Acute changes in lung function following controlled exposure to cookstove air pollution in the Subclinical Tests on Volunteers Exposed to Smoke (SToVES) Study

Abstract

TPS 901: Indoor air pollution, Exhibition Hall, Ground floor, August 28, 2019, 3:00 PM - 4:30 PM Background/Aim: Exposure to cookstove-generated air pollution is a leading contributor to global disease. Effects of household air pollution on adult lung function, however, remain uncertain. It is unclear how much exposure reduction is needed to improve respiratory health. We investigated acute changes in lung function following exposure to cookstove-generated air pollution using a controlled exposure design. Methods: Forty-seven healthy adult volunteers were assigned to sequences of six 2-hour exposures: a filtered-air control and five cookstoves with distinct fine particulate matter (PM2.5) targets: liquefied petroleum gas (LPG), 10 µg/m3; semi-gasifier, 35 µg/m3; fan rocket, 100 µg/m3; rocket elbow, 250 µg/m3; open fire, 500 µg/m3. Spirometry was conducted prior to exposure and immediately, 3 hours, and 24 hours after exposure. Mixed-effect models were used to estimate differences in post-exposure lung function for the stove exposures compared to the control. Measurements and Main Results: At the immediate post-exposure measurement, lung function was lower than the control for the three highest PM2.5 exposures. The largest differences were for the fan rocket stove (forced vital capacity [FVC]: 60 mL, 95%CI 135, 15; forced expiratory volume [FEV1]: 51 mL, 95%CI 117, 16; mid-expiratory flow [FEF25-75]: 116 mL/s, 95%CI 239, 8). At 3 hours post-exposure, lung function was lower than the control for all stoves; differences were of similar magnitude for all stoves but largest for the LPG (FVC: 39 mL, 95%CI 114, 35; FEV1: 68 mL, 95%CI 128, 7; FEF25-75: 122 mL/s, 95%CI 255, 11). At 24 hours post-exposure, results were consistent with a null association for FVC and FEV1; FEF25-75 was lower than the control for the gasifier, fan rocket, and open fire exposures. Conclusion: Relative to a filtered-air control, short-term decreases in lung function occur following controlled exposure to cookstove-generated air pollution even at low PM2.5 levels. This abstract does not represent EPA policy.