Grantee Research Project Results
Household Atmospheric Dynamics under Elevated Smoke (HADES): Holistic Evaluation of Interventions for Reducing Indoor Levels of Wildland Fire EmissionsEPA Grant Number: R840238
Title: Household Atmospheric Dynamics under Elevated Smoke (HADES): Holistic Evaluation of Interventions for Reducing Indoor Levels of Wildland Fire Emissions
Investigators: Gall, Elliott T
Institution: Portland State University
EPA Project Officer: Chung, Serena
Project Period: September 1, 2021 through August 31, 2024
Project Amount: $547,899
RFA: Interventions and Communication Strategies to Reduce Health Risks of Wildland Fire Smoke Exposures (2021) RFA Text | Recipients Lists
Research Category: Early Career Awards , Air Quality and Air Toxics , Wildfires
The overall objective of this research is to conduct field and laboratory measurements to enable accurate modeling of interventions intended to reduce indoor woodsmoke exposures. The first specific objective is: i) parameterize outdoor to indoor transport of woodsmoke during temporary air-sealing and air-handling system operation with recirculation and filtration. These interventions are frequently recommended, but empirical data are needed to validate efficacy and to quantify impacts to air infiltration and particle penetration, since outdoor air is the source of indoor woodsmoke. The second objective is: ii) determine clean air delivery rates of commercial and low-cost air cleaning interventions (including do-it-yourself box-fan filters and indoor humidification) for particle and gas-phase constituents in woodsmoke at realistic challenge concentrations. This will be accomplished using a new, room-scale chamber for indoor woodsmoke studies the Indoor Woodsmoke Dynamics (IWOOD) test facility. The third objective is: iii) elucidate how indoor surfaces may impact exposures to polycyclic aromatic hydrocarbons (PAHs) post-wildfire. Since PAHs are low volatility, they partition to surfaces like walls and filters, creating a potentially persistent indoor PAH reservoir. Surfaces will be exposed to controlled woodsmoke, and PAH surface loading and retention will be measured. Efficacy of cleaning interventions that may reduce PAH surface concentrations will be characterized.
Field studies will be completed in homes in Portland, OR, USA to evaluate building-scale airflows empirically. A new laboratory test facility (IWOOD) will be constructed to enable controlled, repeatable testing with representative indoor woodsmoke challenge concentrations. This facility will be coupled with the PI’s state-of-the-art air pollution monitoring equipment, including size resolved particle counters and proton transfer reaction – time of flight – mass spectrometry (PTR-TOF-MS) for real-time measurement of gas-phase organics. Mathematical models will be used to parameterize woodsmoke source and sink phenomena and to enable development of exposure models that robustly characterize prospective interventions.
Outcomes include: i) field measurement of airtightness, air exchange rate, and pollutant infiltration and penetration factors in homes. Parameterizing particle transport will be the primary goal; PTR-TOF-MS will used in at least one home for the first field measurements of organic compound envelope penetration; ii) the IWOOD test facility will enable clean air delivery rate measurements of commercial and low-cost air-cleaning methods under representative challenge conditions and for particle and gas-phase woodsmoke pollutants; iii) the abundance and retention of PAHs on a representative, authentic indoor surface (painted drywall) will be measured and the impact of cleaning procedures (solvent wipe) will be evaluated. Finally, results will be synthesized in an exposure modeling study to evaluate impacts of layering of tested interventions.
Publications and Presentations:Publications have been submitted on this project: View all 2 publications for this project
Supplemental Keywords:particulates, toxics, VOC, PAH, measurement methods, indoor exposures, ventilation, infiltration, housing
Progress and Final Reports:
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.