title: Drugs of abuse and benzodiazepines in the Madrid Region (Central Spain): seasonal variation in river waters, occurrence in tap water and potential environmental and human risk.
abstract: This work analyzes the seasonal variation (winter and summer) of ten drugs of abuse, six metabolites and three benzodiazepines in surface waters from the Jarama and Manzanares Rivers in the Madrid Region, the most densely populated area in Spain. The occurrence of these compounds in tap water in this region is also investigated and a preliminary human health risk characterization performed for those substances found in tap water. Finally, a screening level risk assessment that combines the measured environmental concentrations (MECs) with dose-response data to estimate Hazard Quotients (HQs) for the compounds studied is also presented. The results of this study show the presence of fourteen out of the nineteen compounds analyzed in winter and twelve of them in summer. The most ubiquitous compounds, with a frequency of detection of 100% in both seasons, were the cocaine metabolite benzoylecgonine (BE), the amphetamine-type stimulant (ATS) ephedrine (EPH), the opioid methadone (METH), the METH metabolite 2-ethylene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), and the three benzodiazepines investigated, namely alprazolam (ALP), diazepam (DIA) and lorazepam (LOR). The highest concentrations observed corresponded to EPH (1020ngL(-1) in winter and 250ngL(-1) in summer). The only compounds not detected in both seasons were heroin (HER) and its metabolite 6-acetylmorphine (6ACM), lysergic acid diethylamide (LSD) and its metabolite 2-oxo-3-hydroxy-LSD (O-H-LSD), and Δ(9)-tetrahydrocannabinol (THC). In terms of overall concentration, all sampling points presented higher concentrations in winter than in summer. Statistical analyses performed to gather evidence concerning occasional seasonal differences in the concentrations of individual substances between summer and winter showed statistically significantly higher concentrations (p<0.05) of BE, EPH and the opioid morphine (MOR) in winter than in summer. Two out of the nineteen compounds studied, namely cocaine (CO) and EPH, were detected in tap water from one sampling point at concentrations of 1.61 and 0.29ngL(-1), respectively. The preliminary human health risk characterization showed that no toxic effects could be expected at the detected concentration level in tap water. The screening level risk assessment showed that MOR, EDDP and the THC metabolite 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol (THC-COOH) were present in at least one of the sampling sites in a concentration leading to a Hazard Quotient (HQ) value between 1.0 and 10.0, thus indicating some possible adverse effects. The cumulative HQ or Toxic units (TUs) calculated for each of the groups studied showed that opioids and cannabinoids were present at concentrations high enough to potentially generate some adverse effects on at least one sampling point.
authors.affiliation: Research Group in Environmental Health and Eco-Toxicology (ToxAmb), Rey Juan Carlos University, Avda. Tulipán, s/n, 28933 Móstoles, Madrid, Spain. Electronic address: angelesmendoza1970@gmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Mendoza
authors.affiliation: Research Group in Environmental Health and Eco-Toxicology (ToxAmb), Rey Juan Carlos University, Avda. Tulipán, s/n, 28933 Móstoles, Madrid, Spain; Centre for Toxicology, School of Environmental Sciences, University of Guelph, Guelph, Ontario N1G2W1, Canada.
authors.forename: J L
authors.initials: JL
authors.lastname: Rodríguez-Gil
authors.affiliation: Research Group in Environmental Health and Eco-Toxicology (ToxAmb), Rey Juan Carlos University, Avda. Tulipán, s/n, 28933 Móstoles, Madrid, Spain.
authors.forename: S
authors.initials: S
authors.lastname: González-Alonso
authors.affiliation: Water and Soil Quality Research Group, Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Mastroianni
authors.affiliation: Water and Soil Quality Research Group, Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: López de Alda
authors.affiliation: Water and Soil Quality Research Group, Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Jordi Girona 18-26, 08034 Barcelona, Spain; Catalan Institute for Water Research (ICRA), H(2)O Building, Scientific and Technological Park of the University of Girona, Emili Grahit 101, 17003 Girona, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Barceló
authors.affiliation: Research Group in Environmental Health and Eco-Toxicology (ToxAmb), Rey Juan Carlos University, Avda. Tulipán, s/n, 28933 Móstoles, Madrid, Spain; Department of Preventive Medicine, Public Health, Immunology and Medical Microbiology, Faculty of Health Sciences, Rey Juan Carlos University, Avda. Atenas, s/n, 28922 Alcorcón, Madrid, Spain. Electronic address: yolanda.valcarcel@urjc.es.
authors.forename: Y
authors.initials: Y
authors.lastname: Valcárcel
mesh_terms: D000328:Adult; D001569:Benzodiazepines / Q000032:analysis*; D060766:Drinking Water / Q000032:analysis*; D013759:Dronabinol / Q000031:analogs & derivatives / Q000032:analysis; D004781:Environmental Exposure; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D013287:Illicit Drugs / Q000032:analysis*; D008238:Lysergic Acid Diethylamide / Q000031:analogs & derivatives / Q000032:analysis; D008297:Male; D009022:Morphine Derivatives / Q000032:analysis; D045483:Rivers / Q000737:chemistry*; D012621:Seasons; D013030:Spain / Q000453:epidemiology; D014877:Water Pollution, Chemical / Q000032:analysis*
chemical_list: D060766:Drinking Water; D013287:Illicit Drugs; D009022:Morphine Derivatives; D001569:Benzodiazepines; C052413:delta(9-11)-tetrahydrocannabinol; C016780:11-nor-delta(9)-tetrahydrocannabinol-9-carboxylic acid; D013759:Dronabinol; D008238:Lysergic Acid Diethylamide; C118789:2-oxo-3-hydroxylysergic acid diethylamide; C026979:6-O-monoacetylmorphine
keywords: Drugs of abuse; Environmental risk; Human risk assessment; Madrid Region; Surface water; Tap water