Optimization of the ultrasound-assisted extraction method for determining high production volume chemicals in fish liver and skin samples.

The aquatic ecosystem is one of the most delicate environments, housing a diverse range of organisms, including fish, all of which are exposed to a wide variety of pollutants. The accumulation of these harmful substances in fish, which are part of the human diet, presents a significant health risk to humans. In our study, we have optimized an extraction technique to determine the presence of 25 high production volume chemicals in liver and skin samples taken from commonly consumed fish species. We have employed ultrasound-assisted extraction in conjunction with gas chromatography tandem mass spectrometry to achieve this goal. Apparent recoveries of the method ranged from 50% to 111% for both sample types with some exceptions such as most of the benzosulfonamides and benzothiazole. Additionally, the method's detection and quantification limits varied from 0.1 to 1.7 ng g-1 (dry weight, d.w) and 0.2-4.5 ng g-1 (d.w), respectively. Our investigation focused on three frequently consumed fish species in Tarragona: sea bass, sea bream, and turbot. Almost all of the samples we analysed contained traces of contaminants, with phthalates being the most commonly detected. The highest concentrations were observed for diethyl phthalate, with levels peaking at 8350 ng g-1 (d.w.). Organophosphate esters, such as triethyl phosphate and tributyl phosphate, also showed notable presence, with peak concentrations of 93.6 and 34.0 ng g-1 (d.w.), respectively.

Seafood consumption as a source of exposure to high production volume chemicals: A comparison between Catalonia and the Canary Islands.

Seafood plays an important role in diet because of its health benefits. However, the fact that chemical compounds such as high production volume chemicals may be present in seafood means that its consumption can be a potential risk for population. To assess the occurrence of HPVs and estimate the exposure and risk associated with their consumption, specimens of the most consumed seafood species in Catalonia and the Canary Islands, Spain, were collected and analysed. Results showed higher levels of HPVs in samples from Catalonia and a prevalence of phthalate esters and benzenesulfonamides over the other target compounds in samples from both locations. Multivariate analysis showed spatial differences between the mean concentration profiles of HPVs for the samples from Catalonia and the Canary Islands. Exposures were higher for the samples from Catalonia, although the intake of HPVs via seafood was not of any real concern in either of the locations.

Determination of benzothiazoles, benzotriazoles and benzenesulfonamides in seafood using quick, easy, cheap, effective, rugged and safe extraction followed by gas chromatography - tandem mass spectrometry: Method development and risk assessment.

The common use of benzothiazoles, benzotriazoles and benzenesulfonamides has led to widespread ubiquity in several environmental matrices. Their occurrence in edible fish could represent an additional exposure route for the population. The present study aims to develop a method for the simultaneous determination of these three compound families in seafood samples. Based on QuEChERS extraction, different salt combinations and clean-up strategies have been evaluated to achieve the highest recoveries while reducing the matrix effect in low and high lipidic content species. The best results were obtained with the original method salts and the lipid-selective push-through clean-up, which combined with gas chromatography-tandem mass spectrometry led to recoveries between 50 and 112% with negligible matrix effects and method detection limits between 0.15-9.50 ng g-1 dw. The application of the method to commercially available samples confirmed the presence of BTs as well as BSAs, with the latter being determined in seafood for the first time. Exposure and risk assessment calculations indicated a minor risk for the population when consuming fish.

High production volume chemicals in the most consumed seafood species in Tarragona area (Spain): Occurrence, exposure, and risk assessment.

Seafood consumption has become a potential exposure route towards high production volume chemicals (HPVs) due to the pathway of these compounds reaching the aquatic environment via industrial and domestic discharges. The present study focuses on the determination of phthalate esters (PAEs), organophosphate esters (OPEs), benzothiazoles (BTs), benzotriazoles (BTRs) and benzenesulfonamides (BSAs) in the ten most consumed fish species in Catalonia. A total of 120 commercially available seafood specimens were purchased throughout February 2019-February 2020 in three different stores (supermarket, local market, and local fishmonger) of the city of Tarragona, Spain, to cover the most typical places where seafood can be obtained. ΣOPEs, ΣBTs, ΣBSAs and ΣPAEs concentrations ranged between 5.99 and 139.45 ng g-1 w.w., 8.41-54.08 ng g-1 w.w., 8.38-304.47 ng g-1 w.w and 2.86-323.80 ng g-1 w.w., respectively. BTRs were not detected in any of the samples. PAEs and BSAs had similar contributions which combined represented nearly the 70% of detected compounds and sardine resulted as the species with the higher HPVs mean concentration. No considerable threat was posed due to the individual intake of these compounds via seafood consumption.

Determination of Organophosphate Ester Metabolites in Seafood Species by QuEChERS-SPE Followed by LC-HRMS.

Organophosphate triesters are compounds widely used in industries and are ubiquitous in the environment, where they can be transformed into organophosphate diesters. Some organophosphate diesters are also used by industry. Several studies suggest organophosphate diesters can have toxic effects for reproduction, and hazardous and mutagenic properties. Due to the impact these compounds can have on marine biota and human beings through the consumption of fish and shellfish, it is necessary to study their presence in widely consumed seafood species. We therefore developed an analytical method for determining six of the most common organophosphate diesters in seafood. The procedure is based on the Quick, Easy, Cheap, Effective, Rugged and Safe extraction method and a solid phase extraction clean-up, followed by liquid chromatography coupled to high-resolution mass spectrometry. The method was optimised and validated for seafood with different lipid content, providing satisfactory relative recoveries (from 89 to 138%) and limits of detection (1.0-50 ng g-1 dry weight), as well as repeatability values (RSD% (n = 5, 100 ng g-1 (dry weight)) lower than 15%. Eight seafood species were analysed using this method and two organophosphate diesters were detected and quantified in all the samples, demonstrating the suitability of the method.

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

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

Presence, behaviour and removal of selected organic micropollutants through drinking water treatment.

This paper investigates the occurrence and removal of 60 organic micropollutants (OMPs) including pharmaceuticals, personal care products, pesticides and per- and polyfluoroalkyl substances in a drinking water treatment plant (DWTP) treating raw water from the Ebro River (NE Spain). The behaviour of the OMPs was evaluated in each treatment: pre-ozonation, flocculation-coagulation-decantation-sand filtration, post-ozonation and granular activated carbon filtration. Thirty-one of the sixty OMPs studied were detected in source water with individual median concentrations below 10 ng L-1 for all the compounds except for caffeine (64.1 ng L-1). The highest concentration peaks in the source water were found for caffeine (124.5 ng L-1), terbuthylazine (52.0 ng L-1), imidacloprid (30.2 ng L-1) and paracetamol (25.6 ng L-1). Of the 31 compounds detected in the source water, 17 were also detected in the finished drinking water. Of these 17 compounds, 10 were PFASs, which indicated that this group of compounds had not been effectively removed throughout the drinking water treatments. The overall removal efficiencies of OMPs in the DWTP ranged from -50.9% to 100%. The most efficient removal technologies were ozonation and granular activated carbon.

Simple method for determining phthalate diesters and their metabolites in seafood species using QuEChERS extraction and liquid chromatography-high resolution mass spectrometry.

In this article we describe a new and simple analytical method based on the Quick, Easy, Cheap, Effective, Rugged and Safe technique followed by dispersive solid-phase extraction clean-up with C18 and Lipifiltr® and LC-HRMS for simultaneously extracting six phthalate diesters and six of their metabolites (phthalate monoesters) from highly consumed seafood species. The method was validated for seafood with high and low lipid contents. Apparent recoveries were up to 79% for all compounds. Matrix effect values ranged from -8 to -48% for all compounds in both types of matrices. Method limits of detection were 1-25 ng g-1 dry weight (d.w.) for most compounds. Five seafood species were analysed using this method, and several phthalate diesters and monoesters were successfully quantified. Phthalate diesters were found at concentrations of up to 982 ng g-1 (d.w.) and phthalate monoesters were found at concentrations of up to 178 ng g-1 (d.w.).

Assessing population exposure to phthalate plasticizers in thirteen Spanish cities through the analysis of wastewater.

Phthalates are widely used plasticizers that produce endocrine-disrupting disorders. Quantifying exposure is crucial to perform risk assessments and to develop proper health measures. Herein, a wastewater-based epidemiology approach has been applied to estimate human exposure to six of the mostly used phthalates within the Spanish population. Wastewater samples were collected over four weekdays from seventeen wastewater treatment plants serving thirteen cities and ca. 6 million people (12.8 % of the Spanish population). Phthalate metabolite loads in wastewater were transformed into metabolite concentrations in urine and into daily exposure levels to the parent phthalates. Considering all the sampled sites, population-weighted overall means of the estimated concentrations in urine varied between 0.7 ng/mL and 520 ng/mL. Very high levels, compared to human biomonitoring data, were estimated for monomethyl phthalate, metabolite of dimethyl phthalate. This, together with literature data pointing to other sources of this metabolite in sewage led to its exclusion for exposure assessments. For the remaining metabolites, estimated concentrations were closer to those found in urine. Their 4-days average exposure levels ranged from 2 to 1347 µg/(day∙inh), exceeding in some sites the daily exposure thresholds set for di-i-butyl phthalate and di-n-buthyl phthalate by the European Food Safety Authority.

Multiresidue Analysis of Organic UV Filters and UV Stabilizers in Fish of Common Consumption.

Fish species can bioaccumulate different pollutants present in the marine environments and incorporate them into the trophic chain. In this work, the occurrence of organic ultraviolet (UV) stabilizers and filters in different species of fishes of high consumption has been studied. A multiresidue method based on microwave-assisted extraction and ultra-high performance liquid chromatography with mass spectrometry detection was developed and then it was applied to nine fish species from markets in the Canary Islands and Catalonia (Spain). Three UV filters (BP-3, OC and BM-DBM) and two stabilizers (UV-328 and UV-329) were found in some of the studied species, in concentrations ranging between 0.067 and 0.683 µg g-1 dry weight (dw). BP-3 (UV filter) was the most frequently detected compound, followed by UV-329 (UV stabilizer). Thunnus thynnus was the most heavily polluted species, with a concentration of 1.201 µg g-1 dw as the sum of all measured compounds.

Assessing alcohol consumption through wastewater-based epidemiology: Spain as a case study.

BACKGROUND: In this study, an alternative and complementary method to those approaches currently used to estimate alcohol consumption by the population is described. This method, known as wastewater-based epidemiology (WBE), allows back-calculating the alcohol consumption rate in a given population from the concentrations of a selected biomarker measured in wastewater. METHODS: Composite (24-h) wastewater samples were collected at the inlet of 17 wastewater treatment plants located in 13 Spanish cities for seven consecutive days in 2018. The sampled area covered 12.8% of the Spanish population. Wastewater samples were analyzed to determine the concentration of ethyl sulfate, the biomarker used to back-calculate alcohol consumption. RESULTS: Alcohol consumption ranged from 4.5 to 46 mL/day/inhabitant. Differences in consumption were statistically significant among the investigated cities and between weekdays and weekends. WBE-derived estimates of alcohol consumption were comparable to those reported by its corresponding region in the Spanish National Health Survey in most cases. At the national level, comparable results were obtained between the WBE-derived annual consumption rate (5.7 ± 1.2 L ethanol per capita (aged 15+)) and that reported by the National Health Survey (4.7 L ethanol per capita (aged 15+)). CONCLUSIONS: This is the largest WBE study carried out to date in Spain to estimate alcohol consumption rates. It confirms that this approach is useful for establishing spatial and temporal patterns of alcohol consumption, which could contribute to the development of health care management plans and policies. Contrary to established methods, it allows obtaining information in a fast and relatively economical way.

Determination of organophosphate ester flame retardants and plasticisers in fish samples by QuEChERs followed by gas chromatography-tandem mass spectrometry. Exposure and risk assessment through fish consumption.

The presence of organophosphate esters (OPEs) in everyday commodities such as furniture, household appliances and baby toys have rendered these contaminants ubiquitous in environmental fates such as air, water, soils and biota. Their presence in food-related species suggests that an additional route of exposure to these esters for the general population is fish intake through diet. Their incipient toxicity and carcinogenetic behaviour make it essential to develop methods for determining OPEs in fish samples. In this paper we have developed a new method for determining 9 OPEs based on the QuEChERS extraction method followed by a simple clean-up using a novel device for selective lipid removal (LipiFiltr) and GC-MS/MS to extract these compounds from fish samples regardless of lipid content. QuEChERS salt packet optimisation and clean-up strategies such as liquid-liquid extraction, dispersive-solid phase extraction and LipiFiltr were tested. Our results showed that EN 15662 method salts and Lipifiltr were the best combination to produce efficient analyte apparent recovery (67-116%) and negligible matrix effects (<10%). Limits of detection ranged from 0.05 ng g-1 (dry weight) for TiBP and TBP to 2.00 ng g-1 (dry weight) for TCEP. Fish samples from four fish species were determined with a median concentration of ΣOPEs 5.31 ng g-1 on a wet weight basis, with TBP, TiBP and TCPP as the main contenders. Estimates of exposure and risk associated with consuming these compounds via dietary intake showed low levels of concern for the population of Tarragona.

A liquid chromatography tandem mass spectrometry method for determining 18 per- and polyfluoroalkyl substances in source and treated drinking water.

Per- and polyfluoroalkyl substances (PFASs) have been determined in waters intended for human consumption, causing concern due to their potential toxic effects in humans and the environment. Drinking water is acknowledged to be one of the major routes of exposure to PFASs, which has led to the implementation of regulatory guidelines for PFASs in drinking water. In this study a fast, simple, sensitive and cost-effective method is developed for the determination of 18 PFASs in river and drinking water. The proposed method consists of directly injecting 900 µL of sample into a liquid chromatograph coupled to a triple quadrupole mass analyser, which involves minimal sample treatment as the sample only needs to be filtered. The method was validated in influent and effluent water from a drinking water treatment plant. Strong matrix effects were found for some of the target PFASs, and matrix-matched calibration curves were performed to enable accurate (87-114%) and precise (%RSD between 3 and 18%) quantification (n = 5, at 5 and 75 ng·L-1) with very good sensitivity (method quantitation limits between 0.1 and 2.0 ng·L-1). The method was applied to water samples from the influent and effluent of a drinking water treatment plant located in Catalonia (Spain), as well as in tap water and bottled water. The most abundant PFAS in all the types of water was PFBA, which represents 48%, 49%, 66% and 69% of total PFASs found in influent, effluent, tap and bottled water respectively. Relative mean abundances and the sum of mean concentrations in influent and effluent water suggests poor removal of PFASs during drinking water treatment. The concentrations of PFASs in bottled waters were generally lower than those in tap waters.

First nation-wide estimation of tobacco consumption in Spain using wastewater-based epidemiology.

Wastewater-based epidemiology (WBE) has become a very useful tool to monitor a population's drug consumption or exposure to environmental and food contaminants. In this work, WBE has been applied to estimate tobacco consumption in seven Spanish regions. To this end, 24 h composite wastewater samples were taken daily for one week in 17 wastewater treatment plants, covering altogether a population of ca. 6 million inhabitants. The samples were treated by enzymatic deconjugation and the wastewater content of two human-specific nicotine metabolites (namely, cotinine and trans-3'-hydroxycotinine) was measured to estimate the daily consumption of nicotine. The population-weighted average nicotine consumption in the seven analyzed regions was 2.2 g/(day∙1000 inh.), without any daily pattern. This average estimated nicotine consumption value agreed with the value derived from official tobacco sales data. Differences in consumption among the seven studied regions were found, being Galicia, the region with the lowest rate, and the Basque Country and Catalonia those with the highest rates. However, no conclusive correlation was found between those values and the prevalence data taken from two different national surveys, nor sociodemographic and health data. This study demonstrates that this tool can complement other indicators in order to accurately assess tobacco consumption rates at regional and national levels and provides the most extensive application of the approach in the Spanish territory.

El análisis de aguas residuales con fines epidemiológicos: presente y futuro en España / Wastewater-based epidemiology: present and future in Spain

El análisis de aguas residuales con fines epidemiológicos es actualmente una herramienta fiable y complementaria a las metodologías basadas en indicadores tradicionales para el control de diferentes sustancias entre las que cabe destacar las drogas. Si bien varios países europeos la utilizan como herramienta de trabajo para la monitorización de drogas de abuso, en España su uso se limita principalmente a estudios realizados por diferentes grupos de investigación, tal y como se describe en el caso práctico puesto de ejemplo en el artículo. Sin embargo, el potencial de la metodología ha quedado evidenciado en los estudios científicos llevados a cabo tanto a nivel español como internacional y, aunque son necesarios más estudios para llegar a conocer todo su potencial, se prevé pueda ser incorporada como herramienta de trabajo complementaria a las que habitualmente se utilizan. En este sentido, la Red Española de Análisis de Aguas Residuales (ESAR-Net), creada en 2017 y formada por diferentes grupos de investigación españoles, pretende contribuir al conocimiento y aplicación de esta metodología en España a través de actividades científicas y de divulgación

Wastewater-Based Epidemiology is currently a reliable and complementary tool to methodologies based on traditional indicators for the control of various substances such as drugs. Although several European countries use it as a working tool for the monitoring of drugs of abuse, in Spain its use is mainly limited to studies carried out by different research groups, as described in the case study used as an example in the article. However, the potential of the methodology has been demonstrated in the scientific studies carried out both at the Spanish and international level and, although more studies are necessary to get to know its full potential, it is expected that it could be incorporated as a complementary work tool to those that are usually used. In this sense, the Red Española de Análisis de Aguas Residuales (ESAR-Net), created in 2017 and formed by different Spanish research groups, aims to contribute to the knowledge and application of this methodology in Spain through scientific and outreach activities

Liquid chromatography tandem mass spectrometry determination of 34 priority and emerging pollutants in water from the influent and effluent of a drinking water treatment plant.

This study evaluates the applicability of a method based on the direct injection of a large volume of water samples to identify and quantify 34 priority and emerging substances, most of them discussed in Directive 2013/39/EU on priority substances in the field of water policy, and Decision 2018/840/EU (Watch List). The method directly injects 500 µL of filtered water sample and so does not use a pre-concentration step. The method was satisfactorily validated for influent and effluent water from a drinking water treatment plant, at three concentrations (1, 10 and 100 ng L-1) with precision and accuracies in the range 1-17% and 71-122% respectively. Sensitivity was good with detection limits in the range 0.15-10 ng L-1 and complied with EU limits in all cases except for estrone, 17-ß-estradiol and 17-α-ethinylestradiol. For these hormones, an on-line solid phase extraction was developed and evaluated. The methods were applied to the analysis of water collected at the influent and effluent of a drinking water treatment plant and revealed the presence of 18 of the target compounds in the influent water and 8 in the effluent water. This showed that most the compounds had been efficiently removed by the processes of the drinking water treatment plant.

Solid phase microextraction Arrow for the determination of synthetic musk fragrances in fish samples.

A novel solid phase microextraction Arrow (SPME Arrow) system has been applied for the first time to determine synthetic musk fragrances in fish samples. The lack of regulation concerning the concentration of musk fragrances in fish along with the risk associated to these compounds has led to an increased development of analytical methods on this topic. This study applies SPME Arrow followed by gas chromatography coupled to tandem mass spectrometry (ion trap) to determine nine musk fragrances and compares this novel technique with its predecessor (SPME). Parameters such as type of coating, extraction time and temperature as well as water addition were optimized to achieve higher sensitivity. Results show that detection limits ranging between 0.5 ng g-1 (for cashmeran, celestolide, phantolide, tonalide and musk ketone) and 2.5 ng g-1 (dry weight) (for musk xylene) when SPME Arrow is used instead of a conventional fibre, with an up to ten-fold increase in sensitivity. Moreover, commercial fish samples were analysed using the method developed and galaxolideand tonalidewere quantified at concentrations ranging from 6.5 ng g-1 to 17.5 ng g-1 (d.w.) and 2.9 ng g-1 and 5.1 ng g-1 (d.w.) in all the species analysed.

A simple, fast method for the analysis of 20 contaminants of emerging concern in river water using large-volume direct injection liquid chromatography-tandem mass spectrometry.

A fast and sensitive method for the determination of a structurally and physico-chemically diverse group of contaminants of emerging concern (CEC) based on large-volume direct injection liquid chromatography-tandem mass spectrometry was developed. The method can be used to determine 20 CECs belonging to different pollutant families (pharmaceuticals, personal care products, and pesticides) in river water at nanogram per liter. A single analytical run is required and the positive and negative ionization modes can be used simultaneously. Because of the large-volume injections of samples and the high sensitivity of the current mass spectrometers, the method has no need of a preconcentration step. The analytes are quantitated with matrix-matched calibration curves. The estimated limits of detection were in the range 0.1-5 ng L-1. The accuracy of the method was in the range 86-114%, and the precision, expressed as a relative standard deviation (RSD %), was below 18% for all the analytes (n = 5, at 5, 10, and 25 ng L-1). The method was applied to water samples taken from different points along the lower course of the Ebro River, Spain. A total of 12 out of the 20 target analytes were detected, and the ones at higher concentrations were caffeine and the pharmaceuticals paracetamol and ibuprofen (184.8 ng L-1, 63.3 ng L-1, and 23.3 ng L-1, respectively).

Preliminary assessment of galaxolide bioaccessibility in raw and cooked FISH.

Generally, dietary intake assessment and risk characterization are evaluated using contaminant concentration in raw fish while it is usually ingested cooked, which can cause an overestimation because one of the essential issues for risk-benefit analysis is to determine the maximum amount of a contaminant that can be released from the food matrix and be absorbed by the human body, called bioaccessibility. Moreover, despite most seafood products are cooked before consumption, risk assessment is still evaluated in raw products, strongly affecting public health guidelines. In the present study, an in vitro bioaccessibility assay was performed for Galaxolide (HHCB) in fish samples. Raw spiked hake samples were in vitro digested and aliquots of each fraction of the digestion process were analysed. HHCB was quantitatively present in the bioaccessibility fraction. The effect of fish cooking on HHCB was also evaluated in cod and mackerel samples. Results demonstrate that steaming and grilling processes lead to a loss of 50-70% HHCB in fish.

[Wastewater-based epidemiology: applications towards the estimation of drugs of abuse consumption and public health in general. The Spanish network ESAR-Net]. / Análisis de aguas residuales con fines epidemiológicos: aplicaciones a la estimación del consumo de sustancias de abuso y en salud pública en general. Red española ESAR-Net.

This manuscript introduces Wastewater-Based Epidemiology (WBE) and its potential in the assessment of diverse aspects related to public health. This methodology can provide data in a relatively short temporal and local scale (typically dialy-weekly at the municipal level) on consumption patterns of illicit drugs (e.g. cocaine or cannabis), licit substances of abuse (e.g. alcohol) by measuring their consumption biomarkers (i.e. the original unmetabolized substance or some of its metabolite) in wastewater. Besides discussing the fundaments, advantages and shortcomings of WBE, it reviews some of the main precedents at international level and most remarkable activities that have been taken place in this field in Spain. Finally, the Spanish Network of Wastewater-Based Epidemiology (ESAR-Net) as is presented. ESAR-Net is an Excellence Network that sums up the efforts of the most relevant Spanish researchers in the field of WBE, aiming to investigate future perspectives of this methodology and its impact on Public Health competences in Spain.

En este artículo se presenta la metodología de análisis de aguas residuales con fines epidemiológicos (wastewater-based epidemiology, WBE) y su potencial para abordar diversos aspectos relacionados con la salud pública. Esta metodología permite obtener datos a una escala temporal y espacial relativamente pequeña (típicamente datos diarios-semanales sobre un municipio) de hábitos de consumo de sustancias de abuso, ilegales (como la cocaína o el cannabis) o legales (como el alcohol) a través de la determinación de biomarcadores de consumo (el compuesto original no metabolizado o alguno de sus metabolitos) en el agua residual. Aparte de discutir los fundamentos, ventajas y limitaciones de WBE, se comentan los precedentes más relevantes a nivel internacional, y las actividades más destacables en España en este ámbito. Finalmente, se exponen, los objetivos de la Red Española de Análisis de Aguas Residuales con Fines Epidemiológicos (ESAR-Net), una "Red de Excelencia" que agrupa a investigadores españoles con amplia experiencia en el área de WBE, así como las perspectivas de futuro de esta metodología puede tener para mejorar las competencias de la Salud Pública en España.