary characteristics and oxidative stress are closely linked to the wellbeing of individuals. In recent years, various urinary biomarkers of food and oxidative stress have been proposed for use in wastewater-based epidemiology (WBE), in efforts to objectively monitor the food consumed and the oxidative stress experienced by individuals in a wastewater catchment. However, it is not clear whether such biomarkers are suitable for wastewater-based epidemiology. This study presents a suite of 30 urinary food and oxidative stress biomarkers and evaluates their applicability for WBE studies. This includes 22 biomarkers which were not previously considered for WBE studies. Daily per capita loads of biomarkers were measured from 57 wastewater influent samples from nine Australian catchments. Stability of biomarkers were assessed using laboratory scale sewer reactors. Biomarkers of consumption of vitamin B2, vitamin B3 and fibre, as well as a component of citrus had per capita loads in line with reported literature values despite susceptibility of degradation in sewer reactors. Consumption biomarkers of red meat, fish, fruit, other vitamins and biomarkers of stress had per capita values inconsistent with literature findings, and/or degraded rapidly in sewer reactors, indicating that they are unsuitable for use as WBE biomarkers in the traditional quantitative sense. This study serves to communicate the suitability of food and oxidative stress biomarkers for future WBE research.

Assessment of human exposure to selected pesticides in Norway by wastewater analysis

Pesticides offer many benefits for humanity and agriculture, but at the same time pose a potential risk to human health because of their widespread use and high biological activity. Human biomonitoring (HBM) studies are the main tool to investigate human exposure to pesticides and other chemicals, but face limitations such as sampling biases, long time to complete and high costs. Wastewater-based epidemiology (WBE) is an alternative approach that is centered on the chemical analysis of biomarkers of (pesticide) exposure in urban wastewater. The present study used WBE to assess human exposure to selected classes of pesticides, triazines, pyrethroids and organophosphates, in Norway. Untreated wastewater samples were collected from four cities, covering approximately 20% of the Norwegian population. The highest population weighted mass loads (mg/day/1000 inhabitants) were for alkyl phosphates and the lowest for triazines. Some differences were observed for the two metabolites, 2-isopropyl-6-methyl-4-pyrimidinol (IMPY) and 3-(2,2-dichlorovinyl)-2,2-dimethyl-(1-cyclopropane) carboxylic acid (DCCA), which were higher in the rural city of Hamar. WBE figures were comparable with HBM findings for the specific metabolite of chlorpyrifos and chlorpyrifos methyl (3,5,6-trichloro-2-pyridinol; TCPY) but were different for the alkyl phosphates. Pyrethroid intake was calculated and was lower than the acceptable daily intake in all the cities, indicating low risk for human health. This is the most extensive WBE study performed to date to assess national human exposure to pesticides. This study demonstrated that WBE has the potential to be a useful complementary biomonitoring tool for assessing population-wide exposure to pesticides, overcoming some of the limitations of HBM.

Sale-based estimation of pharmaceutical concentrations and associated environmental risk in the Japanese wastewater system

Information on sales and emission of selected pharmaceuticals were used to predict their concentrations in Japanese wastewater influent through a >300 of pharmaceuticals data sink. A combined wastewater-based epidemiology and environmental risk analysis follow was established. By comparing predicted environmental concentrations (PECs) of pharmaceuticals in wastewater influent against measured environmental concentrations (MECs) reported in previous studies, it was found that the model gave accurate results for 17 pharmaceuticals (0.5 < PEC/MEC < 2), and acceptable results for 32 out of 40 pharmaceuticals (0.1 < PEC/MEC < 10). Although the majority of pharmaceuticals considered in the model were antibiotics and analgesics, pranlukast, a receptor antagonist, was predicted to have the highest concentration in wastewater influent. With regard to the composition of wastewater effluent, the Estimation Program Interface (EPI) suite was used to predict pharmaceutical removal through activated sludge treatment. Although the performance of the EPI suite was variable in terms of accurate prediction of the removal of different pharmaceuticals, it could be an efficient tool in practice for predicting removal under extreme scenarios. By using the EPI suite with input data on PEC in the wastewater influent, the PEC values of pharmaceuticals in wastewater effluent were predicted. The concentrations of 26 pharmaceuticals were relatively high (>1 μg/L), and the PECs of 6 pharmaceuticals were extremely high (>10 μg/L) in wastewater effluent, which could be attributed to their high usage rates by consumers and poor removal rates in wastewater treatment plants (WWTPs). Furthermore, environmental risk assessment (ERA) was carried out by calculating the ratio of predicted no effect concentration (PNEC) to PEC of different pharmaceuticals, and it was found that 9 pharmaceuticals were likely to have high toxicity, and 54 pharmaceuticals were likely to have potential toxicity. It is recommended that this is further investigated in detail. The priority screening and environmental risk assessment results on pharmaceuticals can provide reliable basis for policy-making and environmental management.

Future perspectives of wastewater-based epidemiology: Monitoring infectious disease spread and resistance to the community level

Infectious diseases are acknowledged as one of the most critical threats to global public health today. Climate change, unprecedented population growth with accelerated rates of antimicrobial resistance, have resulted in both the emergence of novel pathogenic organisms and the re-emergence of infections that were once controlled. The consequences have led to an increased vulnerability to infectious diseases globally. The ability to rapidly monitor the spread of diseases is key for prevention, intervention and control, however several limitations exist for current surveillance systems and the capacity to cope with the rapid population growth and environmental changes. Wastewater-Based Epidemiology (WBE) is a new epidemiology tool that has potential to act as a complementary approach for current infectious disease surveillance systems and an early warning system for disease outbreaks. WBE postulates that through the analysis of population pooled wastewater, infectious disease and resistance spread, the emergence of new disease outbreak to the community level can be monitored comprehensively and in real-time. This manuscript provides critical overview of current infectious disease surveillance status, as well as it introduces WBE and its recent advancements. It also provides recommendations for further development required for WBE application as an effective tool for infectious disease surveillance.

Paradigm shifts and current challenges in wastewater management

Wastewater is a significant environmental and public health concern which management is a constant challenge since antiquity. Wastewater research has increased exponentially over the last decades. This paper provides a global overview of the exponentially increasing wastewater research in order to identify current challenges and paradigm shifts. Besides households, hospitals and typical industries, other sources of wastewater appear due to emerging activities like hydraulic fracturing. While the composition of wastewater needs constant reassessment to identify contaminants of interest, the comprehensive chemical and toxicological analysis remains one of the main challenges in wastewater research. Moreover, recent changes in the public perception of wastewater has led to several paradigm shifts: i) water reuse considering wastewater as a water resource rather than a hazardous waste, ii) wastewater-based epidemiology considering wastewater as a source of information regarding the overall health of a population through the analysis of specific biomarkers, iii) circular economy through the implementation of treatment processes aiming at harvesting valuable components such as precious metals or producing valuable goods such as biofuel. However, wastewater research should also address social challenges such as the public acceptance of water reuse or the access to basic sanitation that is not available for nearly a third of the world population.

Social, demographic, and economic correlates of food and chemical consumption measured by wastewater-based epidemiology

Wastewater is a potential treasure trove of chemicals that reflects population behavior and health status. Wastewater-based epidemiology has been employed to determine population-scale consumption of chemicals, particularly illicit drugs, across different communities and over time. However, the sociodemographic or socioeconomic correlates of chemical consumption and exposure are unclear. This study explores the relationships between catchment specific sociodemographic parameters and biomarkers in wastewater generated by the respective catchments. Domestic wastewater influent samples taken during the 2016 Australian census week were analyzed for a range of diet, drug, pharmaceutical, and lifestyle biomarkers. We present both linear and rank-order (i.e., Pearson and Spearman) correlations between loads of 42 biomarkers and census-derived metrics, index of relative socioeconomic advantage and disadvantage (IRSAD), median age, and 40 socioeconomic index for area (SEIFA) descriptors. Biomarkers of caffeine, citrus, and dietary fiber consumption had strong positive correlations with IRSAD, while tramadol, atenolol, and pregabalin had strong negative correlation with IRSAD. As expected, atenolol and hydrochlorothiazide correlated positively with median age. We also found specific SEIFA descriptors such as occupation and educational attainment correlating with each biomarker. Our study demonstrates that wastewater-based epidemiology can be used to study sociodemographic influences and disparities in chemical consumption.

The role of analytical chemistry in exposure science: Focus on the aquatic environment

Exposure science, in its broadest sense, studies the interactions between stressors (chemical, biological, and physical agents) and receptors (e.g. humans and other living organisms, and non-living items like buildings), together with the associated pathways and processes potentially leading to negative effects on human health and the environment. The aquatic environment may contain thousands of compounds, many of them still unknown, that can pose a risk to ecosystems and human health. Due to the unquestionable importance of the aquatic environment, one of the main challenges in the field of exposure science is the comprehensive characterization and evaluation of complex environmental mixtures beyond the classical/priority contaminants to new emerging contaminants. The role of advanced analytical chemistry to identify and quantify potential chemical risks, that might cause adverse effects to the aquatic environment, is essential. In this paper, we present the strategies and tools that analytical chemistry has nowadays, focused on chromatography hyphenated to (high-resolution) mass spectrometry because of its relevance in this field. Key issues, such as the application of effect direct analysis to reduce the complexity of the sample, the investigation of the huge number of transformation/degradation products that may be present in the aquatic environment, the analysis of urban wastewater as a source of valuable information on our lifestyle and substances we consumed and/or are exposed to, or the monitoring of drinking water, are discussed in this article. The trends and perspectives for the next few years are also highlighted, when it is expected that new developments and tools will allow a better knowledge of chemical composition in the aquatic environment. This will help regulatory authorities to protect water bodies and to advance towards improved regulations that enable practical and efficient abatements for environmental and public health protection.

A National Wastewater Monitoring Program for a better understanding of public health: A case study using the Australian Census

Wastewater contains a large range of biological and chemical markers of human activity and exposures. Through systematic collection and analysis of these markers within wastewater samples it is possible to measure the public health of whole populations. The analysis of effluent and biosolids can also be used to understand the release of chemicals from wastewater treatment plants into the environment. Wastewater analysis and comparison with catchment specific data (e.g. demographics) however remains largely unexplored. This manuscript describes a national wastewater monitoring study that combines influent, effluent and biosolids sampling with the Australian Census. An archiving program allows estimation of per capita exposure to and consumption of chemicals, public health information, as well as per capita release of chemicals into the environment. The paper discusses the study concept, critical steps in setting up a coordinated national approach and key logistical and other considerations with a focus on lessons learnt and future applications. The unique combination of archived samples, analytical data and associated census-derived population data will provide a baseline dataset that has wide and potentially increasing applications across many disciplines that include public health, epidemiology, criminology, toxicology and sociology.

Population histamine burden assessed using wastewater-based epidemiology: The association of 1,4‑methylimidazole acetic acid and fexofenadine

Systematic sampling and analysis of wastewater has become an important tool for monitoring consumption of drugs and other substances, and has been proposed as a method to evaluate aspects of population health using endogenous biomarkers. 1,4‑methylimidazoleacetic acid (MIAA) is an endogenous biomarker and metabolite of histamine turnover. Its urinary excretion is elevated in conditions such as mastocytosis, hay fever, hives, food allergies and anaphylaxis. The aim of this study was to develop and apply methods for MIAA in wastewater and compare its occurrence with antihistamine use in wastewater. Consecutive daily samples were collected from seven catchments serving populations from 3000 to 2 million and covering rural and urban communities during the 2016 Census in Australia. MIAA and the antihistamines (ranitidine, fexofenadine, cetirizine) were quantified consistently. Per capita excretion of MIAA (mg/d/capita) estimated from the WW concentrations were consistent with findings from previous clinical studies. We found significant positive correlations between loads of MIAA and fexofenadine (R² = 0.68, p < 0.0001) and cetirizine (R² = 0.25, p = 0.03) across the various catchments. Sewer reactor experiments on the degradation of MIAA and the antihistamines found that fexofenadine is stable for at least 24 h while MIAA, ranitidine and cetirizine are subject to degradation, and this should be considered in interpretations. To the best of our knowledge, this study is the first wastewater study to introduce and monitor an endogenous metabolite of histamine, and the first study to monitor and relate proxies of disease and treatment of disease.

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.

Enantiomeric profiling of chiral illicit drugs in a pan-European study

The aim of this paper is to present the first study on spatial and temporal variation in the enantiomeric profile of chiral drugs in eight European cities. Wastewater-based epidemiology (WBE) and enantioselective analysis were combined to evaluate trends in illicit drug use in the context of their consumption vs direct disposal as well as their synthetic production routes. Spatial variations in amphetamine loads were observed with higher use in Northern European cities. Enantioselective analysis showed a general enrichment of amphetamine with the R-(-)-enantiomer in wastewater indicating its abuse. High loads of racemic methamphetamine were detected in Oslo (EF = 0.49 ± 0.02). This is in contrast to other European cities where S-(+)-methamphetamine was the predominant enantiomer. This indicates different methods of methamphetamine synthesis and/or trafficking routes in Oslo, compared with the other cities tested. An enrichment of MDMA with the R-(-)-enantiomer was observed in European wastewaters indicating MDMA consumption rather than disposal of unused drug. MDA's chiral signature indicated its enrichment with the S-(+)-enantiomer, which confirms its origin from MDMA metabolism in humans. HMMA was also detected at quantifiable concentrations in wastewater and was found to be a suitable biomarker for MDMA consumption. Mephedrone was only detected in wastewater from the United Kingdom with population-normalised loads up to 47.7 mg 1000 people^-1 day^-1. The enrichment of mephedrone in the R-(+)-enantiomer in wastewater suggests stereoselective metabolism in humans, hence consumption, rather than direct disposal of the drug. The investigation of drug precursors, such as ephedrine, showed that their presence was reasonably ascribed to their medical use.

Wastewater-based tracing of doping use by the general population and amateur athletes

The present study investigates the applicability of the chemical analysis of wastewater to assess the use of doping substances by the general population and amateur athletes. To this end, an analytical methodology that can identify and quantify a list of 15 substances from the groups of anabolic steroids, weight loss products, and masking agents in wastewater has been developed. The method uses solid phase extraction to increase the detection sensitivity of the target analytes, expected to be present at very low concentrations (ng L⁻¹ range), and decrease possible matrix interferences. Instrumental analysis is performed by liquid chromatography coupled to high-resolution mass spectrometry, allowing data acquisition in both full scan and tandem MS mode. The method has been successfully validated at two concentration levels (50 and 200 ng L⁻¹) with limits of quantification ranging between 0.7 and 60 ng L⁻¹, intra- and inter-day precision expressed as relative standard deviation below 15%, procedural recoveries between 60 and 160% and matrix effects ranging from 45 to 121%. The stability of the analytes in wastewater was evaluated at different storage temperatures illustrating the importance of freezing the samples immediately after collection. The application of the method to 24-h composite wastewater samples collected at the entrance of three wastewater treatment plants and one pumping station while different sport events were taking place revealed the presence in wastewater, and hence the use, of the weight loss substances ephedrine, norephedrine, methylhexanamine, and 2,4-dinitrophenol. The use of these stimulants was visible just prior and during the event days and in greater amounts than anabolic steroids or masking agents.

Graphical abstract

Wastewater Analysis for Community-Wide Drugs Use Assessment

Wastewater-based epidemiology (WBE) complements existing epidemiology-based estimation techniques and provides objective, evidence-based estimates of illicit drug use. After consumption, biomarkers - drugs and their metabolites - excreted to toilets and flushed into urban sewer networks can be measured in raw wastewater samples. The quantified loads can serve as an estimate for the collective consumption of all people contributing to the wastewater sample. This transdisciplinary approach, further explained in this chapter, has developed, matured and is now established for monitoring substances such as cocaine and amphetamine-type stimulants. Research currently underway is refining WBE to new applications including new psychoactive substances (NPS).

Estimation of caffeine intake from analysis of caffeine metabolites in wastewater

Caffeine metabolites in wastewater were investigated as potential biomarkers for assessing caffeine intake in a population. The main human urinary metabolites of caffeine were measured in the urban wastewater of ten European cities and the metabolic profiles in wastewater were compared with the human urinary excretion profile. A good match was found for 1,7-dimethyluric acid, an exclusive caffeine metabolite, suggesting that might be a suitable biomarker in wastewater for assessing population-level caffeine consumption. A correction factor was developed considering the percentage of excretion of this metabolite in humans, according to published pharmacokinetic studies. Daily caffeine intake estimated from wastewater analysis was compared with the average daily intake calculated from the average amount of coffee consumed by country per capita. Good agreement was found in some cities but further information is needed to standardize this approach. Wastewater analysis proved useful to providing additional local information on caffeine use.

Wastewater-based epidemiology to assess pan-European pesticide exposure

Human biomonitoring, i.e. the determination of chemicals and/or their metabolites in human specimens, is the most common and potent tool for assessing human exposure to pesticides, but it suffers from limitations such as high costs and biases in sampling. Wastewater-based epidemiology (WBE) is an innovative approach based on the chemical analysis of specific human metabolic excretion products (biomarkers) in wastewater, and provides objective and real-time information on xenobiotics directly or indirectly ingested by a population. This study applied the WBE approach for the first time to evaluate human exposure to pesticides in eight cities across Europe. 24 h-composite wastewater samples were collected from the main wastewater treatment plants and analyzed for urinary metabolites of three classes of pesticides, namely triazines, organophosphates and pyrethroids, by liquid chromatography-tandem mass spectrometry. The mass loads (mg/day/1000 inhabitants) were highest for organophosphates and lowest for triazines. Different patterns were observed among the cities and for the various classes of pesticides. Population weighted loads of specific biomarkers indicated higher exposure in Castellon, Milan, Copenhagen and Bristol for pyrethroids, and in Castellon, Bristol and Zurich for organophosphates. The lowest mass loads (mg/day/1000 inhabitants) were found in Utrecht and Oslo. These results were in agreement with several national statistics related to pesticides exposure such as pesticides sales. The daily intake of pyrethroids was estimated in each city and it was found to exceed the acceptable daily intake (ADI) only in one city (Castellon, Spain). This was the first large-scale application of WBE to monitor population exposure to pesticides. The results indicated that WBE can give new information about the "average exposure" of the population to pesticides, and is a useful complementary biomonitoring tool to study population-wide exposure to pesticides.

Liquid Chromatography-Tandem Mass Spectrometry Analysis of Biomarkers of Exposure to Phosphorus Flame Retardants in Wastewater to Monitor Community-Wide Exposure

Phosphorus flame retardants and plasticizers (PFRs) are increasingly used in consumer goods, from which they can leach and pose potential threats to human health. Monitoring human exposure to these compounds is thus highly relevant. Current assessment of exposure through analysis of biological matrices is, however, tedious as well as logistically and financially demanding. Analysis of selected biomarkers of exposure to PFRs in wastewater could be a simple and complementary approach to monitoring, over space and time, exposure at the population level. An analytical procedure, based on solid-phase extraction (SPE) and liquid chromatography coupled to tandem mass spectrometry, was developed and validated to monitor the occurrence in wastewater of human exposure biomarkers of 2-ethylhexyldiphenyl phosphate (EHDPHP), tris(2-butoxyethyl) phosphate (TBOEP), triphenyl phosphate (TPHP), tris(2-chloroisopropyl) phosphate (TCIPP), and tris(2-chloroethyl) phosphate (TCEP). Various SPE sorbents and extraction protocols were evaluated, and for the optimized method, absolute extraction recoveries ranged between 46% and 100%. Accuracy and precision were satisfactory for the selected compounds. Method detection limits ranged from 1.6 to 19 ng L^-1. Biomarkers of exposure to PFRs were measured for the first time in influent wastewater. Concentrations in samples collected in Belgium ranged from below the limit of quantitation to 1072 ng L^-1, with 2-ethylhexyl phenyl phosphate (EHPHP) and TCEP being the most abundant. Per capita loads of target biomarkers varied greatly, suggesting potential differences in exposure between the investigated communities. The developed method allowed implementation of the concepts of human biomonitoring at the community scale, opening the possibility to assess population-wide exposure to PFRs.

Novel Wastewater-Based Epidemiology Approach Based on Liquid Chromatography-Tandem Mass Spectrometry for Assessing Population Exposure to Tobacco-Specific Toxicants and Carcinogens

Tobacco smoking remains an important public health issue worldwide. Assessment of exposure to tobacco-related toxicants and carcinogens at the population level is thus an essential population health indicator. This can be achieved by wastewater-based epidemiology (WBE), which relies on the analysis of biomarkers in wastewater. However, required analytical methods for the simultaneous measurement of tobacco-related toxicants and carcinogens in wastewater are not available. In this study, a new analytical procedure was developed and validated to measure tobacco-related alkaloids, carcinogens, and their metabolites in raw wastewater, including anabasine (ANABA), anatabine (ANATA), cotinine (COT), trans-3'-hydroxycotinine (COT-OH), N-nitrosoanabasine (NAB), N-nitrosoanatabine (NAT), N-nitrosonornicotine (NNN), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), NNAL-N-β-glucuronide, and NNAL-O-β-glucuronide. Different parameters were optimized for the solid-phase extraction procedure and instrumental analysis using liquid chromatography-tandem mass spectrometry. The optimized method was fully validated, resulting in acceptable within-run and between-run precision (<8% and <10% relative standard deviation, respectively) and accuracy (<9% and <13% bias, respectively). Method quantification limits were at 0.5-120 ng/L in wastewater. Target analytes were stable in wastewater at 4 and 20 °C over 24 h. The developed method was applied to wastewater samples from two Belgian cities. Average concentrations of COT, COT-OH, ANATA, ANABA, and NAT were 5200, 2600, 30, 10, and 0.6 ng/L, respectively, while NAB, NNN, NNK, and NNAL were not detected in the samples. With the developed robust analytical method, our study provided the first insight into the population exposure to both toxicants and carcinogens resulting from tobacco use.

Monitoring Genetic Population Biomarkers for Wastewater-Based Epidemiology

We report a rapid "sample-to-answer" platform that can be used for the quantitative monitoring of genetic biomarkers within communities through the analysis of wastewater. The assay is based on the loop-mediated isothermal amplification (LAMP) of nucleic acid biomarkers and shows for the first time the ability to rapidly quantify human-specific mitochondrial DNA (mtDNA) from raw untreated wastewater samples. mtDNA provides a model population biomarker associated with carcinogenesis including breast, renal and gastric cancers. To enable a sample-to-answer, field-based technology, we integrated a filter to remove solid impurities and perform DNA extraction and enrichment into a low cost lateral flow-based test. We demonstrated mtDNA detection over seven consecutive days, achieving a limit of detection of 40 copies of human genomic DNA per reaction volume. The assay can be performed at the site of sample collection, with minimal user intervention, yielding results within 45 min and providing a method to monitor public health from wastewater.

Estimating nicotine consumption in eight cities using sewage epidemiology based on ammonia nitrogen equivalent population

Sewage epidemiology is a real-time tool used to monitor tobacco consumption. In this study, we investigated the tobacco consumption in eight cities in Jilin province using sewage epidemiology. We collected influent wastewater samples from ten wastewater treatment plants (WWTPs) that serve nearly four million people. Mean nicotine (NIC) loads ranged from 1.42 to 14.2mg/d/capita, whereas mean cotinine (COT) loads showed lower levels with 0.33 to 2.15mg/d/capita. Population size was estimated to provide an accurate and real-time population based on ammonia nitrogen (NH₄-N) concentration in influent. To verify the NH₄-N equivalent population, we compared these results with the corresponding population estimated based on the expert knowledge of the local WWTPs operators. Daily consumption of NIC was estimated to be approximately 2.39±1.47mg/d/capita. Monte Carlo simulation was used to analyze uncertainty and variability in the number of cigarettes consumed by smokers in the range of 9.8 to 31.4 per day with a median of 16.9. The data of tobacco consumption in this study coordinated strongly with a traditional survey on the consumption of tobacco in China, indicating sewage epidemiology with NH₄-N equivalent population estimation may provide a suitable and useful tool for tobacco use monitoring.

The Potential of Knowing More: A Review of Data-Driven Urban Water Management

The promise of collecting and utilizing large amounts of data has never been greater in the history of urban water management (UWM). This paper reviews several data-driven approaches which play a key role in bringing forward a sea change. It critically investigates whether data-driven UWM offers a promising foundation for addressing current challenges and supporting fundamental changes in UWM. We discuss the examples of better rain-data management, urban pluvial flood-risk management and forecasting, drinking water and sewer network operation and management, integrated design and management, increasing water productivity, wastewater-based epidemiology and on-site water and wastewater treatment. The accumulated evidence from literature points toward a future UWM that offers significant potential benefits thanks to increased collection and utilization of data. The findings show that data-driven UWM allows us to develop and apply novel methods, to optimize the efficiency of the current network-based approach, and to extend functionality of today's systems. However, generic challenges related to data-driven approaches (e.g., data processing, data availability, data quality, data costs) and the specific challenges of data-driven UWM need to be addressed, namely data access and ownership, current engineering practices and the difficulty of assessing the cost benefits of data-driven UWM.

Estimating population size in wastewater-based epidemiology. Valencia metropolitan area as a case study

Wastewater can provide a wealth of epidemiologic data on common drugs consumed and on health and nutritional problems based on the biomarkers excreted into community sewage systems. One of the biggest uncertainties of these studies is the estimation of the number of inhabitants served by the treatment plants. Twelve human urine biomarkers -5-hydroxyindoleacetic acid (5-HIAA), acesulfame, atenolol, caffeine, carbamazepine, codeine, cotinine, creatinine, hydrochlorothiazide (HCTZ), naproxen, salicylic acid (SA) and hydroxycotinine (OHCOT)- were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) to estimate population size. The results reveal that populations calculated from cotinine, 5-HIAA and caffeine are commonly in agreement with those calculated by the hydrochemical parameters. Creatinine is too unstable to be applicable. HCTZ, naproxen, codeine, OHCOT and carbamazepine, under or overestimate the population compared to the hydrochemical population estimates but showed constant results through the weekdays. The consumption of cannabis, cocaine, heroin and bufotenine in Valencia was estimated for a week using different population calculations.

Measuring biomarkers in wastewater as a new source of epidemiological information: Current state and future perspectives

The information obtained from the chemical analysis of specific human excretion products (biomarkers) in urban wastewater can be used to estimate the exposure or consumption of the population under investigation to a defined substance. A proper biomarker can provide relevant information about lifestyle habits, health and wellbeing, but its selection is not an easy task as it should fulfil several specific requirements in order to be successfully employed. This paper aims to summarize the current knowledge related to the most relevant biomarkers used so far. In addition, some potential wastewater biomarkers that could be used for future applications were evaluated. For this purpose, representative chemical classes have been chosen and grouped in four main categories: (i) those that provide estimates of lifestyle factors and substance use, (ii) those used to estimate the exposure to toxicants present in the environment and food, (iii) those that have the potential to provide information about public health and illness and (iv) those used to estimate the population size. To facilitate the evaluation of the eligibility of a compound as a biomarker, information, when available, on stability in urine and wastewater and pharmacokinetic data (i.e. metabolism and urinary excretion profile) has been reviewed. Finally, several needs and recommendations for future research are proposed.

Wastewater-based epidemiology to assess human exposure to pyrethroid pesticides

Pesticides are active substances with potentially adverse effects on human health, and therefore great effort is addressed to study the relation between their widespread use and the effects on humans. To track human exposure to pesticides, novel approaches are needed to give additional information on exposure at population level. In this study, a novel application of Wastewater-Based Epidemiology (WBE) was developed to measure the intake of pyrethroid pesticides in a population. Three human urinary metabolites of pyrethroids were selected and validated as biomarkers of exposure by evaluating their sources and stability in wastewater. They were measured by liquid chromatography-tandem mass spectrometry in raw urban wastewater collected from the wastewater treatment plants of six Italian cities. Their concentrations were used as biomarkers to back-calculate the intake of pyrethroid pesticides in the population. WBE results were in line with the urinary biomarker levels of biomonitoring studies considering dilution in wastewater. Significant differences in the metabolites levels were observed among different cities. Seasonal variations in human intake of pyrethroids were also seen, as expected, with higher intakes during spring/summer. Intakes in the six cities were compared with the acceptable daily intake (ADI) and it was concluded that some of the populations examined might face significant health risks. Results confirm that this method can provide supplementary information to biomonitoring studies and can be a valuable tool for obtaining objective, direct information on the real levels of exposure to pyrethroids of different populations.

Monitoring population exposure to pesticides based on liquid chromatography-tandem mass spectrometry measurement of their urinary metabolites in urban wastewater: A novel biomonitoring approach

Biomonitoring studies have documented the high exposure of the population to pesticides which are widely used for crop protection, industrial and household purposes. This is the first study which has measured human urinary metabolites of pesticides in urban wastewater as biomarkers of population exposure. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to measure fifteen urinary metabolites selected from the major classes of pesticides. Raw wastewater samples were processed by solid phase extraction (SPE) or direct injection into the LC-MS/MS system. Recoveries ranged from 75 to 115% and the limits of quantification were 1-15ng/L for the SPE method and 40-800ng/L for direct injection. The method was employed for the analysis of 44 composite 24-h wastewater samples collected in seven Italian cities. Most of the target substances were detected at concentrations ranging from 1.1ng/L to 1.6μg/L. The highest concentrations were for some common metabolites of alkyl phosphates and pyrethroids and the specific metabolite of chlorpyrifos and chlorpyrifos-methyl (3,5,6-trichloro-2-pyridinol). The frequency of detection and abundance of most of the measured metabolites were in line with the profiles reported in urine biomonitoring studies. This method is therefore proposed as a novel "biomonitoring approach" for obtaining objective, direct information on the levels of exposure of a specific population to pesticides, and current research is addressed to validate the method identifying the most reliable biomarkers.

Measuring selected PPCPs in wastewater to estimate the population in different cities in China

Sampling and analysis of wastewater from municipal wastewater treatment plants (WWTPs) has become a useful tool for understanding exposure to chemicals. Both wastewater based studies and management and planning of the catchment require information on catchment population in the time of monitoring. Recently, a model has been developed and calibrated using selected pharmaceutical and personal care products (PPCPs) measured in influent wastewater for estimating population in different catchments in Australia. The present study aimed at evaluating the feasibility of utilizing this population estimation approach in China. Twenty-four hour composite influent samples were collected from 31 WWTPs in 17 cities with catchment sizes from 200,000-3,450,000 people representing all seven regions of China. The samples were analyzed for 19 PPCPs using liquid chromatography coupled to tandem mass spectrometry in direct injection mode. Eight chemicals were detected in more than 50% of the samples. Significant positive correlations were found between individual PPCP mass loads and population estimates provided by WWTP operators. Using the PPCP mass load modeling approach calibrated with WWTP operator data, we estimated the population size of each catchment with good agreement with WWTP operator values (between 50-200% for all sites and 75-125% for 23 of the 31 sites). Overall, despite much lower detection and relatively high heterogeneity in PPCP consumption across China the model provided a good estimate of the population contributing to a given wastewater sample. Wastewater analysis could also provide objective PPCP consumption status in China.

Comparison of pharmaceutical, illicit drug, alcohol, nicotine and caffeine levels in wastewater with sale, seizure and consumption data for 8 European cities

BACKGROUND

Monitoring the scale of pharmaceuticals, illicit and licit drugs consumption is important to assess the needs of law enforcement and public health, and provides more information about the different trends within different countries. Community drug use patterns are usually described by national surveys, sales and seizure data. Wastewater-based epidemiology (WBE) has been shown to be a reliable approach complementing such surveys.

METHOD

This study aims to compare and correlate the consumption estimates of pharmaceuticals, illicit drugs, alcohol, nicotine and caffeine from wastewater analysis and other sources of information. Wastewater samples were collected in 2015 from 8 different European cities over a one week period, representing a population of approximately 5 million people. Published pharmaceutical sale, illicit drug seizure and alcohol, tobacco and caffeine use data were used for the comparison.

RESULTS

High agreement was found between wastewater and other data sources for pharmaceuticals and cocaine, whereas amphetamines, alcohol and caffeine showed a moderate correlation. methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA) and nicotine did not correlate with other sources of data. Most of the poor correlations were explained as part of the uncertainties related with the use estimates and were improved with other complementary sources of data.

CONCLUSIONS

This work confirms the promising future of WBE as a complementary approach to obtain a more accurate picture of substance use situation within different communities. Our findings suggest further improvements to reduce the uncertainties associated with both sources of information in order to make the data more comparable.

Comparison of pharmaceutical, illicit drug, alcohol, nicotine and caffeine levels in wastewater with sale, seizure and consumption data for 8 European cities

BACKGROUND

Monitoring the scale of pharmaceuticals, illicit and licit drugs consumption is important to assess the needs of law enforcement and public health, and provides more information about the different trends within different countries. Community drug use patterns are usually described by national surveys, sales and seizure data. Wastewater-based epidemiology (WBE) has been shown to be a reliable approach complementing such surveys.

METHOD

This study aims to compare and correlate the consumption estimates of pharmaceuticals, illicit drugs, alcohol, nicotine and caffeine from wastewater analysis and other sources of information. Wastewater samples were collected in 2015 from 8 different European cities over a one week period, representing a population of approximately 5 million people. Published pharmaceutical sale, illicit drug seizure and alcohol, tobacco and caffeine use data were used for the comparison.

RESULTS

High agreement was found between wastewater and other data sources for pharmaceuticals and cocaine, whereas amphetamines, alcohol and caffeine showed a moderate correlation. methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA) and nicotine did not correlate with other sources of data. Most of the poor correlations were explained as part of the uncertainties related with the use estimates and were improved with other complementary sources of data.

CONCLUSIONS

This work confirms the promising future of WBE as a complementary approach to obtain a more accurate picture of substance use situation within different communities. Our findings suggest further improvements to reduce the uncertainties associated with both sources of information in order to make the data more comparable.

A case of contagious toxicity? Isoprostanes as potential emerging contaminants of concern

Isoprostanes are useful biomarkers of human and animal health, being representative of oxidative stress processes, and having biological impacts associated with toxicity and disease. Isoprostanes are also chemically stable, a property facilitating population-level health assessments through wastewater sampling. However, as biologically-active entities, the presence of isoprostanes in domestic effluents could have toxic impacts on biota in receiving environments. As such it is proposed that isoprostanes are emerging organic contaminants of particular concern. Fish and aquatic invertebrates may be affected by the presence of isoprostanes in wastewaters through mechanisms such as reproductive impairment, cardiovascular disturbance and/or oxidative stress. This would represent a unique scenario of "contagious" toxicity, whereby human health has a direct toxicological consequence on aquatic animal health.

Spatial and temporal trends in alcohol consumption in Belgian cities: A wastewater-based approach

BACKGROUND

In recent years, scientific evidence has emerged that wastewater-based epidemiology can deliver complementary information concerning the use of different substances of abuse. In this study, the potential of wastewater-based epidemiology in monitoring spatial and temporal trends in alcohol consumption in different populations in Belgium has been examined.

METHODS

Concentrations of ethyl sulphate, a minor Phase-II metabolite of ethanol, in 163 influent wastewater samples from eight wastewater treatment plants in Belgium in the period 2013-2015 were measured with liquid chromatography coupled to tandem mass spectrometry and used to estimate alcohol consumption.

RESULTS

The highest levels of alcohol consumption were detected in the metropoles Antwerp and Brussels compared to smaller villages. Annual variations were detected, with a higher alcohol consumption measured in 2013 compared with 2014. The weekly pattern showed a clear week and weekend difference in alcohol use, with intermediate levels on Monday and Friday. The results were extrapolated and a use of 5.6L pure alcohol per year per inhabitant aged 15+ has been estimated in Belgium. The comparison with available information on drinking habits of the Belgian population further demonstrated the usefulness of the wastewater-based epidemiology approach.

CONCLUSIONS

This is the largest wastewater-based epidemiology study monitoring alcohol consumption to date, demonstrating that objective and quick information on spatio-temporal trends in alcohol consumption on a local and (inter)national scale can be obtained.

Community Sewage Sensors towards Evaluation of Drug Use Trends: Detection of Cocaine in Wastewater with DNA-Directed Immobilization Aptamer Sensors

Illicit drug use has a global concern and effective monitoring and interventions are highly required to combat drug abuse. Wastewater-based epidemiology (WBE) is an innovative and cost-effective approach to evaluate community-wide drug use trends, compared to traditional population surveys. Here we report for the first time, a novel quantitative community sewage sensor (namely DNA-directed immobilization of aptamer sensors, DDIAS) for rapid and cost-effective estimation of cocaine use trends via WBE. Thiolated single-stranded DNA (ssDNA) probe was hybridized with aptamer ssDNA in solution, followed by co-immobilization with 6-mercapto-hexane onto the gold electrodes to control the surface density to effectively bind with cocaine. DDIAS was optimized to detect cocaine at as low as 10 nM with a dynamic range from 10 nM to 5 μM, which were further employed for the quantification of cocaine in wastewater samples collected from a wastewater treatment plant in seven consecutive days. The concentration pattern of the sampling week is comparable with that from mass spectrometry. Our results demonstrate that the developed DDIAS can be used as community sewage sensors for rapid and cost-effective evaluation of drug use trends, and potentially implemented as a powerful tool for on-site and real-time monitoring of wastewater by un-skilled personnel.

Target and suspect screening of psychoactive substances in sewage-based samples by UHPLC-QTOF

The quantification of illicit drug and pharmaceutical residues in sewage has been shown to be a valuable tool that complements existing approaches in monitoring the patterns and trends of drug use. The present work delineates the development of a novel analytical tool and dynamic workflow for the analysis of a wide range of substances in sewage-based samples. The validated method can simultaneously quantify 51 target psychoactive substances and pharmaceuticals in sewage-based samples using an off-line automated solid phase extraction (SPE-DEX) method, using Oasis HLB disks, followed by ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UHPLC-QTOF) in MS(e). Quantification and matrix effect corrections were overcome with the use of 25 isotopic labeled internal standards (ILIS). Recoveries were generally greater than 60% and the limits of quantification were in the low nanogram-per-liter range (0.4-187 ng L(-1)). The emergence of new psychoactive substances (NPS) on the drug scene poses a specific analytical challenge since their market is highly dynamic with new compounds continuously entering the market. Suspect screening using high-resolution mass spectrometry (HRMS) simultaneously allowed the unequivocal identification of NPS based on a mass accuracy criteria of 5 ppm (of the molecular ion and at least two fragments) and retention time (2.5% tolerance) using the UNIFI screening platform. Applying MS(e) data against a suspect screening database of over 1000 drugs and metabolites, this method becomes a broad and reliable tool to detect and confirm NPS occurrence. This was demonstrated through the HRMS analysis of three different sewage-based sample types; influent wastewater, passive sampler extracts and pooled urine samples resulting in the concurrent quantification of known psychoactive substances and the identification of NPS and pharmaceuticals.

Alcohol and cocaine co-consumption in two European cities assessed by wastewater analysis

The quantitative determination of urinary biomarkers in raw wastewater has emerged in recent years as a promising tool for estimating the consumption of illicit drugs, tobacco and alcohol in a population and for comparing local and temporal trends. In this study, a three-year monitoring campaign (2012-2014) was conducted to compare alcohol and cocaine use in two European cities (Santiago de Compostela, Spain, and Milan, Italy) by wastewater analysis. Ethyl sulphate and benzoylecgonine were used, respectively, as biomarkers of ethanol and cocaine consumption and cocaethylene as an indicator of co-consumption of both substances. Biomarkers were measured using liquid chromatography-tandem mass spectrometry and concentrations were converted to rates of consumption using specific correction factors. Results were statistically compared in terms of geographic and temporal tendencies. Alcohol intake was significantly higher in Santiago than in Milan (13.6L versus 5.1L ethanol/1000 people day, averages). Cocaine use was higher in Milan than in Santiago de Compostela (800 versus 632 mg/1000 people day, averages). A significant higher consumption of both alcohol and cocaine was observed during the weekends (~23-75% more than on weekdays) in both cities. In terms of years, slight changes were observed, but no clear trends as representative of the whole year could be identified because of the limited number of days sampled. Co-consumption was evaluated using the cocaethylene/benzoylecgonine ratio, which was higher during the weekend in both cities (58% in Santiago and 47% in Milan over the non-weekend day means), indicating a greater co-consumption when cocaine is used as a recreational drug. Wastewater-based epidemiology gave estimates of alcohol and cocaine use in agreement with previous wastewater studies and with recent European surveillance and prevalence data, and weekly profiles of use and preferential patterns of consumption could be plot.

Analysis of Nucleosides in Municipal Wastewater by Large-Volume Liquid Chromatography Tandem Mass Spectrometry

Nucleosides are components of both DNA and RNA, and contain either a ribose (RNA) or 2deoxyribose (DNA) sugar and a purine or pyrimidine base. In addition to DNA and RNA turnover, modified nucleosides found in urine have been correlated to a diminished health status associated with AIDS, cancers, oxidative stress and age. Nucleosides found in municipal wastewater influent are potentially useful markers of community health status, and as of now, remain uninvestigated. A method was developed to quantify nucleosides in municipal wastewater using large-volume injection, liquid chromatography, and mass spectrometry. Method accuracy ranged from 92 to 139% when quantified by using isotopically labeled internal standards. Precision ranged from 6.1 to 19% of the relative standard deviation. The method's utility was demonstrated by the analysis of twenty-four hour composite wastewater influent samples that were collected over a week to investigate community nucleoside excretion. Nucleosides originating from RNA were more abundant that DNA over the study period, with total loads of nucleosides ranging from 2 to 25 kg/day. Given this relatively high amount of nucleosides found over the study period they present an attractive analyte for the investigation of community health.

A novel DNA biosensor using a ferrocenyl intercalator applied to the potential detection of human population biomarkers in wastewater

A new label-free electrochemical DNA (E-DNA) biosensor using a custom synthesized ferrocenyl (Fc) double-stranded DNA intercalator as a redox marker is presented. Single-stranded DNA (ssDNA) was co-immobilized on gold electrodes with 6-mecarpto-hexanol to control the surface density of the ssDNA probe, and hybridized with complementary DNA. The binding of the Fc intercalator to dsDNA was measured by differential pulse voltammetry. This new biosensor was optimized to allow the detection of single base pair mismatched sequences, able to detect as low as 10 pM target ssDNA with a dynamic range from 10 pM to 100 nM. DNA extracted from wastewater was analyzed by quantitative polymerase chain reaction targeting human-specific mitochondrial DNA (mtDNA). The aim of this approach is to enable the analysis of population biomarkers in wastewater for the evaluation of public health using wastewater-based epidemiology (WBE). The E-DNA biosensor was employed to detect human-specific mtDNA from wastewater before and after PCR amplification. The results demonstrate the feasibility of detecting human DNA biomarkers in wastewater using the developed biosensor, which may allow the further development of DNA population biomarkers for public health using WBE.

Wastewater analysis to monitor use of caffeine and nicotine and evaluation of their metabolites as biomarkers for population size assessment

The use of caffeine, nicotine and some major metabolites was investigated by wastewater analysis in 13 sewage treatment plants (STPs) across Italy, and their suitability was tested as qualitative and quantitative biomarkers for assessing population size and dynamics. A specific analytical method based on mass spectrometry was developed and validated in raw urban wastewater, and included two caffeine metabolites, 1-methylxanthine and 7-methylxanthine, never reported in wastewater before. All these compounds were found widely at the μg/L level. Mass loads, calculated by multiplying concentrations by the wastewater daily flow rate and normalized to the population served by each plant, were used to compare the profiles from different cities. Some regional differences were observed in the mass loads, especially for nicotine metabolites, which were significantly higher in the south than in the center and north of Italy, reflecting smoking prevalences from population surveys. There were no significant weekly trends, although the mean mass loads of caffeine and its metabolites were slightly lower during the weekend. Most caffeine and nicotine metabolites fulfilled the requirements for an ideal biomarker for the assessment of population size, i.e. being easily detectable in wastewater, stable in sewage and during sampling, and reflecting human metabolism. Nicotine metabolites were tested as quantitative biomarkers to estimate population size and the results agreed well with census data. Caffeine and its metabolites were confirmed as good qualitative biomarkers, but additional information is needed on the caffeine metabolism in relation to the multiple sources of its main metabolites. This exploratory study opens the way to the routine use of nicotine metabolites for estimating population size and dynamics.