Translating a novel wildfire smoke exposure chamber system from lab-based experiments to community-engaged activities

Wildfire smoke (WFS) events are an important public health concern for communities in the Pacific Northwest of the United States. Previous studies of portable air cleaners, including high efficiency particulate air (HEPA) filtration and do-it-yourself (DIY) box fan filters built with MERV 13-rated filters, have indicated that their use in residential settings may be an effective way to reduce indoor exposures to fine particulate matter during WFS episodes. The lower-cost, easy to build instructions and availability of materials of DIY box fan filters have made their distribution by both public health agencies and community groups an attractive approach to improve community preparedness. Here, we describe a low-cost, easy-to-assemble, portable exposure chamber system that can be used to support a variety of community-engaged demonstrations of WFS removal efficiency as well as provide a mechanism to estimate the efficiency of filtration systems in a controlled environment. We conducted experiments using the portable chamber to assess the clean air delivery rate (CADR) of a MERV 13-rated DIY box fan filter, which was found to be 92.2 and 145.2 cfm at low and high fan speeds, respectively. In addition to using the chamber system to evaluate the CADR of DIY box fan filters, we also provide a case-study example, working with a tribal community in Central Washington, who used the tent system for a live demonstration of a DIY box fan filter experiment during their community gathering to promote WFS and air quality intervention knowledge and distribution of box fan filters.