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sciencematters

October 2019

Wildland Fire Science

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Table of Contents

About this Issue	1

Studies Advance Air Monitoring and Improve Forecasting of
Smoke	2

Wildfires: How Do They Affect Our Water Supplies?	4

What can Firefighters' Breath Reveal About Chemical Exposure
During a Fire?			6

Smoke Sense App Lets you Participate in Science	7

Advancing Technology to Study the Toxicity of Smoke	8

Understanding Indoor Air Quality During Wildfires	10

Tracking Smoke with Models to Protect Public Health	12

Smoke Ready Toolbox for Wildfires	13

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About this Issue:
Wildland Fire Science

Air quality in the United States has improved significantly over the past
several decades. High air pollution days are decreasing and many more
Americans are enjoying the health benefits from cleaner air.

While skies are clearer and pollution levels have dropped in many parts
of the country larger and more intense wildfires are a growing threat to
air and water quality public health and ecosystems.

EPA is applying its extensive expertise in air quality science to study
wildfires and prescribed burns, referred to as wildland fires. This issue
of Science Matters newsletter highlights research projects by EPA and
partners to assess human health and ecological impacts of wildland
fires; improve tools and technologies to quantify and predict wildland
fire impacts; and provide information to minimize adverse public and
environmental impacts and risks.

The results are leading to new air monitoring capabilities, improved
emissions inventories, better modeling to forecast poor air quality days
during wildland fires, and new ways to identify those at greatest risk from
smoke exposure and effectively communicate the risks.

To learn more, visit:

epa.gov/air-research/wildland-iire-research-protect-health-and-
environment



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Studies Advance Air Monitoring
and Improve Forecasting of Smoke

been set up in wildfire-prone areas in Reno,
Nevada, Boise, Idaho, and Missoula, Montana.
Researchers are collecting air monitoring data
and comparing the performance of regulatory
and portable non-regulatory instruments at
these sites and mobile laboratories during
wildfire smoke events.

"These studies will help us to interpret data
from regulatory monitoring and supplemental
networks during wildfires and also provide
information on the efficacy of using rapidly
deployable devices for fire incident response,"
explains EPA researcher Matt Landis. The
research will continue for three additional fire
seasons in 2020-2022.

The MASIC study is also contributing to
FIREX-AQ, a large interagency field study in
the Northwest and Southeast, led by NASA
and National Oceanic and Atmospheric
Administration (NOAA). Using satellites,
aircraft, and ground monitoring, researchers
are studying how fuel, fire, and meteorological

EPA is conducting field studies to advance
understanding of emissions from
wildfires. The goals are to elucidate the
performance of air monitoring instruments
during smoke events; better understand the
chemical aging of smoke; and evaluate models
used to forecast where smoke from wildland
fires will travel.

The Mobile Ambient Smoke Investigation
Capability (MASIC) study, launched May
2019, is collecting air measurements from both
EPA designated reference and non-regulatory
instruments, to determine their performance
capabilities during impacts from wildfires.
Researchers used two mobile laboratories to
measure emissions near the MP-97 (Oregon)
and Williams Flats (Washington) wildfires. One
mobile laboratory was equipped with primarily
state of-the-art research grade instruments and
regulatory air quality monitors and the other
with portable non-regulatory instruments.

In addition, three comprehensive fixed sites have

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conditions affect the physical and chemical
characteristics, plume height development, and
downwind dispersion of smoke. These factors
determine the local, regional, and national impacts
smoke has on ambient air quality as it undergoes
photochemical chemical transformation and aging.
The results of FIREX-AQ will be applied to remote
sensing monitoring by satellites and models to
improve predictions of the impact of smoke from
wildfires and prescribed burns on ambient air
quality.

Studying Emissions and Fire Behavior

In Fishlake National Forest in Utah, EPA
participated in a week-long air sampling activity
during a controlled forest burn by the U.S. Forest
Service in summer 2019. Over 40 scientists from
the Desert Research Institute (DRI), University
of Idaho, and other agencies and universities
participated in the comprehensive study
called the Eire and Smoke Model Evaluation
Experiment (FASMEE).

The Kolibri air sensor, a lightweight sampler
developed by EPA researchers, sampled chemical,
particle, and biological pollutants as it was carried
through the smoke in an unmanned aircraft system
owned by DRI.

The prescribed burn provided wildfire-like
conditions, with heavy surf ace fuel loads
and high burn intensity, giving researchers a
unique opportunity to study fire behavior, fuel
consumption, smoke dispersion, and emissions.
The prescribed burn will reestablish aspen stands,
allowing for regrowth in what has become a mixed
conifer forest.

"The Fishlake study offered us a unique
opportunity to characterize near-source emissions
under wildfire-like conditions," says Brian Gullett,
EPA lead investigator. "The ultimate goal is to
link emissions with the fuel properties, ignition
methods, and meteorological conditions to enable
better prediction of smoke production during
wildland fires."

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Wildfires: How Do They Affect Our
Water Supplies?

"How do wildfires change the amount of
water and sediment flowing into a stream?"

EPA has been exploring the
impacts of both short-term
and long-term exposure to
wildfire smoke on human health.
More recently, EPA researchers
have begun to look at a less
understood area of research—
the impact of these fires on our
water supply, the natural resource
we depend on for drinking,
irrigation, fishing and recreation.

Just as wildfires impact air
quality, they can also affect the
quantity and quality of water
available. Water supplies can be
adversely affected during the
active burning of a wildfire and
for years afterwards.

During active burning, ash and
associated contaminants settle
on streams, lakes and water
reservoirs. Vegetation that holds
soil in place and retains water is
burned away. In the aftermath of
a large wildfire, rainstorms flush
vast quantities of ash, sediment,
nutrients and contaminants into
streams, rivers, and downstream
reservoirs. The absence of
vegetation in the watershed can
create conditions conducive
to erosion and even flooding,

and naturally occurring and
anthropogenic substances can
impact drinking water quality,
discolor recreational waters, and
may potentially contribute to
harmful algal blooms.

Due to the unpredictable nature
of wildfires, drinking-water
utilities face a considerable
challenge to develop plans and
strategies for managing floods
and treating polluted water.
Information and tools are
needed to help water storage
and treatment managers better
prepare for wildfire impacts.

Research conducted by Mussie
Beyene, an EPA postdoctoral
researcher working with EPA
ecologist Scott Leibowitz, has
examined pre- and post-wildfire
data on streams in the western
United States to understand how
wildfires change the daily flow of

sediment and water in streams.
One of the reasons he focused
on the western states is because
65% of fresh water supply in the
region originates from forested
watersheds, which, depending
on conditions, can be highly
susceptible to forest fires.

"How do wildfires change the
amount of water and sediment
flowing into a stream?" asks
Beyene. "If you are a municipal
water supply manager, you are
most concerned with changes
in the magnitude, frequency
and timing of extreme water
discharge and sediment—what
are the highest and lowest
amounts of water and sediment
that flow into a stream after a
wildfire—because your water
treatment plants and your water
storage systems may not be built
to accommodate them."

4

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Beyene found that there is a
possible increase in stream water
discharge following a wildfire. For
streams in the northwest, this can
be followed by fewer episodes of
very low water levels. In contrast,
for streams in the southwest, the
increase in discharge is followed by
more episodes of very high water
levels. Additionally, the timing of
peak flood events shifted towards
late winter-early spring for regions
that receive the majority of their
waters from winter snowpack. In
terms of water quality, Beyene also
found a significant increase in the

amount of suspended sediments in
streams after a wildfire event.

Beyene's research is just one aspect
of EPA's larger investigation into
the impact of wildfires on water
resources. Researchers are working
to determine whether pollutants,
like mercury and lead left over from
the 20th century mining boom and
other old industries, more easily
find their way into water after
wildfires. They are also exploring
ways to protect water quality
from wildfires through watershed
management. Information
generated from these studies will

be used to protect the quality of
our water supplies and the essential
benefits they provide.

5

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What Can Firefighters' Breath Reveal
About Chemical Exposure During a
Fire?



When firefighters enter a burning
building, they have more than
hot flames to fight. There's also
the smoke to contend with, which often
contains combustion byproducts and
contaminants that are harmful to human
health.

During a structure fire, firefighters' respi-
ratory tracts are protected with a self-
contained breathing apparatus, while skin
is shielded by specially designed clothing.
But even using this protective equipment,
firefighters still have a higher cancer rate
than the general population, which stud-
ies have linked in part to their increased
exposure to the dangerous compounds in
smoke.[1,2]

Recent research led by the National
Institute for Occupational Safety and
Health (NIOSH) examined firefighters'
exposure to volatile organic compounds
(VOCs) during structure fires by analyzing
their exhaled breath before and after
controlled burns. EPA scientists offered
technical support, developing a method
to analyze breath samples, studying the
data, and authoring several reports on
their findings — all in hopes of better
understanding firefighters' chemical
exposure.

"Breath is a relatively non-invasive
biological medium compared to blood or
urine, and participants have been shown to
be more willing to provide these samples,"
M. Ariel Wallace, an EPA scientist
says. She explained that exhaled breath
monitoring is also a comparatively simple
method, since it doesn't involve the extra
post-processing steps that liquid samples
require.

To assess the firefighters' exposure to
VOCs, scientists collaborated with NIOSH
to study 12 controlled structure burns with

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realistic firefighting responses
at the University of Illinois Fire
Service Institute. The burns
were conducted in a wood
framed residential structure with
identical home furnishings as
fuel. Each burn was assigned 12
firefighters in typical fireground
positions - like attack (fire
suppression) or search and
rescue - to fight the fire.

Researchers collected exhaled
breath samples from the
firefighters before and after each
burn exercise, then organized the
data according to their positions
in the field. They also visualized
the data of individual firefighters
to see which individuals
conformed to group trends of
increased or decreased exposure.
The data offered some interesting
insights.

At the group level, scientists saw
statistically significant increases
in post-exposure benzene
concentrations in the fire attack,
victim search, and outside
ventilation firefighting positions.

"What surprised us about the
results of this study was that
some compounds showed
statistically significant decreased
concentrations in post-exposure
samples, when we expected
that all post-exposure VOC
concentrations would be
elevated," Wallace says. "We
found that not all firefighters
displayed the characteristic
response of increased post-
exposure VOC concentrations."

Wallace noted that this may be
due to many factors, including
differences in individual
firefighting positions, how
well the individual adhered to
safety precautions, or how well
their protective equipment fit
and functioned during the fire.
How close each firefighter was

to the active fire, and other
environmental exposures before
and after the fire - including
any off-gassing of VOCs from
protective gear - may have also
contributed to differences in
individuals' breath data.

This research illustrates the
importance of looking not only
at data trends for the group,
but the individual as well, since
certain people may be more
or less susceptible to chemical
exposure than others.

By understanding which
firefighting positions and
individual firefighters
are prone to higher VOC
exposure, firefighting teams
can take action to protect their
health. Researchers say this
information could be used
to rotate firefighters through
different positions during
live fire responses, and to
decrease future exposures of
individual firefighters by making
adjustments and improvements
to the use of their personal
protective gear.

Although this research focused
on firefighting activity, scientists
suggest the concept could also
be applied in other exposure
scenarios, like a forest fire,
to study human health and
ecological effects.

References

1.	Tsai, R.J., S.E. Luckhaupt, P.
Schumacher, R.D. Cress, D.M. Deapen,
and G.M. Calvert: Risk of cancer among
firefighters in California, 1988-2007.
Am. J. Industr. Med. 58(7):715—729
(2015).

2.	Crawford, J.O., T. Winski, D.
McElvenny, R. Graveling, and K.

Dixon: Firefighters and cancer: The
epidemiological evidence. Instit. Occup.
Med. TM/17/01(2017).

Smoke Sense
App Lets you
Participate in
Science

|	EPA's Smoke

Sense app is a
research project
I to evaluate
the health
effects from wildland fires
and to develop health risk
communication strategies for
the public during smoke days.
The app is available on Android
and iOS devices in English
and Spanish. User identities
are anonymous and non-
identifiable.

The app can be used to get
information about air quality
and fire and smoke events and
allows the user to anonymously
log health symptoms and smoke
observations weekly. Badges can
be earned for each week a user
participates.

The app has been available since
2017 with the start of the Smoke
Sense project and grown to
more than 25,000 users.

As an educational tool and
informational resource, the
goal of the project is to change
behaviors that will lead people
to become more prepared to
protect their health from smoke.

Learn more and get the app at:

epa.gov/ air-research/ smoke-
sense

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Advancing Technology to Study
the Toxicity of Smoke

Smoke from wildfires can travel upward
into the atmosphere and has the
potential to cause acute and chronic
health impacts, especially in small children,
the elderly, and people with preexisting
respiratory conditions. Researchers want
to know how hazardous these exposures
can be to human health for people in
the path of smoke plumes, firefighters,
and communities further downwind of
wildfires.

In a laboratory in Research Triangle Park,
NC, researchers built a tube furnace system
to precisely generate different types of
smoke to assess how fuel composition and
combustion conditions affect the chemistry
and subsequent toxicity of biomass smoke.
Using this system, they reported that smoke
samples injected into mouse lungs caused

varying degrees of lung toxicity depending
on the type of fuel, or if the fire was under
flaming or smoldering conditions.

The researchers then went back to the
design board and modified the system
for use in animal inhalation studies so
that the direct effects of smoke on lung
function could be measured. The newer
2019 study published by EPA researcher
Yong Ho Kim and colleagues111 confirmed a
similar profile of effect and concluded that
some biomass fuels emit more polycyclic
aromatic hydrocarbons, which are known
carcinogens, and heavy metals than others.
These toxic emissions also increase when
the fire is hotter. Another paper extended
the work by demonstrating that filtering
the smoke particles partially reversed
the effects suggesting that people can be

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protected to some degree by air filters that
remove smoke particles121.

"All smoke is not created equally" says lead
EPA researcher Ian Gilmour, "Our findings
on the differential toxicity of biomass
smoke emissions will contribute to more-
accurate hazard assessment of biomass
smoke exposures in firefighters
as well as people living in
communities near or
downwind of wildfires."

"Importantly, our i
research suggests
that we should
also measure the
efficacy of control
technologies like
filters and air purifiers
to see what steps can
protect people from these
exposures," he adds.

This study only assessed toxicity of fresh

"All smoke is not
created equally "

smoke from burning of wood. However,
smoke can also be transported into
populated urban areas that are hundreds
of miles away from the fires. While this
smoke moves through the atmosphere it
can age, transform into other substances
and interact with other pollutants. Studies
have found that many people are more
likely to be exposed to wildfire smoke that
is aged in the atmosphere rather
than fresh wildfire smoke[3,4].
Future research will assess
the impact that aging of
smoke in the atmosphere
has on toxicity and health
impacts.

Finally, since wildfires
can reach the wildland-
urban interface and burn
homes, automobiles and their
contents, the researchers are
also exploring how inclusion of these
materials alters the potential toxicity of
wildfire smoke.

References:

1.	Kim, Y. H., King, C., Krantz, T., Hargrove, M. M., George, I. J., McGee, J.,... & Gavett, S. H.
(2019). The role of fuel type and combustion phase on the toxicity of biomass smoke following
inhalation exposure in mice. Archives of Toxicology, 1-13.

2.	Marie McGee Hargrove, Yong Ho Kim, Charly King, Charles E. Wood, M. Ian Gilmour,

Janice A. Dye & Stephen H. Gavett (2019) Smoldering and flaming biomass wood smoke inhibit
respiratory responses in mice, Inhalation Toxicology, DOI: 10.1080/08958378.2019.1654046

3.	Seltenrich N. (2018). Flavors of Fire: Assessing the relative toxicity of smoke from different
types of wildfires. Environmental Health Perspectives, 126 (4): 044003.

4.	Cottle, P., Strawbridge, K, McKendry, I. (2014). Long-range transport of Siberian wildfire
smoke to British Columbia: Iidar observations and air quality impacts^ Atmospheric
Environment, 90,11-17.

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Understanding Indoor Air
Quality During Wildfires

When communities are blanketed by
wildfire smoke for days and weeks,
residents want to know what steps they
can take to reduce their exposure outdoors and
indoors. Building owners are interested in effective
actions to protect their occupants. That is what
happened in Missoula, Montana, during the summer
of 2017 when the community and surrounding areas
experienced significant smoke impacts from nearby
forest fires.

The Missoula City-County Health Department
(MCCHD) was inundated with inquiries about the
risks of smoke, actions to take and how to create
clean air spaces indoors. Following the smoke
episodes, the health department is interested in
learning more about effective risk reduction strategies
they can share with building owners and the public.
As a result, the health department and other partners
have teamed up with EPA researchers to conduct an
indoor and outdoor air measurement study.

EPA researchers and partners have placed over 30
low-cost air sensors that measure fine particulate
matter (P M ) — the main component of smoke
that is of great health concern — inside 18 buildings
and outdoors at 16 locations throughout Missoula
in summer 2019. The buildings are public or
commercial buildings that range in air management
methods from window-only ventilation to central air

"We expect the results will help
us provide our community with
practical advice about creating
cleaner air spaces during wildfire
smoke events "

filtration and represent locations the public may visit
during a summer smoke episode. Buildings include
fitness centers, museums, churches, office buildings,
a senior citizen center, and universities. The health
department is collecting and sending the recorded
data from the sensors to researchers for analysis.

The goal of the field study is to learn more about how
air cleaning and ventilation practices impact indoor
air quality during wildfire events. A complementary
laboratory study in Research Triangle Park, North
Carolina, will evaluate the effectiveness of portable
air cleaners and air filtration systems in removing
PM,5 under simulated pollutant concentrations
typically found during wildfires.

When the lab study begins, researchers will test five
portable air cleaners, ranging from a do-it-yourself
(DIY) cleaner composed of a box fan with attached
EIVAC filter to commercial EIEPA air purifiers. The
cleaners will be evaluated for their effectiveness at
removing PM. and other toxic pollutants, as well

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nfgfc.'-ai



Amara Holder with air cleaner in a
laboratory testing chamber.

as their ease of use and cost to
operate. Wood, tree litter, and
duff collected from the forests
surrounding Missoula will be
burned to create the smoky
conditions needed to evaluate
the air cleaners. These real-world
fuels will enable researchers to
create emissions in the laboratory,
similar to wildfires in the area.
They plan to test the air cleaners at
concentrations slightly above the
air quality standard and at higher
concentrations that can occur
during wildfires.

The research has involved local
partners from the beginning to

identify what information they need
to effectively communicate actions
that building owners and the public
can take to reduce public health risk
during smoke episodes. In addition
to the health department, the
University of Montana in Missoula
is participating.

Sarah Coefield, air quality specialist
with MCCHD said, "We're excited
to be partnering with the EPA on
this study. The data from this field
study will show the variability of
indoor air quality in buildings
across our community and will help
us understand how much outdoor
air comes inside under real-world
conditions. We expect the results
will help us provide our community
with practical advice about creating
cleaner air spaces during wildfire
smoke events."

After the wildfire season ends in
Missoula, EPA plans to conduct a
similar field study of indoor and
outdoor air quality associated with
wildfire smoke episodes with the
Hoop a Valley Tribe in northern
California.

challenges. The research findings
are expected to be applied to help
communities prepare for wildfire
smoke and provide answers about
indoor air quality and clean air
devices.

Amara Holder, one of the EPA
research engineers leading the
project explains, "This research
approach has been gratifying,
as we are designing and quickly
implementing studies to address
time-sensitive questions about
smoke episodes and how to protect
the public when community
members may have limited choices
other than to stay indoors. This
research will be impactful because
of the input and support of our local
partners."

This project is part of EPAs
solutions-driven research initiative,
which emphasizes working directly
with stakeholders to develop
solutions to environmental

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Tracking Smoke with Models to
Protect Public Health

Smoke plumes rising above a wildland fire are
a visible sign of air pollution. What they emit,
where they go, and how they are transported
are all of interest to atmospheric modelers who are
working to protect public health by using the power
of computer technology

EPA's Community Multiscale Air Quality Model
(CMAQ), developed to support air quality regula-
tions, is often used to study wildland fire smoke and
evaluate its impact on air quality EPA researchers
are continually improving the tool's performance
and reliability to simulate the impact of fires on
past, present, and future air quality and human
health.

In a 2018 study by EPAU], researchers used CMAQ
to estimate the impact of wildland fires on elevated
concentrations of air pollutants (e.g. fine particulate
matter and ozone) in the United States from 2008-
2012. The study suggests areas where CMAQ could
improve its ability to model U.S. wildfires by region
and fire characteristics - like an intermountain
region wildfire in the West versus a prescribed
fire in the Southeast - to better improve model
estimation of wildfire smoke impacts on air quality.

The study found that while CMAQ excels at
capturing overall time and space patterns of air

pollution from wildfires nationwide, more lab and
field work is needed to improve the model in areas
such as characterization of "medium-size" fires
under 40,000 acres, long-smoldering peat fires, and
other lesser-studied fires. These types of fires exhibit
different physics than larger or faster-burning fires,
which could influence their effect on air quality and
human health.

"Determining health impacts from models is a
complex issue, and is just one example of model
use," says Joseph L. Wilkins, an atmospheric
modeler at EPA. He adds that some health studies
have correlated CMAQ model results for pollution
exposure with regional health data - like hospital
visitation or mortality - to understand potential
wildland fire impacts and make decisions that
protect vulnerable populations.

Models like CMAQ are an integral part of
protecting public health from wildland fire smoke.
Air Resource Advisors use models to better predict
when smoke in an area may be harmful to health.
State agencies use models to account for wildland
fire smoke contribution to air quality as part of their
planning process to meet air quality standards for
particle pollution, ozone, and regional haze.

12

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EPA researchers are currently advancing modeling
capabilities for wildland fire emissions by:

•	Performing fire stage modeling to study differences
in emissions from residual smoldering fires,
smoldering fires, and active flaming fires

•	Evaluating model perfomance in capturing surface
and aloft impacts from prescribed burning events

•	Advancing emissions and model approaches
for controlled burn plume transport to improve
regulatory modeling, forecasting systems, and
smoke management programs

•	Studying small and low-cost wildfire sensor
technology to improve modeling

•	Conducting plume rise research to improve the
way CMAQ models vertical allocation of smoke

•	Continuing to update CMAQ by incorporating
National Emission Inventory updates, modeling
platform changes and satellite detection algorithm
updates

These and other advances are improving modeling tools
for characterizing wildland fire emissions, transport,
and air quality impacts. Ultimately, the work will be
used to help protect public health from exposure to
wildland fire smoke.

References:

L Wilkins, J., Pouliot G., Foley, K., Appel, W., Pierce. T.,
(2018) The impact of US wildland fires on ozone and
particulate matter: a comparison of measurements and
CMAQ model predictions from 2008 to 2012. International
Journal of Wildland Fire 27, 68:4-698.

Smoke Ready Toolbox
for Wildfires

epa.gov/air-research/ smoke-ready-
toolbox-wildfi res

Daily Air Quality Forecasts

airnow.gov

How Smoke From Fires Can
Affect Your Health

air no w. go v/in dex.
cfm?action=smoke.index

Wildfire Smoke: A Guide for
Public Health Officials

epa.gov/airnow/wildfire-smoke/
wildfire-smoke-guide-revised-2019.
pdf

Wildfire Smoke Exposure
Infographics

epa.gov/air-research/how-order-
infographic-card-reduce-health-
risks-areas-wildfire-smoke

Smoke Sense App

ep a .go v/air-rese arch/sm oke- sen se

Particle Pollution and Your
Patients' Health Course

epa.gov/pmcourse

Online Healthy Heart Toolkit

epa.gov/air-research/healthy-heart-
toolkit-and-research

I 13

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October 2019

United States Environmental Protection Agency

Office of Research and Development (8101R)
Washington, DC 20460

Stay Connected to EPA Research:
Twitter: @EPAresearch
Facebook: facebook.com/EPAresearch

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