Indoor Exposure to
Fine Particulate Matter
and Practical Mitigation Approaches
PROCEEDINGS OF A WORKSHOP
David A. Butler and Joe Alper, Rapporteurs
National Academy of Engineering
Board on Population Health and Public Health Practice
Health and Medicine Division
THE NATIONAL ACADEMIES PRESS
Washington, DC
www.nap.edu
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This activity was supported by Contract No. 68HERC19D0011, Order No. 68HERC20F0334 between the National Academies of Sciences, Engineering, and Medicine and the US Environmental Protection Agency (EPA). Any opinions, findings, conclusions, or recommendations expressed in this publication do not necessarily reflect the views of any organization or agency that provided support for the project. Views expressed in written conference materials or publications and by speakers and moderators do not necessarily reflect the official policies of the EPA, nor does any mention of trade names, commercial practices, or organization imply endorsement by the United States Government.
International Standard Book Number-13: 978-0-309-26328-3
International Standard Book Number-10: 0-309-26328-X
Digital Object Identifier: https://doi.org/10.17226/26331
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Suggested citation: National Academies of Sciences, Engineering, and Medicine. 2022. Indoor Exposure to Fine Particulate Matter and Practical Mitigation Approaches: Proceedings of a Workshop. Washington, DC: The National Academies Press. https://doi.org/10.17226/26331.
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PLANNING COMMITTEE ON THE INDOOR EXPOSURE TO FINE PARTICULATE MATTER AND PRACTICAL MITIGATION STRATEGIES WORKSHOP1
RICHARD L. CORSI (Chair), Dean of Engineering, University of California, Davis
SEEMA BHANGAR, Senior Indoor Air Quality Manager, WeWork
WANYU R. CHAN, Research Scientist and Deputy Indoor Environment Group Leader, Energy Analysis and Environmental Impact Division, Lawrence Berkeley National Laboratory
ELIZABETH C. MATSUI, Professor of Population Health and Pediatrics and Associate Director of the Health Transformation Research Institute, Dell Medical School at the University of Texas at Austin
LINDA A. MCCAULEY, Professor and Dean of Emory University’s Nell Hodgson Woodruff School of Nursing
KIMBERLY A. PRATHER, Professor in Chemistry and Biochemistry, Scripps Institution of Oceanography, University of California, San Diego
DAVID Y. PUI, Regents Professor and the L.M. Fingerson/TSI Inc. Chair in Mechanical Engineering and Director, Particle Technology Laboratory and Center for Filtration Research, University of Minnesota, Minneapolis
JEFFREY A. SIEGEL, Professor of Civil Engineering and Member, Building Engineering Research Group, University of Toronto
MARINA E. VANCE, Assistant Professor and McLagan Family Faculty Fellow, Department of Mechanical Engineering, University of Colorado Boulder
National Academies Staff
DAVID A. BUTLER, J. Herbert Hollomon Scholar
GURU MADHAVAN, Norman R. Augustine Senior Scholar and Senior Director of Programs
KATHLEEN STRATTON, Scholar
COURTNEY HILL, Associate Program Officer
CAMERON H. FLETCHER, Editor
___________________
1 National Academies of Sciences, Engineering, and Medicine planning committees are solely responsible for organizing the workshop, identifying topics, and choosing speakers. The responsibility for the published proceedings rests with the workshop rapporteurs and the institution.
MICHAEL HOLZER, Senior Program Assistant (through June 2021)
MAIYA SPELL, Senior Program Assistant (from June 2021)
Consultant
JOE ALPER, Consulting Writer
Acknowledgments
This Proceedings of a Workshop was reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise. The purpose of this independent review is to provide candid and critical comments that will assist the National Academies of Sciences, Engineering, and Medicine in making each published proceedings as sound as possible and to ensure that it meets the institutional standards for quality, objectivity, evidence, and responsiveness to the charge. The review comments and draft manuscript remain confidential to protect the integrity of the process.
We thank the following individuals for their review of this proceedings:
Diane Gold, Harvard University
Andrew Persily, National Institute of Standards and Technology
Mark Utell, University of Rochester
Although the reviewers listed above provided many constructive comments and suggestions, they did not see the final draft of the proceedings before its release. The review of this proceedings was overseen by Michael Ladisch, Purdue University. He was responsible for making certain that an independent examination of this proceedings was carried out in accordance with institutional procedures and that all review comments were carefully considered. Responsibility for the final content of this proceedings rests entirely with the rapporteurs and the National Academies.
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Contents
Organization of the Proceedings
2 OUTDOOR SOURCES OF INDOOR PARTICULATE MATTER
Outdoor-to-Indoor Transport Mechanisms and Particle Penetration for Fine Particulate Matter
3 INDOOR SOURCES OF INDOOR PARTICULATE MATTER
Fine Particulate Matter Emissions from Cooking
Secondary Aerosol Formation of Fine Particulate Matter in the Indoor Environment
The Effect of Humidity on the Chemistry and Biology of Indoor Air
5 HEALTH EFFECTS OF EXPOSURE TO INDOOR PARTICULATE MATTER
The Overall (Mostly Cardiovascular) Health Burden of Indoor PM2.5 Exposure
6 INDOOR EXPOSURE TO PARTICULATE MATTER: METRICS AND ASSESSMENT
Transcending Complexity: Indoor PM2.5 Measurement, Exposure, and Control
The Challenge of Moving from the Measurement of Indoor PM2.5 to Evaluating Occupant Exposure
The Utility, Use, and Misuse of Low-Cost Consumer Indoor Particulate Matter Sensors
8 INDOOR PARTICULATE MATTER EXPOSURE CONTROL AND MITIGATION
PM2.5 Filtration and Air Cleaning in Residential Environments
PM2.5 Exposure Control in Schools
9 OCCUPANT RESPONSES TO INDOOR PARTICULATE MATTER
Portable Indoor Air Cleaners and Human Behavior
How Building Occupants Interpret and Respond to Indoor Air Quality Sensor Data
Public Health Responses to Reduce Community Exposure to Indoor PM2.5
10 WORKSHOP SUMMARY AND CLOSING REFLECTIONS
Health Effects of Indoor PM2.5
B Biographic Sketches of Planning Committee Members and Workshop Speakers
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Figures
2-1 The diverse origins of ambient PM2.5
2-5 Infiltration of outdoor particulate matter into the indoor environment
2-6 Output from a NASA model showing the different sources of particulate matter
3-1 High particle concentrations observed during cooking activities, with and without ventilation
3-3 Indoor residential activities enhance semivolatile organic compound concentrations
3-4 Particulate matter mass deposited in the respiratory system in different contexts
3-5 Change in solute concentrations at varying relative humidities
3-6 Framework for determining contributors to indoor particulate matter exposure disparities
5-1 Global burden of disease attributable to 20 leading risk factors in 2010
5-2 Overview of diseases, conditions, and biomarkers affected by outdoor air pollution
5-3 Possible mechanistic paths linking particulate matter exposure and cardiovascular disease
5-4 Indoor particulate pollution and asthma morbidity
5-5 Solid fuel use as primary heating source
6-1 One person’s PM2.5 exposure in Singapore on June 25, 2013, during a wildfire smoke event
6-2 Size and spatial complexity of particle deposition in different regions of the lung
6-4 Measurements of particulate matter in a controlled chamber over time
6-5 EPA environmental health paradigm
6-6 Variability of PM2.5 exposures by person, day, and microenvironment
8-2 Fraction of time that a heating, ventilation, and air conditioning system operates
8-3 Single-pass filtration removal of particles at different face velocities
8-4 Results of in situ testing of four types of air filters compared to laboratory results
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Acronyms and Abbreviations
μg/m3 | microgram per cubic meter |
ASHRAE | American Society of Heating, Refrigerating and Air-Conditioning Engineers |
COPD | chronic obstructive pulmonary disease |
EPA | US Environmental Protection Agency |
HEPA | high-efficiency particulate air |
HOMEChem | House Observations of Microbial and Environmental Chemistry |
HVAC | heating, ventilation, and air conditioning |
MERV | minimum efficiency reporting value (a measure of a filter’s ability to capture particles between 0.3 and 10 microns) |
NASEM | National Academies of Sciences, Engineering, and Medicine |
PCAP | persistent cold air pooling |
PM0.1 | ultrafine aerosols |
PM2.5 | fine particulate matter |
PM10 | coarse particulate matter |
SVOC | semivolatile organic compound |
VOC | volatile organic compound |