Democratizing Access to Cleaner Residential Air (DACRA) - Particulate air pollution (PM2.5) is the 4th leading cause of morbidity and mortality. Attention from leading health organizations has recently turned to interventions to reduce exposure and prevent adverse health outcomes. As evidence has begun to mount for the efficacy of these machines, and will likely grow further in the coming years, it has, however, become apparent that for most people, including low-income populations in the US, cannot afford effective commercially available units. Low-cost commercial air purifiers are of low efficacy and often introduce new pollutants into the air. To our knowledge, there are no published intervention studies of Corsi-Rosenthal Boxes (C-R Boxes), the devices we propose to use in this study. We have a study team that is ideally suited for the proposed research. Ms. Creed has extensive experience building and deploying the C-R Boxes which became popular during the Covid pandemic. Dr. Brugge has three published RCTs of high-quality commercial air purifiers and another, full trial, nearing completion. Thus, he has knowledge and experience which qualifies him to lead this proposed study. Drs. Levy Zamora has extensive air monitoring expertise, will direct measurement of indoor and outdoor air pollution concentrations at each home. Dr. Eliasziw is a biostatistician with extensive experience analyzing randomized trials. We have three aims: 1)Conduct focus groups/interviews and BP measurements with participants who meet study inclusion criteria to refine our protocol; 2) Conduct a randomized crossover pilot trial with 65 participants to calculate preliminary effect size estimates to inform a larger crossover efficacy trial; and 3) Determine the feasibility of conducting a larger crossover efficacy multisite trial in the US. We will conduct our randomized cross over trial in three settings with low, medium, and high air pollution. Our low and medium air pollution locations will be in Hartford CT and our high pollution setting will be in Boston Chinatown, where we can reliably expect high pollution levels. Participants (N=65) will have dried blood spots collected and blood pressure measured at the start and end of each 4-week intervention session. Our randomized cross over design controls for time invariant confounding. Interviews and standardized questionnaires with study participants will provide feedback that will inform the decision as to whether to proceed with a full trial. We seek to meet targets for 80% recruitment and retention as well as 80% satisfaction as benchmarks for moving to a full trial. The findings for health end points will provide preliminary data to justify the potential future R01 proposal for a fully powered clinical trial. An expert elicitation process conducted with the research team in the final year will make the final decision about a future, full trial. The significance of this work is that showing efficacy of C-R Boxes for reducing exposure would lead to their widespread use and contribute to improving public health
