Spatial and Temporal Trends of Polyhalogenated Carbazoles in Sediments of Upper Great Lakes: Insights into Their Origin

Jiehong Guo, Zhuona Li, Prabha Ranasinghe, Solidea Bonina, Soheil Hosseini, Margaret B. Corcoran, Colin Smalley, Karl J. Rockne, Neil C. Sturchio, John P. Giesy, An Li

Research output: Contribution to journalArticlepeer-review

54 Scopus citations

Abstract

Polyhalogenated carbazoles (PHCZs) have been increasingly detected in the environment. Their similarities in chemical structure with legacy pollutants and their potential toxicity have caused increasing concern. In this work, 112 Ponar grab and 28 core sediment samples were collected from Lakes Michigan, Superior, and Huron, and a total of 26 PHCZs were analyzed along with unsubstituted carbazole using gas chromatography coupled with single- or triple-quadrupole mass spectrometry. Our results show that the total accumulation of PHCZs in the sediments of the upper Great Lakes is >3000 tonnes, orders of magnitude greater than those of polychlorinated biphenyls (PCBs) and decabromodiphenyl ether (BDE209). The 27 individual analytes differ in spatial distribution and temporal trend. Our results showed that PHCZs with substitution patterns of -Br2-5, -Cl1-2Br2-4, or having iodine, were more abundant in sediment of Lake Michigan deposited before 1900 than those deposited more recently, implying a natural origin. Some "emerging" PHCZs have been increasingly deposited into the sediment in recent decades, and deserve further environmental monitoring and research. Other PHCZs with low halogen substitution may form from in situ dehalogenation of PHCZs having more halogens. Anthropogenic sources of PHCZs may exist, particularly for the emerging and low molecular mass congeners.

Original languageEnglish (US)
Pages (from-to)89-97
Number of pages9
JournalEnvironmental Science and Technology
Volume51
Issue number1
DOIs
StatePublished - Jan 3 2017
Externally publishedYes

Bibliographical note

Funding Information:
This research was part of the Great Lakes Sediment Surveillance Program (GLSSP) funded by a Cooperative Agreement from the U.S. EPA Great Lakes Restoration Initiative with Assistance No. GL-00E00538 (EPA Program Officer Todd Nettesheim). J.G. and S.H. were also supported by Predoctoral Fellowships from the Institute for Environmental Science and Policy at the University of Illinois at Chicago.

Publisher Copyright:
© 2016 American Chemical Society.

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