Understanding Potential Lung Recovery from Coal Mine Fire Smoke exposure

<bold>Introduction:</bold> In 2014 a coal mine fire in Victoria, Australia exposed local residents to fine particulate matter (PM_2.5) for 6wks. PM_2.5 exposure was associated with increased ventilation heterogeneity and worse respiratory mechanics at 4yrs (R1); this was attenuated at 7yrs (R2). <bold>Aim:</bold> To assess the impact of medium-term exposure to PM_2.5 on respiratory function 9yrs later (R3). <bold>Methods:</bold> Participants completed spirometry, gas transfer and oscillometry. Individual PM_2.5 exposure was retrospectively modelled and fitted in mixed-effects regression models to analyse associations between PM_2.5 and lung function. <bold>Results:</bold> 164 exposed and 80 unexposed participants from a cohort (R1: N=519, R2: N=329) completed R3: 59% female, mean age 58.6±15yrs, 44% had BMI≥30kg/m². The attenuated relationships between PM_2.5 exposure at R2 compared with R1 for baseline FVC Z-scores, transformed postBD reactance and area under the curve were maintained at R3 (Figure). There was no association between PM_2.5 and gas transfer. The trend for improvement in postBD Rrs5-19 at R2, reached significance at R3. <bold>Conclusion:</bold> Resolution of increased lung stiffness, associated with medium term PM_2.5 exposure, was maintained long-term. However potential reduction in peripheral resistance took longer. Findings are consistent with recovery of lung function after exposure to coal mine fire smoke. <fig><object-id>erj;64/suppl_68/PA463/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig> <bold>Funding:</bold>Victorian Dept of Health. The abstract presents the views of the authors, not the Dept