Abstract View
Quantifying the Health Benefits of Respirators and Face Coverings to Mitigate Exposure to Wildfire Air Pollution
JACK KODROS, Kate O'Dell, Jon Samet, Christian L'Orange, Jeffrey R. Pierce, John Volckens, Colorado State University
Abstract Number: 458
Working Group: Wildfire Aerosols
Abstract
Public familiarity with the use of face coverings to reduce the risk of respiratory disease has increased during the coronavirus pandemic; however, recommendations for their use outside of the pandemic (in non-occupational settings) remains limited. As wildfire smoke events continue to become an increasing public health concern, recommendations for personal intervention strategies to limit exposure to wildfire smoke are essential. Here, we develop a framework to quantify the potential health benefits of wearing respirators or face coverings to mitigate exposure to wildfire smoke. This modeling framework considers variation in the type, fit, and wearing compliance of a given mask (cotton-fiber masks, synthetic-fiber masks, N95 respirators), aerosol characteristics, and exposure-response data. We find that N95 respirators offer robust protection against wildfire smoke, reducing particulate exposure by more than a factor of 16 when worn with a leakage rate of 5%. Synthetic-fiber masks offer less protection with a strong dependence on aerosol size distribution (exposure reduction factors ranging from 8 to 2). Cotton-fiber masks offer only 20% reductions in exposure. To assess the ability of face coverings to provide population-level health benefits to wildfire smoke, we perform a case study for the 2012 Washington state fire season where daily wildfire smoke PM2.5 ranged from 10-120 µg m-3. After accounting for assumptions on mask-wearing compliance, our modeling framework suggests that while cotton-fiber masks offer minor reductions in respiratory hospitalizations (a 2-7% reduction in smoke-attributable hospital admissions) due to limited filtration efficiency and poor fit, N95 respirators and synthetic-fiber masks may lead to notable reductions in hospitalizations (19-35% and 7-18%, respectively). For all masks, the bypass rate of air around the filtering piece is a key factor governing potential exposure reduction and health benefits during severe wildfire events.