title: Phototransformation pathways of the fungicide dimethomorph ((E,Z) 4-[3-(4-chlorophenyl)-3-(3,4-dimethoxyphenyl)-1-oxo-2-propenyl]morpholine), relevant to sunlit surface waters.
abstract: Dimethomorph (DMM) is a widely used fungicide that shows low toxicity for birds and mammals but can be quite toxic to aquatic organisms. The persistence of DMM in surface waters is thus of high importance, and this work modelled its water half-life time due to photochemical processes. Depending on environmental conditions (e.g. water chemistry, depth, season), DMM lifetime could vary from a few days to a few months. For lifetimes of a few weeks or shorter, photochemistry would be an important pathway for DMM attenuation in surface waters. Such conditions could be reached in summer, in shallow water bodies with low dissolved organic carbon (DOC) and high nitrate and/or nitrite. The main pathways accounting for DMM photodegradation in environmental waters would be the reactions with OH and with the triplet states of chromophoric dissolved organic matter, (3)CDOM* (under the hypothesis that (3)CDOM* reactivity is well described by the triplet state of anthraquinone-2-sulphonate), while direct photolysis would be less important. The OH pathway would be favoured in low-DOC waters, while the opposite conditions would favour (3)CDOM*. It was possible to detect and identify some intermediates formed upon reaction between DMM and (3)CDOM*, namely N-formylmorpholine, 4-chloroacetophenone and 4-chlorobenzoic acid. The transformation of DMM into the detected compounds would not increase the acute toxicity of the fungicide towards mammals, and the acute effects for freshwater organisms could be decreased significantly.
authors.affiliation: Università degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino, Italy. Electronic address: http://www.chimicadellambiente.unito.it.
authors.forename: Paola
authors.initials: P
authors.lastname: Avetta
authors.affiliation: Università degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino, Italy; LAV s.r.l., Strada Carignano 58/14, 10024 Moncalieri, TO, Italy. Electronic address: http://www.chimicadellambiente.unito.it.
authors.forename: Giulia
authors.initials: G
authors.lastname: Marchetti
authors.affiliation: Università degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino, Italy. Electronic address: http://www.chimicadellambiente.unito.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Minella
authors.affiliation: Università degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino, Italy. Electronic address: http://www.chimicadellambiente.unito.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Pazzi
authors.affiliation: Università degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino, Italy. Electronic address: http://www.chimicadellambiente.unito.it.
authors.forename: Elisa
authors.initials: E
authors.lastname: De Laurentiis
authors.affiliation: Università degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino, Italy. Electronic address: http://www.chimicadellambiente.unito.it.
authors.forename: Valter
authors.initials: V
authors.lastname: Maurino
authors.affiliation: Università degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino, Italy. Electronic address: http://www.chimicadellambiente.unito.it.
authors.forename: Claudio
authors.initials: C
authors.lastname: Minero
authors.affiliation: Università degli Studi di Torino, Dipartimento di Chimica, Via P. Giuria 5, 10125 Torino, Italy; Università degli Studi di Torino, Centro Interdipartimentale NatRisk, Via Leonardo da Vinci 44, 10095 Grugliasco, TO, Italy. Electronic address: davide.vione@unito.it.
authors.forename: Davide
authors.initials: D
authors.lastname: Vione
mesh_terms: D005659:Fungicides, Industrial / Q000032:analysis / Q000737:chemistry*; D006207:Half-Life; D008956:Models, Chemical; D009025:Morpholines / Q000032:analysis / Q000737:chemistry*; D055668:Photochemical Processes; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry
chemical_list: D005659:Fungicides, Industrial; D009025:Morpholines; D014874:Water Pollutants, Chemical; C076154:dimethomorph
keywords: Agrochemicals; Dimethomorph; Environmental persistence of fungicides; Indirect photolysis; Photochemical transformation