1. Section of Drug Abuse Research, Department of Forensic Sciences, Oslo University Hospital, Oslo, Norway;
2. Department of Alcohol, Tobacco and Drugs, Norwegian Institute of Public Health, Oslo, Norway;
3. Norwegian Institute for Water Research, Oslo, Norway;
4. Research Institute for Pesticides and Water, University Jaume I, Castellón, Spain;
5. Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Milan, Italy