TY - JOUR

T1 - Critical review on the stability of illicit drugs in sewers and wastewater samples

AU - McCall, Ann Kathrin

AU - Bade, Richard

AU - Kinyua, Juliet

AU - Lai, Foon Yin

AU - Thai, Phong K.

AU - Covaci, Adrian

AU - Bijlsma, Lubertus

AU - van Nuijs, Alexander L.N.

AU - Ort, Christoph

N1 - Funding Information: Financial support by the European Union's Seventh Framework Program for research, technological development and demonstration SEWPROF (project no. 317205 ) is gratefully acknowledged. Phong Thai is partly supported by a UQ Postdoctoral Research Fellowship and a QUT VC Research Fellowship. Alexander van Nuijs acknowledges a post-doctoral fellowship from Flanders Funds for Scientific Research (FWO). Lubertus Bijlsma acknowledges the financial support from Generalitat Valenciana (Group of Excellence Prometeo 2009/054 , Prometeo II 2014/023 ; Collaborative Research on Environment and Food Safety ISIC/2012/016 ). Special thanks to Julianne McCall for proofreading the manuscript. Publisher Copyright: © 2015 Elsevier Ltd.

PY - 2016/1/1

Y1 - 2016/1/1

N2 - Wastewater-based epidemiology (WBE) applies advanced analytical methods to quantify drug residues in wastewater with the aim to estimate illicit drug use at the population level. Transformation processes during transport in sewers (chemical and biological reactors) and storage of wastewater samples before analysis are expected to change concentrations of different drugs to varying degrees. Ignoring transformation for drugs with low to medium stability will lead to an unknown degree of systematic under- or overestimation of drug use, which should be avoided. This review aims to summarize the current knowledge related to the stability of commonly investigated drugs and, furthermore, suggest a more effective approach to future experiments. From over 100 WBE studies, around 50 mentioned the importance of stability and 24 included tests in wastewater. Most focused on in-sample stability (i.e., sample preparation, preservation and storage) and some extrapolated to in-sewer stability (i.e., during transport in real sewers). While consistent results were reported for rather stable compounds (e.g., MDMA and methamphetamine), a varying range of stability under different or similar conditions was observed for other compounds (e.g., cocaine, amphetamine and morphine). Wastewater composition can vary considerably over time, and different conditions prevail in different sewer systems. In summary, this indicates that more systematic studies are needed to: i) cover the range of possible conditions in sewers and ii) compare results more objectively. To facilitate the latter, we propose a set of parameters that should be reported for in-sewer stability experiments. Finally, a best practice of sample collection, preservation, and preparation before analysis is suggested in order to minimize transformation during these steps.

AB - Wastewater-based epidemiology (WBE) applies advanced analytical methods to quantify drug residues in wastewater with the aim to estimate illicit drug use at the population level. Transformation processes during transport in sewers (chemical and biological reactors) and storage of wastewater samples before analysis are expected to change concentrations of different drugs to varying degrees. Ignoring transformation for drugs with low to medium stability will lead to an unknown degree of systematic under- or overestimation of drug use, which should be avoided. This review aims to summarize the current knowledge related to the stability of commonly investigated drugs and, furthermore, suggest a more effective approach to future experiments. From over 100 WBE studies, around 50 mentioned the importance of stability and 24 included tests in wastewater. Most focused on in-sample stability (i.e., sample preparation, preservation and storage) and some extrapolated to in-sewer stability (i.e., during transport in real sewers). While consistent results were reported for rather stable compounds (e.g., MDMA and methamphetamine), a varying range of stability under different or similar conditions was observed for other compounds (e.g., cocaine, amphetamine and morphine). Wastewater composition can vary considerably over time, and different conditions prevail in different sewer systems. In summary, this indicates that more systematic studies are needed to: i) cover the range of possible conditions in sewers and ii) compare results more objectively. To facilitate the latter, we propose a set of parameters that should be reported for in-sewer stability experiments. Finally, a best practice of sample collection, preservation, and preparation before analysis is suggested in order to minimize transformation during these steps.

KW - Biodegradation

KW - Psychoactive substances

KW - Sample preservation

KW - Sewage epidemiology

KW - Transformation

U2 - 10.1016/j.watres.2015.10.040

DO - 10.1016/j.watres.2015.10.040

M3 - Review

C2 - 26618807

AN - SCOPUS:84962738413

VL - 88

SP - 933

EP - 947

JO - Water Research

JF - Water Research

SN - 0043-1354

ER -