Informing the use of N95 respirators by the general public to reduce wildfire smoke exposure Kaitlyn Kelly A thesis submitted in partial fulfillment of the requirements for the degree of Master of Public Health University of Washington 2020 Committee: Tania Busch Isaksen Marc Beaudreau Marissa Baker Program Authorized to Offer Degree: Environmental and Occupational Health Sciences School of Public Health 1 ©Copyright 2020 Kaitlyn Kelly 2 University of Washington Abstract Informing the use of N95 respirators by the general public to reduce wildfire smoke exposure Kaitlyn Kelly Chair of the Supervisory Committee: Tania Busch Isaksen Department of Environmental and Occupational Health Sciences Climate change is increasing the frequency, intensity, and duration of wildfires. To reduce personal exposure to wildfire smoke and resulting adverse health effects, N95 respirators are increasingly used by the general public to filter out fine particles (PM2.5) present in smoke. When mandated in an occupational setting, the use of N95 masks requires medical clearance, proper training, and fit testing. This rigorous attention to training and proper respirator fit is generally, neither required or practiced by, the lay public. A literature resource summary was conducted to understand the current state-of-knowledge around the use of N95 respirators and training in occupational and other settings to inform novel use for the general public during wildfire smoke events. The goal of this study pilot was to assess the efficacy of training materials by quantifying the transference of knowledge from selected interventions into N95 respirator fit in a convenience sample of untrained, lay public. This is the first study to assess efficacy of N95 respirator training materials for the general public during wildfire smoke events. To this end, we administered a Knowledge, Attitude and Practices (KAP) survey to identify baseline knowledge and training retention; conducted a quantitative respirator fit test prior to, and after, each participant received their randomly assigned training material; and observed and analyzed the 3 actions taken by participants during the donning process that affect fit. This study found that without prior knowledge, the selected trainings significantly improved fit, but fit factors equivalent with occupational use were not observed. Pre-training fit testing found that most individuals achieved a fit factor of 2, a 50% decrease in particulate exposure. Post-training fit testing found most individuals reached a fit factor of at least 10, an expected 90% reduction in exposure. In comparing participants pre-intervention KAP survey results with initial fit factors, participants tended to overestimate their knowledge on proper fit. We found that the selected factsheet and manufacturer training significantly improved the fit factor of participants, though the improvement did not achieve the passing fit factor of 100 for required use in an occupational setting. In the absence of fit testing, effective training and risk communication is necessary for the use of N95 respirators by the general public. With training, N95 respirators can provide protection for the general public during wildfire smoke events, but without proper use, N95 respirators may not reduce PM2.5 exposure to levels considered safe for public health. The results of this study will provide evidence on the efficacy of N95 respirators and training for proper fit as a personal intervention to reduce exposure to wildfire smoke. 4 Table of Contents Abstract………………………………………………………………………………….……....3-4 List of Appendices………………………………………………………………………………...6 List of Tables……………………...………………………………………………………......…...7 List of Figures…………………………………………………………….…………….…….…...8 List of Equations…………………………………………………………………………………..9 Abbreviations and Acronyms………………………………………………...………….….…....10 Acknowledgements……………………………………………………...……………….......11-12 Study Aims…………………………………………………………………………………...13-14 Aim 1…………………………………………………………………....……………………15-43 Aim 2…………………………………………………………………………………………44-87 Aim 3………………………………………….………………………………………………….88 Conclusion……………………………………………………………………………………….89 5 List of Appendices Appendix A. Materials and Methods Appendix B. Aim 2 Additional Plots and Tables Appendix C. PNASH Grant Application Appendix D. PNASH Grant Budget Appendix E. PNASH Year-End Report Appendix F. Literature Review Search Terms Appendix G. IRB Application Appendix H. Recruitment Materials: Flyer, In Person Script, Facebook Post Appendix I. Eligibility Screening Questionnaire Appendix J. Consent Form Appendix K. Study Protocols Appendix L. Participant Randomization List, Small and Medium/Large Appendix M. NIOSH-NPPTL Bivariate Test Panel Appendix N. WA DOH Wildfire Smoke and Face Masks Factsheet Appendix O. HDX Manufacturer's Instructions Appendix P. Participant Data Collection Sheet Appendix Q. Pre-Intervention KAP Participant Survey Appendix R. Post-Intervention KAP Participant Survey Appendix S. Participant Demographic Information Questionnaire Appendix T. R Code Appendix U. Research Translation Materials Appendix V. Proposed Methods for Sensitivity Analysis 6 List of Tables Table 1. Definitions of inclusion criteria for identified themes important to use for informing N95 respirators use for the lay public Table 2. Summary of studies examining issues important to consider in the use of N95 respirators by the general public sorted by theme. Table 3. Demographics of participants Table 4. Facial characteristics of participants Table 5. Change in sized mask fit factors prior to and after the intervention and in a one size fits all respirator Table 6. Results of the analysis on the change of the proportion of participants achieving fit factors of 2, 5, 10, 50, 100 Table 7. KAP pre-post survey results by intervention Table B1. Distribution of participants by NIOSH-NPPTL Bivariate Test Panel Table B2. Summary of the proportion of participants achieving fit factors of 2, 5, 10, 50, 100 Table B3. List of the survey questions asked to participants Table B4. Change in number of participants who answered “I don’t know” prior to and after the intervention Table B5. Summary of the participants’ survey answers Table B5A. Summary of the control group’s survey answers Table B5B. Summary of the factsheet group’s survey answers Table B5C. Summary of the manufacturer's instructions group’s survey answers Table B5D. Summary of the video group’s survey answers Table B6. List of the observed actions taken by participants Table B7. Summary of the observed actions taken by participants 7 List of Figures Figure 1. Flow diagram of study protocols Figure 2. Boxplots of participants’ fit factors by intervention Figure 3. Pre-Post fit factors by intervention Figure 4. Post-One size fit factors by intervention Figure 5 . Bar graphs of the proportion of participants achieving fit factors of 2, 5, 10, 50, 100 by intervention Figure 6. Actions taken during the donning process by intervention Figure 7. Key actions in the donning process vs. participants’ fit factors Figure 8. PM2.5 concentrations across WA State during the August statewide smoke event Figure B1. Bar graphs of participant’s survey answers prior to and after the intervention 8 List of Equations Equation 1. Fit Factor = CB + CA / 2CR Equation 2. Ypost = β0 + βVI{V} + βMI{M} + βFI{F} + βpreYpre Equation 3. Yone = β0 + βVI{V} + βMI{M} + βFI{F} + βpostYpost Equation 4. I{Ypost > 2} = β0 + βtI{treatment} + βpreI{Ypre > 2} 9 Abbreviations and Acronyms AQI: Air Quality Index CDC: Center for Disease Control CFR: Code of Federal Regulations COVID-19: disease progression from exposure to SARS-Cov2 CNC: ambient aerosol condensation nuclei counter UW DEOHS: University of Washington Department of Environmental and Occupational Health Sciences DOH: Washington State Department of Health FDA: Food and Drug Administration FFP: Filtering Face Piece HDX: Home Depot Brand IRB: Institution Review Board KAP: Knowledge, Attitudes, and Practice N95: Filter material not resistant to oil with 95% filtration efficiency NIOSH: National Institute for Occupational Safety and Health NPPTL: National Personal Protective Technology Laboratory OSHA: Occupational Safety and Health Association PEL: Permissible Exposure Limit PPE: Personal Protective Equipment PM: Particulate matter PM2.5: Particulate matter less than 2.5 microns in diameter PNASH: Pacific Northwest Agricultural Safety and Health Center 10 Acknowledgements The completion of this project would not have been possible, without the support of my thesis committee. My advisor and committee chair Tania Busch Isaksen not only supported me throughout the project, but through graduate school and into the beginning of my career. Thank you for recognizing my strengths and weakness and pushing me through the challenges towards success. I look forward to working with you as a practice partner in the future. Thank you to my committee member Marc Beaudreau for providing technical expertise, teaching me everything I know about N95 respirators and their nuisances, and assisting with the completion of study protocols. And to my final committee member, Marissa Baker, thank you for providing technical support, guidance on human subject research, and assisting with R-code and statistical methods. To both Marissa and Marc, thank you for your support while completing study protocols with participants, offering assistance, and grabbing coffee together. My committee provided expertise, insight, and support throughout the project, and to all I am grateful. The