title: Biological and photochemical degradation of cytostatic drugs under laboratory conditions.
abstract: Cytostatic drugs, used in chemotherapy, have emerged as new environmental contaminants due to their recurrent presence in surface waters and genotoxic effects. Yet, their degradability and environmental fate is largely unknown. The aim of this study was to determine the degradation kinetics of 16 cytostatic drugs, prioritized according to their usage and occurrence in hospital and wastewater treatment plants (WWTP) effluents, through the following laboratory scale processes: hydrolysis, aerobic biodegradation, UV-C photolysis, UV-C/H2O2and simulated solar radiation. Some drugs were unstable in milli-Q water (vincristine, vinblastine, daunorubicin, doxorubicin and irinotecan); others were photodegraded under UV-C light (melphalan and etoposide) but some others were found to be recalcitrant to biodegradation and/or UV-C, making necessary the use of advanced oxidation processes (AOPs) such as UV-C/H2O2for complete elimination (cytarabine, ifosfamide and cyclophosphamide). Finally, radiation in a solar box was used to simulate the fate of cytostatic drugs in surface waters under natural radiation and complete removal was not observed for any drug. The degradation process was monitored using liquid chromatography coupled to high resolution mass spectrometry and pseudo-first order kinetic degradation constants were calculated. This study provides new data on the degradability of cytostatic compounds in water, thus contributing to the existing knowledge on their fate and risk in the environment.
authors.affiliation: Dept. of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona, Catalonia, Spain.
authors.forename: Helena
authors.initials: H
authors.lastname: Franquet-Griell
authors.affiliation: Chemical Engineering Dept., University of Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalonia, Spain.
authors.forename: Andrés
authors.initials: A
authors.lastname: Medina
authors.affiliation: Chemical Engineering Dept., University of Barcelona, Martí i Franquès 1, 08028 Barcelona, Catalonia, Spain.
authors.forename: Carme
authors.initials: C
authors.lastname: Sans
authors.affiliation: Dept. of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona, Catalonia, Spain. Electronic address: slbqam@cid.csic.es.
authors.forename: Silvia
authors.initials: S
authors.lastname: Lacorte
mesh_terms: D000332:Aerobiosis; D001673:Biodegradation, Environmental; D054697:Cytostatic Agents / Q000737:chemistry* / Q000528:radiation effects; D004350:Drug Residues / Q000737:chemistry / Q000528:radiation effects; D004784:Environmental Monitoring; D017744:Medical Waste Disposal; D010084:Oxidation-Reduction; D010782:Photolysis; D013472:Sunlight; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical
chemical_list: D054697:Cytostatic Agents; D017744:Medical Waste Disposal; D014874:Water Pollutants, Chemical
keywords: Advanced oxidation processes; Biodegradation; Cytostatic drugs; Kinetics; Photolysis