Wastewater analysis and drugs — a European multi-city study

Introduction

The findings of the largest European project to date in the emerging science of wastewater analysis are taken up in this ‘Perspective on drugs’. The project in question analysed wastewater around 70 European cities and towns (hereinafter referred to as ‘cities’) to explore the drug-taking habits of those who live in them. The characteristics of European cities differ considerably; with some being major tourist or business hubs with varying day and night time populations. The results provide a valuable snapshot of the drug flow through the cities involved, revealing marked geographical variations.

Part of the ‘Perspectives on drugs’ (PODs) series, launched alongside the annual European Drug Report, these designed-for-the-web interactive analyses aim to provide deeper insights into a selection of important issues.

Update date :

Thursday, March 12, 2020

1. Analysis: results from a European multi-city study

Wastewater analysis is a rapidly developing scientific discipline with the potential for monitoring real-time data on geographical and temporal trends in illicit drug use. Originally used in the 1990s to monitor the environmental impact of liquid household waste, the method has since been used to estimate illicit drug consumption in different cities (Daughton, 2001; van Nuijs et al., 2011; Zuccato et al., 2008). It involves sampling a source of wastewater, such as a sewage influent to a wastewater treatment plant. This allows scientists to estimate the quantity of drugs consumed by a community by measuring the levels of illicit drugs and their metabolites excreted in urine (Zuccato et al., 2008) .

Wastewater testing in European cities

In 2010 a Europe-wide network (Sewage analysis CORe group — Europe (SCORE)) was established with the aim of standardising the approaches used for wastewater analysis and coordinating international studies through the establishment of a common protocol of action. The first activity of the SCORE group was a Europe-wide investigation, performed in 2011 in 19 European cities, which allowed the first ever wastewater study of regional differences in illicit drug use in Europe (Thomas et al., 2012). That study also included the first intercalibration exercise for the evaluation of the quality of the analytical data and allowed a comprehensive characterisation of the major uncertainties of the approach (Castiglioni et al., 2014). Following the success of this initial study, comparable studies were undertaken over the following years, covering 68 cities and 23 countries in Europe in 2019. A standard protocol and a common quality control exercise were used in all locations, which made it possible to directly compare illicit drug loads in Europe over a one-week period during nine consecutive years (van Nuijs et al., 2018). For the 2019 wastewater monitoring campaign, raw 24-hour composite samples were collected during a single week in March. These samples were analysed for the urinary biomarkers (i.e. measurable characteristics) of the parent drug (i.e. primary substance) for amphetamine, methamphetamine and MDMA. In addition, the samples were analysed for the main urinary metabolites (i.e. substances produced when the body breaks drugs down) of cocaine and cannabis, which are benzoylecgonine (BE) and THC-COOH (11-nor-9-carboxy-delta9-tetrahydrocannabinol).

This report is focused on illicit stimulants. No results for cannabis are reported because cannabis use is estimated by measuring its main metabolite (THC-COOH), which is the only suitable biomarker found so far, but is excreted in a low percentage. More research is needed to understand the excretion percentage of THC-COOH or find alternative biomarkers (Causanilles et al., 2017a).

The specific metabolite of heroin, 6-monoacetylmorphine, was found to be unstable in wastewater. Consequently, the only alternative is to use morphine, although it is not a specific biomarker and can also be excreted as a result of therapeutic use. This underlines the importance of collecting the most accurate figure for morphine use from prescription and/or sales reports.

Patterns of illicit drug use: geographical and temporal variation

2019 key findings

The project revealed a picture of distinct geographical and temporal patterns of drug use across European cities (see Interactive: explore the data from the study).

Overall, the loads of the different stimulant drugs detected in wastewater in 2019 have increased, compared to previous years.

The BE loads observed in wastewater indicate that cocaine use remains highest in western and southern European cities, in particular in cities in Belgium, the Netherlands, Spain and the United Kingdom. Very low levels were found in the majority of the eastern European cities, but the most recent data show signs of increase.

The loads of amphetamine detected in wastewater varied considerably across study locations, with the highest levels reported in cities in the north and east of Europe. Amphetamine was found at much lower levels in cities in the south of Europe.

In contrast, methamphetamine use, generally low and historically concentrated in Czechia and Slovakia, now appears to be present also in Cyprus, the east of Germany, Spain and northern Europe. The observed methamphetamine loads in the other locations were very low to negligible.

The highest mass loads of MDMA were found in the wastewater in cities in Belgium, Germany and the Netherlands.

Seventeen countries participating in the 2019 monitoring campaign included two or more study locations (Austria, Belgium, Cyprus, Czechia, Germany, Finland, France, Greece, Italy, Lithuania, Netherlands, Portugal, Spain, Slovakia, Slovenia, Sweden and Turkey). The study highlighted differences between these cities within the same country, which may be explained in part by the different social and demographic characteristics of the cities (universities, nightlife areas and age distribution of the population). In the large majority of countries with multiple study locations, loads were higher in large cities compared to smaller locations for all four substances.

In addition to geographical patterns, wastewater analysis can detect fluctuations in weekly patterns of illicit drug use. More than three-quarters of cities show higher loads of amphetamine, BE and MDMA in wastewater during the weekend (Friday to Monday) than during weekdays. Higher loads are found during the weekend (Friday to Monday) than during the week for BE and MDMA in three-quarters of the cities and for amphetamine in half, whereas methamphetamine loads are distributed more evenly across the week. The results point to a more recreational use of cocaine and MDMA, and to lesser extent amphetamine, contrasting with a more problematic profile of methamphetamine use.

Thirty-four cities have participated in at least five of the annual wastewater monitoring campaigns since 2011. This allows for time trend analysis of drug consumption based on wastewater testing.

Cocaine

The BE loads observed in wastewater indicate that cocaine use remains highest in western and southern European cities, in particular in cities in Belgium, the Netherlands, Spain and the United Kingdom. Very low levels were found in the majority of the eastern European cities, but the most recent data show signs of increase.

Figure 1
Cocaine residues/metabolite (benzoylecgonine) in wastewater in selected European cities, 2019

A relatively stable picture of cocaine use was observed between 2011 and 2015 in most cities. The general patterns detected were similar in the first five consecutive monitoring campaigns, with the highest and lowest BE loads found in the same cities and regions. Most cities showed either a decreasing or a stable trend between 2011 and 2015. In 2016, there were initial signs that this pattern was changing, with increases observed in the majority of cities each year since then. In 2019 the trend shows a further increase in use, with 27 of the 45 cities with data for 2019 and 2018 reported an increase. Increasing longer-term trends are reported for 13 out of the 14 cities with data for 2011 and 2019.

Figure 2: Aggregated trends in cocaine metabolites in 10 European cities, 2011 to 2019

 

NB: Trends in mean daily amounts of benzoylecgonine in milligrams per 1 000 head of population in Antwerp (Zuid, BE), Barcelona, Castellon and Santiago (ES), Paris (Seine Centre, FR), Zagreb (HR), Milan (IT), Eindhoven and Utrecht (NL), and Oslo (NO). These 10 cities were selected owing to the availability of annual data for 2011-2019.

Several sources indicate that cocaine use is increasing. A 2018 EMCDDA trendspotter study found that the greater availability of cocaine on Europe’s drug markets may be leading to an increasing trend of use in some countries and possibly expanding to eastern Europe, where the drug was previously little used. The picture emerging from general population surveys suggests stable or increasing levels of cocaine use. Analyses of wastewater reveals an increase in cocaine residues in most cities for which data were available for 2015 and 2019. There are three plausible explanations for an upward trend in BE in wastewater: more people are consuming cocaine; the same people are consuming more cocaine; and the purity of the drug has increased. With increased purity, a given quantity of cocaine will result in more BE entering the wastewater. This increase could also be explained by a combination of these three causes (EMCDDA, 2018). 

In the majority of countries with multiple study locations, cocaine loads were higher in large cities compared to smaller locations. In addition to geographical patterns, wastewater analysis can detect fluctuations in weekly patterns of illicit drug use. More than three-quarters of cities show higher loads of BE in wastewater during the weekend (Friday to Monday) than during weekdays, which may reflect a pattern of more recreational use.

MDMA

The highest mass loads of MDMA were found in the wastewater in cities in Belgium, Germany and the Netherlands.

Figure 3
MDMA residues in wastewater in selected European cities, 2019

Until recently, general population surveys in many countries showed that MDMA prevalence was declining from peak levels attained in the early to mid-2000s. In recent years, however, the picture has remained mixed with no clear trends. Where prevalence is high, this may reflect MDMA no longer being a niche or subcultural drug limited to dance clubs and parties, but now being used by a broader range of young people in mainstream nightlife settings, including bars and house parties. 

Looking at longer-term trends in wastewater analysis, for 11 out of the 12 cities with data for both 2011 and 2019, MDMA loads were higher in 2019 than in 2011. Sharp increases were observed in some cities, including Amsterdam, Eindhoven and Antwerp. In most cases the loads increased between 2011-16, decreased in 2017 and remained stable in 2018. However, 2019 data point to increases in most cities.

Figure 4: Aggregated trends in MDMA residues in 10 European cities, 2011 to 2019

 

NB: Trends in mean daily amounts of MDMA in milligrams per 1 000 head of population in Barcelona and Castellon (ES), Zagreb (HR), Milan (IT) and Oslo (NO). These 5 cities were selected owing to the availability of annual data for 2011-2019.

In the large majority of countries, MDMA loads were higher in large cities compared to smaller locations. Also, more than three-quarters of cities showed higher loads of MDMA in wastewater during the weekend (Friday to Monday) than during weekdays reflecting the predominantly recreational use of ecstasy now seen in a range of social settings.

Amphetamine and methamphetamine

Amphetamine and methamphetamine, two closely related stimulants, are both consumed in Europe, although amphetamine is much more commonly used. Methamphetamine consumption has historically been restricted to Czechia and, more recently, Slovakia, although recent years have seen increases in use in other countries.

The loads of amphetamine detected in wastewater varied considerably across study locations, with the highest levels reported in cities in the north and east of Europe. Amphetamine was found at much lower levels in cities in the south of Europe.

Methamphetamine loads also varied across locations. The drug was present in wastewater in cities in Cyprus, the east of Germany, Spain, several northern European countries (Denmark, Finland, Lithuania and Norway) as well as Czechia and Slovakia. The observed methamphetamine loads in the other locations were very low to negligible.

Figure 5
Amphetamine residues in wastewater in selected European cities, 2019

Figure 6
Methamphetamine residues in wastewater in selected European cities, 2019

Overall, the data related to amphetamine and methamphetamine from the nine monitoring campaigns showed no major changes in the general patterns of use observed. However, the most recent data show that 21 of the 41 cities with data for 2018 and 2019 reported an increase for amphetamine, with the loads found being higher during weekends. 

Figure 7: Aggregated trends in amphetamine residues in 6 European cities, 2011 to 2019

 

NB: Trends in mean daily amounts of amphetamine in milligrams per 1 000 head of population in Antwerp (Zuid, BE), Barcelona, Castellon and Santiago (ES), Paris (Seine Centre, FR) and Zagreb (HR). These 6 cities were selected owing to the availability of annual data for 2011-2019.

Figure 8: Aggregated trends in methamphetamine residues in 7 European cities, 2011 to 2019

 

NB: Trends in mean daily amounts of methamphetamine in milligrams per 1 000 head of population in Antwerp Zuid (BE), Barcelona, Castellon and Santiago (ES), Paris Seine Centre (FR), Milan (IT) and Oslo (NO). These 7 cities were selected owing to the availability of annual data for 2011-2019.

No differences could be detected for amphetamine and methamphetamine when comparing the loads found in large cities compared to smaller locations.

For amphetamine, since 2018, more cities show higher loads of amphetamine in wastewater during the weekend (Friday to Monday) than during weekdays, possibly indicating more use in recreational settings as compared to the past. In contrast, methamphetamine use was found to be distributed more evenly over the whole week, possibly reflecting methamphetamine being associated with more ongoing and high-risk consumption by a small cohort of users. 

Comparison with findings from other monitoring tools

Because different types of information are provided by wastewater analysis (collective consumption of substances within a community) and by established monitoring tools, such as population surveys (prevalence in the last month or year), a direct comparison of the data is difficult. However, the patterns and trends being detected by wastewater analysis are largely, but not completely, in line with the analyses coming from other monitoring tools. 

For example, both seizure and wastewater data present a picture of a geographically divergent stimulant market in Europe, where cocaine is more prevalent in the south and west, while amphetamines are more common in central and northern countries (EMCDDA, 2017). Similar results are also found in data coming from population surveys on drug use. While the general pattern detected in wastewater is in line with established monitoring tools, there are some exceptions: the amphetamine loads in wastewater in Paris have been below the level of quantification over the consecutive annual monitoring campaigns, contrary to indications from other monitoring tools. 

Data from established indicators show that methamphetamine use has historically been restricted to Czechia, and more recently also Slovakia, although recent years have seen increased use in other countries (EMCDDA, 2016a). These findings have been confirmed by recent wastewater-based epidemiology, with the highest methamphetamine loads found in Czech, Slovak, German and Finnish cities.

Established indicators show that, until recently, MDMA prevalence was declining in many countries from peak levels in the early to mid-2000s. Data from wastewater and from established indicators show that this appears to be changing, with the large majority of cities reporting higher wastewater MDMA loads in 2016 or 2017 than in 2011.

Similarly, studies based on self-reported drug use and those using wastewater data both point towards the same weekly variations in use, with stimulants such as amphetamine and cocaine being primarily used at weekend music events and in celebratory contexts (Tossmann et al., 2001).

  1. limited but steadily increasing number of studies have been published comparing drug use estimates obtained through wastewater analysis and estimates provided by epidemiological surveys (EMCDDA, 2016b; van Wel et al., 2015). While in 2012 only one reported study tried to evaluate sewage analysis alongside traditional epidemiological techniques (Reid et al., 2012), this number has now increased to over 20 published research articles that are focused on comparing information provided by wastewater analysis and information provided by other indicators.

A first study, performed in Oslo, Norway, and published in 2012, compared the results from three different datasets (a general population survey, a roadside survey and wastewater analysis) (Reid et al., 2012).

Other, more recent studies compare and correlate wastewater-based consumption estimates of illicit drugs with other data sources, including self-reported data (Been et al., 2015; Castiglioni et al., 2016; van Wel et al., 2016a), consumption offences (Been et al., 2016a), illicit drug seizures (Baz-Lomba et al., 2016; Kankaanpää et al., 2014, 2016), purity of drug seizures (Bruno et al., 2018), syringe distribution estimates (Been et al., 2015), toxicological data (Kankaanpää et al., 2014, 2016) and the number of drug users in treatment (Krizman et al., 2016). 

The majority of comparative studies have been carried out within Europe, including in Belgium (van Wel et al., 2016a), Croatia (Krizman et al., 2016), Germany (Been et al., 2016a), Finland (Kankaanpää et al., 2014, 2016), Italy (Castiglioni et al., 2016), Spain (Bijlsma et al., 2018), Switzerland (Been et al., 2015; Been et al., 2016b), Turkey (Daglioglu, 2019) and across European countries (Baz-Lomba et al., 2016; Castrignanò et al., 2018; Löve et al., 2018). Outside Europe, in recent years studies have been published comparing wastewater-based estimates with other data sources in China (Du et al., 2015), Australia (Tscharke et al., 2015) and in countries where data on drug use are limited due to financial constraints or lack of monitoring tools (Archer et al., 2018; Moslah et al., 2018; Nguyen et al., 2018). 

These examples confirm the promising future of wastewater-based epidemiology as a complementary approach to obtain a more accurate and balanced picture of substance use within different communities. Wastewater analysis can predict results from population surveys and can be used as a ‘first alert’ tool in the identification of new trends in drug consumption. In order to check the quality and accuracy of data, further comparisons between wastewater analysis and data obtained through other indicators are needed.

Limitations of this method

Wastewater analysis offers an interesting complementary data source for monitoring the quantities of illicit drugs used at the population level, but it cannot provide information on prevalence and frequency of use, main classes of users and purity of the drugs. Additional challenges arise from uncertainties associated with the behaviour of the selected biomarkers in the sewer, different back-calculation methods and different approaches to estimate the size of the population being tested (Castiglioni et al., 2013, 2016; Lai et al., 2014; EMCDDA, 2016b). The caveats in selecting the analytical targets for heroin, for example, make monitoring this drug in wastewater more complicated compared to other substances (Been et al., 2015). Also, the purity of street products fluctuates unpredictably over time and in different locations. Furthermore, translating the total consumed amounts into the corresponding number of average doses is complicated, as drugs can be taken by different routes and in amounts that vary widely (Zuccato et al., 2008).

Efforts are being made to enhance wastewater monitoring approaches. For example, work has been undertaken on overcoming a major source of uncertainty related to estimating the number of people present in a sewer catchment at the time of sample collection. This involved using data from mobile devices to better estimate the dynamic population size for wastewater-based epidemiology (Thomas et al., 2017).

New developments and the future

Wastewater-based epidemiology has established itself as an important tool for monitoring illicit drug use and future directions for wastewater research have been explored (EMCDDA, 2016b).

First, wastewater analysis has been proposed as a tool to address some of the challenges related to the dynamic new psychoactive substances (NPS) market. This includes the large number of individual NPS, the relatively low prevalence of use and the fact that many of the users are actually unaware of exactly which substances they are using. A technique has been established to identify NPS that involves the collection and analysis of pooled urine from stand-alone portable urinals from nightclubs, city centres and music festivals, thereby providing timely data on exactly which NPS are currently in use at a particular location (Archer et al., 2013a, 2013b, 2015; Causanilles et al., 2017b; Kinyua, et al., 2016; Mackulak et al., 2019; Mardal et al., 2017; Reid et al., 2014;). The European project ‘NPS euronet’ aimed to improve the capacity to identify and assess the NPS being used in Europe. The project applied innovative analytical chemical and epidemiological methods and a robust risk-assessment procedure to improve the identification of NPS, to assess risks, and to estimate the extent and patterns of use in specific groups (e.g. at music festivals) and among the general population (Bade et al., 2017; González-Mariño et al., 2016).

Second, in addition to estimating illicit drug use, wastewater-based epidemiology has been successfully applied in recent years to providing detailed information on the use and misuse of alcohol (Boogaerts et al., 2016; Mastroianni et al., 2017; Rodríguez-Álvarez et al., 2015), tobacco (Senta et al., 2015; van Wel et al., 2016b) and medicines in a specific population (Baz-Lomba et al., 2016, 2017; Been et al., 2015; Krizman-Matasic et al., 2018; Salvatore et al., 2016). Furthermore, wastewater analysis can potentially provide information on health and illness indicators within a community (Kasprzyk-Hordern et al., 2014; Thomaidis et al., 2016; Yang et al., 2015).

Third, the potential for wastewater-based epidemiology to be used as an outcome measurement tool, in particular in the evaluation of the effectiveness of interventions that target drug supply (e.g. law enforcement) or drug demand (e.g. public health campaigns) has not yet been fully explored. Close collaboration between the different stakeholders involved, including epidemiologists, wastewater experts and legal authorities, is highly recommended in order to start examining these potential wastewater-based epidemiology applications (EMCDDA, 2016b). The WATCH project included a 30-day synthetic drug production monitoring campaign in three cities in Belgium and the Netherlands. High levels of MDMA were recorded during the whole monitoring period in one city in the Netherlands, suggesting continuous discharges of unconsumed MDMA from sources within the wastewater catchment area, indicating drug production was taking place in this region.

Fourth, by back-calculating the daily sewer loads of target residues, wastewater analysis can provide total consumption estimates, and specific efforts are now being directed towards finding the best procedures for estimating annual averages. In 2016 the EMCDDA presented for the first time illicit drug retail market size estimates in terms of quantity and value for the main substances used (EMCDDA and Europol, 2016). It is envisaged that findings from wastewater analysis can help to further develop work in this area.

Finally, new methods such as enantiomeric profiling have been developed to determine if mass loads of drugs in wastewater originated from consumption or from the disposal of unused drugs or production waste. It is now important to assess the possible utility of wastewater analysis to report on drug supply dynamics, including synthetic drug production (Emke et al., 2014). For example, recent malfunctioning of a small wastewater treatment plant in the Netherlands was caused by direct discharges in the sewage system of chemical waste from a drug production site. Further analysis revealed the actual synthesis process used to manufacture the corresponding drugs. The study confirmed that the chemical waste from the illegal manufacturing of stimulants will result in a specific chemical fingerprint that can be tracked in wastewater and used for forensic purposes. Such profiles can be used to identify drug production or synthesis waste disposal in the wastewater catchment area (Emke et al., 2018).

Wastewater analysis has demonstrated its potential as a useful complement to established monitoring tools in the drugs area. It has some clear advantages over other approaches as it is not subject to response and non-response bias and can better identify the true spectrum of drugs being consumed, as users are often unaware of the actual mix of substances they take. This tool also has the potential to provide timely information in short timeframes on geographical and temporal trends. In order to check the quality and accuracy of data, further comparisons between wastewater analysis and data obtained through other indicators are needed.

As a method, wastewater analysis has moved from being an experimental technique to being a new method in the epidemiological toolkit. Its rapid ability to detect new trends can help target public health programmes and policy initiatives at specific groups of people and the different drugs they are using.

Footnotes

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  • Nguyen, H. T., Thai, P. K., Kaserzon, S. L., O'Brien, J. W., Eaglesham, G. and Mueller, J. F. (2018), ‘Assessment of drugs and personal care products biomarkers in the influent and effluent of two wastewater treatment plants in Ho Chi Minh City, Vietnam’, Science of the Total Environment 631-632, pp. 469–475.
  • Reid, M. J., Langford, K. H., Grung, M., et al. (2012), ‘Estimation of cocaine consumption in the community: A critical comparison of the results from three complimentary techniques’, BMJ Open, 2(6).
  • Reid, M. J., Baz-Lomba, J. A., Ryu, Y. and Thomas, K. V. (2014), ‘Using biomarkers in wastewater to monitor community drug use: A conceptual approach for dealing with new psychoactive substances’, Science of the Total Environment 487, pp. 651–658.
  • Rodríguez-Álvarez, T., Racamonde, I., González-Mariño, I., et al. (2015), ‘Alcohol and cocaine co-consumption in two European cities assessed by wastewater analysis’, Science of the Total Environment 536, pp. 91–98.
  • Senta, I., Gracia-Lor, M., Borsotti, A., et al. (2015), ‘Wastewater analysis to monitor use of caffeine and nicotine and evaluation of their metabolites as biomarkers for population size assessment’, Water Research 74, pp. 23–33.
  • Thomaidis, N., Gago-Ferrero, P., Ort, C., et al. (2016), ‘Reflection of socioeconomic changes in wastewater: licit and illicit drug use patterns’, Environmental Science & Technology 50, 18 pp.100651–0072.
  • Thomas, K. V., Bijlsma, L., Castiglioni, S., et al. (2012), ‘Comparing illicit drugs use in 19 European cities through sewage analysis’, Science of the Total Environment 432, pp. 432–439.
  • Thomas, K. V., Amador, A., Baz-Lomba, J. A. and Reid, M. (2017), ‘Use of mobile device data to better estimate dynamic population size for wastewater-based epidemiology’, Environmental Science and Technology 51, 19, pp.113631–1370.
  • Tossmann, P., Boldt, S. and Tensil, M.-D. (2001), ‘The use of drugs within the techno party scene in European metropolitan cities’, European Addiction Research 7(1), pp. 2–23.
  • Tscharke, B. J., Chen, C., Gerber, J. P. and White, J. M. (2015), Trends in stimulant use in Australia: A comparison of wastewater analysis and population surveys’, Science of the Total Environment 536, pp. 331–337.
  • van Nuijs, A., Mougel, J.-F., Tarcomnicu, I., et al. (2011), ‘Sewage epidemiology: A real-time approach to estimate the consumption of illicit drugs in Brussels, Belgium’, Environment International 27, pp. 612–621.
  • van Nuijs, A., Lai, Y., Been, F., et al. (2018), ‘Multi-year inter-laboratory exercises for the analysis of illicit drugs and metabolites in wastewater: Development of a quality control system’, Trends in Analytical Chemistry 103, pp. 34–43.van Wel, J., Kinyua, J., van Nuijs, A., van Hal, G., Covaci, A. (2015), ‘Methodological considerations for combining wastewater-based epidemiology with survey research’, Archives of Public Health, 73, Suppl. 1, p. 29.
  • van Wel, J, H. P., Kinyua, J., van Nuis, A. L. N., et al. (2016a), ‘A comparison between wastewater-based drug data and an illicit drug use survey in a selected community’, International Journal of Drug Policy, 34, pp. 20–26.
  • van Wel, J. H. P., Gracia-Lor, E., van Nuijs, A. L. N., et al. (2016b), ‘Investigation of agreement between wastewater-based epidemiology and survey data on alcohol and nicotine use in a community’, Drug and Alcohol Dependence 162, pp. 170–175.
  • Yang, Z., Anglès d’Auriac, M., Goggins, S., et al. (2015) ‘A novel DNA biosensor using a ferrocenyl intercalator applied to the potential detection of human population biomarkers in wastewater’, Environmental Science and Technology 49(9), pp. 5609–5617.
  • Zuccato, E., Castiglioni, S., Senta, I., Borsotti, A., et al. (2016), ‘Population surveys compared with wastewater analysis for monitoring illicit drug consumption in Italy in 2010–2014’, Drug and Alcohol Dependence 161, pp. 178–188.
  • Zuccato, E., Chiabrando, C., Castiglioni, S., Bagnati, R. and Fanelli, R. (2008), ‘Estimating community drug abuse by wastewater analysis’, Environmental Health Perspectives 116(8), pp. 1027–1032.
  • Archer, J. R. H., Dargan, P. I., Hudson, S. and Wood, D. M. (2013a), ‘Analysis of anonymous pooled urinals in central London confirms the significant use of novel psychoactive substances’, QJM 106(2), pp. 147–152.
  • Archer, J. R. H., Hudson, S., Wood, D. M. and Dragan, P. I. (2013b), ‘Analysis of urine from pooled urinals: a novel method for the detection of novel psychoactive substances’, Current Drug Abuse Reviews, online publication, 5 December.
  • Archer, J. R. H., Hudson, S. and Jackson, O. (2015), ‘Analysis of anonymized pooled urine in nine UK cities: variation in classical recreational drug, novel psychoactive substance and anabolic steroid use’, QJM 108 (12), pp. 929–933.
  • Archer, E., Castrignanò, E., Kasprzyk-Hordern, B. and Wolfaardt, G. M. (2018), ‘Wastewater-based epidemiology and enantiomeric profiling for drugs of abuse in South African wastewaters’, Science of the Total Environment 625, pp. 792–800.
  • Bade, R., Bijlsma, L., Sancho, J., et al. (2017), ‘Liquid chromatography-tandem mass spectrometry determination of synthetic cathinones and phenethylamines in influent wastewater of eight European cities’, Chemosphere 168, pp. 1032–1041.
  • Baz-Lomba, J. A., Salvatore, S., Gracia-Lor, E., et al. (2016), ‘Comparison of pharmaceutical, illicit drug, alcohol, nicotine and caffeine levels in wastewater with sale, seizure and consumption data for 8 European cities’, BMC Public Health 16, 1, 1035.
  • Baz-Lomba, J. A., Harman, C., Reid, M. and Thomas, K. V. (2017), ‘Passive sampling of wastewater as a tool for the long-term monitoring of community exposure: Illicit and prescription drug trends as a proof of concept’, Water Research 121, pp. 221–230.
  • Been, F., Benaglia, L., Lucia, S., et al. (2015), ‘Data triangulation in the context of opioids monitoring via wastewater analyses’, Drug and Alcohol Dependence 151, pp. 203–210.
  • Been, F., Bijlsma, L., Benaglia, L., et al. (2016a), ‘Assessing geographical differences in illicit drug consumption: A comparison of results from epidemiological and wastewater data in Germany and Switzerland’, Drug and Alcohol Dependence 161, pp. 189–199.
  • Been, F., Schneider, C., Zobel, F., Delémont, O. and Esseiva, P. (2016b), ‘Integrating environmental and self-report data to refine cannabis prevalence estimates in a major urban area of Switzerland’, International Journal of Drug Policy 36, pp. 33–40.
  • Bijlsma, L., Celma, A., González-Mariño, I., et al. (2018), ‘Wastewater-based epidemiology: applications towards the estimation of drugs of abuse consumption and public health in general. The Spanish network ESAR-Net’, Revista Española de Salud Pública, 92. pii: e201808053.
  • Boogaerts, T., Covaci, A., Kinyua, J., et al. (2016), ‘Spatial and temporal trends in alcohol consumption in Belgian cities: A wastewater-based approach’, Drug and Alcohol Dependence 160, pp. 170–176.
  • Bramness, J. G., Reid M. J., Solvik, K. F. and Vindenes, V. (2014), ‘Recent trends in the availability and use of amphetamine and methamphetamine in Norway’, Forensic Science International 246, pp. 92–97.
  • Bruno, R., Edirisinghe, M., Hall, W., Mueller, J. F., Lai, F. Y., O’Brien J. W. and Thai, P. K. (2018), ‘Association between purity of drug seizures and illicit drug loads measured in wastewater in a South East Queensland catchment over a six year period’, Science of the Total Environment 635, pp. 779–783.
  • Castiglioni, S., Borsotti, A., Riva, F. and Zuccato, E. (2016), ‘Illicit drug consumption estimated by wastewater analysis in different districts of Milan: A case study’, Drug and Alcohol Review 35, pp. 128–132.
  • Castiglioni, S., Thomas, K. V., Kasprzyk-Hordern, B., Vandam, L. and Griffiths, P. (2014), ‘Testing wastewater to detect illicit drugs: State of the art, potential and research needs’, Science of the Total Environment 487, pp. 613–620.
  • Castiglioni, S., Bijlsma, L., Covaci A., et al. (2013), ‘Evaluation of uncertainties associated with the determination of community drug use through the measurement of sewage drug biomarkers’, Environmental Science and Technology 47(3), pp. 1452–1460.
  • Castrignanò, E., Yang, Z., Bade, R., et al. (2018), ‘Enantiomeric profiling of chiral illicit drugs in a pan-European study’, Water Research 130, pp.151–160.
  • Causanilles, A., Baz-Lomba, J. A., Burgard, D. A., et al. (2017a), ‘Improving wastewater-based epidemiology to estimate cannabis use: Focus on the initial aspects of the analytical procedure’, Analytica Chimica Acta 988, pp. 27–33.
  • Causanilles, A., Kinyua, J., Ruttkies, C., et al. (2017b), ‘Qualitative screening for new psychoactive substances in wastewater collected during a city festival using liquid chromatography coupled to high-resolution mass spectrometry’, Chemosphere 184, pp. 1186–1193.
  • Daglioglu, N., Guzel, E. Y. and Kilercioglu, S. (2019), ‘Assessment of illicit drugs in wastewater and estimation of drugs of abuse in Adana Province, Turkey’, Forensic Science International 294, pp. 132–139.
  • Daughton, C. G. (2001), ‘Emerging pollutants, and communicating the science of environmental chemistry and mass spectrometry: pharmaceuticals in the environment’, American Society for Mass Spectrometry 12, pp. 1067–1076.
  • Du, P. (2015), ‘Methamphetamine and ketamine use in major Chinese cities, a nationwide reconnaissance through sewage-based epidemiology’, Water Research, Volume 84, pp. 76–84.
  • EMCDDA (European Monitoring Centre for Drugs and Drug Addiction) (2016a), European drug report: tends and developments, Publications Office of the European Union, Luxembourg.
  • EMCDDA (2016b), Assessing illicit drugs in wastewater: advances in wastewater-based drug epidemiology, Insights, Publications Office of the European Union, Luxembourg.
  • EMCDDA (2017), European drug report: trends and developments, Publications Office of the European Union, Luxembourg.
  • EMCDDA (2018), Recent changes in Europe’s cocaine market: results from an EMCDDA trendspotter study, Publications Office of the European Union, Luxembourg.
  • EMCDDA and Europol (2016), EU Drug Markets Report, Joint publications, Publications Office of the European Union, Luxembourg.
  • Emke, E., Evans, S., Kasprzyk-Hordern, B. and de Voogt, P. (2014), ‘Enantiomer profiling of high loads of amphetamine and MDMA in communal sewage: a Dutch perspective’, Science of The Total Environment 487, pp. 666–672.
  • Emke, E., Vughs, D., Kolkman, A. and de Voogt, P. (2018) ‘Wastewater-based epidemiology generated forensic information: amphetamine synthesis waste and the impact on a small sewage treatment plant’, Forensic Science International 286, e1–e7.
  • González-Mariño, I., Gracia-Lor, E., Rousis, N., et al. (2016), ‘Wastewater-based epidemiology to monitor synthetic cathinones use in different European countries’, Environmental Science and Technology 50, pp. 10089−10096.
  • Hall, W., Prichard, J., Kirkbride, P., et al. (2012), ‘An analysis of ethical issues in using wastewater analysis to monitor illicit drug use’, Addiction 107(10), pp. 1767–1773.
  • Kankaanpää, A., Ariniemi, K., Heinonen, M., Kuoppasalmi, K. and Gunnar T. (2016), ‘Current trends in Finnish drug abuse: Wastewater based epidemiology combined with other national indicators’, Science of the Total Environment 568, pp. 864–874.
  • Kasprzyk-Hordern, B., Bijlsma, L., Castiglioni, S., et al. (2014), ‘Wastewater-based epidemiology for public health monitoring’, Water and Sewerage Journal 4, pp. 25–26.
  • Kinyua, J., Negreira, N., Miserez, B., et al. (2016), ‘Qualitative screening of new psychoactive substances in pooled urine samples from Belgium and United Kingdom’, Science of the Total Environment 573, pp. 1527–1535.
  • Krizman, I., Senta, I., Ahel, M., Terzic, S. (2016), ‘Wastewater-based assessment of regional and temporal consumption patterns of illicit drugs and therapeutic opioids in Croatia’, Science of the Total Environment, 566-567 pp. 454–462.
  • Krizman-Matasic, I., Kostanjevecki, P., Ahel, M. and Terzic, S. (2018), ‘Simultaneous analysis of opioid analgesics and their metabolites in municipal wastewaters and river water by liquid chromatography-tandem mass spectrometry’, Journal of Chromatography A 19, pp. 102–111.
  • Lai, F. Y. , Anuj, S., Bruno, R., et al. (2014), ‘Systematic and day-to-day effects of chemical-derived population estimates on wastewater-based drug epidemiology’, Environmental Science and Technology 49, pp. 999–1008.
  • Löve A. S. C., Baz-Lomba, J. A., Reid, M., et al. (2018), ‘Analysis of stimulant drugs in the wastewater of five Nordic capitals’, Science of the Total Environment 627, pp.1039–1047. 
  • Mackuľak, T., Brandeburová, P., Grenčíková, A., Bodík, I., Staňová, A. V., Golovko, O., Koba, O., Mackuľaková, M., Špalková, V., Gál, M. and Grabic, R. (2019), ‘Music festivals and drugs: Wastewater analysis’, Science of the Total Environment 659, pp. 326–334. 
  • Mardal, M., Kinyua, J., Ramin, P., et al. (2017), ‘Screening for illicit drugs in pooled human urine and urinated soil samples and studies on the stability of urinary excretion products of cocaine, MDMA, and MDEA in wastewater by hyphenated mass spectrometry techniques’, Drug Testing and Analysis 9, pp. 106–114.
  • Mastroianni, N., López-García, E., Postigo, C., et al. (2017), ‘Five-year monitoring of 19 illicit and legal substances of abuse at the inlet of a wastewater treatment plant in Barcelona (NE Spain) and estimation of drug consumption patterns and trends’, Science of the Total Environment 609, pp. 916–926.
  • Moslah, B., Hapeshi, E., Jrad, A., Fatta-Kassinos, D. and Hedhili, A. (2018), ‘Pharmaceuticals and illicit drugs in wastewater samples in north-eastern Tunisia’, Environmental Science and Pollution Research International 25, 19, pp. 18226–18241.
  • Néfau, T., Sannier, O., Hubert, C., Karolak, S. and Lévi, Y. (2017), ‘Analysis of drugs in sewage: an approach to assess substance use, applied to a prison setting’, Observatoire Français des Drogues et des Toxicomanies, Paris.
  • Nguyen, H. T., Thai, P. K., Kaserzon, S. L., O’Brien, J. W., Eaglesham, G. and Mueller, J. F. (2018), ‘Assessment of drugs and personal care products biomarkers in the influent and effluent of two wastewater treatment plants in Ho Chi Minh City, Vietnam’, Science of the Total Environment 631-632, pp. 469–475.
  • Ort, C., van Nuijs A. L. N., Berset J.-D., et al. (2014), ‘Spatial differences and temporal changes in illicit drug use in Europe quantified by wastewater analysis’, Addiction 109, doi: 10.1111/add.12570
  • Prichard, J., Hall, W., de Voogt, P. and Zuccato, E. (2014), ‘Sewage epidemiology and illicit drug research: the development of ethical research guidelines’, Science of the Total Environment 47(2), pp. 550–555.
  • Prichard, J., Hall, W., Zuccato, E., de Voogt, P., Voulvoulis, N., Kummerer, K., Kasprzyk-Hordern, B., et al. (2016), ‘Ethical research guidelines for wastewater-based epidemiology and related fields’, available at EMCDDA Documents Library. 
  • Reid, M. J., Langford, K. H., Grung, M., et al. (2012), ‘Estimation of cocaine consumption in the community: a critical comparison of the results from three complimentary techniques’, BMJ Open 2(6).
  • Reid, M. J., Baz-Lomba, J. A., Ryu, Y. and Thomas, K. V. (2014), ‘Using biomarkers in wastewater to monitor community drug use: a conceptual approach for dealing with new psychoactive substances’, Science of The Total Environment 487, pp. 651–658. 
  • Rodríguez-Álvarez, T., Racamonde, I., González-Mariño, I., et al. (2015), ‘Alcohol and cocaine co-consumption in two European cities assessed by wastewater analysis’, Science of the Total Environment 536, pp. 91–98.
  • Senta, I., Gracia-Lor, M., Borsotti, A., et al. (2015), ‘Wastewater analysis to monitor use of caffeine and nicotine and evaluation of their metabolites as biomarkers for population size assessment’, Water Research 74, pp. 23–33.
  • Thomaidis, N., Gago-Ferrero, P., Ort, C., et al. (2016), ‘Reflection of socioeconomic changes in wastewater: licit and illicit drug use patterns’, Environmental Science & Technology 50, 18 pp. 10065–10072.
  • Thomas, K. V., Bijlsma, L., Castiglioni, S., et al. (2012), ‘Comparing illicit drugs use in 19 European cities through sewage analysis’, Science of the Total Environment 432, pp. 432–439.
  • Thomas, K. V., Amador, A., Baz-Lomba, J. A. and Reid, M. (2017), ‘Use of mobile device data to better estimate dynamic population size for wastewater-based epidemiology’, Environmental Science and Technology 51, 19, pp. 11363–11370.
  • Tossmann, P., Boldt, S. and Tensil, M.-D. (2001), ‘The use of drugs within the techno party scene in European metropolitan cities’, European Addiction Research 7(1), pp. 2–23.
  • Tscharke, B. J., Chen, C., Gerber, J. P and, White, J. M. (2015), Trends in stimulant use in Australia: A comparison of wastewater analysis and population surveys’, Science of the Total Environment 536, pp. 331–337.
  • van Nuijs, A., Mougel, J.-F., Tarcomnicu, I., et al. (2011), ‘Sewage epidemiology: a real-time approach to estimate the consumption of illicit drugs in Brussels, Belgium’, Environment International 27, pp. 612–621.
  • van Nuijs, A., Lai, Y., Been, F., et al. (2018), ‘Multi-year inter-laboratory exercises for the analysis of illicit drugs and metabolites in wastewater: Development of a quality control system’, Trends in Analytical Chemistry 103, pp. 34–43.
  • van Wel, J., Kinyua, J., van Nuijs, A., van Hal, G., Covaci, A. (2015), ‘Methodological considerations for combining wastewater-based epidemiology with survey research’, Archives of Public Health 73, Suppl. 1, p. 29.
  • van Wel, J, H. P., Kinyua, J., van Nuijs, A. L. N., et al. (2016a), ‘A comparison between wastewater-based drug data and an illicit drug use survey in a selected community’, International Journal of Drug Policy 34, pp. 20–26.
  • van Wel, J. H. P., Gracia-Lor, E., van Nuijs, A. L. N., et al. (2016b), ‘Investigation of agreement between wastewater-based epidemiology and survey data on alcohol and nicotine use in a community’, Drug and Alcohol Dependence 162, pp. 170–175.
  • Yang, Z., Anglès d’Auriac, M., Goggins, S., et al. (2015) ‘A novel DNA biosensor using a ferrocenyl intercalator applied to the potential detection of human population biomarkers in wastewater’, Environmental Science and Technology 49(9), pp. 5609–5617.
  • Zuccato, E., Chiabrando, C., Castiglioni, S., Bagnati, R. and Fanelli, R. (2008), ‘Estimating community drug abuse by wastewater analysis’, Environmental Health Perspectives 116(8), pp. 1027–1032.
  • Zuccato, E., Castiglioni, S., Senta, I., et al. (2016), ‘Population surveys compared with wastewater analysis for monitoring illicit drug consumption in Italy in 2010–2014’, Drug and Alcohol Dependence 161, pp. 178–188.
  • Zuccato, E., Gracia-Lor, E., Rousis, N. I., Parabiaghi, A., Senta, I., Riva, F. and Castiglioni, S. (2017), ‘Illicit drug consumption in school populations measured by wastewater analysis’, Drug and Alcohol Dependence 178, pp. 285–290.

2. Interactive: explore the data from the study

Loading interactive feature… please wait. Note that this interactive feature requires a modern web browser. In particular, older versions of Internet Explorer (prior to 10) or Internet Explorer 10 running in 'compatibility view' may not work.

The 2019 Europe-wide study including over 70 cities revealed a picture of distinct geographical and temporal patterns of drug use across European cities. There are two ways to visualise the data from this study, either viewing the data on a map or using a specially-developed charting tool. You can switch between the two views at any point.

Preview of map based tools
Preview of charting tool

How to use the charting tool? To explore the findings of the study, select the 'city' of choice and the 'target drug'. You can compare sites or explore daily and yearly trends. Weekend means refer to the mean loads detected on Friday, Saturday, Sunday and Monday. Weekday means refer to mean loads detected on the other days of the week. The findings from 2011-2018 are included in this tool. Wastewater samples are analysed for the urinary biomarkers of the parent drug for amphetamine, methamphetamine and mdma and for the main metabolite of cocaine (benzoylecgonine) (for more information, consult the analysis section).

Filter sites

Filter results by selecting which sites to display from the list below. Note that not all sites have data entries for all possible drug, year and day values.

Select target drug:

*cocaine: refers to benzoylecgonine, the main excreted metabolite of cocaine.

Select something to visualise:

 
 

Select a year:

Select target drug*:

Explore daily patterns:

Click anywhere on the map to zoom out

Click on a location to zoom in

 
 
 
 
 
 
 
 

How to use this map? By scrolling over the bubbles, the city name and data become visible. By zooming in on your country of interest, additional cities will show allowing further exploration of the city level data in your country of interest. To further explore the findings of the study, select the ‘target drug’ and the ‘temporal pattern’ of choice. Weekend means refer to the mean loads detected on Friday, Saturday, Sunday and Monday. Weekday means refer to mean loads detected on the other days of the week. The findings from the 2011-2019 period are included in this map. Bubble sizes are not comparable between different target drugs, but are comparable within one substance. Wastewater samples are analysed for the urinary biomarkers of the parent drug for amphetamine, methamphetamine and mdma and for the main metabolite of cocaine (benzoylecgonine) (for more information: consult the analysis section)

 

Additional notes:

The graphical tool was fully updated 12 March 2020.

Population-normalised loads: All values indicate the amount of drug residues quantified in raw sewage. No values were corrected with excretion factors.

Cities with multiple sewage treatment plants (STPs): The numbers or letters in brackets specifies the STPs, which provided data for the corresponding city in this study. E.g. Berlin (4) indicates the population-weighted average of four different STPs in the city of Berlin.

Values below limit of quantification: Values below the method limit of quantification are indicated as zero.

Benzoylecgonine: this is the main excreted metabolite of cocaine.

City-specific remarks

Berlin: when merging the data for the four plants, it was taken into account the fact that no samples were collected in Berlin M in 2014 for Saturday and Sunday, in 2015 for Sunday and Monday, in 2018 for Saturday; for Berlin R in 2017 for Sunday and Monday.
Bordeaux: when merging the data for the two plants, it was taken into account the fact that no sample was collected on Wednesday in Bordeaux II in 2018.
Bratislava: in 2017 the method of estimating the population has changed (mobile phone connections, including non-permanent residents such as students) compared to previous years (based on census for permanent residents, de jure population).
Eindhoven: exhibited high values for MDMA in 2012, 2013 and 2014, which was likely due to the release of unconsumed MDMA into the sewer system. Moreover, Eindhoven exhibited very high values for amphetamine in 2013 (Ort et al., 2014). In 2018 abnormal values of MDMA and amphetamine on Monday and Tuesday were not used for the calculation of weekend/weekday means because they were influenced by discharges of unconsumed MDMA and amphetamine. Methamphetamine and amphetamine 2019 results are not shown due to abnormal values probably caused by the release of unconsumed substances into the sewer system.
Geneva: in 2019 no sample was collected on Sunday, consequently week and weekend means were calculated respectively on six and three days.
Istanbul: results labelled “Istanbul I” represents a population of less than 1 % (69,000 people) of the Greater Istanbul population. Results labelled “Istanbul II-VII” are based on six other STPs covering a population of approx. 16.5 million people.
Madrid: results are based on one of multiple STPs, covering approximately 10 % of the population. Due to working activities at the waste water plant in the sampling period of 2018 part of the normal flow was redirected towards another treatment plant; for this reason the population used for normalization of 2018 results was lower (n=227,869).
Saarbrucken: data for 2018 derive from the merging of two plants for all substances but methamphetamine, for which values were above the level of quantification in one STP only.
Santiago: in 2019 no sample was collected on Thursday, while samples were collected on two Tuesdays; consequently the weekly averages were calculated using the samples of two Tuesdays and no Thursdays.
Stockholm: results labelled “Stockholm (2)” reflect the population-weighted average of two separate inlets from two Stockholm catchments, treated in the same STP. In 2019 samples were collected during one week in April and one week in October; the 2019 results presented are an average of the two weeks.
Velenje: in 2019 no sample was collected on Thursday, while samples were collected on two Tuesdays; consequently the weekly averages were calculated using the samples of two Tuesdays and no Thursdays.

3. Terms and definitions

In addition to the glossary below, see also Frequently-asked questions on wastewater-based epidemiology and drugs.

Back-calculation 

Back-calculation is the process whereby researchers calculate/estimate the consumption of illicit drugs in the population based on the amounts of the target drug residue entering the wastewater treatment plant.

LC-MS/MS

Liquid chromatography–tandem mass spectrometry (LC-MS/MS) is the analytical method most commonly used to quantify drug residues in wastewater. LC-MS/MS is an analytical chemistry technique that combines the separation techniques of liquid chromatography with the analysis capabilities of mass spectrometry. Considering the complexity and the low concentrations expected in wastewater, LC-MS/MS is one of the most powerful techniques for this analysis, because of its sensitivity and selectivity.

Metabolite

Traces of drugs consumed will end up in the sewer network either unchanged or as a mixture of metabolites. Metabolites, the end products of metabolism, are the substances produced when the body breaks drugs down.

Residue

Wastewater analysis is based on the fact that we excrete traces in our urine of almost everything we consume, including illicit drugs. The target drug residue is what remains in the wastewater after excretion and is used to quantify the consumption of illicit drugs in the population.

Urinary biomarkers

Analytical chemists look for urinary biomarkers (measurable characteristics to calculate population drug use) in wastewater samples, which can be the parent drug (i.e. the primary substance) or its urinary metabolites.

Enantiomeric profiling

Enantiomeric profiling is an analytical chemistry technique used to determine if studied drugs in wastewater originate from consumption or direct disposal (eq. production waste). It is based on the fact that chiral molecules (if only one chiral centre is present) exist as two enantiomers (opposite forms) which are non-superimposable mirror images of each other. As the enantiomeric ratio will change after human metabolism, the enantiomeric fraction can be used to determine whether the studied drugs in wastewater originate from consumption.

4. Understanding the wastewater method, and addressing ethical issues

In order to estimate levels of drug use from wastewater, researchers attempt first to identify and quantify drug residues, and then to back-calculate the amount of the illicit drugs used by the population served by the sewage treatment plants (Castiglioni et al., 2014). This approach involves several steps (see figure). Initially, composite samples of untreated wastewater are collected from the sewers in a defined geographical area. The samples are then analysed to determine the concentrations of the target drug residues. Following this, the drug use is estimated through back-calculation by multiplying the concentration of each target drug residue (nanogram/litre) with the corresponding flow of sewage (litre/day). A correction factor for each drug is taken into account as part of the calculation. In a last step, the result is divided by the population served by the wastewater treatment plant, which shows the amount of a substance consumed per day per 1 000 inhabitants. Population estimates can be calculated using different biological parameters, census data, number of house connections, or the design capacity, but the overall variability of different estimates is generally very high.

flow chart

Although primarily used to study trends in illicit drug consumption in the general population, wastewater analysis has also been applied to small communities, including workplaces, schools (Zuccato et al., 2017), music festivals, prisons (Nefau et al., 2017) and specific neighbourhoods (Hall et al., 2012).

Using this method in small communities can involve ethical risks (Prichard et al., 2014), such as possible identification of a particular group within the community.

In 2016 the SCORE group published ethical guidelines for wastewater-based epidemiology and related fields (Prichard et al., 2016). The objective of these guidelines is to outline the main potential ethical risks for wastewater research and to propose strategies to mitigate those risks. Mitigating risks means reducing the likelihood of negative events and/or minimising the consequences of negative events.

References

  • Castiglioni, S., Thomas, K. V., Kasprzyk-Hordern, B., Vandam, L. and Griffiths, P. (2014), ‘Testing wastewater to detect illicit drugs: State of the art, potential and research needs’, Science of the Total Environment 487, pp. 613–620.
  • Hall, W., Prichard, J., Kirkbride, P., et al. (2012), ‘An analysis of ethical issues in using wastewater analysis to monitor illicit drug use’, Addiction 107(10), pp. 1767–1773.
  • Néfau, T., Sannier, O., Hubert, C., Karolak, S., Lévi, Y. (2017), ‘Analysis of drugs in sewage: an approach to assess substance use, applied to a prison setting’, Observatoire Français des Drogues et des Toxicomanies, Paris.
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