Defining VOC signatures of airway epithelial cells with PM2.5 exposure.

Volatile organic compounds (VOCs) produced by the lung in response to exposure to environmental pollutants can be utilized to study their impact on lung health and function. Previously, we developed a method to measure VOCs emitted from well-differentiated tracheobronchial epithelial cells in vitro. Using this method, we exposed well-differentiated proximal (PECs) and distal airway epithelial cells (DECs) to varying doses of traffic-related air pollutants (TRAP) and wildfire particulates to determine specific VOC signatures after exposure. We utilized PM2.5 TRAP collected from the Caldecott tunnel in Oakland, CA and the 2018 Camp Fire to model "real-life" exposures. The VOCs were collected and extracted from Twisters and analyzed using gas chromatography-mass spectrometry. Exposure to both types of particulate matter (PM) resulted in specific VOC responses grouped by individual subjects with little overlap. Interestingly the VOCs produced by the PECs and DECs were also differentiated from each other. Our studies suggest that PM exposure induces a specific compartmentalized cellular response that can be exploited for future studies. This response is cell-type specific and potentially related to a phenotype we have yet to uncover.