Wastewater-based epidemiology to assess human exposure to personal care and household products - A review of biomarkers, analytical methods, and applications

Wastewater-based epidemiology to assess pharmaceutical consumption. Spanish perspective

Wastewater-based epidemiology (WBE) is a well-established approach that can provide objective and real-time data on the consumption of substances such as pharmaceuticals. However, most of the studies reported so far compares consumption data obtained using WBE with those derived from prescription data from public health systems, which is often incomplete and might represent a source of uncertainty. This study aims to compare the measured pharmaceutical consumption back calculated with the WBE approach with consumption derived from dispensed pharmaceuticals in two regions of Spain, managed by two different Health Systems. To do so, a group of 17 pharmaceuticals, including the most representative ones of every therapeutic family, were monitored in influent wastewater (IWW) samples collected over a week campaign in spring 2022 at four different wastewater treatment plants (WWTPs) in Spain: two WWTPs in Madrid city (center of Spain) and two WWTPs in Catalonia (Northeast of Spain). Population-normalized daily loads (PNDL) revealed that the patterns of pharmaceutical occurrence in the different WWTPs are very similar, being acetaminophen, 4-acetamidoantipyrine and valsartan the pharmaceuticals with the highest PNDL values: 17162 ± 1457 mg day-1 1000 inh-1 for acetaminophen, 2365 ± 696 and 2429 ± 263 mg day-1 1000 inh-1 for 4-acetamidoantipyrine, 2006 ± 541 and 2041 ± 352 mg day-1 1000 inh-1 for valsartan. Pharmaceutical PNLDs were then transformed into measured pharmaceutical consumption (MC) and compared with dispensed consumption (DC) data obtained from the pharmacies in the catchment area where the WWTPs are located. A ratio MC/DC within 0.8 to 1.2 was obtained for 11 out of the 17 studied pharmaceuticals. Highlighting a match in all the cardiovascular system pharmaceuticals, with the exception of losartan (1.29-1.39 ratio) and valsartan (1.35-1.43) in all WWTPs. In summary, the degree of correlation between MC/DC is higher than those previously reported comparing with the prescribed pharmaceutical consumption.

Wastewater-based epidemiology methodology to investigate human exposure to bisphenol A, bisphenol F and bisphenol S

Wastewater-based epidemiology (WBE) has become an invaluable tool for tracking the evolution of use or exposure of/to numerous substances. Bisphenols, commonly utilized in manufacturing plastic goods, have been categorized as endocrine disrupting chemicals, underscoring the critical need for real-time data on their local-level exposure to safeguard public health. In this study, we have developed a novel analytical method and WBE framework for the assessment of population-level exposure to bisphenol A (BPA) and its most prominent substitutes, bisphenols F and S (BPF and BPS), through the determination their Phase II metabolites in wastewater by WBE. Stability and exclusivity tests denoted that glucuronides are not stable in sewage, whereas sulfate metabolites are good biomarkers. Therefore, a solid-phase extraction followed by liquid chromatography-tandem mass spectrometry method was developed for the bisphenols' monosulfates and BPA bissulfate. The analytical method was validated with three different wastewater matrices, providing trueness (as recovery) in the 79-112 % range with relative standard deviations < 12 %, and method quantification limits below 2 ng L-1 for monosulfates, but higher (35 ng L-1) for BPA bissulfate. Subsequently, the method was applied to 24h-composite raw wastewater samples collected over a week in 4 different locations in Spain and Portugal. BPA bissulfate was not detected, but the three monosulfate metabolites of each bisphenol were positively detected in the samples, being the metabolite of BPA the most prevalent, followed by those of BPF and BPS. Community-wide BPA intake was then estimated to be higher than the European Food Safety Agency (EFSA) tolerable daily intake (TDI) of 2 × 10-4 µg kg-1day-1 in all locations. In the case of BPF and BPS, there is not enough metabolism data or even established limit, but they would also surpass safe levels in several locations if a similar metabolism and TDI would be assumed. This innovative method could be used to a larger set of wastewater-treatment plants as an early-warning approach on human exposure to bisphenols.

Exposure to environmental pollutants: A mini-review on the application of wastewater-based epidemiology approach

Wastewater-based epidemiology (WBE) is considered an innovative and promising tool for estimating community exposure to a wide range of chemical and biological compounds by analyzing wastewater. Despite scholars' interest in WBE studies, there are uncertainties and limitations associated with this approach. This current review focuses on the feasibility of the WBE approach in assessing environmental pollutants, including pesticides, heavy metals, phthalates, bisphenols, and personal care products (PCPs). Limitations and challenges of WBE studies are initially discussed, and then future perspectives, gaps, and recommendations are presented in this review. One of the key limitations of this approach is the selection and identification of appropriate biomarkers in studies. Selecting biomarkers considering the basic requirements of a human exposure biomarker is the most important criterion for validating this new approach. Assessing the stability of biomarkers in wastewater is crucial for reliable comparisons of substance consumption in the population. However, directly analyzing wastewater does not provide a clear picture of biomarker stability. This uncertainty affects the reliability of temporal and spatial comparisons. Various uncertainties also arise from different steps involved in WBE. These uncertainties include sewage sampling, exogenous sources, analytical measurements, back-calculation, and estimation of the population under investigation. Further research is necessary to ensure that measured pollutant levels accurately reflect human excretion. Utilizing data from WBE can support healthcare policy in assessing exposure to environmental pollutants in the general population. Moreover, WBE seems to be a valuable tool for biomarkers that indicate healthy conditions, lifestyle, disease identification, and exposure to pollutants. Although this approach has the potential to serve as a biomonitoring tool in large communities, it is necessary to monitor more metabolites from wastewater to enhance future studies.

Feasibility of sulfated BPA and BPS as wastewater-based epidemiology biomarkers: Insights from wastewater and reported human urine analysis

In wastewater-based epidemiology (WBE), the selection of appropriate biomarkers presents a significant challenge. Recently, sulfated bisphenols have garnered attention as potential WBE biomarkers due to their increased stability in wastewater compared to glucuronide conjugates. This study aims to comprehensively assess the feasibility of employing sulfated BPA and BPS as WBE biomarkers by analyzing both WBE and human biomonitoring data. To conduct this research, wastewater samples were collected from six domestic wastewater treatment plants in Guangzhou, China, and urinary concentration of BPA and BPS were obtained from peer-reviewed literature. The results revealed that mean urinary concentrations of BPA and BPS, calculated using Monte Carlo simulations, significantly exceeded those reported in human biomonitoring studies. Furthermore, the per capita mass load ratio of sulfated BPA and BPS in human urine to the mass load in wastewater was found to be below 10 %. This outcome suggests that the excretion of BPA-S and BPS-S in urine does not make a substantial contribution to wastewater, hinting at the existence of other notable sources. Consequently, our study concludes that sulfated BPA-S and BPS-S are not suitable candidates as WBE biomarkers. This work provides a referenceable analytical framework for evaluating the feasibility of WBE biomarkers and emphasizes the necessity for caution when utilizing WBE to assess human exposure to chemicals.

New analytical method for the determination of endocrine disruptors in human faeces using gas chromatography coupled to tandem mass spectrometry

Endocrine-disrupting chemicals are environmental pollutants that can enter our bodies and cause diverse pathologies. Some bisphenols and parabens have been shown to be capable of modifying proper functioning of the endocrine system. Among other dysfunctions, endocrine-disrupting chemicals can cause changes in intestinal microbiota. Faeces are a convenient matrix that can be useful for identifying the quantity of endocrine disruptors that reach the intestine and the extent to which the organism is exposed to these pollutants. The present work developed a new analytical method to determine 17 compounds belonging to the paraben and bisphenol families found in human faeces. The extraction method was optimized using an ultrasound-assisted extraction technique followed by a clean-up step based on the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) technique. Optimization was performed using the design of experiments technique. In validation analysis, the method was proven to be linear over a wide range. R-squared outcomes were between 95 and 99%. Selectiveness and sensitivity outcomes were acceptable, with detection limits being between 1 and 10 ng g-1 in all cases, whilst quantification limits were between 3 and 25 ng g-1 in all instances, with the exception of bisphenol AF. The method was deemed accurate, with recovery values being close to 100% and relative standard deviations being lower than 15% in all cases. Applicability was examined by analysing 13 samples collected from volunteers (male and female). All samples were contaminated with at least one of the analytes studied. The most commonly found compounds were methylparaben and bisphenol A, which were detected in almost all samples and quantitatively determined in 11 and 12 samples, respectively. Of the 17 compounds analysed, 11 were found in at least one sample. Outcomes demonstrate that faeces can be a good matrix for the determination of exposure to contaminants of interest here.

Wastewater-based epidemiology for tracking bacterial diversity and antibiotic resistance in COVID-19 isolation hospitals in Qatar

BACKGROUND

Hospitals are hotspots for antimicrobial resistance genes (ARGs), and play a significant role in their emergence and spread. Large numbers of ARGs will be ejected from hospitals via wastewater systems. Wastewater-based epidemiology has been consolidated as a tool to provide real-time information, and represents a promising approach to understanding the prevalence of bacteria and ARGs at community level.

AIMS

To determine bacterial diversity and identify ARG profiles in hospital wastewater pathogens obtained from coronavirus disease 2019 (COVID-19) isolation hospitals compared with non-COVID-19 facilities during the pandemic.

METHODS

Wastewater samples were obtained from four hospitals: three assigned to patients with COVID-19 patients and one assigned to non-COVID-19 patients. A microbial DNA quantitative polymerase chain reaction was used to determine bacterial diversity and ARGs.

FINDINGS

The assay recorded 27 different bacterial species in the samples, belonging to the following phyla: Firmicutes (44.4%), Proteobacteria (33.3%), Actinobacteria (11%), Bacteroidetes (7.4%) and Verrucomicrobiota (3.7%). In addition, 61 ARGs were detected in total. The highest number of ARGs was observed for the Hazem Mebaireek General Hospital (HMGH) COVID-19 patient site (88.5%), and the lowest number of ARGs was found for the HMGH non-patient site (24.1%).

CONCLUSION

The emergence of contaminants in sewage water, such as ARGs and high pathogen levels, poses a potential risk to public health and the aquatic ecosystem.

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

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

Improving Wastewater-Based Tobacco Use Estimates Using Anabasine

In wastewater-based epidemiology (WBE), nicotine metabolites have been used as biomarkers for monitoring tobacco use. Recently, the minor tobacco alkaloids anabasine and anatabine have been suggested as more specific biomarkers for tobacco use since nicotine use can be from both tobacco and non-tobacco sources. This study aimed to provide an in-depth evaluation of the suitability of anabasine and anatabine as WBE biomarkers of tobacco and subsequently estimate their excretion factors for WBE applications. Pooled urine (n = 64) and wastewater samples (n = 277), collected between 2009 and 2019 in Queensland, Australia, were analyzed for nicotine and its metabolites (cotinine and hydroxycotinine), as well as anabasine and anatabine. Anabasine performed as the better biomarker, showing a similar per capita load in pooled urine (2.2 ± 0.3 μg/day/person) and wastewater samples (2.3 ± 0.3 μg/day/person), while the per capita load of anatabine in wastewater was 50% higher than its load in urine. It is estimated that 0.9 μg of anabasine was excreted per cigarette smoked. Triangulation of tobacco sales data and tobacco use estimated from either anabasine or cotinine showed that anabasine-based estimates were 5% higher than sales data, while cotinine-based estimates were between 2 and 28% higher. Our results provided concrete evidence to confirm the suitability of anabasine as a specific biomarker for monitoring tobacco use by WBE.

Utilizing a National Wastewater Monitoring Program to Address the U.S. Opioid Epidemic: A Focus on Metro Atlanta, Georgia

The opioid epidemic has continued to be an ongoing public health crisis within Metro Atlanta for the last three decades. However, estimating opioid use and exposure in a large population is almost impossible, and alternative methods are being explored, including wastewater-based epidemiology. Wastewater contains various contaminants that can be monitored to track pathogens, infectious diseases, viruses, opioids, and more. This commentary is focusing on two issues: use of opioid residue data in wastewater as an alternative method for opioid exposure assessment in the community, and the adoption of a streamlined approach that can be utilized by public health officials. Opioid metabolites travel through the sanitary sewer through urine, fecal matter, and improper disposal of opioids to local wastewater treatment plants. Public health officials and researchers within various entities have utilized numerous approaches to reduce the impacts associated with opioid use. National wastewater monitoring programs and wastewater-based epidemiology are approaches that have been utilized globally by researchers and public health officials to combat the opioid epidemic. Currently, public health officials and policy makers within Metro Atlanta are exploring different solutions to reduce opioid use and opioid-related deaths throughout the community. In this commentary, we are proposing a new innovative approach for monitoring opioid use and analyzing trends by utilizing wastewater-based epidemiologic methods, which may help public health officials worldwide manage the opioid epidemic in a large metro area in the future.

Long-term stability of several endocrine disruptors in the first morning urine samples and their associations with lifestyle characteristics

Parabens, triclosan (TCS), bisphenols, benzophenones, and phthalates are typical endocrine disruptors (EDs) with short half-lives in the human body. The concentration levels of those EDs in a spot urine sample are frequently used in exposure assessment studies, and the reproducibility of urinary levels of these nonpersistent EDs should be considered. In the present study, we consecutively collected 45-day first morning void (FMV) urine samples, as well as daily questionnaires, in six recruited participants and measured the urinary concentrations of six parabens, TCS, nine bisphenols, five benzophenones, and ten phthalate metabolites by using high-performance liquid chromatography-tandem mass spectrometry. MeP, EtP, PrP, TCS, BPA, BPS, BPF, and most phthalate metabolites were frequently detected (over 62 % of samples). The intraclass correlation coefficients (ICCs) for ED concentrations in FMV urine samples ranged from fair to excellent for MeP (0.683), EtP (0.702), BPA (0.505), BPS (0.908), BPF (0.887), BP-3 (0.712), mMP (0.661), mEP (0.523), mBP (0.500), miBP (0.724), mBzP (0.961) and all metabolites of DEHP (0.867-0.957), whereas they were low for PrP (0.321) and TCS (0.306). After creatinine adjustment, the values of ICCs for most target EDs were increased with mild to significant improvement. The stability of ED concentrations was affected by daily diet (MeP, TCS, BPA, mMP, miBP, mBP and mBzP), food containers (PrP and mECPP), use of personal care products (HMWP metabolites), pharmaceuticals (EtP) and recorded activities (BPS, mEHP, mBzP, mEHHP and mEOHP), as confirmed by a general linear mixed model. Furthermore, extending the FMV sampling period improved the probability of acceptable reproducibility (ICCs > 0.40) of MeP, EtP, BP-3 and mEP concentrations. For BPS, BPF and HMWP metabolite concentrations showed high probabilities (>80 %) of acceptable reproducibility in the last three days, and the increasing sample size slowly improved the ability to discriminate the subjects. The results were exactly the opposite for BPA concentrations.

Applicability of an on-line solid-phase extraction liquid chromatography - tandem mass spectrometry for the wastewater-based assessment of human exposure to chemicals from personal care and household products

Wastewater-based epidemiology (WBE) can be a useful complementary approach to assess human exposure to potentially harmful chemicals, including those from personal care and household products. In this work, a fully automated multiresidue method, based on on-line solid-phase extraction liquid chromatography - tandem mass spectrometry, was developed for the determination of 27 biomarkers of human exposure to selected chemicals from personal care and household products, including parabens, UV filters, phthalates and alternative plasticizers, phosphorous flame retardants/plasticizers (PFRs), and bisphenols. These biomarkers include both the parent compounds and their human metabolites. In addition, two oxidative stress biomarkers, 8-epi-prostaglandin F2α and 4-hydroxy nonenal mercapturic acid, were also considered in the study. The method was carefully optimized to tackle the challenges of analyzing compounds with different physico-chemical properties in a highly complex raw wastewater matrix, while model experiments were performed to investigate filtration losses and analyte stability. The applicability of the developed method was tested by analyzing raw wastewater from four European cities: Antwerp, Brussels (Belgium), Girona (Spain), and Zagreb (Croatia). Twenty-one biomarkers (10 parent compounds and 11 metabolites) were detected in all analyzed wastewater samples. The parent compounds with the highest mass loads were PFRs, parabens, and bisphenol S, while phthalate monoesters were the most prominent metabolites. The mass loads of most compounds were quite similar across cities, but geographic differences were observed for some biomarkers, such as metabolites of phthalates and alternative plasticizers. Exposure was then assessed for seven substances for which quantitative urinary excretion data are known. Our results indicate that safe reference values were exceeded for several contaminants, including butylated phthalates, bisphenol A, and tris(2-butoxyethyl) phosphate, particularly for toddlers. With this relatively simple method, which requires less sample manipulation, it is possible to promptly identify and monitor exposure to harmful chemicals at the population level using the WBE approach.

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.

Opportunities and limits of wastewater-based epidemiology for tracking global health and attainment of UN sustainable development goals

Wastewater-based epidemiology (WBE) emerged as a powerful, actionable health management tool during the COVID-19 pandemic. Hypothesizing future uses, we explored its potential for real-time, tracking of progress in attaining United Nations Sustainable Development Goals (SDGs) globally as a non-expensive method using existing infrastructure. We inventoried (i) literature-documented sewerage infrastructure, (ii) demographics of populations served, and (iii) WBE markers informative of 9 SDGs. Among the 17 different sustainable development goals listed by the UN 2030 agenda, more than half of these may be monitored by using WBE monitoring at centralized treatment infrastructure as tabulated in this study. Driven mainly by COVID-19, WBE currently is practiced in at least 55 countries, reaching about 300 million people. Expansion of WBE to 109,000 + treatment plants inventoried in 129 countries would increase global coverage 9-fold to 34.7% or 2.7 billion, leaving out 5 billion people not served by centralized sewerage systems. Associations between population demographics and present-day infrastructure are explored, and geospatial regions particularly vulnerable to infectious disease outbreaks are identified. The results suggest that difference in the differential outcomes in well-being is an outcome of the sanitation infrastructure inequalities and lack of sanitation infrastructure creates doubly disadvantaged populations at risk of poor hygiene and cut off from the early-warning benefits of conventional WBE. This is the first study to explore the feasibility and potential barriers to the use of WBE for tracking the attainment of SDGs globally with at least 9 out of 17 SDGs.

Changes in Sewage Sludge Chemical Signatures During a COVID-19 Community Lockdown, Part 2: Nontargeted Analysis of Sludge and Evaluation with COVID-19 Metrics

Sewage sludge and wastewater include urine and feces from an entire community, and it is highly likely that this mixture contains chemicals whose presence is dependent on levels of SARS-CoV-2 in the community. We analyzed primary sewage sludge samples collected in New Haven, Connecticut, USA, during the initial wave of the COVID-19 pandemic using liquid chromatography coupled with high-resolution mass spectrometry and performed an exploratory investigation of correlations between chemical features and COVID-19 metrics including concentrations of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) RNA in the sludge and local COVID-19 case numbers and hospital admissions. Inclusion of all chemical features in this analysis is key for discovering potential indicator compounds for COVID-19, whose structures may not be known. We found correlations with COVID-19 metrics for several identified chemicals as well as many unidentified features in the data, including three potential indicator molecules that are recommended for prioritization in future studies on COVID-19 in wastewater and sludge. These features have molecular weights of 108.0935, 318.1214, and 331.1374. While it is not possible to achieve prediction of COVID-19 epidemiological metrics from the one data set used in the present study, advances in this research area are important to share as scientists worldwide work on discovering efficient methods for tracking SARS-CoV-2 in wastewater and the environment. Environ Toxicol Chem 2022;41:1193-1201. © 2021 SETAC.

Fluorenone-Based Fluorescent and Colorimetric Sensors for Selective Detection of I- Ions: Applications in HeLa Cell Imaging and Logic Gate

Fluorenone-based fluorescent and colorimetric sensors 1 and 2 have been developed that displayed selective detection of iodide ions in the presence of interferences. Sensors displayed the fluorescence emission enhancement response toward I- with detection limits of 8.0 and 11.0 nM, respectively, which is accomplished through inhibition of intramolecular charge transfer and C=N isomerization. Excellent sensitivity and unique fluorescence enhancement response of sensors toward I- make them superior because most of the previously reported iodide sensors are based on the fluorescence quenching mechanism and are less sensitive. The sensing potential of sensors toward I- ions was investigated through 1H NMR titration, dynamic light scattering, Job's plots, and density functional theory analysis. Further, sensors displayed reversible behavior by the alternate addition of I- and Cu2+ ions that substantiate their role as recyclable sensors for the on-site detection of I- ions. Advantageously, fluorescence enhancement response of sensors was favorably used for fluorescence imaging of I- in live HeLa cells and the design of the logic gate. These sensors were successfully applied in diversified applications such as the preparation of sensors' coated paper strips and the determination of I- ions in blood serum, food, and real water samples.

Change in the chemical content of untreated wastewater of Athens, Greece under COVID-19 pandemic

COVID-19 pandemic spread rapidly worldwide with unanticipated effects on mental health, lifestyle, stability of economies and societies. Although many research groups have already reported SARS-CoV-2 surveillance in untreated wastewater, only few studies evaluated the implications of the pandemic on the use of chemicals by influent wastewater analysis. Wide-scope target and suspect screening were used to monitor the effects of the pandemic on the Greek population through wastewater-based epidemiology. Composite 24 h influent wastewater samples were collected from the wastewater treatment plant of Athens during the first lockdown and analyzed by liquid chromatography mass spectrometry. A wide range of compounds was investigated (11,286), including antipsychotic drugs, illicit drugs, tobacco compounds, food additives, pesticides, biocides, surfactants and industrial chemicals. Mass loads of chemical markers were estimated and compared with the data obtained under non-COVID-19 conditions (campaign 2019). The findings revealed increases in surfactants (+196%), biocides (+152%), cationic quaternary ammonium surfactants (used as surfactants and biocides) (+331%), whereas the most important decreases were estimated for tobacco (-33%) and industrial chemicals (-52%). The introduction of social-restriction measures by the government affected all aspects of life.

Identification of biomarkers in wastewater-based epidemiology: Main approaches and analytical methods

Wastewater-based epidemiology (WBE) has become popular to estimate the use of drugs of abuse and recently to establish the incidence of CoVID 19 in large cities. However, its possibilities have been expanded recently as a technique that allows to establish a fingerprint of the characteristics of a city, such as state of health/disease, healthy/unhealthy living habits, exposure to different types of contaminants, etc. with respect to other cities. This has been thanks to the identification of human biomarkers as well as to the fingerprinting and profiling of the characteristics of the wastewater catchment that determine these circumstances. The purpose of this review is to analyze the different methodological schemes that have been developed to perform this biomarker identification as well as the most characteristic analytical techniques in each scheme, their advantages and disadvantages and the knowledge gaps identified. We also discussed the future scope for development.

Mass Spectrometry in Wastewater-Based Epidemiology for the Determination of Small and Large Molecules as Biomarkers of Exposure: Toward a Global View of Environment and Human Health under the COVID-19 Outbreak

Wastewater-based epidemiology (WBE) estimates collective consumption or exposure to chemicals or pathogens by monitoring the substances excreted in the population's wastewater. Advances in mass spectrometry (MS) and the application of some clinical diagnostic tools and proteomics to wastewater fingerprinting have been linked to the discovery of new biomarkers and indicators of population health and are broadening the scope of WBE that nowadays cover not only small molecule biomarkers but also genetic biomarkers, large molecules, viruses, infection diseases, resistance, etc. This mini-review highlights recent WBE advances using MS and how this progress can create a fingerprint of a city's health hazards, habits, and lifestyle, which is gaining in public health emphasis.

Source identification of amphetamine-like stimulants in Spanish wastewater through enantiomeric profiling

Amphetamine (AMP), methamphetamine (MAMP) and 3,4-methylenedioxymethamphetamine (MDMA) occur in wastewater not only as a result of illicit consumption, but also, in some cases, from prescription drug use or by direct drug disposal into the sewage system. Enantiomeric profiling of these chiral drugs could give more insight into the origin of their occurrence. In this manuscript, a new analytical methodology for the enantiomeric analysis of amphetamine-like substances in wastewater has been developed. The method consists of a solid-phase extraction (SPE) followed by liquid chromatography-triple quadrupole-tandem mass spectrometry (LC-MS/MS), which showed low quantification limits in the 2.4-5.5 ng L^-1 range. The LC-MS/MS method was first applied to characterize a total of 38 solid street drug samples anonymously provided by consumers. The results of these analysis showed that AMP and MDMA trafficked into Spain are synthesized as racemate, while MAMP is exclusively produced as the S(+)-enantiomer. Then, the analytical method was employed to analyse urban wastewater samples collected from the wastewater treatment plants (WWTPs) of five different cities in 2018 and 2019. Consumption estimated through normalized population loads in wastewater showed an increased pattern of AMP use in the Basque Country. Furthermore, the enantiomeric profiling of wastewater samples was contrasted to lisdexamfetamine (LIS) and selegiline (SEL) prescription figures, two pharmaceuticals which metabolize to S(+)-AMP, and to R(-)-AMP and R(-)-MAMP, respectively. From this analysis, and considering uncertainties derived from metabolism and adherence to treatment, it was concluded that LIS is a relevant source of AMP in those cases with low wastewater loads, i.e. up to a maximum of 60% of AMP detected in wastewater in some samples could originate from LIS prescription, while SEL does not represent a significant source of AMP nor MAMP. Finally, removal efficiencies could be evaluated for the WWTP (serving ca. 860,000 inhabitants) with higher AMP influent concentrations. The removal of AMP was satisfactory with rates higher than 99%, whereas MDMA showed an average removal of approximately 60%, accompanied by an enrichment of R(-)-MDMA.

Two-dimensional liquid chromatography - mass spectrometry as an effective tool for assessing a wide range of pharmaceuticals and biomarkers in wastewater-based epidemiology studies

The biomarkers used in wastewater-based epidemiology studies have a wide range of physicochemical properties, making simultaneous analysis extremely challenging or even impossible. So far, the majority of analytical procedures employed in this field have focused on specific classes or a limited number of analytes. The heart-cutting two-dimensional liquid chromatography tandem mass spectrometry technique (2D-LC-MS/MS) has enabled the incorporation of compounds with significantly different polarities in a single analytical method. In this study, a 2D-LC-MS/MS method has been developed and optimized for the simultaneous analysis of various biomarkers in wastewater, providing relevant information about lifestyle habits (the usage of alcohol, tobacco, and caffeine), health and well-being (pharmaceuticals), and a population size biomarker (5-HIAA) that is useful for correct calculation of human population during wastewater-based epidemiology studies. A single-laboratory validation procedure showed satisfactory analytical performance, with the mean trueness for most compounds falling in the range of 80÷110 % and the mean repeatability being less than 20 %. The applicability of the method was evaluated by testing 28 wastewater samples collected at different wastewater treatment plants in Latvia. The obtained results revealed the occurrence of 44 out of 62 selected biomarkers, with the lowest quantified concentration at 1.1 ng L^-1 in the case of xylometazoline and up to 148 μg L^-1 in the case of metformin and 156 μg L^-1 for caffeine.

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.