Late Breaking Abstract - Assessing Inflammatory Response to Air Pollution via VOCs in Exhaled Breath

Air pollution, particularly particulate matter less than 2.5 μg/m³ (PM2.5), is classified as a Group 1 carcinogen and contributes to lung cancer and respiratory diseases. Lung inflammation is a response to pollutants, releasing volatile organic compounds (VOCs) in breath, which could serve as non-invasive markers for assessing inflammation. This randomized double-blind crossover study examined breath VOCs over 24 hours following acute high exposure to PM2.5 in 20 non-smoking, healthy individuals. Participants underwent two separate exposures in the UBC Air Pollution Exposure Lab booth: 300 μg/m³ of PM2.5 from a diesel engine, and to filtered air, spaced a minimum of six weeks apart. Breath collected using Breath Biopsy® before exposure, immediately after, and at 0.5, 1, 3, 6, and 24 hours post-exposure. Samples were analysed by GC-MS, both untargeted and targeted analyses was conducted. iData analysis included univariate analysis and multivariate techniques such as ANOVA simultaneous component analysis (ASCA). ASCA revealed a significant effect of exposure type (300 μg/m³ PM2.5 vs. sham, p < 0.01) and a significant interaction (p < 0.05) between post-exposure time and exposure type. From targeted analysis, inflammation-related compounds significantly increased in individuals exposed to PM2.5 compared to controls. From untargeted analysis, 12 VOCs significantly increased in breath of the 300 μg/m³ PM2.5 group, which diminished in samples collected 24 hours post-exposure. A distinct breath VOC profile is detectable in individuals exposed to inflammation triggers, suggesting that breath VOCs may detect acute airway inflammation and assess respiratory diseases secondary to air pollution.