In Vivo Monitoring Air Pollution Health Impacts using Breath-borne VOCs

LU ZHANG, Xinyue Li, Haoxuan Chen, Zhijun Wu, Min Hu, Maosheng Yao, Peking University

     Abstract Number: 98
     Working Group: Aerosol Exposure

Abstract
Direct observation of air pollution health impact on humans is difficult and lacking. Here, we investigated the use of breath-borne volatile organic compounds (VOCs) for in vivo monitoring air pollution health effects on humans. Forty-six healthy college students were recruited; and their exhaled breath samples (n=235) were collected and analyzed for VOCs before, on and after two separate haze pollution episodes using Gas Chromatograph-Ion Mobility Spectrometer (GC-IMS). Paired t-test and machine leaning model (Gradient Boosting Machine, GBM) were conducted to discriminate the VOC profiles of pre-, on- and post-exposure to haze pollution. Six exhaled VOC species including propanol and isoprene were detected to differ significantly among pre-, on- and post-exposure in both haze episodes; while no statistically significant differences were found between clean control days (p-value>0.05). GBM model was shown to differentiate pre- and on-exposure to haze pollution for both haze episodes with a precision of up to 90-100%. However, the same model had poor performance of differentiating the differences in breath-borne VOC profiles between two different clean days. Correlation analysis revealed that NH4+, NO3-, acetic, mesylate, CO, NO2, PM2.5, and O3 played important roles in the changes of breath-borne VOC fingerprints following haze pollution exposure. Results not only showed a gender difference in response to the haze pollution, but also different health impacts from different haze episodes. This work has demonstrated direct evidences of human health impacts of haze pollution, while developing a protocol for non-invasively in vivo tracking the impacts of air pollution on human health.