AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Exposure to Polycyclic Aromatic Hydrocarbons and Associated Oxidative Damage: A Natural Experiment between Los Angeles and Beijing
YAN LIN, Xinghua Qiu, Yifang Zhu, University of California Los Angeles
Abstract Number: 190 Working Group: Haze in China: Sources, Formation Mechanisms, and Current Challenges
Abstract Polycyclic aromatic hydrocarbons (PAHs) are major toxic components of PM2.5. It was estimated that the PAHs concentration in the air was one magnitude higher in Beijing compared with Los Angeles. In this study, the urinary concentration of hydroxylated PAHs (HOPAHs) and malondialdehyde (MDA) in a panel of young healthy volunteers, who travelled between Los Angeles and Beijing in summer, was investigated to assess their exposures to PAHs and associated oxidative damage, respectively. The urinary level of total hydroxylated PAHs (∑HOPAHs) in Beijing (geometric mean, same as below, 9.16 microgram per gram creatinine) was 2.1 folds higher than that in Los Angeles (4.23 mcirogram per gram creatinine), indicating higher exposure in Beijing. The characteristic ratios of HOPAHs isomers also changed significantly between the two cities, indicating a shift in the metabolism pathways of PAHs. Based on a mixed-effect model, all the measured HOPAHs was significantly associated with MDA (p<0.05), except for 1-hydroxypyrene (p=0.07) and naphthols (p=0.11). However, no significant difference in MDA was observed between the two cities (33.7 microgram per gram creatinine in Beijing and 35.1 microgram per gram creatinine in Los Angeles, p=0.94). Our study provided evidence showing a higher PAHs exposure and a significant shift in PAHs metabolism pathways in Bejing compared with Los Angeles. Future studies revealing the potential mechanism for non-elevated MDA levels in Beijing (i.e. the inducement of anti-oxidation system) are needed.