| Biography | |
|---|---|
 Prof. Bo Pan Dean of Faculty of Environmental Sciences and Engineering, Kunming University of Science and Technology, China |
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| Title: Generation of environmentally persistent free radicals and the new challenges in environmental geochemistry | |
| Abstract: Environmentally persistent free radicals (EPFRs) are defined as organic free radicals stabilized on or inside particles. They are persistent because of the protection by the particles and show significant toxicity to organisms. Increasing research interests have been attracted to study the potential environmental implications of EPFRs. Because of their different physical forms from conventional contaminants, it is not applicable to use the commonly used technique and strategy to predict and assess the geochemical behavior and risks of EPFRs. Thus a new challenge is now encountered. For example, the mining and burning of low-rank coal in Xuanwei, China have attracted a great deal of research attention because of the generated polyaromatic hydrocarbons (PAHs) and the high incidence of lung cancer in this region. Importantly, we detected strong electron paramagnetic resonance (EPR) signals of 3.20 × 1017 - 3.10 × 1019 spins/g in environmental samples, including chimney soot, coal, soil and total suspended particles (TSP). These EPR signals did not significantly change after 18-months storage and had g-values in the range of 2.0039-2.0046, suggesting typical organic free radicals. Similar strong EPR signals were observed in PAH (anthracene and pyrene as model compounds) degradation on simulated soil particles and lasted over one month even when the applied PAHs were 100% degraded. Based on g-value and bond width, we propose that EPR signals detected in TSP and soot originated from both coal combustion and PAH photodegradation. We emphasized that EPFRs are formed in this region and the potential risk had not been addressed. For future studies, quantitative analysis of the interactions between organic contaminants and EPFRs will greatly improve the predictive accuracy of the multimedia environmental fate models. In addition, the health risks will be better evaluated when considering the toxicity contributed by EFPRs. | |
| Biography: Dr. Pan is Dean of Faculty of Environmental Sciences and Engineering, Kunming University of Science and Technology, and Director of Yunnan Provincial Key Laboratory of Environmental Soil Sciences. Dr. Pan earned a Ph.D in Environmental Science from Peking University in 2006 and B.S. in Environmental Engineering from Kunming University of Science and Technology in 1999. He completed postdoctoral work at University of Massachusetts, Amherst, USA. Dr. Pan received a National Science Fund for Distinguished Youth Scholars Award of China. He is an associate editor of European Journal of Soil Science. His research interests are environmental applications and implications of nanotechnology, carbon turnover and organic contaminant fate, and environmental implications of natural organic matter. Dr. Pan has published more than 100 papers indexed by Web of Science, mostly in leading international journals. His work has received over 3500 citations, and his H index is 31. | |
