title: Illicit drug consumption estimations derived from wastewater analysis: a critical review.
abstract: The consumption of illicit drugs causes indisputable societal and economic damage. Therefore it is necessary to know their usage levels and trends for undertaking targeted actions to reduce their use. Recently, a new approach (namely sewage epidemiology) was developed for the estimation of illicit drug use based on measurements of urinary excreted illicit drugs and their metabolites in untreated wastewater. This review aims at critically evaluating the published literature and identifying research gaps of sewage epidemiology. Firstly, the existing analytical procedures for the determination of the four most used classes of illicit drugs worldwide (cannabis, cocaine, opiates and amphetamine-like stimulants) and their metabolites in wastewater are summarized and discussed. The focus lies on the sample preparation and on the analysis with chromatographic techniques coupled to mass spectrometry. Secondly, back-calculations used to transform measured concentrations in wastewater (in ng/L) into an amount of used illicit drug (in g/day per 1000 inhabitants or doses/day per 1000 inhabitants) are discussed in detail for the four groups of illicit drugs. Sewage epidemiology data from Spain, Belgium, UK, Italy, Switzerland and USA are summarized and compared with data from international organisations, such as the European Monitoring Centre for Drug and Drug Addiction (EMCDDA) and the United Nations Office on Drugs and Crime (UNODC). The results derived from wastewater analysis show in general good agreement with existing prevalence data (percentage of a population that uses illicit drugs at a given time) and demonstrate the potential of sewage epidemiology. However, this review confirms that future work should focus on further optimisation and standardisation of various important parameters (e.g. sample collection and back-calculations). In the future, sewage epidemiology could be used in routine drug monitoring campaigns as a valuable tool in addition to the classical socio-epidemiological studies for the determination of local, national and international illicit drug use.
authors.affiliation: Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium.
authors.forename: Alexander L N
authors.initials: AL
authors.lastname: van Nuijs
authors.forename: Sara
authors.initials: S
authors.lastname: Castiglioni
authors.forename: Isabela
authors.initials: I
authors.lastname: Tarcomnicu
authors.forename: Cristina
authors.initials: C
authors.lastname: Postigo
authors.forename: Miren
authors.initials: M
authors.lastname: Lopez de Alda
authors.forename: Hugo
authors.initials: H
authors.lastname: Neels
authors.forename: Ettore
authors.initials: E
authors.lastname: Zuccato
authors.forename: Damia
authors.initials: D
authors.lastname: Barcelo
authors.forename: Adrian
authors.initials: A
authors.lastname: Covaci
mesh_terms: D001530:Belgium / Q000453:epidemiology; D002853:Chromatography, Liquid; D004784:Environmental Monitoring / Q000379:methods*; D062665:Epidemiological Monitoring; D006801:Humans; D013287:Illicit Drugs / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D007558:Italy / Q000453:epidemiology; D013058:Mass Spectrometry; D011159:Population Surveillance / Q000379:methods*; D012722:Sewage / Q000737:chemistry*; D012959:Socioeconomic Factors; D013030:Spain / Q000453:epidemiology; D019966:Substance-Related Disorders / Q000453:epidemiology*; D013557:Switzerland / Q000453:epidemiology; D006113:United Kingdom / Q000453:epidemiology; D014481:United States / Q000453:epidemiology; D014865:Waste Disposal, Fluid
chemical_list: D013287:Illicit Drugs; D012722:Sewage