title: Estimating daily and diurnal variations of illicit drug use in Hong Kong: a pilot study of using wastewater analysis in an Asian metropolitan city.
abstract: The measurement of illicit drug metabolites in raw wastewater is increasingly being adopted as an approach to objectively monitor population-level drug use, and is an effective complement to traditional epidemiological methods. As such, it has been widely applied in western countries. In this study, we utilised this approach to assess drug use patterns over nine days during April 2011 in Hong Kong. Raw wastewater samples were collected from the largest wastewater treatment plant serving a community of approximately 3.5 million people and analysed for excreted drug residues including cocaine, ketamine, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA) and key metabolites using liquid chromatography coupled with tandem mass spectrometry. The overall drug use pattern determined by wastewater analysis was consistent with that have seen amongst people coming into contact with services in relation to substance use; among our target drugs, ketamine (estimated consumption: 1400-1600 mg/day/1000 people) was the predominant drug followed by methamphetamine (180-200 mg/day/1000 people), cocaine (160-180 mg/day/1000 people) and MDMA (not detected). The levels of these drugs were relatively steady throughout the monitoring period. Analysing samples at higher temporal resolution provided data on diurnal variations of drug residue loads. Elevated ratios of cocaine to benzoylecgonine were identified unexpectedly in three samples during the evening and night, providing evidence for potential dumping events of cocaine. This study provides the first application of wastewater analysis to quantitatively evaluate daily drug use in an Asian metropolitan community. Our data reinforces the benefit of wastewater monitoring to health and law enforcement authorities for strategic planning and evaluation of drug intervention strategies.
authors: The University of Queensland, The National Research Centre for Environmental Toxicology (Entox), 39 Kessels Road, Coopers Plains, QLD 4108, Australia. Electronic address: foon.lai@uqconnect.edu.au.
authors: Foon Yin
authors: FY
authors: Lai
authors: Raimondo
authors: R
authors: Bruno
authors: Ho Wing
authors: HW
authors: Leung
authors: Phong K
authors: PK
authors: Thai
authors: Christoph
authors: C
authors: Ort
authors: Steve
authors: S
authors: Carter
authors: Kristie
authors: K
authors: Thompson
authors: Paul K S
authors: PK
authors: Lam
authors: Jochen F
authors: JF
authors: Mueller
mesh_terms: D002853:Chromatography, Liquid; D003042:Cocaine / Q000031:analogs & derivatives / Q000032:analysis; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D007649:Ketamine / Q000031:analogs & derivatives / Q000032:analysis; D008694:Methamphetamine / Q000032:analysis; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000032:analysis; D009294:Narcotics / Q000032:analysis*; D010865:Pilot Projects; D015813:Substance Abuse Detection / Q000379:methods*; D019966:Substance-Related Disorders / Q000453:epidemiology*; D053719:Tandem Mass Spectrometry; D013997:Time Factors; D014505:Urban Population; D062065:Wastewater / Q000737:chemistry*
chemical_list: D003042:Cocaine; D007649:Ketamine; D008694:Methamphetamine; D018817:N-Methyl-3,4-methylenedioxyamphetamine; D009294:Narcotics; D062065:Wastewater; C005618:benzoylecgonine; C033419:norketamine
keywords: China; Cocaine; Ketamine; MDMA; Methamphetamine; Substance consumption