Research project DR/32 (Research action DR)
Cocaine is an addictive substance used as drug of abuse. The use of cocaine has direct physical and physiological effects, such as central nervous system overstimulation, altered serotonine levels, an increased lifetime risk of heart attack, and pulmonary complications. The recreational use of cocaine has increased dramatically over the last 25 years because of its increased availability and production. The trends of drug abuse are currently estimated indirectly from population surveys, consumer interviews, individual medical records and crime statistics. However, these general indicators most likely do not realistically represent the local use of cocaine. A new, more direct and realistic approach for the estimation of cocaine usage is based on the measurement of urinary excretion products of cocaine in the local waste- and surface waters. In humans, only a fraction of cocaine is excreted in urine as parent compound, while the largest amount is excreted as benzoylecgonine (BE), the most common metabolite that is also used to obtain evidence of cocaine use.
The COWAT project aims at monitoring cocaine and its metabolites in a number of representative wastewater streams and surface waters covering the whole surface of Belgium. Sampling sites will be situated in water courses upstream and downstream of the most important urban agglomerations. Furthermore, the influents of important domestic wastewater treatment plants (WWTPs), together with several reference sites will also be sampled. Two sampling approaches will be compared, i.e. the classical water sampling procedure providing a daily average of the contamination and an approach using passive samplers which integrate contamination over several weeks. The sampling campaign will include ~40 WWTPs and ~40 surface water sites, which should provide a clear picture regarding the release of cocaine and related compounds in Belgium. Since the stability of cocaine is temperature-dependent, the sampling sites will be monitored in two seasons, 4-5 months from each other. Additionally, samples are to be taken on the Monday and Friday of each sampling week, the days of expected peak and through concentrations. Water samples will be filtered to separate the dissolved phase from suspended matter. The analysis of cocaine and its metabolites will be done on both fractions. Passive samplers will also be deployed during the same period at 10 sites and will remain in the water for several weeks.
Both reference and water courses with expected high levels of cocaine and/or BE will be selected based upon data delivered by the Belgian District Courts (judicial data). Sampling sites will be situated in water courses upstream and downstream of the most important urban agglomerations in Belgium. The exact location of the sites will be defined in consultation with the ‘Vlaamse Milieu Maatschappij’ (VMM) and Aquafin for Flanders, with the ‘Direction Générale des Ressources Naturelles et de l'Environnement’ (DGRNE) for the Walloon provinces and the ‘Compagnie Intercommunale Bruxelloise des Eaux’ (CIBE) for Brussels.
An important objective of the COWAT project is the optimization and validation of the analytical procedure, with emphasis on the suitability of solid-phase extraction and of liquid chromatography-tandem mass spectrometry (LC/MS-MS). As a novelty, all major metabolites of cocaine (e.g. benzoylecgonine, ecgonine methyl ester and ecgonine) will be investigated together with cocaine. An interlaboratory analytical validation exercise will be organized to evaluate the analytical procedures and to assess the inter-laboratory variability.
The environmental levels of a drug of abuse and/or its metabolites, together with their pharmacokinetics, metabolism and environmental fate, can be used to assess the drug consumption. The proposed models will use data on the number of people served by a waste water treatment plant or living in the river’s catchment basin (provided by VMM, DGRNE, and CIBE), the age distribution of the local population and the estimated average dose of cocaine used per day (data obtained from statistics and questionnaires). Sampling at different days (before and after a weekend) will allow estimating the weekly fluctuation in cocaine usage by the local population, while passive integrative sampling will allow for trend assessment in cocaine usage within a certain time frame (e.g. weeks to months). An estimate of the local consumption will be obtained from all available information at the level of local community: yearly statistics from Vereniging voor Alcohol-en Drugsproblemen, the Scientific Institute of Public Health and as well as from the Department of Justice.
Finally, a monitoring strategy and protocol will be proposed that can be used for routine application in the environmental cocaine screening for drug abuse management and control puroposes.
Cocaïne en metabolieten in Belgische afval- en oppervlaktewateren (COWAT) = Cocaïne et ses métabolites dans les eaux de surface et les eaux de stations d'épuration en Belgique (COWAT°
van Nuijs, Alexander - Pecceu, Bert - Theunis, Laetitia ... et al Brussel : Federaal Wetenschapsbeleid, 2008 (SP1898)
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Cocaïne en metabolieten in Belgische afval- en oppervlaktewateren : samenvatting
Brussel : Federaal Wetenschapsbeleid, 2008 (SP1917)
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Cocaïne et ses métabolites dans les eaux de surface et les eaux de stations
d’épuration en Belgique : résumé
Bruxelles : Politique scientifique fédérale, 2008 (SP1918)
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Cocaine and its metabolites in surface and waste water in Belgium : summary
Brussels : Belgian Science Policy, 2008 (SP1919)
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