Radio Joe Reports – Workshop on the Health Risks of Indoor Exposure to Particulate Matter

Air Date: 2-12-2016| Episode: 401

Radio Joe attended the 1.5 day Workshop on the Health Risks of Indoor Exposure to Particulate Matter at the The National Academies of Sciences, Engineering and Medicine…

Full Description:

Radio Joe attended the EPA sponsored 1.5 day “Workshop on the Health Risks of Indoor Exposure to Particulate Matter” at the The National Academies of Sciences, Engineering and Medicine this week. The workshop was a who’s who of indoor air quality researchers, regulators, stakeholders, industry leaders and others. It was held at the National Academies building in DC and was sponsored by EPA. Over 400 people watched the webinar live and learned more than they ever thought was possible about particulate matter, indoor air quality and health affects. In this episode Radio Joe summarizes the key points from 1.5 day program. LEARN MORE about what we know and what we still need to learn about particulate matter health risks on IAQ Radio.

Radio Joe’s Blog:

ON IAQ Radio Feb. 12th Radio Joe went over his highlights and takeaways from attending the EPA Sponsored “Workshop on the Health Risks of Indoor Exposure to Particulate Matter”.

We started with definitions.

Per the EPA:

“Particulate matter,” also known as particle pollution or PM, is a complex mixture of extremely small particles and liquid droplets. Particle pollution is made up of a number of components, including acids (such as nitrates and sulfates), organic chemicals, metals, and soil or dust particles.

The size of particles is directly linked to their potential for causing health problems. EPA is concerned about particles that are 10 micrometers in diameter or smaller because those are the particles that generally pass through the throat and nose and enter the lungs. Once inhaled, these particles can affect the heart and lungs and cause serious health effects. EPA groups particle pollution into two categories:

  • “Inhalable coarse particles,” such as those found near roadways and dusty industries, are larger than 2.5 micrometers and smaller than 10 micrometers in diameter.
  • Fine particles,” such as those found in smoke and haze, are 2.5 micrometers in diameter and smaller. These particles can be directly emitted from sources such as forest fires, or they can form when gases emitted from power plants, industries and automobiles react in the air.
  • Ultrafine particles less than 100 nanometers or .1 micrometers

The workshop included presentations from experts on particulate matter and hazard communication. It was held at the National Academies of Science Engineering and Medicine Building in Washington DC.

David Rowson of EPA stated that EPA wants to take a holistic approach to IAQ and encourage holistic interventions. EPA will use the results to inform the work EPA does. There were over 400 people online and about 40 that attended in DC.

Chair and Moderator

-William Nazaroff, Ph.D.

Session Moderators

-Terry Brennan, M.S.

-Richard Corsi, Ph.D.

-Howard Kipen, M.D., M.P.H.

-Tina Reponen, Ph.D.

Brent Stephens, Ph.D. – Assistant Professor of Architectural Engineering, Illinois Institute of Technology

Outdoor Air and Appliances as Sources of Indoor Particulate Matter 

  • 130,000 deaths attributed to elevated outdoor PM 2.5 in 2005

Things we do not know

  • The variability in infiltration into homes or Air Exchange Rates (AER)
  • Window opening frequency and its impact on AER
    • How does air exchange safer vary with window opening
      • 2-4 times higher (not good data)
    • Envelope penetrations factor, not much info and what we have is highly size dependent

UF and Course penetrate envelope less readily than FP

  • During 3-D printing huge numbers of particles emitted
  • With heated surfaces ultrafine particles increase

Lynn M. Hildemann, Ph.D. – Professor of Civil and Environmental Engineering, Stanford University

Indoor Sources of Airborne Allergens and Smoke

  • Combustion PM is sub-micron and UFP which is <O.1um
    • Some sources are well studied such as cigarettes, incense and wood combustion
  • Combustion source needing more study is cooking
  • Grilling and burning may cause highest PM
  • Natural Gas Stoves & Ovens emit mostly UFP’s
  • E-Cigarettes UFP can form but sizes and evaporation rates depend on dilution
  • Neighbor infiltration issue needs more study
  • Source Proximity
    • Within 1 meter of a source exposure can be 10-20 times as high as in a well-mixed environment
  • Indoor Sources of Airborne Allergens
    • People, pets, house dust, damp surfaces
  • Aspergillus and Penicillium spores tend to be higher indoors
  • Vacuuming
    • 5 times increase in fine PM concentrations
    • Exception is with well-sealed vacuums with minimal bypass of the high efficiency filter
  • More Study Needed
    • Factors affecting emission rates of bacteria and fungi
    • Effects of airflow and vibration by size of particle

Brandon E. Boor, Ph.D. -Assistant Professor of Civil Engineering, Purdue University

Surrounded by a Cloud of Dust: Particle Re-suspension in Indoor Environments

  • Walking and other activities re-suspend particles by a large factor
  • Infants create their own floor microenvironment
  • There are micro environments when walking, sleeping and with exposure to clothing from workers in different occupations
  • Multi-layer particulate has significantly greater re-suspension than mono layer particulate
  • Need good info on adhesion for instance with respect to particle adhesion on fabric fibers such as clothing and carpet there is no data

Jeffrey Siegel, Ph.D.  -Professor of Civil Engineering, University of Toronto

Dynamics of Particle Size and Concentration Indoors: A Building Science Perspective

  • There is a large variation in measured and modeled deposition rates
  • Re-suspension is affected by whether there is a monolayer or multilayer of particles deposited on hard surface
  • Components can act as a source or sink
  • HVAC run time measurements are needed in literature; we are very likely assuming higher run times.
  • Heterogeneity: Importance for Exposure
  • Ventilation dynamics and sink dynamics need to be better understood
  • Electrostatic filter efficiency reduces quickly
  • We do not know enough about unseen surfaces and spaces such as attics, crawlspaces, pipe chases and plenums
  • To address knowledge gaps we need a long form building census

Glenn Morrison, Ph.D.  –Professor of Civil, Architectural, and Environmental Engineering, Missouri University of Science and Technology

Indoor Chemistry and Aerosols

  • Discussed how oxidation creates Secondary Organic Aerosols (SOA’s
  • The indoor precursors to SOA’s are terpenes, nitrate radicals and ozone.
  • This is an emerging science and we need to make advancements in the measurements and modeling of SOA’s
  • We also need to learn more about reactive oxygen species
  • Another topic in need of study is the chemistry induced particle nucleation at surfaces
  • Occupancy reduces ozone concentrations
  • Field analysis of these issues is a knowledge gap

Charles Weschler, Ph.D.  –Adjunct Professor, Rutgers University; Visiting Professor, Technical University of Denmark and Tsinghua University

Composition of Indoor PM, Including the Influence of SVOC Partitioning

  • UFP <0.1 mm, Fine PM <2.5 mm, Course >2.5 mm
  • Emerging topics include processes that change chemical composition of outdoor particles
  • Particles can change significantly when they come indoors
  • Outdoor PM acquires SVOCs when it comes indoors
  • Humans shed entire outer layer of skin every 2-4 weeks
    • Phase state of indoor PM; Liquid – semi-solid and glassy
  • Many holes in knowledge about chemical composition of indoor PM
  • Grey Dust – Ultrasonic humidifiers need deionized or purified water

Barbara Turpin, Ph.D.  -Professor of Environmental Sciences and Engineering, University of North Carolina Gillings School of Global Public Health

Fine PM Exposure Characterization Provides Insights into Sources and Transformations

  • Indoor generated PM largely organic and about 70% of indoor organic PM came from outdoors
  • There is an increase in hospital admissions for respiratory issues when there is a 10 um/ M3 increase in outdoor PM
  • The increase in hospital admissions is smaller in the SW than in the NE
  • Measured VOC levels are much higher indoors
  • What are these VOC’s?

Roy Harrison, Ph.D., D.Sc. -Queen Elizabeth II Birmingham Centenary Professor of Environmental Health, University of Birmingham

Some Determinants of Indoor Concentrations and Exposures to Particulate Matter -presenting via web

  • In an unoccupied building they studied 75% indoor particles came from outdoors
  • There was about a 20 minute lag time between particles coming from outdoors to indoors
  • Unresolved questions include
    • Understanding the differential toxicity of particles from different sources with different composition is crucial
    • Are particles from food cooking, etc. as toxic as the outdoor pollutant mixture?
    • What are determinants and significance of personal clouds?

Gary Adamkiewicz, Ph.D., M.P.H. -Assistant Professor of Environmental Health and Exposure Disparities, Harvard T.H. Chan School of Public Health

Socioeconomic Determinants of Indoor PM Exposure: Understanding Sources, Structures and Settings

  • We need to take a multi-level view of the issue -Neighborhood, Building and Household determinants.
  • Beyond that we need to look at Indoor Environmental Sources (ETS),  Structures (single vs multi family) and Behaviors (inside vs outside smoking)
  • Nicotine – Highest levels – winter and in elderly disabled units
  • CDC Green Housing Study green vs. control no difference PM 2.5

William Fisk, M.S. –Retired; formerly, Senior Scientist and Leader, Indoor Environment Group, Lawrence Berkeley National Laboratory

Indoor Particle Mitigation with Filtration

  • Particle mitigation with filtration
  • Electrostatic technologies are advancing
  • Issues to understand, rate and duration of air flow and removal efficiency as function of size
  • Health Benefits of Filtration
    • Filtration sometimes improves health outcomes in subjects with allergies and asthma when an allergen source is present.

Sergey A. Grinshpun, Ph.D. –Professor of Environmental Health, University of Cincinnati College of Medicine

Methods and Approaches for Controlling Exposure to Biological Aerosols

“Removal of fine and ultrafine particles from indoor air environments by the unipolar ion emission” Byung Uk Lee, Mikhail Yermakov, Sergey A. Grinshpun

  • It was concluded that the corona discharge ion emitters (either positive or negative), which are capable of creating an ion density of 105–106e±cm−3, can be efficient in controlling fine and ultrafine aerosol pollutants in indoor air environments, such as a typical office or residential room. At a high ion emission rate, the particle mobility becomes sufficient so that the particle migration results in their deposition on the walls and other indoor surfaces.
  • Ozone Generator in a 25 m3 room. Ozone generator does not clean air
  • Discussed thermal inactivation of aerosolized spores, not very effective on spores

Brett C. Singer, Ph.D. –Staff Scientist, Residential Building Systems, Indoor Environment Group,

Lawrence Berkeley National Laboratory

Indoor PM Exposure Mitigation in Low-SES Households

  • PM removal –  low Socio Economic Status Housing
  • Air sealing was very effective for UFP

Ryan Allen, Ph.D.  -Associate Professor, Faculty of Health Sciences, Simon Fraser University

Indoor Particulate Matter Air Pollution and Cardiovascular Health

  • Hottest topic with respect to health & PM is cardiovascular health issues
  • Casual relationship between PM 2.5 exposure and cardiovascular mortality
  • Effects are occurring at even low levels of PM 2.5
  • Air filter intervention studies -Randomized crossover study HEPA filter vs. Placebo. Associated with improved blood vessel function and inflammation markers.
  • Found association for those impacted by traffic PM not by wood burning PM
  • Incense use daily for 20 years increase cardiovascular mortality by 10%
  • Links between indoor PM and increased systemic inflammation

David Rich, Sc.D., M.P.H. –Associate Professor of Public Health Sciences, University of Rochester Medical Center

Ambient Particulate Matter (PM) Air Pollution and Adverse Birth Outcomes: Targets for Studies on Health Effects of Indoor PM

  • Ambient PM and Adverse Birth Outcomes
  • Outcomes Studied – Pre-maturity, Fetal Growth Restriction, Pregnancy complications, Still birth
    • Risk of PTB (Pre Term Birth) associated with increase PM 2.5, 7 days prior to birth
    • PTB in surrounding area dropped after Utah Valley steel mill closed
    • SO2 and TSP increase in third trimester associated with increase in PTB

Marc Weisskopf, Ph.D., Sc.D. -Associate Professor of Environmental and Occupational Epidemiology, Harvard T.H. Chan School of Public Health

Particulate Matter Air Pollution: Neurological and Psychiatric Disorders

  • Air pollution has established consequences for cardiovascular health and vascular issues also affect the brain.

PM can reach the brain through respiratory track/blood and directly through olfactory route

  • Neuro-inflammation exposure leads to lateral ventricle increase in exposed animals
  • Autism, could PM affect autism?
  • Sculpting pruning back neuron to neuron connections does not occur as will in autistic
  • Increased risk of autism for children of mothers exposed to higher levels of PM 10 during pregnancy and during the third trimester of pregnancy
  • Anxiety Nurses’ Health Study PM 2.5 but not PM 10 or distance to road is associated with increased anxiety
  • PM and Neurologic Disease Some studies suggest an association between PM and Parkinson’s / Alzheimer’s / Dementia

George Gray, Ph.D. –Professor of Environmental and Occupational Health, Milken Institute School of Public Health, George Washington University

The Challenge of Communicating Indoor PM Risk

  • Quantitative factors; how big is the risk and for whom?
  • Qualitative factors; how do people think about risk?
  • Reviewed risk perception factors for example; Fatal or Non Fatal, Involuntary or Voluntary, etc.
  • Why is indoor PM risk hard to communicate? It’s a familiar risk, It can be voluntary, there are some benefits for instance I like my candles, I love my cat
  • Things that may help communicate the risk, children can be at risk, people have some knowledge of the issue for instance Environmental Tobacco Smoke ETS
  • Other challenges include understanding and communicating the magnitude of risk, communicating relative contribution of sources especially indoor vs. outdoor, mitigation approaches that require changes in personal behavior and risk tradeoffs such as ventilation vs. energy consumption
  • Can we borrow from similar issues such as Radon, ETS, and indoor pesticide use?
  • Communicating requires good information, knowledge on the magnitude of risk and understanding on how the public thinks about risk

William K. Hallman, Ph.D.  –Professor and Chair, Department of Human Ecology, Rutgers University

Empowering People to Reduce Indoor Exposures to Particulate Matter: What Can We Learn from Communicating About Other Health Risks?

  • Risk Communication is integral to the risk analysis process
  • Three common goals for risk communication are education, advocacy of persuasion and fostering partnerships for decision making
  • The invisibility of PM matters a lot, what your neighbor is doing influences your exposure when you are responsible it’s easy to ignore
  • How do we make the invisible visible
  • When asked about indicators of germs this is what people thought, clean looking home is germ free, 83% believe mold is a good indicator of germs, dirt/filth indicate germs
  • Important to know what people want to know about an issue
  • Important to know what people already know
  • Size does not seem to matter it’s hard to get people to understand these very small numbers
  • Mental Models matter
  • Mental Models are tied to advertising claims
  • Advice must be practical, effective, affordable
  • Advice must be dependable

Lee Ann Kahlor, Ph.D. -Associate Professor, Stan Richards School of Advertising, University of Texas at Austin

Public Understanding and Information Seeking Related to Indoor PM Risk: Need for a Benchmark Study

  • We need a baseline understanding of what people think, know and do not know about PM
    • We need to keep in mind the audience, We are a privileged group; 29% of adults 25 years old or older have a 4 yr degree, 43% of people live in rental properties, 15% live in poverty
  • We have many audiences and they need to be reached separately
  • Mass Communication
    • Who
    • Says What
    • To Whom
    • Via which channel
    • With what effect
  • What will make PM relevant and compelling topic
  • Fine particulate is that a good particulate? Its fine!
  • Should we even bother with communicating with everyone (cost)
  • Remember we must be willing to accept that what we put out there may well take on a life of its own
  • What does Wiki say about indoor PM?, What does Web MD say about PM?
  • What will make PM a relevant and compelling topic!!


Radio Joe