title: Halogenated indigo dyes: a likely source of 1,3,6,8-tetrabromocarbazole and some other halogenated carbazoles in the environment.
abstract: In recent years, a number of halogenated carbazoles have been detected in environmental samples. These emerging contaminants have been shown to be persistent and possess dioxin-like toxicological potential. The goal of this research was to examine the literature to determine likely anthropogenic origin(s) of halogenated carbazoles in the environment. The scientific literature indicated a number of pathways by which 1,3,6,8-tetrabromocarbazole could form in the manufacture of 5,5',7,7'-tetrabromoindigo. The U.S. production history of 5,5',7,7'-tetrabromoindigo correlates well with the concentration rise, decline, and disappearance of 1,3,6,8-tetrabromocarbazole in dated Lake Michigan sediments. Additionally, other halogenated carbazoles that have been found in environmental sediments can be explained by the production of other halogenated indigo dyes. 1,8-dibromo-3,6-dichlorocarbazole can be accounted for by the manufacture of 7,7'-dibromo-5,5'-dichloroindigo, while 1,3,6,8-tetrachlorocarbazole was found at relatively high concentration near the outfall of a U.S. manufacturer of 5,5',7,7'-tetrachloroindigo. Carbazoles containing an iodo-substituent can be explained by the use of iodine as a catalyst in the manufacture of halogenated indigo dyes. 3,6-Dichlorocarbazole measured in soils and dibromocarbazoles measured in more recently deposited sediments are not easily rationalized on the basis of an indigo related source and may be related to other anthropogenic sources or natural origins.
authors: Matson & Associates, Inc., 331 E. Foster Ave, State College, PA 16801, USA. Electronic address: bparette@matson-associates.com.
authors: Robert
authors: R
authors: Parette
authors: Dept. of Chemistry, University of Guelph, Guelph, ON N1G 2W1, Canada; Wellington Laboratories Inc., 345 Southgate Dr, Guelph, ON N1G 3M5, Canada.
authors: Robert
authors: R
authors: McCrindle
authors: Matson & Associates, Inc., 331 E. Foster Ave, State College, PA 16801, USA.
authors: Katherine S
authors: KS
authors: McMahon
authors: Ontario Ministry of the Environment, 125 Resources Rd, Toronto, ON M9P 3V6, Canada; Dept. of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada.
authors: Miren
authors: M
authors: Pena-Abaurrea
authors: Ontario Ministry of the Environment, 125 Resources Rd, Toronto, ON M9P 3V6, Canada; Dept. of Chemistry, University of Toronto, Toronto, ON M5S 3H6, Canada.
authors: Eric
authors: E
authors: Reiner
authors: Wellington Laboratories Inc., 345 Southgate Dr, Guelph, ON N1G 3M5, Canada.
authors: Brock
authors: B
authors: Chittim
authors: Wellington Laboratories Inc., 345 Southgate Dr, Guelph, ON N1G 3M5, Canada.
authors: Nicole
authors: N
authors: Riddell
authors: Johannes Kepler University, Institute for Organic Solar Cells, Altenberger Str 69, 4040 Linz, Austria.
authors: Gundula
authors: G
authors: Voss
authors: Dept.of Biochemistry and Molecular Biology, Penn State University, University Park, PA 16802, USA.
authors: Frank L
authors: FL
authors: Dorman
authors: Matson & Associates, Inc., 331 E. Foster Ave, State College, PA 16801, USA.
authors: Wendy N
authors: WN
authors: Pearson
mesh_terms: D002227:Carbazoles / Q000032:analysis* / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D004777:Environment; D004784:Environmental Monitoring; D054879:Halogenation; D007203:Indigo Carmine / Q000737:chemistry*; D008824:Michigan; D000072317:Polychlorinated Dibenzodioxins / Q000737:chemistry; D012987:Soil; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: C509933:1,3,6,8-tetrabromocarbazole; C558653:3,6-dichlorocarbazole; D002227:Carbazoles; D004396:Coloring Agents; D000072317:Polychlorinated Dibenzodioxins; D012987:Soil; D012989:Soil Pollutants; D007203:Indigo Carmine
keywords: Dibromodichlorocarbazole; Emerging contaminants; Indigo; Source identification; Tetrabromocarbazole; Tetrachlorocarbazole