title: Occurrence of the antidiabetic drug Metformin and its ultimate transformation product Guanylurea in several compartments of the aquatic cycle.
abstract: In 2030, the World Health Organization estimates that more than 350 million people will be diagnosed with diabetes. Consequently, Metformin - the biguanide drug of choice orally administered for diabetes type II - is anticipated to see a spike in production. Unlike many pharmaceutical drugs, Metformin (Met) is not metabolized by humans but passes through the body unchanged. Entering aquatic compartments, such as in sewage, it can be bacterially transformed to the ultimate transformation product Guanylurea (Gua). Sampling over one week (n=5) from a Southern German sewage treatment plant revealed very high average (AV) concentrations in influent (AVMet=111,800ng/L, AVGua=1300ng/L) and effluent samples (AVMet=4800ng/L, AVGua=44,000ng/L). To provide a more complete picture of the distribution and potential persistence of these compounds in the German water cycle, a new, efficient and highly sensitive liquid chromatography mass spectrometric method with direct injection was used for the measurement of Metformin and Guanylurea in drinking, surface, sewage and seawater. Limits of quantification (LOQ) ranging from 2-10ng/L allowed the detection of Metformin and Guanylurea in different locations such as: Lake Constance (n=11: AVMet=102ng/L, AVGua=16ng/L), river Elbe (n=12: AVMet=472ng/L, AVGua=9ng/L), river Weser (n=6: AVMet=349ng/L, AVGua=137ng/L) and for the first time in marine North Sea water (n=14: AVMet=13ng/L, AVGua=11ng/L). Based on daily water discharges, Metformin loads of 15.2kg/d (Elbe) and 6.4kg/d (Weser) into the North Sea were calculated. Lake Constance is used to abstract potable water which is further purified to be used as drinking water. A first screening of two tap water samples contained 2ng/L and 61ng/L of Metformin, respectively. The results of this study suggest that Metformin and Guanylurea could be distributed over a large fraction of the world's potable water sources and oceans. With no natural degradation processes, these compounds can be easily reintroduced to humans as they enter the food chain.
authors: Chair of Microsystem Simulation, IMTEK, Department of Microsystems Engineering, University of Freiburg, Georges-Koehler-Allee 103 DG, D-79110 Freiburg, Germany; Sustainable Chemistry and Material Resources, Institute of Environmental Chemistry, Faculty of Sustainability, Leuphana University Lüneburg, Scharnhorststrasse 1, D-21335 Lüneburg, Germany. Electronic address: christoph.trautwein@imtek.uni-freiburg.de.
authors: Christoph
authors: C
authors: Trautwein
authors: Office of Water and Waste Management (AWA), Water and Soil Protection Laboratory (WSPL), Schermenweg 11, CH-3014 Bern, Switzerland. Electronic address: jean-daniel.berset@bve.be.ch.
authors: Jean-Daniel
authors: JD
authors: Berset
authors: Sustainable Chemistry and Material Resources, Institute of Environmental Chemistry, Faculty of Sustainability, Leuphana University Lüneburg, Scharnhorststrasse 1, D-21335 Lüneburg, Germany; Department for Environmental Chemistry, Institute of Coastal Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Straße 1, D-21502 Geesthacht, Germany. Electronic address: hendrik.wolschke@hzg.de.
authors: Hendrik
authors: H
authors: Wolschke
authors: Sustainable Chemistry and Material Resources, Institute of Environmental Chemistry, Faculty of Sustainability, Leuphana University Lüneburg, Scharnhorststrasse 1, D-21335 Lüneburg, Germany. Electronic address: klaus.kuemmerer@uni.leuphana.de.
authors: Klaus
authors: K
authors: Kümmerer
mesh_terms: D001419:Bacteria / Q000378:metabolism; D001711:Biotransformation; D060766:Drinking Water / Q000032:analysis / Q000382:microbiology; D004784:Environmental Monitoring; D007004:Hypoglycemic Agents / Q000032:analysis* / Q000378:metabolism; D007700:Kinetics; D008687:Metformin / Q000032:analysis* / Q000378:metabolism; D045483:Rivers / Q000737:chemistry / Q000382:microbiology; D012722:Sewage / Q000737:chemistry / Q000382:microbiology; D013890:Thiourea / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism
chemical_list: D060766:Drinking Water; D007004:Hypoglycemic Agents; D012722:Sewage; D014874:Water Pollutants, Chemical; D008687:Metformin; D013890:Thiourea
keywords: Drinking water; Emerging contaminants; Pharmaceuticals; Pollution; Seawater; Waste water