Illicit Drugs in the Environment E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Serie: Wiley-Interscience Series on Mass Spectrometry
• Sprache: Englisch

Seitenzahl: 580

Veröffentlichungsjahr: 2011

Beschreibung

Illicit drugs are an emerging class of environmental contaminants and mass spectrometry is the technique of choice for their analysis. This landmark reference discusses the analytical techniques used to detect illicit drugs in wastewater and surface water, details how to estimate the levels of contaminants in the environment, and explores the behavior, fate, and toxic effects of this new class of contaminants, now a ubiquitous presence in wastewater and surface water. The book details how an estimate of illicit drug consumption in a given population can be developed from an analysis of the residues of illicit drugs in wastewater. An important resource for analytical chemists, environmental researchers, forensic scientists, biologists, and toxicologists.

Leseprobe

Contents

Cover

Series

Title Page

Copyright

Preface

PRESENTATION OF THE BOOK

STATE-OF-THE-ART

ORGANIZATION OF THE BOOK

Contributors

SECTION I: INTRODUCTION

Chapter 1: Illicit Drugs and the Environment

1.1 INTRODUCTION

1.2 WHAT IS AN “ILLICIT” DRUG?

1.3 DIFFERENCES DIFFERENCES BETWEEN ILLICIT AND LICIT DRUGS AS ENVIRONMENTAL CONTAMINANTS

1.4 THE CORE ILLICIT DRUGS AND THE ENVIRONMENT

1.5 LARGE-SCALE EXPOSURE OR SOURCE ASSESSMENTS VIA DOSE RECONSTRUCTION

1.6 ILLICIT DRUGS AND ENVIRONMENTAL IMPACT

1.7 THE FUTURE

ACKNOWLEDGMENT

SECTION II: THE PHYSIOLOGY OF ILLICIT DRUGS

Chapter 2: Metabolism and Excretion of Illicit Drugs in Humans

2.1 INTRODUCTION

2.2 COCAINE

2.3 OPIOIDS

SECTION III: MASS SPECTROMETRY IN ILLICIT DRUGS DETECTION AND MEASUREMENT – CURRENT AND NOVEL ENVIRONMENTAL APPLICATIONS

Chapter 3: Analytical Methods for the Detection of Illicit Drugs in Wastewaters and Surface Waters

3.1 INTRODUCTION

3.2 SAMPLE PREPARATION

3.3 CHROMATOGRAPHY AND MASS SPECTROMETRY ANALYSIS

3.4 ADVANCED HIGH-RESOLUTION APPROACHES

3.5 CONCLUDING REMARKS

Chapter 4: Wide-Scope Screening of Illicit Drugs in Urban Wastewater by UHPLC–QTOF MS

4.1 TOF AND QTOF MS ANALYSIS

4.2 ANALYTICAL STRATEGIES FOR THE DETERMINATION OF ILLICIT DRUGS IN THE ENVIRONMENT

4.3 SCREENING BY UHPLC–QTOF MS

4.4 CONCLUSIONS

Chapter 5: Determination of Illicit Drugs in the Water Cycle by LC−Orbitrap MS

5.1 INTRODUCTION

5.2 ORBITRAP MASS SPECTROMETRY

5.3 METHODS AND MATERIALS

5.4 RESULTS

5.5 CONCLUSIONS

5.6 ACKNOWLEDGMENT

SECTION IVA: MASS SPECTROMETRIC ANALYSIS OF ILLICIT DRUGS IN THE ENVIRONMENT

Chapter 6: Occurrence of Illicit Drugs in Wastewater in Spain

6.1 Introduction

6.2 WASTEWATER ANALYSIS

6.3 OCCURRENCE OF ILLICIT DRUGS AND METABOLITES IN INFLUENT WASTEWATER

6.4 OCCURRENCE OF ILLICIT DRUGS AND METABOLITES IN EFFLUENT WASTEWATER

6.5 REMOVAL OF ILLICIT DRUGS AND METABOLITES IN WASTEWATER TREATMENT PLANTS

6.6 EFFECT OF DISCHARGED TREATED WASTEWATER ON SURFACE WATER QUALITY

6.7 CONCLUSIONS

ACKNOWLEDGMENTS

Chapter 7: Occurrence of Illicit Drugs in Wastewater and Surface Water in Italy

7.1 INTRODUCTION

7.2 ANALYTICAL METHODOLOGY

7.3 ILLICIT DRUGS IN WASTEWATER

7.4 REMOVAL OF ILLICIT DRUGS IN WWTPS

7.5 ILLICIT DRUGS IN SURFACE WATER

7.6 CONCLUSION

Chapter 8: Occurrence of Illicit Drugs in Surface Water and Wastewater in the UK

8.1 INTRODUCTION

8.2 ABUSE OF ILLICIT DRUGS IN THE UNITED KINGDOM

8.3 OCCURRENCE OF ILLICIT DRUGS IN WASTEWATER AND SURFACE WATER IN THE UNITED KINGDOM

8.4 EFFECT OF SEASONAL VARIATIONS AND VARIABLE FLOW CONDITIONS ON ILLICIT DRUG CONCENTRATIONS IN WELSH RIVERS

8.5 ILLICIT DRUGS IN THE UNITED KINGDOM AQUEOUS ENVIRONMENT IN THE CONTEXT OF EUROPEAN FINDINGS

8.6 CONCLUSIONS AND FUTURE RESEARCH DIRECTION

Chapter 9: On the Frontier: Analytical Chemistry and the Occurrence of Illicit Drugs in Surface Waters in the United States

9.1 INTRODUCTION

9.2 PHYSICOCHEMICAL PROPERTIES OF ILLICIT DRUGS

9.3 SAMPLING OF ILLICIT DRUGS IN SURFACE WATERS

9.4 ANALYTICAL METHODS FOR ILLICIT DRUGS

9.5 CONCLUSIONS

ACKNOWLEDGMENTS

Chapter 10: Monitoring Nonprescription Drugs in Surface Water in Nebraska (USA)

10.1 INTRODUCTION

10.2 USE OF PASSIVE SAMPLERS FOR MONITORING OCCURRENCE AND FATE OF ILLICIT DRUGS IN SURFACE WATERS

10.3 DETERMINATION OF LABORATORY UPTAKE RATES FOR PHARMACEUTICALS

10.4 OCCURRENCE OF ILLICIT DRUGS IN NEBRASKA SURFACE WATERS INFLUENCED BY WWTP EFFLUENT

10.5 FATE OF ILLICIT DRUGS IN SURFACE WATERS DOWNSTREAM OF WWTP DISCHARGES

SECTION IVB: MASS SPECTROMETRIC ANALYSIS OF ILLICIT DRUGS IN THE ENVIRONMENT

Chapter 11: Presence and Removal of Illicit Drugs in Conventional Drinking Water Treatment Plants

11.1 ILLICIT DRUGS IN DRINKING WATER

11.2 ILLICIT DRUGS THROUGH DRINKING WATER TREATMENT

11.3 DISINFECTION BY-PRODUCTS

11.4 ANALYSIS OF DRINKING WATER SAMPLES: A REAL CASE STUDY

11.5 CONCLUDING REMARKS

Chapter 12: Analysis of Illicit Drugs in Water Using Direct-Injection Liquid Chromatography-Tandem Mass Spectrometry

12.1 INTRODUCTION

12.2 EXPERIMENTAL STUDIES

12.3 RESULTS

12.4 CONCLUSIONS

SECTION IVC: MASS SPECTROMETRIC ANALYSIS OF ILLICIT DRUGS IN THE ENVIRONMENT

Chapter 13: Psychotropic Substances in Urban Airborne Particulates

13.1 INTRODUCTION

13.2 CHEMICAL APPROACH TO MONITORING PSYCHOTROPIC SUBSTANCES

13.3 CONCENTRATIONS AND SOURCES OF PSYCHOTROPIC SUBSTANCES IN AIR

13.4 FUTURE NEEDS AND FIELDS OF INVESTIGATION

ACKNOWLEDGMENTS

SECTION V: APPLICATIONS OF ILLICIT DRUG ANALYSIS IN THE ENVIRONMENT

Chapter 14: Illicit Drugs in the Environment: Implication for Ecotoxicology

14.1 LITERATURE REVIEW

14.2 RISK ASSESSMENT

14.3 GENERAL CONCLUSIONS AND FUTURE DIRECTIONS

Chapter 15: Drug Addiction – Potential of a New Approach to Monitoring Drug Consumption

15.1 INTRODUCTION

15.2 DRUG MONITORING IN EUROPE AND THE WORLD

15.3 THE WATER HAS KNOWLEDGE AND MEMORY

15.4 SUMMARY: “WASTEWATER DATA” - THE WWTP AS A PUBLIC “BODY”

Chapter 16: Assessing Illicit Drug Consumption by Wastewater Analysis: History, Potential, and Limitation of a Novel Approach

16.1 INTRODUCTION

16.2 METHOD OF CALCULATION

16.3 RESULTS AND DISCUSSION

Chapter 17: Cocaine and Metabolites in Wastewater as a Tool to Calculate Local and National Cocaine Consumption Prevalence in Belgium

17.1 INTRODUCTION

17.2 ANALYTICAL ASPECTS OF THE DETERMINATION OF COCAINE AND METABOLITES IN WASTEWATER AND SAMPLE COLLECTION

17.3 BACK-CALCULATION OF COCAINE CONSUMPTION FROM CONCENTRATIONS OF COC, BE, AND EME IN WASTEWATER

17.4 LOCAL AND NATIONAL RESULTS OF COCAINE CONSUMPTION IN BELGIUM

17.5 CONCLUSIONS AND FUTURE TRENDS AND RESEARCH

ACKNOWLEDGMENTS

Chapter 18: Measurement of Illicit Drug Consumption in Small Populations: Prognosis for Noninvasive Drug Testing of Student Populations

18.1 INTRODUCTION

18.2 EXPERIMENTAL

18.3 RESULTS AND DISCUSSION

18.4 CONCLUSION

SECTION VI: CONCLUSIONS

Chapter 19: Conclusions and Future Perspectives

Index

WILEY-INTERSCIENCE SERIES IN MASS SPECTROMETRY

Series Editors

Dominic M. DesiderioDepartments of Neurology and BiochemistryUniversity of Tennessee Health Science Center

Nico M. M. NibberingVrije Universiteit Amsterdam, The Netherlands

John R. de Laeter • Applications of Inorganic Mass Spectrometry

Michael Kinter and Nicholas E. Sherman • Protein Sequencing and Identification Using Tandem Mass Spectrometry

Chhabil Dass • Principles and Practice of Biological Mass Spectrometry

Mike S. Lee • LC/MS Applications in Drug Development

Jerzy Silberring and Rolf Eckman • Mass Spectrometry and Hyphenated Techniques in Neuropeptide Research

J. Wayne Rabalais • Principles and Applications of Ion Scattering Spectrometry: Surface Chemical and Structural Analysis

Mahmoud Hamdan and Pier Giorgio Righetti • Proteomics Today: Protein Assessment and Biomarkers Using Mass Spectrometry, 2D Electrophoresis, and Microarray Technology

Igor A. Kaltashov and Stephen J. Eyles • Mass Spectrometry in Biophysics: Confirmation and Dynamics of Biomolecules

Isabella Dalle-Donne, Andrea Scaloni, and D. Allan Butterfield • Redox Proteomics: From Protein Modifications to Cellular Dysfunction and Diseases

Silas G. Villas-Boas, Ute Roessner, Michael A.E. Hansen, Jorn Smedsgaard, and Jens Nielsen • Metabolome Analysis: An Introduction

Mahmoud H. Hamdan • Cancer Biomarkers: Analytical Techniques for Discovery

Chabbil Dass • Fundamentals of Contemporary Mass Spectrometry

Kevin M. Downard (Editor) • Mass Spectrometry of Protein Interactions

Nobuhiro Takahashi and Toshiaki Isobe • Proteomic Biology Using LC-MS: Large Scale Analysis of Cellular Dynamics and Function

Agnieszka Kraj and Jerzy Silberring (Editors) • Proteomics: Introduction to Methods and Applications

Ganesh Kumar Agrawal and Randeep Rakwal (Editors) • Plant Proteomics: Technologies, Strategies, and Applications

Rolf Ekman, Jerzy Silberring, Ann M. Westman-Brinkmalm, and Agnieszka Kraj (Editors) • Mass Spectrometry: Instrumentation, Interpretation, and Applications

Christoph A. Schalley and Andreas Springer • Mass Spectrometry and Gas-Phase Chemistry of Non-Covalent Complexes

Riccardo Flamini and Pietro Traldi • Mass Spectrometry in Grape and Wine Chemistry

Mario Thevis • Mass Spectrometry in Sports Drug Testing: Characterization of Prohibited Substances and Doping Control Analytical Assays

Sara Castiglioni, Ettore Zuccato, and Roberto Fanelli • Illicit Drugs in the Environment: Occurrence, Analysis, and Fate Using Mass Spectrometry

Copyright © 2011 by John Wiley & Sons, Inc. All rights reserved.

Published by John Wiley & Sons, Inc., Hoboken, New Jersey. Published simultaneously in Canada.

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Library of Congress Cataloging-in-Publication Data:

Illicit drugs in the environment : occurrence, analysis, and fate using mass spectrometry / edited by Sara Castiglioni, Ettore Zuccato, Roberto Fanelli. p. cm. Includes index. ISBN 978-0-470-52954-6 (cloth) 1. Drugs of abuse–Analysis. 2. Drugs of abuse–Environmental aspects. 3. Drugs of abuse–Spectra. 4. Water–Analysis. 5. Organic water pollutants. 6. mass spectrometry. I. Castiglioni, Sara, 1976– II. Zuccato, Ettore, 1952– III. Fanelli, Roberto, 1944– RS190.D77I65 2011 363.739′4–dc22 2010036825

Preface

PRESENTATION OF THE BOOK

Following the preliminary observation that traces of illicit drugs could be found in the aqueous environment, there was an obvious request for a better characterization of these novel contaminants to assess possible risks for the environment and human health. A less obvious consequence of this finding was the discovery that the residues of illicit drugs in wastewater, and sometimes in surface water receiving untreated wastes, could be used to estimate drug consumption in the group of individuals producing the waste itself. In particular, the potential applications linked to this second issue reinforced the need for a specific, sensitive, and accurate measurement of these substances. Environmental scientists, on the one hand, and social scientists and persons involved in the phenomenon of drug addiction, on the other, have sought analytical methods for the detection and quantification of illicit drugs and metabolites in environmental media, particularly, wastewater. Illicit drugs and their metabolites are commonly measured in forensic sciences, but concentrations in urine, blood, and other fluids or in hair, are much higher and interference much lower than in wastewater. Wastewater is a complex milieu of thousands of different substances, dissolved, mixed, or suspended in water. The list of compounds in wastewater, and by extension, in the downstream environment, is long. Chemicals from industrial or agricultural activities are well known contributors to this milieu, but pharmaceuticals are a recent acquisition, and the same is true for the thousands of products we use daily for personal care. Remnants derived from an enormous number of production and household activities end up in wastewater and contribute to an increase in the complexity of its composition and, thus, the difficulties to detect specific target substances.

Fortunately, given the physicochemical similarities, the previous experience with therapeutic drugs has substantially helped in developing appropriate analytical methods for illicit drugs; the first proposed were actually based on the extension to these molecules of multiresidue methods previously established for therapeutic pharmaceuticals, or alternatively, on methods previously established for forensic investigations, which were adapted to the analysis of these substances in environmental matrices. The methods proposed were mainly based on HPLC-MS, and sometimes on GC-MS. This is not surprising as liquid chromatography is considered the most appropriate technique for the analysis of polar substances and mass spectrometry the most powerful technique for multitrace analysis of compounds in complex matrices, such as wastewater.

This present book “Illicit Drugs in the Environment: Occurrence, Analysis and Fate Using Mass Spectrometry” will describe a new application of mass spectrometry in the detection and measurement of a novel class of environmental contaminants (illicit drugs). This novel application assesses risks of these newly identified pollutants for ecosystem and man and explores the potentials of this innovative approach to estimate illicit drug consumption in the population.

STATE-OF-THE-ART

To our knowledge, there was no trace in the scientific literature of any investigation on illicit drugs in the aqueous environment until year 2001, when Christian Daughton, without having any direct evidence of their presence in the environment, hypothesized that remnants of illicit drugs excreted with the urine of the consumers could end up in wastewater and that their levels could be used to back-calculate the intake of drugs by the population. In a field study in 2004, Jones-Lepp first reported the real occurrence of amphetamines in treated wastewater in the United States and, in 2005, our group measured cocaine and metabolites in rivers and in raw wastewater samples, and used the results to back-calculate the consumption of cocaine in the population. Later, in 2006, the method originally established for cocaine by our group was extended to the analysis of other illicit drugs, which were measured in surface and wastewaters. Thus far, occurrence, behavior, and fate of illicit drugs in waste-, surface, ground, and drinking water has been investigated in several European countries, and traces of various illicit drugs have also been detected in airborne particulates in many places around the world. Later, the approach to estimate cocaine abuse by wastewater analysis was also used to test community-wide consumption of cannabis, heroin, and amphetamines in several countries in Europe and the United States.

The rationale of this approach is known: traces of almost everything we eat, smoke, drink, ingest, or absorb, are excreted with our urine or stool and end up in the sewage system. Therefore, monitoring wastewater has the potential to extract useful epidemiological information from qualitative and quantitative profiling of biological indicators entering the sewage system. This is the basis of what we called “sewage epidemiology;” illicit drugs were the first application of this new branch of environmental epidemiology. Residues of the illicit drugs consumed by a collectivity are excreted in wastewater and their levels, knowing kinetic, metabolism, and behavior in wastewater, and characteristics of the sewage system, such as flow rate and population size, can be used to collectively back-calculate for the type and amount of illicit drugs consumed (Diagram 1).

DIAGRAM 1 The pathway of illicit drugs: from the consumer to the wastewater treatment plant (WWTP) and the environment.

Thus far, the ecological implications of the presence of illicit drugs in surface water of rivers and lakes have been less explored. Effluents of wastewater treatment plants are probably the major sources (Diagram 1). Concentrations in surface water are generally low but, as previously shown for therapeutic pharmaceuticals, these molecules might also exert potent and specific biological activities on nontargeted organisms. Moreover, interactions with the effects of other licit and illicit drugs are possible and toxicity in the aquatic ecosystem cannot, therefore, be excluded. At the moment, there are several ongoing studies on the effects on the environment of therapeutic pharmaceuticals and is easy to predict the extension in the near future of these investigations to also include illicit drugs.

It is, therefore, expected that the number of scientists interested in these issues will substantially increase in the future. Environmental and social scientists will probably use these new applications of mass spectrometry to measure illicit drugs in waste- and surface water or in air, with the aim of studying their ecological effects or tracking illicit drug consumption in the population. This new branch of science is still in its infancy, but this book will collect all the available knowledge and the new ongoing research on this novel topic. We hope it will become a reference text for future investigations.

ORGANIZATION OF THE BOOK

The focus of this book is on illicit drugs in, mainly, the aqueous environment, and on mass spectrometry, used for their analysis to study occurrence and fate. This twofold novel application of mass spectrometry is : to study risks for ecosystems and man of these newly identified pollutants and to explore the potentials of this innovative approach to estimate illicit drug consumption in communities. Therefore, the goal of the book is to provide information on all the aspects of the mass spectrometry detection of illicit drugs in environmental media, to address the ecotoxicological implications, and to present and discuss this novel approach to estimate drug consumption by wastewater analysis.

Section I, begins with a contribution from Christian Daughton, of the US National Exposure Research Laboratory, entitled “Illicit Drugs and the Environment”. It gives an introduction to this issue by providing basic, but detailed, information on what it is an illicit drug, recalls the history of the discovery of illicit drugs in the environment, including ambient air and money supply, and gives some hypotheses on the future development of this branch in the environmental and the social sciences.

Section II of the book examines the physiological properties of the illicit drugs, with a chapter entitled “Metabolism and Excretion of Illicit Drugs in Humans” by Manuela Melis and co-workers. It reviews what is known about metabolism and excretion of these substances in man. As for therapeutic pharmaceuticals, it is supposed that the main source of the spreading of illicit drugs in the environment is the excretion in wastewater of the unmetabolized parent compounds and their break-down products still contained in the urine and the stools of consumers. An extensive knowledge of pharmacokinetic, metabolism, and excretion in human is, therefore, central to study these substances in the environment, to predict which of them will end up in the environment, and to estimate their concentrations, with the aim of identifying the proper target residues for the analysis of illicit drugs.

Section III, entitled “Mass Spectrometry in Illicit Drug Detection and Measurement; Current and Novel Environmental Applications,” is the “core” for MS analysis. The first chapter by Bagnati and Davoli reviews the published methods currently used to measure illicit drugs in environmental media and examines novel potential applications of MS to detect these chemical contaminants. This last issue is also discussed by two other chapters in this section, the first by Hernandez et al., of the Spanish Research Institute for Pesticide and Water, which explores the potential of UHPLC-QTOF MS, and the second by de Voogt and co-workers, from the University of Amsterdam, which outlines the chances offered by Orbitrap MS in the analysis of illicit drugs in the environment.

Section IV, “Mass Spectrometric Analysis of Illicit Drugs in the Environment,” reports field results of the MS analysis of illicit drugs in waste- and surface waters around the world, with contributions from Spain (Postigo, López de Alda, and Barceló), Italy (Castiglioni and Zuccato), UK (Kasprzyk-Hordern), Nebraska (Bartelt-Hunt and Snow), and the United States (Jones-Lepp and co-workers), in drinking water, exploring the presence and the removal of these substances in conventional drinking water treatment plants in Spain (Huerta-Fontela, Galceran, and Ventura) and the United States (Trenholm and Snyder), and in air and suspended particulate matter around the world (Cecinato and Balducci). Overall, these chapters report on the detection in various environmental media of about 40 different substances, including cocaine and metabolites, cannabinoids, heroin, morphine and their metabolites and conjugates, amphetamine-like molecules, and other related substances, such as, methadone and its metabolite EDDP, codeine, and more.

Section V deals with the applications of MS analysis of illicit drugs in the environment. This twofold analysis was intended to assess risks of these newly identified pollutants for ecosystem and man, and to explore the potentials of an innovative approach to estimate illicit drug consumption in the population. Domingo and Bracale, from Varese University and Schirmer and Pomati from EAWAG, thus explore the implications for ecotoxicology of the presence of illicit drugs in the environment, reviewing what is known on this issue and trying to predict what is still unknown by an original model-based approach.

A second chapter by Norbert Frost, from EMCDDA, introduces the method of estimating illicit drug consumption by wastewater analysis, discussing the potentials offered by this innovative approach from the point of view of a regulatory agency. A third chapter, from Zuccato and Castiglioni, reviews the applications of this approach published in the recent literature and critically discusses its potential and limitations in estimating community-wide illicit drug consumption. A fourth chapter, from van Nuijs and co-workers, shows that this approach, which was established to estimate illicit drug consumption at the community level, can be extended to estimate illicit drug use at nation-wide level, reporting results from a case-study carried out in Belgium. Last, a contribution, from Chiarelli and co-workers from Loyola University, introduces another intriguing potential application of this approach, in studying consumption rates in communities much smaller than those monitored thus far—students of a school. Monitoring the trends of drug use and assessing the overall consumption levels in students are critical to understanding the extent of the drug problem in this age group, with the aim to develop, target, and evaluate preventive interventions.

The book is then concluded by Roberto Fanelli, who sketches a brief history of the MS analysis of environmental contaminants, highlighting potential and limitations of its use in studying illicit drugs in the environment, and discusses the future perspective of the “sewage epidemiology approach” in investigating other substances, such as therapeutic pharmaceuticals, with the aim to monitor patients’ compliance to the treatment, or food and air contaminants, and to estimate population exposure.

The most intriguing consequence of the discovery of illicit drugs in wastewater and other environmental media is in the potential to monitor illicit drug use in the population. Diagram 1 shows the mechanism through which the quantification of illicit drug residues in wastewater can be exploited to assess consumption by the population. We think that this application will probably become a major target for the analysis of these substances in environmental media.

ETTORE ZUCCATO SARA CASTIGLIONI

Contributors

Alvarez David United States Geological Survey, Columbia Environmental Research Center, Columbia, Missouri, USA.

Bagnati Renzo Analytical Instrumentation Unit, Mario Negri Institute for Pharmacological Research, Milan, Italy.

Balducci Catia Institute of Atmospheric Pollution Research CNR, Monterotondo Stazione, Rome, Italy

Barceló Damià Institute of Environmental Assessment and Water Research, Spanish Council for Scientific Research, Barcelona, Spain.

Bartelt-Hunt Shannon University of Nebraska-Lincoln, Lincoln, Nebraska, USA.

Bervoets Lieven Laboratory for Ecophysiology, Biochemistry and Toxicology, Department of Biology, University of Antwerp, Antwerp, Belgium.

Bijlsma Lubertus Research Institute for Pesticides and Water, University Jaume I Castellón, Castellón, Spain.

Blust Ronny Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Antwerp, Belgium.

Bracale Marcella University of Insubria, Varese, Italy.

Castiglioni Sara Mario Negri Institute for Pharmacological Research, Milan, Italy.

Cecinato Angelo Institute of Atmospheric Pollution Research CNR, Monterotondo Stazione, Rome, Italy.

Chiarelli Paul Loyola University, Chicago, Illinois, USA.

Covaci Adrian Toxicological Centre, University of Antwerp, Antwerp, Belgium and Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Antwerp, Belgium.

Daughton Christian G. Environmental Chemistry Branch, National Exposure Research Laboratory, U.S. Environmental Protection Agency, Las Vegas, Nevada, USA.

Davoli Enrico Mass Spectrometry Laboratory, Mario Negri Institute for Pharmacological Research, Milan, Italy.

de Voogt Pim Earth Surface Science, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands and KWR Watercycle Research Institute, Chemical Water Quality and Health, Nieuwegein, The Netherlands.

Domingo Guido University of Insubria, Varese, Italy.

Emke Erik KWR Watercycle Research Institute, Chemical Water Quality and Health, Nieuwegein, The Netherlands.

Fanelli Roberto Mario Negri Institute for Pharmacological Research, Milan, Italy.

Frost Norbert Addiction Medicine, European Monitoring Centre for Drugs and Drug Addiction (EMCDDA), Addiction Medicine-Lisbon, Lisbon, Portugal.

Galceran Maria Teresa University of Barcelona, Barcelona, Spain.

Helmus Rick KWR Watercycle Research Institute, Chemical Water Quality and Health, Nieuwegein, The Netherlands.

Hernández Félix Research Institute for Pesticides and Water, University Jaume I Castellón, Castellón, Spain.

Huerta-Fontela Maria AGBAR-Aigües de Barcelona, Barcelona, Spain, University of Barcelona, Barcelona, Spain.

Jones-Lepp Tammy Environmental Sciences Division, National Exposure Research Laboratory, Office of Research and Development, United States Environmental Protection Agency, Las Vegas, Nevada, USA.

Jorens Philippe G. University of Antwerp, Antwerp University Hospital, Antwerp, Belgium.

Kasprzyk-Hordern Barbara Department of Chemistry, University of Bath, Bath, UK.

Loganathan Bommanna Center for Reservoir Research, Murray State University, Murray, Kentucky, USA.

López de Alda Miren Institute of Environmental Assessment and Water Research, Spanish Council for Scientific Research, Barcelona, Spain.

Melis Manuela Mario Negri Institute for Pharmacological Research, Milan, Italy.

Neels Hugo Toxicological Centre, University of Antwerp, Antwerp, Belgium.

Panawennage Deepika Loyola University, Chicago, Illinois, USA.

Panteliadis Pavlos Earth Surface Science, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands.

Pomati Francesco Eawag, Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland.

Postigo Cristina Institute of Environmental Assessment and Water Research, Spanish Council for Scientific Research, Barcelona, Spain.

Sancho Juan V. Research Institute for Pesticides and Water, University Jaume I Castellón, Castellón, Spain.

Schirmer Kristin Eawag, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland.

Snow Daniel D. Water Sciences Laboratory, University of Nebraska-Lincoln, Lincoln, Nebraska, USA.

Snyder Shane A. Southern Nevada Water Authority, Applied Water Quality Research and Development Center, River Mountain Warer Treatment Facility, Las Vegas, Nevada, USA.

Trenholm Rebecca A. Southern Nevada Water Authority, Applied Water Quality Research and Development Center, River Mountain Warer Treatment Facility, Las Vegas, Nevada, USA.

van Leerdam Jan A. KWR Watercycle Research Institute, Chemical Water Quality and Health, Nieuwegein, The Netherlands.

van Nuijs Alexander L. N. Toxicological Centre, University of Antwerp, Antwerp, Belgium.

Ventura Francesc AGBAR-Aigües de Barcelona, Barcelona, Spain.

Zuccato Ettore Mario Negri Institute for Pharmacological Research, Milan, Italy.

SECTION I

INTRODUCTION

Chapter 1

Illicit Drugs and the Environment

Christian G. Daughton

1.1 INTRODUCTION

The spectrum of chemicals recognized as contributing to widespread contamination of the environment began to be extended to pharmaceutical ingredients as early as the 1970s. However, the topic did not begin to attract broader scientific attention until the mid-1990s (Daughton, 2009a). Occurring generally at levels below 1 μg/liter in ambient waters, the near ubiquitous presence of pharmaceuticals in a wide variety of environmental compartments serves as a stunning measure of advancements in analytical chemistry in expanding our understanding of the scope of environmental pollution.

The extent of progress and effectiveness of pollution regulation, mitigation, control, and prevention over the last 40 years is now reflected by a focus on trace-level chemical contaminants—a phenomenon only hypothesized as a possibility in the early 1970s. This focus is particularly embodied with the so-called “emerging” contaminants (Daughton, 2009b) and the myriads of others not yet noticed or identified and which could be referred to as the “quiet contaminants.”

Up through the 1990s, the emerging study of pharmaceuticals in the environment (PiE) inexplicably excluded from consideration the contributions by the so-called “illicit” drugs. Involving a structurally diverse group of chemical agents possessing extremely high potential for biological effects in humans and nontarget organisms, the magnitude of worldwide illicit drug trafficking is presumably enormous, but can only be very roughly estimated. The potential for illicit drugs to enter the environment should not differ markedly from that of medical pharmaceuticals—with contributions from excretion, bathing, disposal, and discharge of manufacturing waste. While known for many decades that illicit drugs and metabolites (just as with medicinal pharmaceuticals) are excreted in urine, feces, hair, and sweat, not until 1999 (Daughton and Ternes, 1999) and 2001 (Daughton, 2001a, 2001c) was the scope of concerns surrounding PiE expanded to include illicit drugs. In characterizing and assessing risks incurred from PiE, both licit and illicit drugs need to be seamlessly considered.

Perhaps the first published indication that illicit drugs might be pervasive contaminants of our immediate surroundings and the larger environment was a 1987 FBI study in response to a newspaper report 2 years earlier that cocaine was present on money in general circulation (Aaron and Lewis, 1987). Over the intervening 20 years, analogous seminal surveys of illicit drugs as ambient contaminants have been published for sewage wastewaters (Khan, 2002), surface waters (Zuccato et al., 2005), air (Cecinato and Balducci, 2007), sewage sludge (Kaleta et al., 2006) and biosolids (Jones-Lepp and Stevens, 2007), and, most recently, drinking water (Huerta-Fontela et al., 2008b). An examination of the US EPA's bibliographic database on PiE (USEPA, 2009a), shows that the core journal references having a major focus on illicit drugs in wastewaters, ambient waters, drinking water, or air total around 60 (this excludes those published on the topic of drugs on money). References (in any type of technical publication) dealing with illicit drugs in the environment total fewer than 200—composing only 2% of the documents (approaching 10,000) surrounding the broader topic of PiE, in general.

Presented here is a broad overview of illicit drugs as environmental contaminants. Perspectives are provided on their occurrence in various environmental compartments, what their occurrence might mean with regard to risk, and how their occurrence can be used as an analytical measurement tool to assess society-wide usage of illicit drugs.

A chronology of seminal publications on significant aspects of illicit drugs and the environment is presented in Table 1.1. The topic is transdisciplinary, involving a variety of disparate, but intersecting, fields, including healthcare, pharmacology, criminology, forensic sciences, epidemiology, toxicology, environmental and analytical chemistry, and sanitary engineering, among others.

TABLE 1.1 Chronology of Some Selected Seminal Publications Regarding Illicit Drugs in the Environment

1.2 WHAT IS AN “ILLICIT” DRUG?

Discussions regarding illicit drugs can become confused by the ambiguity in what exactly defines an “illicit” drug. Confusion stems from the fact that illicit drugs are not necessarily illegal. Many are licit medical pharmaceuticals having valuable therapeutic uses—two common examples being morphine and oxycodone. Instead, whether a drug is illicit is defined by international convention or national law, not necessarily by any inherent property of the drug. Some discussion is essential to better understand the scope of drug substances that can be considered illicit.

1.2.1 Terminology

There is no single, widely used term that accurately captures the myriad substances that become abused by habitual or addictive use. Although widely used, the term “illicit drug” is not accurate in the sense that most of the widely known abused drugs have bona fide medical uses as licit pharmaceuticals; the few that do not are incorporated in various listings or schedules of controlled substances maintained by various countries.

A variety of terms are used, often interchangeably, including: street drugs, designer drugs, club drugs, drugs of abuse, recreational drugs, clandestinely produced drugs, and hard and soft drugs. The term “designer” drug gained popularity in the 1980s when 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) was introduced to the black market. Perhaps the most notable first designer drugs were introduced in the 1920s—dibenzoylmorphine and acetylpropionylmorphine.

Regardless of the terminology, much overlap exists with licit pharmaceuticals (those with approved medical uses). This can lead to much confusion or ambiguity as to exactly what the scope of the topic is. Discussion of the confusion surrounding illicit drug terminology is provided by Sussman and Ames (2008). In the overview provided here, the guiding definition used is that of the United Nations Office on Drugs and Crime (UNODC), which focuses not on the chemical identity of the drug itself, but rather on the life-cycle pathway traveled by a drug. The UNODC does not recognize any distinction between the chemical identity of licit and illicit drugs—only the way in which they are used (UNODC, 2009a). In this sense, the term “illicit” refers to the way in which these drugs are manufactured, distributed, acquired, and used, and by the fact that they are being used for nonmedical purposes.

This definition allows the inclusion of legal pharmaceuticals—that is, when they are manufactured, distributed, trafficked, or used illegally, or diverted from legal sources. The wide spectrum of sources and routes by which legal drugs become diverted for illicit use range from the relatively large-scale diversion from pharmaceutical distributors, pharmacies, and healthcare facilities, to the smaller scale (e.g., “theft” from home storage locations, such as for teen “pharming”) and reuse of used medical devices, especially dermal medical patches, which present lethal hazards for both intentional and accidental exposures (Daughton and Ruhoy, 2009).

Whether a drug is classified as illicit is a complicated function of mores and evidence-based health studies, which are sometimes at odds with one another and under increasing scrutiny and debate [e.g., see Nutt (2009)]. Illicit substances (drugs and the precursors used for their manufacture) are captured on various government lists (controlled-substance schedules) that specify their allowable use. The primary criteria evaluated for listings are health risks, potential for abuse/addiction, therapeutic value, and utility as precursors for illicit manufacturing. The unifying worldwide scheme, used by the EU, for regulation comprises the schedules of the three UN Conventions of: 1961 (United Nations Single Convention on Narcotic Drugs, New York, amended 1972), 1971 (Convention on Psychotropic Substances, Vienna), and 1988 (Convention against Illicit Traffic in Narcotic Drugs and Psychotropic Substances, introducing control on precursors, Vienna). Combined, these schedules currently comprise about 250 explicitly named controlled substances (EMCDDA, 2009a).

Showing how the lines of demarcation become blurred, prescription analgesic opioids have overcome heroin and cocaine in the United States in leading to fatal drug overdoses (Leonard and Yongli, 2008). Indeed, the use of certain licit drugs, including over-the-counter (OTC) medications, for nonmedical purposes has recently surpassed the use of illicit drugs (NIDA, 2008). For example, of the top 10 drugs misused by high-school seniors in the United States, seven were legal prescription or OTC medications.

Numerous other illicit substances (such as structural analogs) exist but can only be captured implicitly by generalized chemical criteria that preemptively ban their synthesis; not all countries, however, have control acts that implicitly capture chemical analogs. Unknown numbers of additional substances exist but their chemical identities are elucidated only after they have experienced sufficient illegal use. A resource that provides the chemical structures for many of these substances (those listed by the Canadian Controlled Drugs and Substances Act) is maintained by Chapman (2009).

Adding further confusion regarding the distinctions between illicit drugs and medical pharmaceuticals, the laws dealing with illicit drugs dramatically vary from country to country. Long-standing drug policies in certain countries are also in a state of flux, because various changes are underway and adjustments are under consideration. These range from “reducing harm” (e.g., via decriminalization of possession and use) to acknowledgment from the American Medical Association regarding the medical benefits of a Schedule I drug (namely, cannabis) and calling for its clinical research (AMA, 2009). Beginning with Portugal in 2001 with the decriminalization of drug use, possession, and acquisition by drug end-users (Law no. 30/2000, which focuses on harm reduction) [see Greenwald [2009)], the array of laws dealing with illicit drugs has become quite diverse, but growing, illegal manufacturing, and trafficking remain criminal offenses. Among the EU States, the spectrum of law is captured by EMCDDA (2009b).

1.3 DIFFERENCES DIFFERENCES BETWEEN ILLICIT AND LICIT DRUGS AS ENVIRONMENTAL CONTAMINANTS

With respect to understanding their overall significance in the environment, seven aspects of illicit drug use contrast sharply with legitimate pharmaceutical use:

1. For most illicit drugs, there are no accurate quantitative data available concerning production or usage. For regulated pharmaceuticals, sales figures and regional real-time prescribing data can be used in models to calculate predicted environmental concentrations (PECs); these values can then be compared with measured environmental concentrations (MECs).

2. Although the chemical identities for the core group of illicit drugs are known, an ever-increasing number of new drugs (such as structural analogs with minor modifications of regulated pharmaceuticals and of previously known illicit drugs) can elude detection by forensics laboratories for years before they are noticed and identified. The myriad numbers of designer drugs and constant synthesis of new ones will pose challenges for mass spectrometrists for years to come and also introduce great uncertainty regarding the true scope of synthetic chemicals that contaminate the environment. Even though many of these unique chemicals are probably produced in relatively small quantities, the fact that they belong to relatively few chemical classes possibly means that they share only a few mechanisms of biological action. This makes additive action very likely, especially with substantial numbers of licit and illicit drugs often sharing the same mechanism of action. Since some have extremely low effective doses (e.g., in the range of 1 μg per human use), this has relevance especially for aquatic exposure. As examples, cis-3-methylfentanyl and β-hydroxy-3-methylfentanyl (as with carfentanyl, a large-animal tranquilizer) are extraordinarily potent designer drugs, being three to five orders of magnitude more potent than morphine.

3. Drugs manufactured via illicit routes are commonly contaminated with unintended impurities and purposeful adulterants. These are often present at extremely high levels (e.g., sometimes more than one-half of the total mass, as opposed to milligram per kilogram [parts per million] levels for impurities in registered medicines) and are often more toxic than the sought-after drug.

4. The manufacture of illicit drugs (particularly methamphetamine) can cause extensive ecological damage as well as irreversible damage to infrastructures, such as buildings (USEPA, 2009b).

5. To date, the primary interest in residues of illicit drugs in the environment has been their occurrence in sewage (mainly untreated raw sewage) for use as a tracking tool to calculate community-wide consumption. This relatively new tool has been termed sewage (or sewer) forensics or epidemiology. In contrast to the licit use of pharmaceuticals, interest in their potential as biological stressors in the environment has been secondary, and very little is known.

6. Much less is known regarding the toxicology (including pharmacokinetics) of most illicit drugs.

7. With respect to environmental impact, numerous measures can be implemented to reduce the entry of licit pharmaceuticals into the environment. Routes of entry span an enormous spectrum of possibilities (Daughton and Ruhoy, 2008). With illicit drugs, pollution prevention measures—that is, to discourage their manufacture, distribution (e.g., via unapproved Internet pharmacies), and end use—are straightforward, but more difficult to implement.

Note that the frequent changes in the introduction of new pharmaceuticals with potential for abuse, as well as new illicit substances, preclude any comprehensive definitive worldwide compilation of chemicals. The INCB (International Narcotics Control Board) maintains three major listings (INCB, 2009): Yellow List (Narcotic Drugs Under International Control), Green List (Psychotropic Substances under International Control), and Red List (Precursors and Chemicals frequently used in the Illicit Manufacture of Narcotic Drugs and Psychotropic Substances under International Control). A convenient listing of many of the corresponding chemical structures is provided by Chapman (2009).

1.4 THE CORE ILLICIT DRUGS AND THE ENVIRONMENT

The types of drugs commonly abused are described in various ways, depending on their origin and biological effect. They can either be naturally occurring, semisynthetic (chemical manipulations, such as analogs, of substances extracted from natural materials), or synthetic (created entirely by laboratory synthesis and manipulation). The primary categories are opiates, other CNS depressants (sedative-hypnotics), CNS stimulants, hallucinogens, and cannabinoids.

The scope of chemicals that could be considered illicit can be viewed in terms of the following categories of medical efficacy:

1. No known medical use (and are illegal in all circumstances according to various conventions) (e.g., benzylpiperazine; heroin in the United States),

2. Limited established medical use, but which are also manufactured illegally and used primarily for nonmedical purposes (e.g., methamphetamine),

3. Firmly established wide medical use, but are diverted illegally (e.g., theft; illegal prescribing such as via unapproved Internet “pharmacies”),

4. Firmly established wide medical use and are obtained “legally,” but for nonmedical use (e.g., doctor/hospital shopping or by other con schemes),

5. Similar biological action to prescription drugs but are synthesized as analogs (which are not individually and explicitly categorized as illegal; examples include the numerous analogs of phosphodiesterase type-5 inhibitors).

All of these categories comprise drugs with high potential for abuse or that enjoy recreational use. Methadone is usually included in these discussions even though most of its use is legal; it serves to track opiate addiction but is also used and abused as an analgesic.

Some drug residues in the environment have substantial multiple origins (both legal and illegal), making it difficult to ascribe monitored levels to illicit use. Morphine is one example. It can originate from medical use of morphine itself or from codeine (via O-demethylation). It can also originate from diverted morphine or codeine, as well as from heroin. By collecting data on other (and more unique) metabolites, these pathways can be teased apart. Using morphine as the example, by monitoring for the heroin metabolite 6-AM (6-acetylmorphine), a more representative picture can be obtained for that portion of morphine originating from heroin.

While drug usage patterns and prevalence vary among countries as well as with time, those drugs in frequent use in the United States can serve as an organizing framework for further discussion. The annual reports of the US DEA's National Forensic Laboratory Information System, NFLIS (USDEA, 2008), provide the best insights regarding which known drugs are most used in nonmedical circumstances (see Table 1.2).

TABLE 1.2 Drugs of Abuse Frequently Detected by United States Forensics Labsa

25 Abused DrugsOther Abused DrugsMost frequentNarcotic analgesicsTetrahydrocannabinol (THC)ButorphanolCocaine (benzoylmethylecgonine)DihydrocodeineMethamphetamineFentanylHeroin (diacetylmorphine; diamorphine)MeperidineNalbuphineNarcotic analgesicsOpiumBuprenorphineOxymorphoneCodeinePentazocineHydrocodonePropoxypheneHydromorphoneTramadolMethadoneMorphineBenzodiazepinesOxycodoneChlordiazepoxideFlunitrazepamBenzodiazepinesMidazolamAlprazolamTemazepamClonazepamTriazolamDiazepamLorazepam“Club” drugs1-(3-Trifluoromethylphenyl)piperazine (TFMPP)Others1-Benzylpiperazine (BZP) 3,4-Methylenedioxyamphetamine (MDA) 3,4-Methylenedioxymethamphetamine (MDMA) Amphetamine Carisoprodol Methylphenidate Phencyclidine (PCP) Pseudoephedrine Psilocin3,4-Methylenedioxy-N-ethylamphetamine (MDEA)5-Methoxy-N,N-diisopropyltryptamine (5-MeO-DIPT)γ-Hydroxybutyrate/γ-butyrolactone (GHB/GBL)KetamineStimulantsCathinoneEphedrinePhentermineAnabolic steroidsMethandrostenoloneNandroloneStanozololaUSDEA's National Forensic Laboratory Information System (USDEA, 2008).

Of all the samples analyzed in 2008 by US local and state forensic labs for the presence of nonmedically used drugs, 25 controlled substances (Table 1.2) composed 90% of all samples. The most frequent four were tetrahydrocannabinol (THC), cocaine (benzoylmethylecgonine), methamphetamine, and heroin. Of these 25, only 15 have been targeted in environmental studies of illicit drugs: amphetamine, cocaine, codeine, heroin, hydrocodone, MDA, MDMA, methadone, methamphetamine, methylphenidate, morphine, oxycodone, PCP (phencyclidine), pseudoephedrine, and THC (Δ9-tetrahydrocannabinol).

Note that the top 25 detected by NFLIS are all among the most commonly abused drugs in the United States. The major ones missing (but which are captured in the remaining 10% of samples analyzed by NFLIS) are barbiturates (e.g., seconal and phenobarbital, but whose rate of abuse has been declining), certain benzodiazepines (except flunitrazepam, such as alprazolam, diazepam, and $ \nobreak{chlordiazepoxide}$), methaqualone, mescaline (3,4,5-trimethoxyphenethylamine), and dextromethorphan (NIDA, 2009). Extensive statistics on rates of drug use worldwide (including those maintained by the UNODC) can be found on the ONDCP web page (ONDCP, 2009). The UNODC World Drug Report (UNODC, 2009b) provides comprehensive statistics on world illicit drug supply and demand.

From a comprehensive examination of the published literature on illicit drugs and their metabolites in a variety of environmental compartments (wastewaters, surface waters, drinking water, sewage sludge, sewage biosolids, air, and banknotes), positive occurrence data as well as indications of negative occurrence (data of absence) were compiled (data not shown here). From these data, those analytes with absence of data (i.e., those that have yet to be targeted in monitoring studies) can be deduced. For example, Postigo et al. (2008) noted that norcocaethylene and ecgonine ethyl ester have not been targeted in any monitoring study. Major reviews of illicit drugs in the environment are provided by Huerta-Fontela et al. (2010) and Zuccato and Castiglioni (2009).

The published data reveal that the drugs with the most positive occurrence data across all environmental compartments are among the top 25 detected by NFLIS —notably codeine, morphine, methadone, amphetamine, methamphetamine, cocaine, and THC, and the primary metabolites of methadone (i.e., EDDP), cocaine (i.e., BZE, benzoylecgonine), and THC (i.e., 11-nor-9-carboxy-9-THC [THC-COOH]). Although widely detected in drug screens, the occurrence of heroin (diacetylmorphine) in an environmental compartment is limited primarily to banknotes—because of its propensity to hydrolyze in water. Likewise, the cannabinoids are detected most frequently in air. Not surprisingly, no illicit drug (or metabolite) frequently reported with environmental occurrence data is missing from the 25 most frequently identified by forensic labs.

Nine of the remaining 25 drugs most frequently identified by the forensic testing labs have not yet been targeted in environmental studies focused on illicit drugs: alprazolam, buprenorphine, BZP (1-benzylpiperazine), carisoprodol, clonazepam, diazepam, hydromorphone, lorazepam, and psilocin (4-hydroxydimethyltryptamine, 4-HO-DMT). Of these nine drugs, environmental occurrence data have been published in studies targeted at medical pharmaceuticals for: alprazolam, carisoprodol, diazepam, and lorazepam. Data do not exist for buprenorphine, BZP, clonazepam, hydromorphone, and psilocin. Depending on their pharmacokinetics and extent of excretion unchanged, these latter five drugs could be considered for targeting in future environmental monitoring.

Some illicit drug analytes, when targeted, are infrequently reported possibly as a result of their considerably higher detection limits. Normorphine and THC-COOH are examples, sometimes having limits of detection one to two orders of magnitude higher than other analytes. Other targeted analytes are not detected because they are extensively metabolized or excreted as conjugates. Conjugation undoubtedly plays a critical role in determining whether a free parent drug will be found in waters. Many drugs are extensively conjugated, and without a hydrolysis step in analysis, these will be missed (Pichini et al., 2008; Daughton and Ruhoy, 2009).

Important to note is that some illicit drugs are metabolic/transformation daughter products of others, explaining why their concentrations in sewage or receiving waters are routinely higher than their parents. One example is heroin, which is quickly deacetylated to 6-AM followed by hydrolysis to morphine. This means that the probability is higher that these parent drugs, when detected in waters (especially waters distanced from impact by sewage), are present because they were directly flushed down the toilet (or excreted via sweat), rather than being excreted via urine; an alternative source is run-off into streams, such as during clandestine manufacturing. Another example is fentanyl, which is extensively excreted as norfentanyl.

Environmental occurrence data from most of the major studies on illicit drugs have been reviewed by Huerta-Fontela et al. (2010) and Zuccato and Castiglioni (2009).

1.4.1 Adulterants and Impurities

In contrast to pharmaceuticals produced under Good Manufacturing Practices, drugs made illegally contain myriad other chemical substances in addition to (or sometimes even in place of) the sought-after drug. Adulterants are often used to enhance desired biological effects. Included are diluents, which are added to mimic the physical appearance of the sought-after drug when the objective is economic gain (to extend the doses per mass). Impurities are sometimes integral to the natural chemistry of the native plant from which a drug is isolated and, other times, a function of the synthetic route to the desired drug (as dictated by the skill of the operator/ chemist).

Many dozens of impurities and adulterants are possible for any given drug synthesis. Impurities, in turn, can each yield numerous metabolites, most of which are not yet known. Adulterants can range from common substances such as caffeine (albeit in very high concentrations) to more insidious chemicals, such as the cytotoxic veterinary dewormer drug levamisole, which has led to a number of deaths; in this way, illicit drugs can serve as a route of entry to the environment for licit drugs that otherwise would never themselves experience nonmedical use. Adulteration of illicit drugs has grown to become a major health risk for drug users.

These substances are often present at very high levels, especially in intentionally mislabeled drugs. They sometimes represent the bulk of the purported drug (e.g., noscapine can be present at levels up to 60% in heroin, or phenacetin, which can be present at levels up to 50% in cocaine). These contaminants include products of synthesis or processing (precursors, intermediates, by-products), natural impurities (e.g., natural product alkaloids), products of degradation (e.g., oxidation during storage), and pharmacologically active adulterants (e.g., many licit drugs and other chemicals, obtained illegally, such as levamisole, xylazine, lidocaine, phenacetin, hydroxyzine, and diltiazem). Some of these impurities or adulterants are more potent than the sought-after drug (cocaethylene being one example, which is a synthesis by-product as well as a metabolite of cocaine when consumed together with ethanol). Some have considerable toxicity. In the course of reviewing the literature, over 90 common adulterants and impurities were noted just for the four illicit drugs cocaine, MDMA, methamphetamine, and heroin. These represent but a very small sampling of the variety of chemicals that can compose illicit drugs.

1.5 LARGE-SCALE EXPOSURE OR SOURCE ASSESSMENTS VIA DOSE RECONSTRUCTION

Interest in illicit drugs in the environment has both prospective and retrospective dimensions. The prospective dimension concerns the questions surrounding the exposure of aquatic organisms and of humans to environmental residues. Of the environmental studies conducted, however, the major objective in collecting data on the presence and scope of illicit drugs in sewage and wastewaters has not been for prospectively assessing their significance as environmental contaminants and their potential for ecological or human health exposure. Rather, the objective has been the use of these data as a retrospective tool for reconstructing society-wide drug usage. This could be considered a large-scale version of exposure assessment called “dose reconstruction” [e.g., see ATSDR (2009)].

Separate but analogous approaches have also been attempted making use of the presence of drug residues on banknote currency and in airborne particulates. These could be more accurately referred to not as dose reconstruction, but rather as source reconstruction (deciphering the source and intensity of the origin of the drugs).

1.5.1 Sewage Epidemiology or Forensics

First proposed in 2001 (Daughton, 2001a), the analysis of sewage for residues of illicit drugs unique to actual consumption (rather than originating from disposal or manufacture) for the purpose of back-calculating estimates of community-wide usage rates has since been discussed under a variety of terms, including “sewage epidemiology” (a term first reported in the literature by Zuccato et al. (2008b)], “sewage forensics,” and “community-wide urinalysis” or “community drug testing.” None of these terms, however, fully captures the multiple purposes that can be served by the methodology.

Epidemiology can be defined simply as the study of populations sharing similar characteristics of disease (or health status). Among its uses are identifying at-risk subpopulations, monitoring the incidence of exposure/disease, and detecting/controlling epidemics. Elements of illicit drug use fit all of these. In its simplest state, “forensics” involves the extraction of pertinent information to support an argument or investigation (Daughton, 2001b). One of its best known modern renditions is to assist in resolving legal issues—and the worldwide legal system plays an integral role in all aspects of illicit drug use.

Since this still-evolving approach for measuring drugs in sewage to estimate collective drug usage has elements of both forensics and epidemiology, it would be more accurately captured under the newer term “Forensic Epidemiology,” which integrates the principles and methods used in public health epidemiology with those used in forensic sciences (Goodman et al., 2003; Loue, 2010).

With this in mind, a more accurate descriptive term should be considered in order to better unify the published literature. One possibility could be “Forensic Epidemiology Using Drugs in Sewage” (FEUDS). Use of a unique term and acronym would have the added benefit of more easily facilitating communication across disciplines and would greatly facilitate literature searches. In the remainder of this discussion, however, the shorthand term “Sewage (or Sewer) Forensic Epidemiology” (SF/E) will be used.

1.5.2 SF/E Used in Community-Wide Dose Reconstruction for Illicit Drugs

After its conceptualization in 2001 (Daughton, 2001a), SF/E was first implemented in a field-monitoring study by Zuccato et al. (2005). SF/E was originally proposed as the first evidence-based approach for measuring drug use, because the long-practiced approaches that use population surveys are fraught with limitations, not the least of which involve numerous sources of potential error that are difficult to define, control, or measure (especially self-reporting bias) (Daughton, 2001a). This has been corroborated in “concordance” studies (comparisons of self-report data with empirical bioanalysis data), which point to gross underreporting by self-reports (often at rates as low as one-half). These conventional approaches to estimating illicit drug usage also suffer from two inherent limitations: (a) extreme delays in times before results can be compiled and reported and (b) costs associated with data collection and interpretation.

Like public surveys, SF/E also suffers from a large number of sources of potential error. However, SF/E is in its infancy, and its error derives from variables still under investigation and which could be better controlled. While conceptually rather straightforward, the back-calculations used in SF/E are a function of numerous variables, including demographics, population flows (transient visitors and commuters) served by a sewage treatment facility, sewage flows, and pharmacokinetics. Combined, these pose a major challenge for modeling to accurately reconstruct dose. The numerous problems facing SF/E are discussed in Frost and Griffiths (2008). Most SF/E investigators couple drug concentrations in sewage with per-capita sewage flows to calculate what is sometimes called “index loads” or “per capita loads,” expressed as milligram/person/day. Many of the sources of uncertainty are covered by Banta-Green et al. (2009) and Zuccato et al. (2008b).

Despite the plethora of uncertainties in the many variables involved in SF/E back-calculations, the ability to provide estimates of near real-time community-wide usage is something that is not possible with any other known approach. This also opens the possibility of detecting real-time trends or changes in drug use. Example applications include verifying reductions in drug use as a result of interdictions, or detecting the emergence of newly available drugs or overall changes in drug-use patterns. Data on real-time usage could better inform decisions regarding drug control and mitigation. Correlating policy actions with resulting society-wide impacts cannot be effectively done when collected data are significantly delayed in reporting.

Of great potential significance, there is also no apparent technical obstacle to designing automated continuous monitors for use in sewage collection/distribution systems. Implementing continuous monitoring to support SF/E would serve to better inform decisions regarding control and mitigation of drug use.

Another advantage with SF/E as opposed to population surveys is that not all drug use is necessarily known to the users themselves, who then unintentionally report to surveys incorrect drug identities and usage quantities. Illicit-drug users often do not know the identity or the quantity of the active substances they have consumed because the purity is unknown. Often the active substance or quantity is not what the distributor claims. Adulterants are often substituted, in part or in whole, for the purported drug. One general route of uninformed exposure is the surreptitious incorporation of designer drugs into otherwise legal OTC diet supplements or recreational or life-style products. An example is the relatively new (and probably incompletely characterized) synthetic analogs of the approved phosphodiesterase type-5 (PDE-5) inhibitors (used primarily in treating erectile dysfunction), such as sildenafil, vardenafil, and tadalafil (Poon et al., 2007; Venhuis and de Kaste, 2008). The legal registered versions of PDE-5 inhibitors have only recently been detected in wastewaters (Nieto et al., 2010). The extent of such adulteration in the drug and supplements industry is unknown, largely because the targets for analysis are often not known to forensic analysts.

Hagerman (2008) provides a brief history of SF/E research in the United States. The ONDCP performed the first SF/E monitoring in the United States in 2006, targeting about 100 wastewater treatment plants (WWTPs) across two dozen regions (Bohannon, 2007). The first conference devoted to SF/E was organized by EMCDDA in Lisbon, Portugal in April of 2007 (EMCDDA, 2007). It led to the first published overview of many of the aspects of the topic (including scientific, technical, social, privacy, ethical, and legal concerns), as provided by Frost and Griffiths (2008).

1.5.3 Summary of Published Research in SF/E

Overviews and discussion of the SF/E studies published up until 2008 are provided by Postigo et al. (2008) and Zuccato et al. (2008b). The major published articles regarding the SF/E approach are compiled in the chronology of Table 1.3. As of the beginning of 2010, there had been fewer than two dozen studies. All but a handful have been published after 2007.

TABLE 1.3 Selected SF/E Studies (Arranged Roughly According to Chronology)

YearTitle (and reference)2001Illicit drugs in municipal sewage: Proposed new nonintrusive tool to heighten public awareness of societal use of illicit/abused drugs and their potential for ecological consequence (Daughton, 2001a)2005Cocaine in surface waters: New evidence-based tool to monitor community drug abuse (Zuccato et al., 2005)2006High cocaine use in Europe and US proven – Stunning data for European countries: First ever comparative multicountry study of cocaine use by a new measurement technique (Sörgel, 2006)2007Using environmental analytical data to estimate levels of community consumption of illicit drugs and abused pharmaceuticals (Bones et al., 2007)2008Occurrence of psychoactive stimulatory drugs in wastewaters in northeastern Spain (Huerta-Fontela et al., 2008a)Estimating community drug abuse by wastewater analysis (Zuccato et al., 2008a)2009Cocaine and metabolites in waste and surface water across Belgium (van Nuijs et al., 2009b)Cocaine and heroin in waste water plants: A 1-year study in the city of Florence, Italy (Mari et al., 2009)Monitoring of opiates, cannabinoids and their metabolites in wastewater, surface water and finished water in Catalonia, Spain (Boleda et al., 2009)Can cocaine use be evaluated through analysis of wastewater? A nation-wide approach conducted in Belgium (van Nuijs et al., 2009a)Illicit drugs and pharmaceuticals in the environment – Forensic applications of environmental data, Part 1: Estimation of the usage of drugs in local communities (Kasprzyk-Hordern et al., 2009a)Assessing illicit drugs in wastewater: Potential and limitations of a new monitoring approach (Frost and Griffiths, 2008)Municipal sewage as a source of current information on psychoactive substances used in urban communities (Wiergowski et al., 2009)2010The spatial epidemiology of cocaine, methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA) use: a demonstration using a population measure of community drug load derived from municipal wastewater (Banta-Green et al., 2009)Drugs of abuse and their metabolites in the Ebro River basin: Occurrence in sewage and surface water, sewage treatment plants removal efficiency, and collective drug usage estimation (Postigo et al., 2010)

Published SF/E studies have been conducted in a number of countries, with assessments at the local, regional, or national levels, primarily in Belgium, Germany, Ireland, Italy, Spain, Switzerland, the United States (i.e., Oregon), and Wales. To date, SF/E assessments have focused on a select few parent drugs (primarily cannabis, cocaine, heroin, and MDMA) using various metabolites. They have been performed using a broad range of sampling methodologies ranging from single-event discrete grab sampling to longer-term (e.g., 12-month) integrative continuous sampling over numerous WWTPs or rivers, servicing regions with populations exceeding millions. Many of these studies have searched for temporal usage patterns—comparing yearly seasons or the day of the week (e.g., higher cocaine use on weekends). Usage rates are reported on various comparative bases, often involving per capita (e.g., g/day/1000 population, usually ranging only up to several grams), total consumption (e.g., tonnes/year/geographic area), or flows (mass/river/day). Discrete monitoring must acknowledge the cyclic or episodic drug use pattern fluctuations in concentrations that can result from diurnal cycles, seasons, or day of the week. This can be particularly pronounced for recreational drugs. Limits of detection (LOD) will dictate the extent to which a monitoring study will produce meaningful data-of-absence (negative data).

An enormous published literature surrounds the forensic chemistry of illicit drugs. The numbers of illicit drugs analyzed in the environment, however, is but a small fraction of those that have been targeted in countless studies published on biological tissues and fluids for the purposes of forensics and patient compliance monitoring and for the study of pharmacokinetics in animals. Accurate mass identification of unknowns (for example, via LC/TOF−MS) plays a central role especially when authentic reference standards are not available. While this conventional forensics literature can serve as a guide for environmental analysis, it is not directly relevant. There are numerous variables involved with (and impacting) the procedural steps used in analysis for SF/E, ranging from sampling design and matrix interferences to analyte determination and need for extremely low limits of detection. Some major overviews and discussion of the analytical approaches for measuring illicit drugs in wastewaters and other waters are available (Castiglioni et al., 2008; Postigo et al., 2008; Zuccato and Castiglioni, 2009).