title: Aqueous secondary formation of brominated, chlorinated, and mixed halogenated pyrene in presence of halide ions.
abstract: We examined the secondary production of halogenated derivatives of polycyclic aromatic hydrocarbons (PAHs) in surface seawater. Pyrene was selected as the model compound and exposed to UV irradiation in synthetic seawater for various irradiation times. Pyrene underwent rapid photochemical reactions that produced various halogenated derivatives including 1-chloropyrene, 1-bromopyrene, three unidentified dichloropyrenes, and three unidentified bromochloropyrenes. The production of 1-chloropyrene (220-360 nM) was higher than that of 1-bromopyrene (7.3-12 nM), reflecting the high chlorine content of seawater. A pilot field survey was conducted to test the environmental implications of these results, and fresh, brackish, and seawater samples were collected in southwestern Japan. The variation in the concentration ratios between 1-chloropyrene and pyrene implied the presence of a specific source of 1-chloropyrene in coastal water, which can be partly explained by the secondary production observed in our photolysis experiments. In sum, the photochemical reactions of PAHs are a potential secondary source of halogenated PAHs, especially in marine environments heavily contaminated with PAHs.
authors.affiliation: Graduate School of Science and Technology, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama 338-8570, Japan. Electronic address: sankodakenshi@mail.saitama-u.ac.jp.
authors.forename: Kenshi
authors.initials: K
authors.lastname: Sankoda
authors.affiliation: Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, 3-1-100 Tsukide, Higashi-ku, Kumamoto 862-8502, Japan.
authors.forename: Izumi
authors.initials: I
authors.lastname: Toda
authors.affiliation: Graduate School of Science and Technology, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama 338-8570, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Sekiguchi
authors.affiliation: Center for Marine Environmental Sciences (CMES), Ehime University, 2-3 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan.
authors.forename: Kei
authors.initials: K
authors.lastname: Nomiyama
authors.affiliation: Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, 3-1-100 Tsukide, Higashi-ku, Kumamoto 862-8502, Japan.
authors.forename: Ryota
authors.initials: R
authors.lastname: Shinohara
mesh_terms: D001966:Bromine / Q000737:chemistry*; D002713:Chlorine / Q000737:chemistry*; D004784:Environmental Monitoring; D054879:Halogenation; D010782:Photolysis; D011721:Pyrenes / Q000032:analysis* / Q000737:chemistry*; D012623:Seawater / Q000737:chemistry*; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry
chemical_list: D011721:Pyrenes; D014874:Water Pollutants, Chemical; D002713:Chlorine; D001966:Bromine
keywords: Halogenated polycyclic aromatic hydrocarbons; Photochemical transformation; Polycyclic aromatic hydrocarbons