title: Photolytic fate and genotoxicity of benzophenone-derived compounds and their photodegradation mixtures in the aqueous environment.
abstract: This study investigates the environmental fate of eight benzophenone derivatives (the pharmaceutical ketoprofen, its phototransformation products 3-ethylbenzophenone and 3-acetylbenzophenone, and five benzophenone-type UV filters) by evaluating their photolytic behaviour. In addition, the genotoxicity of these compounds and the produced photodegradation mixtures was studied. Laboratory-scale irradiation experiments using a medium pressure UV lamp revealed that photodegradation of benzophenones follows pseudo-first-order kinetics. Ketoprofen was the most photolabile (t1/2 = 0.8 min), while UV filters were more resistant to UV light with t1/2 between 17 and 99 h. The compounds were also exposed to irradiation by natural sunlight and showed similar photostability as predicted under laboratory conditions. Solar photodegradation experiments were performed in distilled water, lake and seawater, and revealed that photosensitizers present in natural waters significantly affect the photolytic behaviour of the investigated compounds. In this case, the presence of lake water resulted in accelerated photodecomposition, while seawater showed different effects on photodegradation, depending on a compound. Further, it was shown that the transformation products of ketoprofen 3-ethylbenzophenone and 3-acetylbenzophenone were formed under environmental conditions when ketoprofen was exposed to natural sunlight. Genotoxicity testing of parent benzophenone compounds using the SOS/umuC assay revealed that UV filters exhibited weak genotoxic activity in the presence of a metabolic activation system, however the concentrations tested were much higher than found in the environment (≥125 μg mL(-1)). After irradiation of benzophenones, the produced photodegradation mixtures showed that, with the exception of benzophenone that exhibited weak genotoxic activity, all the other compounds tested did not elicit any activity when exposed to UV light.
authors.affiliation: Jožef Stefan Institute, Department of Environmental Sciences, Jamova cesta 39, 1000 Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana, Slovenia; Ecological Engineering Institute Ltd, Ljubljanska ulica 9, 2000 Maribor, Slovenia.
authors.forename: Kristina
authors.initials: K
authors.lastname: Kotnik
authors.affiliation: Jožef Stefan Institute, Department of Environmental Sciences, Jamova cesta 39, 1000 Ljubljana, Slovenia.
authors.forename: Tina
authors.initials: T
authors.lastname: Kosjek
authors.affiliation: National Institute of Biology, Department of Genetic Toxicology and Cancer Biology, Večna pot 111, 1000 Ljubljana, Slovenia.
authors.forename: Bojana
authors.initials: B
authors.lastname: Žegura
authors.affiliation: National Institute of Biology, Department of Genetic Toxicology and Cancer Biology, Večna pot 111, 1000 Ljubljana, Slovenia.
authors.forename: Metka
authors.initials: M
authors.lastname: Filipič
authors.affiliation: Jožef Stefan Institute, Department of Environmental Sciences, Jamova cesta 39, 1000 Ljubljana, Slovenia; Jožef Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana, Slovenia. Electronic address: ester.heath@ijs.si.
authors.forename: Ester
authors.initials: E
authors.lastname: Heath
mesh_terms: D001577:Benzophenones / Q000528:radiation effects / Q000633:toxicity; D005618:Fresh Water; D007700:Kinetics; D009152:Mutagenicity Tests; D009153:Mutagens / Q000528:radiation effects / Q000633:toxicity; D010782:Photolysis; D012623:Seawater; D013472:Sunlight; D013473:Sunscreening Agents / Q000528:radiation effects / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000528:radiation effects / Q000633:toxicity
chemical_list: D001577:Benzophenones; D009153:Mutagens; D013473:Sunscreening Agents; D014874:Water Pollutants, Chemical
keywords: Benzophenone; Environment; Genotoxicity; Ketoprofen; Photodegradation; UV filter