Comparison of data from WBE with other sources A summary of findings Been F., Lai F. Y., van Nuijs A. L. N., Covaci A.

Why would you want to compare? “Realising the full potential of wastewater-based information will depend on integrating it into the existing set of epidemiological indicators“ EMCDDA Insights 22; Assessing illicit drugs in wastewater: advances in wastewater-based drug epidemiology, 2016  “Realising the full potential of wastewater-based information will depend on integrating it into the existing set of epidemiological indicators“ EMCDDA Insights 22; Assessing illicit drugs in wastewater: advances in wastewater-based drug epidemiology, 2016 

Why would you want to compare? Measuring drug use General population surveys Deaths & Mortality Infectious diseases Problem drug use Treatment demand Law enforcement Wastewater-based epidemiology Measuring drug use General population surveys Deaths & Mortality Infectious diseases Problem drug use Treatment demand Law enforcement Wastewater-based epidemiology WBE is only one piece of the puzzle

Complementarity Surveys and other indicators Wastewater analysis Consumption Consumers Illicit drug loads [Milligrams per day per 1000 inhabitants] Prevalence Treatment Seizures …

International studies European multi-city study

International studies Cities across Europe 2011: 19 cities …. 2017: 50 cities Illicit drug loads [Milligrams per day per 1000 inhabitants] Prevalence At the time, the estimated illicit drug loads measured from wastewater analysis were compared to prevalence figures. In particular using data which was derived from the European Drug Report of 2012 and 2013.

International studies Cocaine Findings 2011-2013 Wastewater: stable use Other indicators: decline 2016 Wastewater: increased use European drug report: Increased availability (seizures) Stable prevalence Wastewater as an early warning of an upcoming surge in cocaine use? Looking at cocaine as an example, in 2013 WBE showed that consumption was overall stable Other indicators mentioned in the Eu Drug Report were on the other hand suggesting a decline. 3 years later, WBE results reported in the Eu Drug Report indicate that there had been an increase This appears to be confirmed by an increased availability, based on seizures, yet prevalence estimates indicate that consumption has remained stable. Looking at this data one might ask whether WBE (and seizures) are not suggesting a potential upcoming increase in COC use across europe

International studies Alcohol Wastewater 1 week, 2014, 20 cities Comparisons WHO: Global Status Report on Alcohol and Health Sales Surveys

International studies Alcohol Findings Wastewater: daily consumption higher for 11/20 cities compared to WHO Cities might be different than entire countries Longer sampling periods could potentially provide different results Interestingly, comparison of WBE results about alcohol use and figures from the WHO show that actual consumption appears to be higher to current figures in 11/22 cities across the world. However…

International studies Alcohol Findings Correlation with illicit drug use (from wastewater analysis)

National studies Italy Wastewater: 1 week, 2011-2014, 17 cities General population surveys (mail) 2010, 2012, 2014 NE, NW, Centre and S Stratified, 18-24y/25-34y/35-64y Last-month prevalence

National studies Italy Findings Overall WBE and GPS gave similar results Substance GPS [last month prevalence %] WBE [back-calculated consumption g/day 1000 inhab] Cannabis (THC) 3.0 4.35 (THC) Cocaine 0.43 0.78 Opioids 0.17 0.092 (Heroin) Amphetamines 0.14 0.103 (MA + MDMA) Time trends Period GPS [last month prevalence %] WBE [back-calculated consumption g/day 1000 inhab] 2010-2012 Amphetamines: -86% Opioids: -53% Cannabis: -39% Cocaine: -39% MA + MDMA: -87% Heroin: -29% Cannabis: +3% Cocaine: ND 2012-2014 Amphetamines: ND Opioids: ND Cannabis: +102% MA + MDMA: ND Heroin: ND Cannabis:+48%

National studies Finland Wastewater Complementary data 1, week, 14 cities, 2012 and 2014 Almost 40% of Finnish population Complementary data DUID statistics Seizures data Market size estimates

National studies Finland Findings Amphetamine dominates Confirmed increase by all indicators Increased purity in recent years Methamphetamine stable MDMA marked increase (WBE and DUID) Cocaine increasing popularity (all indicators)

Regional studies Mid-sized city – Switzerland Wastewater Two samples per week every second week 15 months (October ’13 – December ’14) Complementary data GPS (prevalence) Web-surveys (consumption habits) Purity (forensic) Surveys Forensic analysis Waste water Estimate cannabis use

Regional studies Mid-sized city – Switzerland Estimates Model Daily cannabis consumption [g.day-1.1000inhab-1] Number of users Prevalence (12 months) Epidemiological data only Estimate 8.1 11’830 6.2% 95% CI 3.8 - 13.8 7’078 – 16’860 5.3 - 7.1% Wastewater data only 17.2 - 5.0 - 51.3 Epidemiological and wastewater data 14.0 19010 9.4% 8.9 - 22.0 13’370 – 26’720 8.5 - 10.5% Model Daily cannabis consumption [g.day-1.1000inhab-1] Number of users Prevalence (12 months) Epidemiological data only Estimate 8.1 11’830 6.2% 95% CI 3.8 - 13.8 7’078 – 16’860 5.3 - 7.1% Model Daily cannabis consumption [g.day-1.1000inhab-1] Number of users Prevalence (12 months) Epidemiological data only Estimate 8.1 11’830 6.2% 95% CI 3.8 - 13.8 7’078 – 16’860 5.3 - 7.1% Wastewater data only 17.2 - 5.0 - 51.3

Conclusion WBE appears to anticipate results from GPS and other indicators  Early warning Provides more easily temporal and geographical information If a sufficient number of samples is collected Figures from other indicators are and remain vital

Conclusion Additional efforts are required Beyond comparisons with prevalence Develop interpretative frameworks including WBE and other indicators Prevalence Consumption habits User types Consumption estimates (WBE) … Uncertainties Inference approaches

Added value Corroborate/ confute Refine estimates Evaluate Policies Hypotheses Prevalence Prevention programs Trends Users Quantities Market size

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