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南开大学环境科学与工程学院

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讲座时间:2016年6月2日 15:00

讲座地点:环科院楼B119报告厅

讲座题目:Understanding Polyhalogenated Carbazoles

讲座专家:An Li, PhD, Professor,School of Public Health, University of Illinois at Chicago, Chicago, Illinois, United States

    In recent years, increasing detection of polyhalogenated carbazoles (PHCZs) has caused concern. PHCZs resemble polyhalogenated dibenzofurans in chemical structure with a planar molecular conformation that promotes toxicity. As such, PHCZs are termed nitrogenated dioxins and are considered as novel persistent organic pollutants. In this work, 26 PHCs and carbazole were measured in the sediments of Lakes Superior, Michigan and Huron of North America. the total accumulation of 26 PHCZs is >2,500 tonnes, which exceeds those of known anthropogenic organic pollutant groups by orders of magnitude. Spatial and temporal patterns in PHCZ concentrations and depositional fluxes indicate that the majority was formed naturally. In addition, photolysis of 11 individual and 5 mixtures of PHCZs in hexane was investigated under natural sun radiation. The results show that PHCZs containing iodine degraded within 10 min, while those containing chlorines only were more stable compared to those containing bromine and iodine with equal number of total halogen substitutions. Furthermore, PHCZs were detected in the fish collected from the Great Lakes, indicating they are bioaccumulative. Embryonic developmental toxicity of a few PHCZs was tested on zebra fish embryos (Danio rerio). Symptoms commonly shown in the acute toxicity of 2,3,7,8-TCDD were observed with several PHCZs. Real-time PCR also showed CYP1A was greatly induced by those toxic PHCs. Further investigation on the source, fate, and toxicity of PHCs was needed in future studies.

李安教授的简介如下:

 Dr. An Li is a professor of Environmental and Occupational Health Sciences in the University of Illinois at Chicago. Her researchfocuses on the behavior of persistent, bioaccumulative, and toxic organic pollutants in the environment and in humans. In the past 15 years, herteam is one of the leading groups in monitoring and surveillance on variouslegacy and emerging organic pollutants in the Great Lakes region of the North America. Dr. Li has published 2 books, nearly 80 journal papers, 5 book chapters, and numerous project reports and conference presentation abstracts.

 


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