The Analysis and Assessment of Exhaled VOCs in Adults under Ambient Ozone Exposure

Rapidly monitoring and accurately assessing the direct impacts of air pollution on human health is a long-standing challenge. Exhaled breath analysis, as a real-time and sensitive human biomonitoring technique, is causing significant concerns. This study aims to analyze and assess volatile organic compounds (VOCs) in human exhaled breath under ambient ozone (O₃) exposure. A comprehensive correlation analysis involving 288 VOCs are identified in the exhaled breath of healthy adults (n = 1130), uncovering 12 VOCs including methanol, propyne, and 1-butene etc. that show strong exposed correlations with ambient O₃ levels. Nonlinear modeling indicated the dose-response commencing at O₃ concentrations as low as 58 μg/m³_. Moreover, the presence of PM_2.5 significantly exacerbates the effect of O₃ on the filtered 12 VOCs. The most pronounced interplay is observed at 140 μg/m³ for O₃ and 150 μg/m³ for PM_2.5. Finally, an in-vivo study using rats validates the result, with all of the 12 exhaled breath biomarkers exhibit obvious differences (O₃ exposure group vs control group). This work demonstrates direct evidence that ambient O₃ pollution impacts on human exhaled VOCs, and also offers valuable insights for establishing O₃ exposure thresholds.