Wildfire, Air Quality, and Public Healthpubs.awma.org/flip/EM-June-2020/emjune20.pdf · 2020-06-02 · Wildfire, Air Quality, and Public Health ... researchers around the globe dedicated

Wildfire, Air Quality,and Public Health

The Magazine for Environmental Managers June 2020

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Back In Time: A&WMA’s Annual Critical Review Turns 502006 Critical Review: Health Effects of Fine Particulate Air Pollution: Lines that Connectby C. Arden Pope and D. Dockery

Wildfire, Air Quality, and Public Healthby John D. Kinsman

This month’s focus topic addresses wildland fires and air quality, with fourarticles by U.S. federal and state agency authors from the U.S. Environ-mental Protection Agency, the U.S. Department of Agriculture’s ForestService, and the Bay Area Air Quality Management District. The agenciescontributing articles to this issue of EM are providing critical services to the public by addressing wildfire, smoke, air emissions, and air pollution.Through extensive collaborations, they are monitoring fire conditions andair quality; projecting changes in wildfire spread, smoke, and air pollution;educating the public; disseminating critical information during fires to alertthe public; and helping citizens and outdoor workers protect themselves.EM thanks them for their critical work and these excellent contributions.

Features

The Interagency Wildland FireAir Quality Response Programby Peter Lahm and Narasimhan K. Larkin

Protecting Air Quality andPublic Health During Wildfiresby Erin DeMerritt

Drones Save Landfill Operators Time andMoney with AdvancedEmissions Measurementsby Pete Roos and Ben Losby

Illustrating Wildland Fire AirQuality Impacts Using an EPA Emission Inventoryby K.R. Baker, V. Rao, J. Beidler, J. Vukovich, S. Koplitz, and L. Avey

A Summary of the 50th AnnualA&WMA Critical Review: Wildfire and Prescribed BurningImpacts on Air Quality in the United Statesby Daniel A. Jaffe

DepartmentsMessage from the President: Certainty and the Unknownby Kim Marcus

Reducing Risk from Wildfire Smokeby Erika N. Sasser and Peter Lahm

Waste ManagementCornerNew for 2020, EM is expand-ing its content coverage ofwaste management issues with a special section of waste-themed articles in every issue,called Waste ManagementCorner. In this month’s article, PeteRoos and Ben Losby describea new landfill methane-moni-toring technology.

Photo courtesy Andrea Holland.

em • The Magazine for Environmental Managers • A&WMA • June 2020

Table of Contents

The new virtual format will include live webcasts, presenter slides with audio, video presentations, and opportunities to connect with speakers, exhibitors, sponsors, and colleagues online. Plus, virtual registration provides unlimited access to presentations for one year.

Tune in for these featured livestream presentations: • The Keynote Plenary Session “Environmental Challenges for Transportation”

• The 50th Critical Review by Dr. Daniel A. Ja�e on Wild�re and Prescribed Burning Impacts on Air Quality • Select panels and platform sessions on hot topics including: EPA Priorities 2020-2021 Per- and Poly�uoralkyl Substances (PFAS) AERMOD Modeling System New Source Review Electric Power Generation Land�ll Gas

• Special presentations including the Women’s Professional Development Presentation, Student Keynote, Career Panel, and YP Breakfast Club

Plus, over 200 on demand presentations, the e-poster gallery with audio, interactive Q & A and more!

Join us online for ACE this year and discover the latest information on the environmental industry’s challenges, regulations, and solutions.

Thank you to our sponsors:

Check out the livestream schedule for the Virtual Gateway to Innovation at www.awma.org/ACE2020.

Register now!

The most comprehensive virtual conference on environmental technology and solutions

Upper Midwest Section West Coast Section

ACE 2020 GATEWAY TO INNOVATION Air & Waste Management Association’s 113th Annual Conference & Exhibition

Virtual Conference June 30 – July 2, 2020


Cover Story by Melanie L. SattlerMessage from the President

We are all members of families—your home family, your work family, your non-work family. Your, and yourfamilies’, health is our focus during these unprecedentedand challenging times. It has been more than five generations since a single disease has been this pervasivethroughout the world. We will persevere, but at a painfulprice, and valuable lessons will be learned that will notsoon be forgotten. This is a rare unifying moment and an extremely powerful demonstration of our human abilityto focus on a common goal.

Right now, there is a major effort by scientists and researchers around the globe dedicated to developing mitigations to the current pandemic. In a reflective moment, it dawned on me that our Association exists toassess, evaluate, and develop scientifically based data thatcan be used to help policymakers, industry, governments,and the general public better understand, manage, andfind solutions to challenges created by anthropogenic and natural activities. Health is a big part of our mission.And we have a lot of different people to thank for thework that is done—from students and professors, scientistsand researchers, government employees and legislatures,doctors and lawyers, industry, and NGOs.

This month’s EM focuses on a microcosm of a morelocalized challenge and another significant impact tohuman health and the environment: wildfire. A major environmental challenge in North America, wildfire’s adverse effects on air quality and public health reach farand wide. The articles in this issue present various federal,state, and regional perspectives on wildfire issues, includ-ing those of the U.S. Forest Service, U.S. EnvironmentalProtection Agency, and Bay Area Air Quality ManagementDistrict. Additionally, the focus topic complements thisyear’s Critical Review—A&WMA’s 50th Annual Critical Review—“Wildfire and Prescribed Burning Impacts on

Air Quality in the United States” by Dr. Daniel A. Jaffe,University of Washington. You can read a summary in this month’s EM. The full paper can be found in the Juneissue of JA&WMA. The paper will also be presented aspart of A&WMA’s 2020 Annual Conference (ACE).

Speaking of ACE, hosting a conference like ACE with all its complexity and activities requires a small army of volunteers and staff. It also requires hundreds of members,exhibitors, sponsors, students, and others to be involved.We have an exciting program in place for ACE 2020, butthe uncertainty around travel and the ability to be face toface—whether due to federal, state, or local regulations;company mandates; or personnel choice—means therewas a high degree of uncertainty around safety and attendance. Therefore, as I am sure you have heard already, we have canceled the face-to-face portion of theconference, and A&WMA’s staff, leadership, Councils, andCommittees are actively working on a virtual solution todeliver conference content and networking opportunitiesfor our attendees, while allowing for greater participationand accessibility. As our focus temporarily shifts from aface-to-face to a virtual presentation, A&WMA’s ability tooffer a wide range of important environment and healthtopics in a timely manner is critical to engaging membersand non-members alike. Please be sure to bookmark andvisit our website regularly to learn more as this excitingnew program progresses.

As we have done since 1907, A&WMA’s Board, Councils,and members continue to assess member needs and interest in content, technology, delivery, financial implica-tions, outreach, and messaging. It is important in these uncertain times to continue these activities.

Stay safe and listen to the science. em

Kim Marcus » [email protected]

•

A E

Certaintyand the Unknown

This month’s focus topic addresses wildland fires (wildfire) and air quality, with four articlesby U.S. federal and state agency authors from the U.S. Environmental Protection Agency(EPA), the U.S. Department of Agriculture’s Forest Service (USDA–Forest Service), and the BayArea Air Quality Management District (BAAQMD). The agencies contributing articles tothis issue of EM are providing critical services to the public by addressing wildfire, smoke,air emissions, and air pollution. Through extensive collaborations, they are monitoring fireconditions and air quality; projecting changes in wildfire spread, smoke, and air pollution;educating the public; disseminating critical information during fires to alert the public; andhelping citizens and outdoor workers protect themselves. EM thanks them for their criticalwork and these excellent contributions.

WildfirePhoto courtesy Andrea Holland.

Cover Story by John D. Kinsman


Wildfires across the world are front page news; in the UnitedStates, the wildfire challenge is most acute in the westernstates, with forest management practices and climate believedto be important influences. Wildfires emit particles andgaseous precursors that react to form fine particles (PM2.5),

ozone, and other pollutants. Wildfires cause many of the high-est PM2.5 pollution events. Burning man-made structures canrelease hazardous air pollutants. Air pollution from wildfiresand smoke impairs visibility and affects human health, mostnotably of vulnerable populations such as those with heart and


Cover Story by John D. Kinsman

lung disease, or asthma; the elderly; firefighters and supportingstaff; and workers, exercisers, and children outdoors. Althoughnot the focus of this issue of EM, wildfire impacts carbonstored in vegetation and soils.

Monitoring and projecting wildfire, smoke, emissions, and air pollution are essential but difficult. Wildfires can start suddenly and spread rapidly. Winds can transport smoke andair pollution long distances and often many fires are burningin different locations concurrently. Modeling air quality is chal-lenging due to uncertain emissions inputs and factors such ascomplex chemistry, terrain, and meteorology. Yet, significantadvances are underway in monitoring and modeling and thesame data and tools used to address wildfires help in planningrelated to National Ambient Air Quality Standards (NAAQS),regional haze, and controlled, prescribed burning with itslesser smoke and emissions impacts.

The issue’s first article by Peter Lahm and Narasimhan Larkinof the USDA–Forest Service, entitled “The Interagency Wild-land Fire Air Quality Response Program,” discusses this For-est Service-led program, which focuses on wildfire risks topublic health and safety, risks to transportation safety, andrisks to the health and safety of fire personnel (includingboth firefighters and supporting management positions). Theprogram works across agencies, including air quality, publichealth, fire management, and land management entities, toprovide interagency coordination as well as smoke expertiseto enhance monitoring, modeling, and messaging duringwildfire smoke episodes. With assessments and forecasts,messaging helps the public respond and reduce smoke exposure and health effects. In this and the second article,authors raise the potential for sensitive individuals, which mayinclude those with viruses like COVID-19 and influenza, tobe more at risk when breathing wildfire air pollution.

Our second article by EPA’s Erika Sasser and Peter Lahm ofthe USDA–Forest Service, on “Reducing Risk from WildfireSmoke,” describes wildfire smoke’s complex mixture of com-bustion emissions that contribute to elevated levels of air pollution and cause an array of adverse health outcomes.The authors discuss populations at risk from wildfire smokeand resources that are currently available to help protectpeople from smoke exposures. The Smoke Ready Commu-nities framework builds on work already being done bystates, tribes, and local areas to prepare communities to assess vulnerabilities in advance, plan for appropriate responses, and take action during a fire. Federal agenciesprovide real-time air quality information, including via

AirNow and NowCast AQI. The federal partners help areasaccess continuous PM2.5 monitors. EPA helps support statesand local agencies to take advantage of improvements in low-cost sensor technologies.

The next article, “Protecting Air Quality and Public HealthDuring Wildfires” by Erin DeMerritt of the BAAQMD, examines the air quality and public health impacts of wildfiresmoke in the San Francisco Bay Area of California, and details strategies in place to prepare the community andminimize such impacts. During the October 2017 NorthBay wildfires in Sonoma and Napa counties, hourly PM2.5

concentrations reached 435 µg/m3 (compared to the federal 24-hr PM2.5 standard of 35 µg/m3). The BAAQMDimplements a multifaceted strategy to reduce the air qualityand public health impacts from wildfire smoke, includingregulations such as banning residential wood burning ondays when high PM2.5 concentrations are expected; grantsand incentives to create a network of clean air centers for sheltering and evacuation; and partnerships to developand implement response plans and disseminate key information.

The fourth article comes from Kirk Baker, et al. of EPA on “Illustrating Wildland Fire Air Quality Impacts Using an EPADeveloped Emission Inventory.” The article discusses emis-sions inventories and air quality modeling, while providingseveral case studies. The authors note that variation in fuels,size, combustion efficiency, radiative impacts, and non-linearchemical interactions make estimating emissions and pollu-tant concentrations downwind of fires challenging. EPA an-nually develops a comprehensive National Fire EmissionsInventory (NFEI) to support air quality-related demonstrationsof wildland fire impacts. The authors present information on the development of the NFEI, and several case studieswhere a photochemical grid model was applied to assess air quality impacts from a wildland fire and less intensiveprescribed fire.

Lastly, the 2020 Annual A&WMA Critical Review, “Wildfireand Prescribed Burning Impacts on Air Quality in the UnitedStates” by Daniel A. Jaffe, et al., also focuses on the topic of fire and air quality. This the 50th Annual Critical Reviewdraws on a team of leading experts to address wildfire, air quality, and health issues, including key uncertainties and unknowns. The full-length review paper appears in the June 2020 issue of the Journal of the Air & Waste Management Association (JA&WMA). A summary is included in this issue of EM. em

John D. Kinsman is Senior Director, Environment with Edison Electric Institute. He is long-time member of A&WMA, an elected member ofthe A&WMA Board of Directors, and the in-coming Chair of the Publications Committee. E-mail: [email protected].

s we have learned throughout California and other western states, serious wildfire effects are not restricted to rural forested or chaparral areas; they can have devasting effects on residential communities where natural and structural fuels are enough to sustain the wildfire. There is an ongoing effort to prevent wildfire in communitiesmost at risk; however, there are no guarantees that devastating wildfirewill not strike again. With this in mind, A&WMA’s planned Wildfires Conference will provide knowledge and guidance for professionals,businesses, and government agencies to help them better understand theimpacts and prepare for a future wildfire event.

The restoration of communities devasted by wildfires lays a heavyburden on all involved: individuals, businesses, insurance providers, andgovernment agencies at all levels. There are several communities whichhave successfully dealt with all aspects of wildfire and this conferencewill feature presentations from those directly involved and present howthese efforts have been planned and carried out over the past few years.We intend to explore the challenges through discussions of the results of state-coordinated cleanups and case studies of fire impacts and rebuilding in California’s Sonoma, Santa Barbara, and Butte Counties. We will be pursuing the following questions, among others:

What was the scope-of-damage and how was it assessed? The nature of wildfire-related damage may be distinctly different basedon the affected property and the relative importance to the community. Anoverview of the post-fire conditions will be presented and put in context for each major fire location.

What are the public health risks in the post-fire setting? How have they been monitored? What has been done duringclean up to protect residents and workers? The effects of wildfire smoke on public health are a familiar problem, one broadly studied and a focus in the Association’s programming. Wildfires in the heart of our communities present a new suite of pollutants beyond those from open biomass combustion. This conferencewill present the strategies and monitoring practices used in the majorwildfire areas, including the monitoring strategy, instrument details, and an overview of findings.

What have been the environmental concerns in the post-fire settings?The major focus of post-fire cleanup has been the elimination of thehealth hazards presented by the contaminated environment. Air andwater quality conditions are dramatically and negatively affected. Identifying risks, protecting against ongoing exposure, providing guidance to private cleanup projects, and restoration will be discussed.

How did these fires affect local public health and environmental health agencies? Local agencies, because of their close connections to the affected areasand public, are key to the focusing of disaster response, cleanup, andrestoration efforts. The challenges of working with a distressed publicand coordinating with state and federal agencies will be addressed incase studies and as part of a session focused on agency coordination.

Everyone recognizes there is an immediate need to address the destruc-tion of property and infrastructure, the disruption of community, the disabling of services, and the eradication of the existing natural habitat.What often receives little attention are the psychological impacts on thelives of everyone affected. Dealing with such psychological aspects ofwildfire destruction is an integral part of stabilizing and rebuilding a community and will be discussed in the health effects session.

How well did our emergency preparedness planning work in these situations? What have these communities learned in establishing and executing recovery plans? Communities in the western United States have significant collective experience in dealing with wildfire impacts. Wildfires in the hearts of ourcommunities have further raised the stakes for wildfire planning efforts.The significant efforts governments and businesses to improve readinesswill be discussed in the context of the most recent experiences.

There is no reasonable expectation that wildfire events will lessen in thefuture. Even with efforts to protect the most vulnerable locations, risks remain and planning for devastating wildfire events is the only prudentcourse. This conference will provide firsthand information on the impactsof and restoration after the recent serious wildfires and is essential foranyone with the responsibility to prepare for such events.

Thanks to the following participants on our Steering Committee who assisted greatly in the planning of this meeting:

Conference Steering and Planning ParticipantsBrian Bunger, BAAQMDJoseph Crisologo, Cal EPADoug Colley, National ECONLaura Greer, ANCON ServicesSuzanne Grimmesey, Santa Barbara County, CARobert Healy, Cal RecycleMichael Kleinman, Ph.D., UC IrvinePaul Lowenthal, City of Santa Rosa, CAElaine McSpadden, Butte County, CADanielle Nuzum, Butte County, CAAdam Palmer, Cal EPAKaren Riveles, Cal EPA/UC-DavisChristine Sosko, Sonoma County, CA

August 18–19, 2020, Sacramento, CA

Learn solutions and preparedness planning from experts directly engaged in addressing the environment, restoration, health, and safetyconcerns of communities.

Make your plans to attend and register online at www.awma.org/wildfires.

A

Community Wildfire Recovery: Environmental and Public Health Perspectives

By Scott Freeburn, Conference Chair and A&WMA Past-President

Community Wildfire Recovery: Environmental and Public Health Perspectives


A brief overview of the Interagency Wildland Fire Air Quality Response Program,

how it functions, and a description of efforts underway to prepare for the 2020

wildfire season.

The InteragencyWildland Fire

Air Quality Response Program

An Air Resource Advisor monitoring smoke to better understand impacts on the public and fire personnel. Photo courtesy Andrea Holland.

Interagency Wildland Fire Air Quality Response Program by Peter Lahm and Narasimhan Larkin



Wildfire smoke impacts millions of households across theUnited States each year. Providing smoke impact informa-tion to the public, firefighters, air quality agencies, local gov-ernments, community organizations, and health departmentsrequires the generation and analysis of specialized informa-tion from smoke monitoring and modeling to support thedevelopment of coordinated messaging. Nationwide effortsto create this type of integrated response during wildfiresmoke episodes date back many decades but have recentlybecome formally recognized.

Specifically, after the large-scale impacts from wildfires in2017 and 2018, the U.S. Congress recognized the need for a coordinated program, which provides wildland fire smokeprojections and the Interagency Wildland Fire Air Quality Response Program (IWFAQRP) was codified within the 2019John D. Dingell, Jr. Conservation, Management and Recre-ation Act.1 The IWFAQRP (http://www.wildlandfiresmoke.net)is a joint operational and research-based response that hasbeen growing since 2007 to address the impacts of wildlandfire smoke—both from wildfires and from prescribed fires (i.e., planned ignitions done to meet specific resource management objectives such as restoring ecological health or reducing the buildup of fuels that can lead to wildfire). The IWFAQRP is led by the U.S. Forest Service (USFS) with assistance from many interagency partners.

The IWFAQRP focuses on three areas of primary concernfrom wildfire smoke: risks to public health and safety, risks to transportation safety, and risks to the health and safety offire personnel. Smoke exposure can lead to adverse healtheffects, particularly for people with heart or lung disease,people with asthma, people with diabetes, older adults, children, pregnant women, and outdoor workers. Smokecan limit roadway visibility posing a threat to the public andfire personnel. Fire personnel can be directly affected bysmoke, including both on the fire lines and in fire campswhere incident management and support personnel workand rest, putting fire personnel at further risk. These realiza-tions became critical drivers for the IWFAQRP.

The IWFAQRP has several components, including smokemonitoring capabilities and modeling tools, and a cadre oftechnical specialists, called the Air Resource Advisors. Air

Resource Advisors are routinely deployed to wildfire responseefforts. Functionally, the IWFAQRP works across agencies, in-cluding air quality, public health, fire management, and landmanagement entities, to provide interagency coordination, aswell as smoke expertise that can enhance monitoring, mod-eling, and messaging during wildfire fire smoke episodes.

Evolution of Smoke Response EffortsThe impacts of wildfire smoke are highly variable from yearto year. In an average year, such smoke impacts are still ex-tremely broad, typically impacting millions of people acrossmultiple states. During the extreme western U.S. fire seasonsof 2017 and 2018, high levels of smoke covered much ofthe country. For example, Figure 1 shows the maximum fineparticulate matter (PM2.5) Air Quality Index (AQI) categoryfrom monitors across the western United States duringApril–November 2018.

The AQI, developed by the U.S. Environmental ProtectionAgency (EPA), provides a health effects-based scale to betterunderstand air quality impacts. Those areas in the category“Unhealthy for Sensitive Groups (USG)” or above prompthealth-based activity recommendations to reduce health effects. Much of the western United States experienced conditions in the “Unhealthy” category or worse for extended periods during 2017 and 2018.

Given this geographic scale of impact, trying to mitigate theworst effects by providing information about the level ofsmoke conditions, how they are likely to change, and potential mitigation actions is of paramount concern. Effortsto reduce effects on the public and communicate aboutsmoke impacts by the federal government go back to the1970s, but approaches continue to evolve.

Early efforts often focused less on wildfire smoke and more onmitigating impacts from prescribed burns. While these earlyefforts did not focus on the larger impacts of wildfires, theyhelped develop the underlying models of fire consumption,fire emissions, and smoke dispersion that were later repur-posed to address wildfire smoke.

During the early 2000s, efforts were made to place additionalsmoke monitors around large wildfires, such as the 2002

The IWFAQRP focuses on three areas of primaryconcern from wildfire smoke: risks to public healthand safety, risks to transportation safety, and risks tothe health and safety of fire personnel.

Photo courtesy Andrea Holland.



Hayman Fire in Colorado and Rodeo–Chediski Fire in Ari-zona. Calculating PM2.5 is the primary focus of monitoringsmoke, since PM2.5 poses the greatest risk to public health.2

Additionally, computer models originally developed for prescribed burns, such as the BlueSky Smoke Modeling Framework,3 were adapted to model smoke from multiplewildfires across a broad region. All of this provided the corecapacity and experience upon which later efforts were built.

Starting in 2007, newer approaches to addressing wildfiresmoke emerged. During October 2007, smoke from South-ern California wildfires impacted Los Angeles, and rapid re-sponse efforts were undertaken to utilize larger scale smokeforecast models. This initial wildfire smoke forecasting mod-eling effort was utilized by a number of media outlets to in-form the public. In 2008, an uncharacteristic early summerlightning event in California ignited hundreds of wildfireswith large-scale smoke impacts. Building on the 2007

response, there was extensive modeling of the smoke, a newemergency deployment of PM2.5 monitors, and, for the firsttime, use of USFS fire suppression funding to support thesmoke response.

In 2011, the Wallow Fire—the largest in modern Arizona history covering over 2,000 km2—caused widespread smokeimpacts across the Southwest United States. This led to awide array of issues, beyond just public health. For example,911 systems were overwhelmed by calls reporting smoke,and smoke disrupted transportation on roads. Smoke fromthe Wallow Fire also heavily impacted firefighting personnelin fire camps. Adding further complexity to the overall airquality situation during this period were other new, butsmaller, wildfires that started across the Southwest. This created the need for regional air quality forecasts and analy-ses that incorporated all the fires. In response, a multi-agencyeffort was assembled to deploy PM2.5 monitors to Arizona

Figure 1. Maximum daily PM2.5-based AQI observed April–November 2018.

Source: Collected data by the Western Regional Climate Center (WRCC); AirNow; AirSis.



and New Mexico. This integrated monitoring network pro-vided regionwide data on air quality conditions throughoutthe smoke-affected region. A team of research and opera-tional personnel also developed forecasts of smoke impacts,combining information from satellites, as well as informationfrom the wildfire incident management teams (IMT). Theprojected fire growth modeling done for the IMT and ob-served fuel (biomass) moistures and consumption known tothe IMT were particularly valuable in addressing uncertain-ties in the smoke models.

Also, during the Wallow Fire, coordinating teleconferenceswere held with more than 20 federal, state, tribal, and localparticipating agencies to ensure consistent messaging aboutprojected smoke impacts. Agreed upon summaries of ob-served air quality monitoring data were posted and distrib-uted widely via the internet, as well as through the IMT’sinformation system and the regional public wildfire

information system. Through this coordination, problems associated with mixed smoke messaging that had occurredon previous incidents were avoided.

Air Resource Advisors The success of the 2011 Wallow Fire response effort led directly to the development of a new technical specialist position—the Air Resource Advisor, or ARA—within the U.S. Incident Command System used for wildfire. TheseARAs now form a pivotal component of the currentIWFAQRP effort.

ARAs assess information from a wide variety of sources (seeFigure 2) and work closely with other positions on the IMT,as well as coordinating with state, tribal, and/or local air reg-ulators; state forestry agencies; health departments; law en-forcement; and public safety officials. ARAs are on-incidentresources who amass information about the fire, including

operational and strategic fire management decisionsthat can have significant impacts on expected fireemissions, and therefore future smoke impacts. Thisincludes both suppression activities and burnout op-erations. From this, ARAs can develop customizedsmoke forecasts that best reflect what is likely tohappen. ARAs then assess the smoke model resultsand incorporate these results with telemeteredsmoke monitoring observations, and other informa-tion including satellite data and other models thatcan provide a comprehensive picture of what to expect over the next several days about the fire,weather, and overall air quality.

Being on-incident allows Incident Commanders to have access to ARAs with the current and bestinformation on smoke impacts for both internal fire-related decisions, as well as for public messaging and community meetings. Messages and smokeforecast products are typically coordinated withmany of the air quality and health partners notedabove and are available online and posted throughthe IMT information trap-lines.

Serving as technical specialists, ARAs are requestedand then dispatched to the IMT, similar to how Inci-dent Meteorologists are deployed, for 14- or 21-dayassignments. New ARAs are trained annually, andcontinuing education allows new information, mod-els, and tools to be brought in each year. ARAscome from a wide variety of backgrounds and agen-cies, with current ARAs having come from federalagencies, such as the USFS, EPA, Bureau of LandManagement (BLM), National Park Service (NPS),Fish and Wildlife Service (FWS), Centers for DiseaseControl (CDC), National Resource ConservationService (NRCS), and the National Weather Service(NWS), as well as from state forestry agencies,

Figure 2. Air Resource Advisor position within the Incident Management Team and generalized structureof data flow.

(Acronyms for positions: PSC = planning section chief;IMET = incident meteorologist; FBAN = fire behavioranalyst; SOF = safety officer; PIO = public information officer.)

Source: IWFAQRP.



and create messaging based on the best available scienceand current/forecast conditions. This allows the public to respond and reduce their smoke exposure and reduce negative effects on their health.

A key product of ARAs is a daily Smoke Outlook (see Figure 4), which provides an overview of the current wildfire,as well as specific guidance on expected smoke impacts atlocations of concern, typically population centers. The SmokeOutlook provides an information with a consistent format forall incidents that focuses on impacts using EPA’s AQI valuesfor PM2.5 and includes associated health and behavior modi-fication messages to reduce public smoke exposure. Addi-tional information or discussions beyond the Smoke Outlookare often created to meet specific community needs. For example, as needed by the incident or situation, ARAs willalso assess and provide input on the potential for reducedvisibility from smoke on roadways, as well as on smoke impacts on fire-fighting camps and operational areas whichcan affect firefighter health and safety as well as operations.

Technical Smoke Information DevelopmentCritical to the success of the IWFAQRP is the ability to bringtogether all available information on current air quality con-ditions, as well as projections of future smoke impacts. Anumber of technical models, databases, and analysis toolshave been developed, notably by USFS Pacific NorthwestResearch Station’s AirFire Team and partners. Wherever feasible, the underlying codebases are being distributedthrough open-source license agreements, and the collecteddata are being made publicly accessible. The developmentof these models, tools, and data is done through a variety of

tate/tribal/local regulatory and health agencies, and contractors who have many years of previous fire and smokeforecasting experience.

ARA deployments have occurred across the United Stateson individual wildfires, as well as in roles forecasting multiplefires for entire state areas (see Figure 3). The number ofARA deployments shows a sharp increase in adoption overtime coupled with intense wildfire seasons in 2017 and2018, followed by a dip reflecting the light wildfire season in2019. ARAs have become proficient in serving critical needsof both the IMTs and the communities affected by the fires.A significant function of the ARAs is to identify communitieswithout established air quality monitors and to deploy tem-porary PM2.5 monitors to provide these communities withreal-time information on the smoke affecting them. The IW-FAQRP maintains a cache of emergency PM2.5 monitors andworks with other agencies that also have similar equipment.

After deploying monitors and assessing smoke impacts,ARAs conduct air quality modeling and interpret dailysmoke model outputs. Using information from the fire event,often customized smoke modeling is employed that useslikely fire growth, including burnout operations that aid infire suppression, observed fuel and fuel moisture conditions,and other aspects of fire emissions and smoke modeling thatcan reduce the uncertainties inherent in such models. ARAsutilize all available modeling, including assessing meteoro-logical conditions that will affect anticipated smoke disper-sion, as well as the observed monitoring data and trends tocreate an overall picture of likely smoke impacts. The goal isto provide timely smoke impact and forecast information

Figure 3. Map of ARA deployments, 2013–2019.

Source: IWFAQRP.


day, but those runs that complete early in the morning aregenerally the most valuable, since many incident decisionsand daily messages are determined early in the daytime.

In addition to automated forecasts, customized smoke fore-casts are also set up and run based on information gatheredby ARAs from the incident, including observed fuel moisturesand projected fire growth rates. These are done both throughlarge customized runs and through smaller simulations avail-able through an interactive, customizable online tool (BlueSkyPlayground) for individual fires. BlueSky Playground allowsusers to perform the full range of emissions and smoke modeling for simulating smoke dispersion (see Figure 5).

Multi-model outputs provide ARAs with a picture of the expected smoke impacts, as well as the difference in smokespread between the different models’ predictions. Thisspread can often serve as a proxy for the uncertainty in theforecast. A more complete smoke model ensemble forecastsystem that includes weightings of each component multiplebased on past performance is under development. Mostmodel runs are both viewable and downloadable throughthe IWFAQRP tool website (https://wildlandfiresmoke.net/tools).

Next StepsThe IWFAQRP, led by the USFS, is designed to address the need for additional information, expertise, and messag-ing during wildfire smoke episodes. Although new in nameand recognition, it is based on a long history of respondingto smoke episodes and technical development, with themost direct lineage dating back to the California fires in October 2007.

close partnerships, including several federal agencies, stateagencies, universities, and private corporations.

Of particular note is a collected database of PM2.5 observa-tions that includes both permanent in-situ networks, as well as the temporary monitors installed by the ARAs and stateagencies. Both the database and an analysis package arefreely available. Maps and web tools available at the IW-FAQRP tools website (https://wildlandfiresmoke.net/tools) provide quick access to visualizations and data downloads.The maps are used by ARAs and other professionals for situa-tional awareness and to improve their forecasts, as well as forpublic information purposes. Most recently, for example, anew fire and smoke mapping tool has been developed inconjunction with EPA’s redesign of the public-oriented AirNowair quality website(https://airnow.gov) for public use.

Smoke model forecasts by the IWFAQRP and various partnerorganizations are collected for analysis by ARAs and others.These include model runs by the U.S. National Oceanic andAtmospheric Administration High Resolution Rapid Refresh-Smoke4 model and Environment and Climate ChangeCanada’s FIREWORK5,6 system. Additionally, the IWFAQRPperforms approximately 30 smoke model runs daily to sup-port smoke impact planning by ARAs, air quality regulators,and health departments. Each model run is based off aweather model output and has a specific area of coverage(domain) and resolution. These areas range from nationalcoverage to regional coverage. Regional model runs have theadvantage of allowing for a finer resolution, which can en-hance model performance in areas with variable topographylike valleys and ridges. Model runs for a particular area areperformed throughout the day, usually 2–4 times during the


Figure 4. Example of Smoke Outlook.

Source: IWFAQRP smoke outlook issued for the Sierra Broder and Cow Fires in the eastern Sierra–Nevada Mountains on September 2, 2019.



Through a dedicated smoke technical specialist position, theARA, as well as dedicated scientific datasets, smoke models,tools, and monitoring equipment, the IWFAQRP works bothwithin the Incident Command System and across federal,state, tribal, and local agencies impacted by smoke to ad-dress public health, transportation safety, and firefightersafety issues. The work of the IWFAQRP and ARAs is

continually evolving as our scientific understanding of smoke and its effectson human health evolve, and as our ability to measure and predict smoke impacts improves.

This year, the need for predicting smokeimpacts on communities has never beenmore timely given the reach of the novelcoronavirus (SARS-CoV-2) pandemic causing COVID-19 respiratory disease. Although there is no direct research related to novel coronavirus and wildfiresmoke exposure, there appears to be the potential for wildfire smoke to increasesusceptibility to infection from viruses andinfluenza, as well as the severity of the effects of those diseases.7 The novelcoronavirus raises particular concerns over the need for effective responses towildfire smoke this summer. To meet thischallenge the IWFAQRP is working closelywith a variety of federal agencies includingthe CDC and EPA, seeking to enhance

smoke prediction tools through a combined model-ensembleprojection, and to develop an early warning system for identi-fying potential smoke impacts to communities. These tools,specifically targeted to help address needs during the currentpandemic, will also greatly enhance capacity to forecast andwarn about wildland fire smoke in the future well past the endof the current situation. em

Figure 5. BlueSky Playground smoke-dispersion model output. Model accessible at https://wildlandfiresmoke.net/tools.

Source: USFS PNW AirFire / IWFAQRP.

References1. Congressional Register, 2019; https://www.congress.gov/bill/116thcongress/senate-bill/47/text (accessed April 4, 2020).2. Wildfire Smoke: A Guide for Public Health Officials; U.S. Environmental Protection Agency, July 2019; https://www.airnow.gov/publications/wildfire-smoke-

guide/wildfire-smoke-a-guide-for-public-health-officials.3. Larkin, N.K.; O’Neill, S.M.; Solomon, R.; Raffuse, S.; Strand, T.; Sullivan, D.C.; Krull, C.; Rorig, M.; Peterson, J.; Ferguson, S.A. The BlueSky smoke modeling

framework; Int. J. Wildland Fire 2009, 18 (8), 906-920; doi: 10.1071/WF07086.4. Grell, G.A.; Freitas, S.R.; Stuefer, M.; Fast, J. Inclusion of biomass burning in WRF-Chem: Impact of wildfires on weather forecasts; Atmos. Chem. Phys. 2011,

11 (11), 5289-5303; doi: 10.5194/acp-115289-2011. 5. Pavlovic, R.; Chen, J.; Anderson, K.; Moran, M.D.; Beaulieu, P.A.; Davignon, D.; Cousineau, S. The FireWork air quality forecast system with near-real-time

biomass burning emissions: Recent developments and evaluation of performance for the 2015 North American wildfire season; J. Air Waste Manage. Assoc.2016, 66 (9), 819-841; doi: 10.1080/10962247.2016.1158214.

6. Chen, J.; Anderson, K.; Pavlovic, R.; Moran, M.D.; Englefield, P.; Thompson, D.K.; Munoz-Alpizar, R.; Landry, H. The FireWork v2.0 air quality forecast systemwith biomass burning emissions from the Canadian Forest Fire Emissions Prediction System v2.03; Geosci. Model Dev. 2019, 12 (7), 3283-3310; doi:10.5194/gmd-12-3283-2019.

7. Landguth, E.L.; Holden, Z.A.; Graham, J.; Stark, B.; Mokhtari, E.B.; Kaleczyc, E.; Anderson, S.; Urbanski, S.; Jolly, M.; Semmens, E.O.; and Warren, D.A. The delayed effect of wildfire season particulate matter on subsequent influenza season in a mountain west region of the USA; Environ. Inter. 2020, 139,p.105668.

Peter Lahm is with the U.S. Department of Agriculture (USDA) Forest Service, Fire and Aviation Management Program in Washington,DC; and Narasimhan K. Larkin is with USDA Forest Service, PNW Research Station in Seattle, WA. E-mail: [email protected].

Acknowledgments: For Sue Ferguson and Miriam Rorig who helped advance smoke forecasting and operational response. This workrepresents the efforts of parties and teams too numerous to accurately list here. On the policy and operational sides, particular thanks withinthe USFS to Josh Hall, Susan O’Neill, and Ron Sherron, to the many early adopter IMTs, the National Park Service and Mark Fitch, NorthCarolina Forest Service and Gary Curcio, and other agencies taking a leadership role in the IWFAQRP. On the technical side, particularthanks to the entire USFS PNW Research Station’s extended AirFire research team, which includes key partnerships with the University ofWashington School of Environmental and Forest Sciences and Mazama Science for their leadership in development of the datasets, models,and tools discussed here, and to Amy Marsha, Gina Wing, and Marlin Martinez for figure development for this article.

A look at the risks from wildfire smoke and the tools and resources available to

monitor and combat major smoke events.

Reducing Riskfrom

Wildfire Smoke

Whiskeytown National Recreation Area, CA.Photo Courtesy of U.S. National Park Service.


Reducing Risk from Wildfire Smoke by Erika Sasser and Peter Lahm



Wildfires are increasing in size and frequency and aremaking headlines across the globe. Between November2019 and February 2020, unprecedented bush fires consumed over 25.5 million acres in Australia.1 In theUnited States, data from NASA’s RECOVER program indicate wildfires in the West—including megafires burningmore than 100,000 acres—have increased in number, size,and intensity between 1950 to 2017.2 Wildfires can startsuddenly and spread rapidly; furthermore, smoke from thesefires can impact public health far away from the fire. Theconsequences of smoke can be damaging to both healthand property; in 2018, for example, smoke impacts fromthe Ferguson Fire that burned in three National Forests inCalifornia threatened the health of both the public and outdoor park personnel, leading to the closure of YosemiteNational Park and affecting surrounding communities forseveral weeks.

Wildfire smoke contains a complex mixture of combustionemissions that contribute to elevated levels of air pollutiondownwind. This includes pollutants such as particulate matter,ozone, and carbon monoxide, as well as an array of haz-ardous air pollutants. In cases where wildfires move into the wildland–urban interface (WUI), they can consume manmade materials such as plastics and structures that mayrelease other chemicals into the air. However, the largestthreat from wildfire smoke is particle pollution, which can get deep into your lungs and may even enter the blood-stream. Fine particulate matter (PM2.5) poses the greatest riskto health. The most obvious effects are symptoms such ascoughing and burning eyes, but in fact, particle pollution can cause serious damage to the heart and lungs. Since U.S.National Air Quality Standards were first issued for PM2.5

in 1997, extensive federally funded research efforts have uncovered a wide array of health effects associated with fineparticle exposure, including premature death.3

At-Risk PopulationsRecent studies support a direct link between wildfire smokeexposures and an array of adverse health outcomes, includ-ing respiratory and cardiovascular impacts.4 Furthermore,some people have underlying conditions that may increasetheir risk of adverse health effects following exposure towildfire smoke, including: people with heart or lung disease,people with asthma, people with diabetes, children orteenagers with asthma who enjoy spending time outside,pregnant women, outdoor workers, and the elderly.

The U.S. Environmental Protection Agency (EPA) and otherfederal, state, and tribal partners have long recognized thatpeople with these underlying conditions are more at riskfrom breathing wildfire smoke. Recent developments withthe COVID-19 pandemic have raised the question of howair pollution and wildfire smoke may affect susceptibility torespiratory infection. Some preliminary studies haveemerged; however, it is too early to draw conclusions linking

COVID-19 infection rates and health outcomes with particlepollution exposure. Peer reviewed toxicological, controlledhuman exposure, and epidemiological studies have demon-strated that inhaled particles do reduce immune responseagainst influenza and respiratory viruses and can worsen theoutcomes among the already infected individuals.5 Addition-ally, studies have shown that viruses can be transported onparticles and the ambient concentrations of PM can increasethe risk of exposure to viruses.6

Together, federal partners have worked to develop special-ized materials that help ensure at-risk populations haveready access to the resources they need to address risksfrom smoke exposures. For example, EPA and the U.S. Centers for Disease Control and Prevention (CDC) jointly developed a special online course for physicians, registerednurses, asthma educators, and others involved in clinical orhealth education, entitled Wildfire Smoke and Your Patients’Health (https://www.epa.gov/wildfire-smoke-course). Thecourse is designed to provide information about the healtheffects associated with wildfire smoke and actions for patients to take before and during a wildfire to reduce exposure.

In addition, EPA’s Office of Children’s Health Protection hasdeveloped a fact sheet on Protecting Children from WildfireSmoke and Ash (https://www.epa.gov/sites/production/files/2018-11/documents/protecting-children-from-wildfire-smoke-and-ash.pdf) endorsed by the American Academy ofPediatrics. Children are a population of concern becausetheir lungs are still developing, which puts them at higherrisk for health effects from exposure to wildfire smoke. Furthermore, respirators designed for adults, including thepopular N95 masks, may not fit children properly. Furtherresearch is needed to determine the most effective devicesfor protecting children from smoke exposures. Identifyingthe needs of at-risk populations and addressing them effectively is a high priority for reducing adverse health outcomes from smoke exposure.

Smoke Ready Communities FrameworkOne of the most effective things that vulnerable individualsand communities can do is to plan for smoke events. Suchplanning—particularly appropriate for communities down-wind of wildlands that are ecologically fire dependent, are inareas with high wildfire risk or have had wildfires previ-ously—can improve communities’ ability to respond quicklyand effectively and take the actions necessary to reducepublic health impacts from wildland fire smoke. EPA and the U.S. Forest Service (USFS) have joined forces with otherfederal agencies, including the CDC, to provide communitiesand individuals accurate information to help them plan forsmoke events. This is being done under a broad SmokeReady Communities Framework, which will build on work already being done by states, tribes, and local areas to pre-pare communities for smoke events and reduce potential



health impacts. EPA also plans to include a robust researchcomponent to measure how available tools and resourcesare used and whether these strategies result in improvedhealth outcomes during smoke events.

The ideal “smoke ready” community is prepared and empowered to provide its residents with evidence-based, locally relevant information during fire-related smoke eventsand to recommend actions to reduce public health impactsfrom smoke. A range of preparedness activities may be appropriate, depending on the forecasted risk for wildfires,the frequency and severity of smoke impacts, the nature of the fire event (e.g., size, duration, fuel type), underlyingvulnerabilities of local populations, and other attributes of the community.

For example, communities economically dependent ontourism, outdoor recreation, agriculture, viticulture, orforestry may have a particularly strong incentive to engagein advanced planning, as may those which experiencesmoke impacts frequently. A smoke ready community willassess these vulnerabilities in advance, plan for appropriateresponses, and act during a fire, with the goal of reducingthe health impacts of breathing smoke.

Key preparedness activities may include local action to:

• Identify populations vulnerable to smoke and how toreach them during a smoke event;

• Set up information delivery methods in advance so community members know where to go for critical information;

• Distribute ready-made communications/education materials, including resources about how to plan for wildfire smoke impacts and ways to reduce exposure and risk;

• Establish decision points for a tiered set of response actions that meet the needs of that community (e.g.,when to limit outdoor activity; how to safely operateschools; and when to encourage people to prepare andutilize “clean rooms” within the home or seek out “clean

air spaces” [i.e., publicly accessible locations that providefiltered air, if public gathering is appropriate]);

• Create and prepare to effectively utilize clean air spacesand other mitigation measures, including clearly assigningroles and responsibilities for implementing these measures;

• Purchase and store adequate protective equipment, suchas N95 masks (when available) and air filtration systems,and provide instructions on proper use of this equipment(NOTE: other types of face coverings, including manyused for COVID-19 protection, are not designed to protect against smoke exposures); and Identify suitablelocations for deployment of additional air quality monitorsand sensors during a fire.

Community ResourcesFederal, state, and tribal partners have already developed asuite of tools and resources to help communities develop preparedness plans, and more are being created. In 2019,EPA led a collaborative effort with CDC, USFS, and Californiastate agencies (California Air Resources Board, California Environmental Protection Agency, and California Departmentof Health) to update the Wildfire Smoke: A Guide for PublicHealth Officials (https://www3.epa.gov/airnow/wildfire-smoke/wildfire-smoke-guide-revised-2019.pdf), a compre-hensive online resource to help health officials prepare forsmoke events and communicate health risks and take meas-ures to protect the public when wildfire smoke is present.Along with the guide, there are many wildfire-related factsheets available online in both English and Spanish(https://www.epa.gov/smoke-ready-toolbox-wildfires/wildland-fire-publications-fact-sheets-and-other-resources#h_fact_sheets). These fact sheets offer actionable advice on impor-tant topics of interest to affected communities, for example,how to reduce smoke exposure indoors and outdoors. Cur-rently, USFS, EPA, CDC, and other federal agencies havecome together to identify additional resources communitieswill need to further their preparedness activities. In addition,the agencies have recently embarked on new cooperative research efforts to better understand the health implications of managed prescribed fire versus uncontrolled wildfire, recognizing that the size, timing, and fire dynamics can vary

Identifying the needs of at-risk populations and addressing them effectively is a high priority for reducing adverse health outcomes from smoke exposure.


being impacted severely by smoke from wildfires whichhave an Air Resource Advisor (ARA) assigned to theincident. [Editor’s Note: For more information about the (IWFAQRP), see companion article elsewhere in this issueby Lahm and Larkin].

ARA’s are technical experts who work with federal, state,tribal, and local agencies during smoke events to assist withunderstanding and predicting smoke impacts on the publicand fire personnel. Smoke exposures had traditionally takena back seat to other health and safety risks in wildfire situa-tions, but in fact smoke exposures can affect large numbersof people and may be one of the most significant risks thatneed to be considered by public officials. Having ARAs onthe incident command teams during wildfires provides thepublic with access to important on-the-ground informationand advice on a daily basis to reduce exposures. A commu-nity that has identified in advance where smoke monitoringis needed as part of being smoke ready will be one stepahead when an ARA arrives on scene with monitoringequipment.

With wide-ranging expertise in air quality monitoring andmodeling, ARAs bring unique skills to wildfires. Thesetrained technical specialists work as integral members of anIncident Management Team to assist state, tribal, or local airregulators, state forestry and health departments, and thepublic. Their main task is to provide timely smoke impactand forecast information and messaging based on the bestavailable science and current monitored conditions. A com-munity that is smoke ready will be prepared to utilize themessages created by ARAs.

The demand for the ARA program has increased over theyears. In 2012, 13 ARAs were dispatched, but 2017 and


significantly, having potentially significant effects on the publichealth impacts of the fire event and communities’ ability to prepare.

During smoke events, federal agencies offer severalresources that provide information in real time. One source of real-time information is AirNow. The “Fire and SmokeMap” link at airnow.gov takes users to an interactive map(see Figure 1) with Air Quality Index (AQI) information layered with current wildfire locations. EPA is working tocontinually improve the information available on AirNow, refining and applying the latest analytical tools [Editor’s Note:For more information about EPA’s tools. See companion article elsewhere in this issue by Baker et al.]

One example is the development of the NowCast AQI,which is designed to be responsive to rapidly changing airquality conditions, such as during a wildfire. The NowCastcalculation (https://airnow.zendesk.com/hc/en-us/articles/212303417-How-is-the-NowCast-algorithm-used-to-report-current-air-quality-) uses longer averages during periods ofstable air quality and shorter averages when air quality ischanging rapidly. NowCast allows AirNow’s current condi-tions to align more closely with what people are seeing orexperiencing in real time. This gives people information theycan use to protect their health when air quality is poor; andhelp them get outdoors and get exercise when air quality is good.

Areas without continuous PM2.5 monitors may be able toget temporary, portable monitors through their federal,state, tribal, or local air quality agencies or the USFS. As partof the USFS-led Interagency Wildland Fire Air Quality Re-sponse Program (IWFAQRP) (https://wildlandfiresmoke.net),a cache of monitors is available for deployment for areas

Figure 1. Fire and smoke map. Source: AirNow: www.airnow.gov

Figure 2. ARA deployments by year. Source: IWFAQRP: wildandfiresmoke.net



2018 saw the need for over 100 deployments (see Figure2). That year, ARA’s produced over 1200 daily smoke fore-casts. With expected increase in the number and magnitudeof fire events in the future, this demand is likely to grow.

Some states and local agencies are taking advantage of improvements in low-cost sensor technologies to track and

report localized, and often rapidly changing, conditions asso-ciated with wildfires. In addition, the public is taking a moreactive role in measuring and understanding air quality, andthey become particularly engaged when impacted bysmoke. Federal and state agencies are doing a tremendousamount of work related to sensors, from understanding theperformance of these devices to helping the public makesense of what sensor data means. A host of resources areavailable on the Air Sensor Toolbox website (https://www.epa.gov/air-sensor-toolbox/videos-air-sensor-measurements-data-quality-and-interpretation). EPA recently released a series of informational videos (https://www.epa.gov/air-sensor-toolbox) describing how the agency collects and usesair quality data, how air quality health risks are communi-cated, and how to interpret data collected using air sensors.

SummaryWildfire smoke can be dangerous for those who are vulnera-ble to its effects and can adversely impact those who arehealthy. Although most healthy adults and children will recover quickly from wildfire smoke, reducing or avoidingexposure is the best approach. This requires advance planning to educate the public, prepare communities to be smoke ready, and ensure that measures are in place toprotect people during wildfire events. Federal agencies remain committed to providing the tools and resources necessary to help communities prepare. em

References1. Calma, J. What you need to know about the Australia bushfires: The timing and intensity of the fires were unprecedented; theverge.com, Feb 13, 2020;

https://www.theverge.com/2020/1/3/21048891/australia-wildfires-koalas-climate-change-bushfires-deaths-animals-damage.2. Patel, K. Six trends to know about fire season in the western U.S.; NASA Blog, NASA's Earth Observatory, December 5, 2018; https://climate.nasa.gov/

blog/2830/six-trends-to-know-about-fire-season-in-the-western-us/.3. Integrated Science Assessment (ISA) for Particulate Matter; Final Report, 2019; EPA/600/R-19/188; U.S. Environmental Protection Agency, Washington,

DC, 2019.4. See, e.g., (1) Jones, C.; Rappold, A.; Vargo, J.; Cascio, W.; Kharrazi, M.; McNally, B.; Hoshiko, S. Out‐of‐Hospital Cardiac Arrests and Wildfire‐Related

Particulate Matter During 2015–2017 California Wildfires; J. Am. Heart Assoc. 2020 9, 8, 10.1161/JAHA.119.014125; (2) DeFlorio‐Barker, S.; Crooks, J.;Reyes, J.; Rappold, A.G. Cardiopulmonary effects of fine particulate matter exposure among older adults, during wildfire and non‐wildfire periods, in theUnited States, 2008–2010; Environ Health Perspect. 2019, 127, 037006; (3) Reid, C.E.; Brauer, M.; Johnston, F.H.; Jerrett, M.; Balmes, J.R.; Elliott, C.T. Criticalreview of health impacts of wildfire smoke exposure; Environ Health Perspect. 2016, 124, 1334-1343, http://dx.doi.org/10.1289/ehp.1409277.

5. See, e.g., (1) Rebuli, M.E.; Speen, A.M.; Martin, E.M.; Addo, K.A.; Pawlak, E.A.; Glista-Baker, E.; Robinette, C.; Zhou, H.; Noah, T.L.; Jaspers, I. Wood Smoke Exposure Alters Human Inflammatory Responses to Viral Infection in a Sex-Specific Manner: A Randomized, Placebo-controlled Study; Am. J. Respir. Crit. CareMed. 2019, 199 (8), 996-1007, doi: 10.1164/rccm.201807-1287OC; (2) Contiero, P.; Boffi, R.; Tagliabue, G., et al. A Case-Crossover Study to Investigate theEffects of Atmospheric Particulate Matter Concentrations, Season, and Air Temperature on Accident and Emergency Presentations for Cardiovascular Events inNorthern Italy; Int. J. Environ. Res. Public Health. 2019, 16 (23), 4627, doi:10.3390/ijerph16234627.

6. See, e.g., (1) Chen, G.; Zhang, W.; Li, S., et al. The impact of ambient fine particles on influenza transmission and the modification effects of temperature inChina: A multi-city study; Environ Int. 2017, 98, 82-88, doi: 10.1016/j.envint.2016.10.004; (2) Cui, Y.; Zhang, Z.F.; Froines, J., et al. Air pollution and case fatality of SARS in the People’s Republic of China: An ecologic study; Environ. Health 2003, 2 (1), 15, doi: 10.1186/1476-069X-2-15.

Erika N. Sasser, Ph.D., is Director of the Health and Environmental Impacts Division of the Office of Air Quality Planning and Standardsfor the U.S. Environmental Protection Agency, Research Triangle Park, NC; and Peter Lahm is with the U.S. Department of Agriculture(USDA) Forest Service, Fire and Aviation Management Program in Washington, DC. E-mail: [email protected].

Be sure to visit www.awma.org regularly forthe latest important information from A&WMA.


This article examines the air quality and public health impacts of wildfire smoke

in the San Francisco Bay Area and details the strategies in place to prepare the

community and minimize such impacts.

Protecting Air Qualityand Public HealthDuring Wildfires

Wildfires from within California and from outside the state have all had major air quality impacts in the San Francisco Bay Area.

Wildfire Preparedness, Prevention, and Response by Erin DeMerritt



The wildfires that have plagued California in recent yearsare some of the deadliest and most destructive in the state’shistory, bringing unprecedented smoke and hazardousbreathing conditions to both rural and metropolitan commu-nities. Recurring wildfires and dense smoke are the result ofyears of impacts brought on by climate change as highertemperatures and longer dry periods lengthen the fire season and increase the risk of fires throughout the state.1

In the San Francisco Bay Area, wildfire smoke has the poten-tial to impact large numbers of people due to the region’sterrain and weather patterns that create conditions ideal fortrapping and concentrating smoke near the ground. Windscan transport smoke long distances into communities farfrom where a fire originated, as seen during the November2018 Camp Fire in Butte County when wind patterns spreadsmoke into the Bay Area from over 200 miles away withinhours of the fire’s ignition.

Fires within the Bay Area (most notably the October 2017North Bay wildfires in Sonoma and Napa counties), fires farnorth of the region, and fires from outside the state have allhad major air quality impacts in the Bay Area. The 24-hrhealth standard for fine particulate matter (PM2.5) establishedby the U.S. Environmental Protection Agency is 35 μg/m3;hourly PM2.5 concentrations reached 435 µg/m3 during theNorth Bay fires, a level never before experienced in the

region. Figure 1 shows the hourly ambient concentrations of PM2.5 in the Bay Area during the November 2018 CampFire, during which concentrations up to 302 µg/m3 wererecorded. High concentrations of pollution were sustained for 24 hours per day for two weeks, creating a public healthemergency as air quality ranged from unhealthy to hazardous.

Figure 2 lists the 20 days with the highest recorded ambientconcentrations of particulate pollution in the Bay Area sincemeasurements began in 1999. While the Bay Area generallyenjoys good air quality, wildfires are erasing the gains wehave made in reducing particulate matter pollution—16 ofthe 20 most polluted days in this period are due to wildfires.In 2017, 14 of the 18 days for which air quality exceeded thefederal health standard for PM2.5 were due to wildfire smoke.In 2018, 16 of the 20 exceedance days were due to wildfiresmoke (see Figure 3).

Although we know wildfire smoke causes immediate respira-tory health effects, the long-term effects of exposure to wild-fire pollution are not well understood.2 Emergency roomvisits due to respiratory and cardiac illness spiked by 20 per-cent compared to previous years in affected areas followingthe North Bay fires.3 Exposure to the PM2.5 in wildfire smokecan impact even healthy adults, but protecting vulnerablepopulations like the homeless and the 1 in 7 people in theBay Area that has a respiratory illness is of great concern.

Figure 1. Hourly PM2.5 concentrations in the Bay Area during the November 2018 Camp Fire.



wildfires, and ensure health-protective measures and strate-gies are in place during air pollution emergencies. The program is specific to the San Francisco Bay Area; however,the principles can be widely applied.

The major facets of the program are: rule development, legislative initiatives, grants and incentives, partnerships, andcommunity information and resources.

Rule DevelopmentDespite hazardous pollution levels and a ban on wood burn-ing for almost two weeks during the November 2018 CampFire, 37 violations were issued for residential wood burning. In 2019, the Air District strengthened its wood burning rule to ban residential wood burning year-round on days whenPM2.5 concentrations are expected to exceed the federalhealth standard. Smoke from the 1.4 million fireplaces in theBay Area contributes over a third of regional PM2.5 from November through February. The wood burning ban ensureshigh concentrations of air pollution experienced during wild-fires are not exacerbated by residential wood burning activities.

To complement statewide fuel reduction efforts, the Air Districtamended an existing regulation to reduce potential cost barri-ers associated with prescribed burning to prevent wildfires.Prescribed burning is the burning of vegetation on selectedareas of land to safely reduce excess flammable fuels. The rule encourages prescribed burning year-round for wildfire

People living close to a fire that are instructed to evacuate orthose who lost their homes to a wildfire need protections inplace during a smoke event. Since thousands may not havefiltered air available, a more robust and comprehensive pub-lic health strategy is required.

Wildfires are a pressing challenge for public health and envi-ronmental professionals and action from community organiza-tions, fire protection agencies, and all levels of government isnecessary to mitigate the risks associated with dense smoke.With dangerous levels of air pollution likely to continue im-pacting air quality and public health, action must be taken tosupport wildfire prevention and preparedness.

Wildfire Preparedness, Prevention, and ResponseAs the frequency and intensity of catastrophic wildfires likethose California experienced in 2017 and 2018 increases,the best public health strategy is to be aware that heavysmoke is in our future and to be prepared for smoke events.

With the lessons learned from recent California wildfires, theBay Area Air Quality Management District (Air District)—theregional agency responsible for protecting air quality in theBay Area—is implementing a multifaceted strategy to reducethe air quality and public health impacts from wildfire smoke.The Wildfire Air Quality Response Program is intended tohelp the Bay Area prepare, prevent, and respond to future

Figure 2. Highest PM2.5 pollution days in the Bay Area since 1999.



prevention and control by waiving associated fees charged topublic agencies while balancing air quality needs.

Legislative InitiativesCalifornia Assembly Bill 836, signed by Governor GavinNewsom, provides funding for clean air centers to provideequitable access to filtered air—particularly for low-incomeresidents and communities with diverse racial and ethnicpopulations. The law directs funding to build or retrofit ventilation systems with high-efficiency filtration to create anetwork of clean air centers to mitigate the adverse publichealth impacts due to wildfires, especially for vulnerable populations.4

The law allows local air districts to work with their communi-ties to identify publicly accessible locations, such as schools,hospitals, libraries, community centers, and senior centers,for designation as clean air shelters. To balance need andequity issues, facilities in areas that experience a higher con-centration of air pollution than other areas in the region areprioritized to efficiently create clean air shelters where theyare needed most.

Grants and IncentivesAiding residents who lose their homes to wildfires is a signifi-cant aspect of recovery and offers an opportunity to minimizethe climate impacts of new constructions. In Sonoma andNapa counties, over 5,500 residences were destroyed by the2017 wildfires. The Wildfire Recovery Assistance Program pro-vides rebates for Bay Area residents that have lost their homesin wildfires to support rebuild efforts and encourage the build-ing of energy-efficient homes that reduce climate impacts.

Additional grant development is aimed at establishing clean air centers across the region and providingcleaner air at shelteringfacilities and evacuationcenters during emer-gencies. Investing incleaner air facilities is a safe option to protect public healthduring air quality emergencies.

Partnerships and Regional AlliancesCoordinating with regional partners prior toan emergency event en-sures health-protectiveactions are taken to pre-pare for future wildfiredisasters and regional

smoke impacts. The Air District formed partnerships withemergency managers, fire and public health officials, cities,and counties to development and implement response plans.

Continued work with the U.S. Red Cross has allowed for the development of strategies for prioritizing better air filtrationat wildfire evacuation and shelter facilities. There are approxi-mately 1,000 facilities affiliated with the Red Cross in thenine Bay Area counties, including schools, recreation centers,government buildings, and event centers. Through this partnership, funding to purchase portable air filtration unitsis provided for these facilities to enhance the Red Cross’ National Shelter System database.

Community Information and ResourcesA critical challenge during the North Bay fires was coordinating consistent messaging across agencies. Discus-sions with public health officers began following the 2017fires to develop consistent wildfire public health informationand preparedness tips to protect the public from smoke mpacts. The main principles of public health messaging during and before smoke events are to weatherize homesand buildings, shelter in place or go to a clean air center,and remember that protection from intense heat takesprecedence over exposure to unhealthy air quality. Thishealth messaging should be kept simple, consistent, and repeated often.

The addition of various other organizations and associations,such as Bay Area Urban Areas Security Initiative, Air QualityCommunications Alliance, and the San Francisco Departmentof Emergency Management, worked to align messaging with

Figure 3. Bay Area PM2.5 exceedance trend.



applicable agencies and develop a regional communicationstoolkit (https://www.sccgov.org/sites/oes/partners/Documents/by-area-aq-msg-toolkit.pdf). The toolkit facilitates regionaldiscussions on protective health measures for air quality incidents, provides public information resources to local municipalities, and includes guidance for disseminating accurate, timely, relevant, and accessible public informationfor all populations.

Through collaboration with California Air Pollution ControlOfficers Association, guidance was developed to assistschools with making decisions about outdoor activities and

class cancellations. Recommendations (https://www.face-book.com/photo?fbid=2616760928416194&set=a.954661744626129) were provided for each level of the air qualityindex to provide the information in an easily understood,health-based format.

ConclusionWildfires occur without warning, quickly degrade air quality,and pose immediate health risks—but we can be prepared.Through action to support wildfire prevention and minimizethe consequences of wildfire pollution, we can protect air qual-ity and public health during these extraordinary times. em

References1. Westerling, A.L.R. Increasing western U.S. forest wildfire activity: Sensitivity to changes in the timing of spring; Phil. Trans. R. Soc. 2016, B 371, 20150178;

http://dx.doi.org/10.1098/rstb.2015.0178.2. Reid, C.E.; Considine, E.; Watson, G.; Telesca, D.; Pfister, G.G.; Jerrett, M. Associations between ozone and fine particulate matter with respiratory health during

a wildfire event; Environ. Int. 2019, 129, 291-298; doi: 10.1016/j.envint.2019.04.033.3. Glantz, A.; Neilson, S. The smoke’s gone, but hearts and lungs still may be in danger months after wildfires; Reveal from the Center for Investigative Reporting,

2018; https://www.revealnews.org/article/the-smokes-gone-but-hearts-and-lungs-still-may-be-in-danger-months-after-wildfires/.4. Assem. Bill 836, 2019. Reg. Sess. (Cal. 2019).

Erin DeMerritt is a Public Information Officer with the Bay Area Air Quality Management District, San Francisco, CA.E-mail: [email protected].

Sessions will cover all aspects of PFAS, including:

• Chemistry• Health E�ects• Water Issues• Soils and Biosolids• Land�lls and Leachate• Air

As the concern for per- and poly�uoroalkyl substances (PFAS) increases, A&WMA has developed this conference to bring together scientists, researchers, academics, practitioners, regulators, and the regulated community to discuss the current state of PFAS science and to help develop solutions for the future.

Conference sessions will explore the chemistry, health e�ects, and current regulatory approaches and guidance for PFAS in water, soil, biosolids, land�lls, and air, as well as methods for their measurement, treatment, and destruction.

An EPA Facility Tour will be o�ered Monday, September 14.

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September 15-17, 2020 Durham, NC

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An overview of the development of the wildland fire portion of the National Emission

Inventory and describes several case studies in which the U.S. Environmental

Protection Agency (EPA) estimated air quality impacts from wild and prescribed fire

using photochemical modeling.

by K.R. Baker, V. Rao, J. Beidler, J. Vukovich, S. Koplitz, and L. Avey

Illustrating Wildland FireAir Quality Impacts

Using an EPA Emission Inventory

Wildland Fire Air Quality Impacts by K.R. Baker, et al.




The development of wildland fire emissions inventories iscomplex and involves integrating information about fire lo-cation, timing, size, fuels burned, and emission factors. Someaspects of this process are done in collaboration with federaland state/local/tribal agencies on a triennial basis. The U.S.Environmental Protection Agency (EPA) routinely uses thesefire emissions to support regulatory assessments.

Wildland fires emit particles and gas-phase precursors thatcan react in the atmosphere to form ozone (O3) and otherpollutants.1-3 Understanding the air quality degradation fromwildland fires is therefore a priority for EPA. Variation in fuels,area burned, combustion efficiency, vertical mixing, andnon-linear chemical interactions make estimating emissionsand pollutant concentrations downwind of fires challenging.4

Further, wildland fire smoke impacts on O3 are likelydependent on many additional factors in the plume’s physical and chemical environment, both near the fire andas the plume moves downwind.

Determining wildland fire contribution to O3 and fine partic-ulate matter (PM2.5) is important to support effective strate-gies to meet U.S. National Ambient Air Quality Standards(NAAQS) at all locations and regional haze goals at Class Iareas (e.g., national parks and national monuments). Landmanagers are increasingly seeking opportunities to expandthe scope of prescribed burning to meet ecological goalsand minimize the impacts of large wildfires. Tools such asphotochemical grid models can provide valuable informationabout how best to maximize land management practiceswhile minimizing days with unhealthy levels of pollutants.1

Photochemical models such as the Community MultiscaleAir Quality (CMAQ) (http://www.epa.gov/cmaq) model andComprehensive Air Quality Model with eXtensions (CAMx)(http://www.camx.com) treat emissions, physical processessuch as transport and deposition, and chemical reactions.These models have been used to estimate local to continen-tal scale pollutant impacts from specific wildland fires5-7

and wildland fires collectively.8 Photochemical models applied with fire emission inventories offer opportunities to(1) estimate air quality impacts from fires at local, regional,and national scales; and (2) evaluate wildland fire emissioninventories to help guide future priorities.

A 2005 report by an international consortium identified

wildland fire emissions as a poorly characterized sector inCanadian, Mexican, and U.S. emissions inventories.9 Partly inresponse to those criticisms, wildland fire emissions in theNational Emission Inventory (NEI) have been estimated onan event (fire) basis starting with the 2008 NEI to provideday-specific emissions using satellite fire detection informa-tion and incident report data. Fire type, location, and sizedata are collected from other federal partners (e.g., U.S. For-est Service, U.S. Fish & Wildlife Service, and U.S. Depart-ment of the Interior) and state/local/tribal agencies toaugment or correct data from routine sources. A completeNEI is released by EPA every three years; however, EPA annually develops a comprehensive National Fire EmissionsInventory (NFEI) to support air quality-related demonstra-tions of wildland fire impacts.10 The NFEI covers wildfires,prescribed fires, and agricultural fires.

Wildland Fire Emission Inventory ApproachFor purposes of emission inventory preparation, wildland fireis defined as “any non-structure fire that occurs in the wild-land (an area in which human activity and development are essentially non-existent, except for roads, railroads, powerlines, and similar transportation facilities).” Wildland fire activity is categorized as wild or prescribed by the conditionsunder which the fire occurs. These conditions influence important aspects of fire behavior, including smoke emis-sions. In the NEI, data processing is conducted differentlydepending on whether the fire type is wild or prescribed.Preparation of the EPA wildland fire emissions begins withraw input data and ends with daily estimates of emissions for criteria pollutants, criteria pollutant precursors, and haz-ardous air pollutants from flaming and smoldering combus-tion phases. Emissions from man-made structures burnedduring a wildfire are not included in the NFEI.

Fire Location, Size, and TimingEPA has been using the Satellite Mapping Automated Re-analysis Tool for Fire Incident Reconciliation version 2 (Smart-Fire2 or SF2)11 and BlueSky Framework12 since 2005 toestimate emissions from wildland fires. SF2 is an algorithmand database system that combines multiple sources of fire information and reconciles them into a unified geospatialdatabase. It reconciles fire data from satellite sensors andground-based reports, thus drawing on the strengths of bothdata types while avoiding double-counting of fire events.12,13

Month(s) State(s)

5, 6, 7, 8 Alaska

5, 6, 7, 8, 9, 10 California, Nevada, Utah

4, 5, 6, 7 Arizona, New Mexico

6,7,8 Washington, Oregon, Idaho, Montana, Wyoming, Colorado

Table 1. Default wildfire assignment by state and month in cases where the fire type is not knownbased on incident reports and the only information is a satellite detection.

data. These data are input into SF2and then merged and reconciledtogether based on user-definedweights for each fire informationdataset.

If fire type (wild or prescribed) wasnot explicitly provided as part of aninput data source, then fire type assignment is based on climatologyby state and month (see Table 1).For instance, a fire detected in Cali-fornia without incident informationwould be categorized as a wildfire inAugust when wildfires are morecommon, or as a prescribed fire ifthe detection happened in February.This approach may lead to some un-certainty in the final fire type assign-ments, especially for prescribed fires.

Fuel Type, AmountBurned, and EmissionsThe BlueSky Framework estimatesfuel type, fuel loading, fuel con-sumption, and emissions based onthe location, type, and size informa-tion provided by SF2 for each wild-land fire in the contiguous UnitedStates and Alaska (see Figure 1).NEI emissions were generated with

the BlueSky Framework, which includes Fuel CharacteristicClassification System (FCCS) fuel loading data. For the 2017NEI, the FCCS fuel-bed characteristics were enhanced usinginformation from LANDFIRE (http://www.landfire.gov) to



For years that coincide with the triennial NEI developmentprocess (e.g., 2011, 2014, and 2017), fire location, timing,and acres burned data are more robust because state/local/tribal fire information supplements national level activity

Figure 1. Modeling framework used to characterize wildland fire emissions and air quality impacts.

Fire Type

Prescribed tons

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50,000 tons

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Fire Type

Prescribed acres

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Figure 2. Total 2017 NEI acres burned (top) and PM2.5 emissionsby state (bottom).



provide better fuel classification. Previous NFEIs used onlyFCCS to provide fuel load information. Fuel consumption isbased on the CONSUME module in the BlueSky Frame-work. The Fire Emissions Production Simulator (FEPS) in theBlueSky Framework generated emission factors for wildland

fires. Emissions for some hazardousair pollutants were derived from re-gional emissions factors available inliterature.3

State Total Wild and Prescribed Fire Emissionsin 2017Figure 2 shows SF2-estimated wild-land fire acres burned and emis-sions by state for 2017. The redparts of the pie represent wildfireand green represent prescribedfire. The diameter of the circles rep-resents the magnitude of the totalacres burned. Wildfires dominatethe acres burned in the westernUnited States, while prescribed firesdominate the southeastern andeastern United States. In 2017, thestates with the highest total acresburned were Kansas, Texas, Califor-nia, and Florida. PM2.5 emissionsare largest in western states, whichis related to the amount of wildfirein that region and differences intypical fuel consumption betweenwild and prescribed fire.

Annual Variability in U.S. Wild and PrescribedFire Emissions

Figure 3 provides the 12-year (2006–2017) record of wildland fire acres burned and PM2.5 emissions for the contiguous states. Year-to-year variation in acres burned andemissions is driven mostly by differences in wildfire activity.The estimates for 2008, 2011, 2014, 2016, and 2017 are

Figure 3. Annual comparison of area burned (top) and PM2.5

emissions (bottom) for the contiguous United States.

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activity data including fire size and timing are accurate, themodel does well capturing plume rise.6,7 Model predictionsof O3 from wildfire tend to be systematically overpredictedat the surface.5,6 Predicting O3 is challenging since O3 pro-duction can be highly variable in space and time. For in-stance, at the fire location O3 production is largely inhibitedby chemical reactions involving fresh nitric oxide (NO) emis-sions. Further downwind, O3 may be produced at the topand edges of the plume where precursors and sunlight areabundant, but not mix down to the surface.

Routine surface monitors, remotely-sensed products (e.g.,visible images from satellites, aerosol optical depth, etc.), anddata collected from comprehensive field studies is valuablein understanding model predictions of wildland fire emis-sions, plume transport, and plume chemical ransformations.2

This type of data provides an opportunity for model evalua-tion to understand aspects of the modeling system (i.e., me-teorological, emissions, and chemistry) that need refinement.

Illustrative Example: Modeled Impacts of a 2013 California WildfireField measurements were used to evaluate CMAQ predic-tions of wildfire impacts from the 2013 Rim Fire, which wasthe fifth largest wildfire in California history.6 Figure 4 showsmodel predicted O3 from all sources and also just wildlandfire impacts for August 25, 2013, when large wildfires wereoccuring in California and the Pacific Northwest. Model pre-dictions are also compared with aircraft in-situ observed O3

made in a transect following the Rim Fire plume downwind.



more robust than other years because a more thoroughprocess was used that includes state-provided data andstate/local/tribal review. For other years, national default activity datasets were the sole source of fire occurrence information.

Dataset availability and the extent of the collaborative reviewprocess with federal partners and state/local/tribal agenciesimpacts when emissions can be made available to users. A lag time of approximately six months after a calendar yearis needed to incorporate national datasets and the processcan add even more time before data is available.

Photochemical Model Estimated WildlandFire ImpactsThe Sparse Matrix Operator Kernel Emissions (SMOKE)(https://www.cmascenter.org/smoke/) model converts theNFEI data to the format necessary for use in a photochemi-cal grid model. SMOKE is used to apply a fire type-specificdiurnal profile and allocates total emissions of nitrogen ox-ides (NOx), volatile organic compounds (VOCs), and PM2.5

to specific model species needed for chemical mechanisms.Speciation profiles are based on those available in the SPECIATE database (http://www.epa.gov/air-emissions-mod-eling/speciate).

Previous studies using the NFEI and CMAQ to predict wild-land fire impacts show reasonable representation of plumetransport, although PM2.5 may be notably over- or under-predicted on certain days and locations.5,8 Further, when

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Figure 5. Model predicted O3 (top row) and PM2.5 (bottom row) at 2 and 8 hours after ignition forthe same prescribed fire modeled for one day each in November and March.



The modeling system does well to capture smoke plume risesince the aircraft altitude was at the top of the plume. However, the model overpredicts the downwind extent ofO3 production compared against measurements.

Illustrative Example: Modeled Impacts of Prescribed Grassland BurningGrasslands in the Flint Hills region of central Kansas are in-tentionally burned during late March and early April eachyear for ecological, agribusiness, and cultural reasons. Thesefires are often a significant portion of the NFEI during thespringtime. When prescribed fire activity is high in this re-gion and meteorology is conducive to O3 formation, moni-tor data in the area have exceeded the NAAQS.14 CMAQwas used to estimate the air quality impacts of an actual prescribed fire in this region that occurred on November 15,2017, and a hypothetical scenario of that same fire (same location, size, and emissions) occurring during the traditionalspring burn season: March 18, 2017, when regional burn-ing activity was elevated. Here, the BlueSky Framework wasapplied with prescribed fire incident information for location,timing, and acres burned.

Model predicted O3 and PM2.5 (see Figure 5) impacts areshown at multiple time intervals (2 and 8 hours) from igni-tion for the prescribed fires modeled on November 15 andMarch 18, 2017. Maximum hourly O3 impacts were pre-dicted to be higher by 46% at 2 hours from ignition andhigher by a factor of 2 at 8 hours from ignition for theMarch burn day compared to November burn day. This is consistent with meteorological conditions generally morefavorable for O3 production in March compared to

November. The March day modeled had more solar radiation, higher temperatures, and lower wind speeds compared to the November day modeled. Model predictedPM2.5 impacts were higher by 32% for the March burn dayat 2 hours from ignition but comparable at 8 (2% higher)hours from ignition. Surface mixing layer heights were simi-lar for the March and November days used in this sensitivity analysis. The modeling system suggests higher local to re-gional-scale O3 impacts and comparable regional-scale PM2.5

impacts March and November burn days modeled as partof this assessment.

Future Areas of Study and ImprovementWhile improvements have been made to the NFEI andmodeling of those emissions using photochemical models,there are some areas where continued improvements areneeded:

• Improve the default characterization of prescribed fires in the inventory when satellite detection is the only source of information for the identification of the fire; • Work with federal and state/local/tribal agencies toward better tracking systems that provide information about timing (day of the year and time of day) and size of prescribed fires; • Improve chemical speciation of PM2.5, NOx, and VOC emissions by fire type and combustion phase; and • Improve representation of O3 contribution from wildland fire smoke plumes: precursor emissions, vertical mixing in plumes, and plume chemistry. em

References1. Hu, Y.; Odman, M.T.; Chang, M.E.; Jackson, W.; Lee, S.; Edgerton, E.S.; Baumann, K.; Russell, A.G. Simulation of air quality impacts from prescribed fires on

an urban area; Environ. Sci. Technol. 2008, 42 (10), 3676-3682.2. Prichard, S.; Larkin, N.S.; Ottmar, R.; French, N.H.; Baker, K.; Brown, T.; Clements, C.; Dickinson, M.; Hudak, A.; Kochanski, A. The Fire and Smoke Model

Evaluation Experiment—A Plan for Integrated, Large Fire—Atmosphere Field Campaigns; Atmosphere 2019, 10 (2), 66.3. Urbanski, S. Wildland fire emissions, carbon, and climate: Emission factors; Forest Ecology and Management 2014, 317, 51-60.4. Jiang, X.; Wiedinmyer, C.; Carlton, A.G. Aerosols from fires: An examination of the effects on ozone photochemistry in the Western United States; Environ.

Sci. Technol. 2012, 46, (21), 11878-11886.5. Baker, K.; Woody, M.; Tonnesen, G.; Hutzell, W.; Pye, H.; Beaver, M.; Pouliot, G.; Pierce, T. Contribution of regional-scale fire events to ozone and PM2.5 air

quality estimated by photochemical modeling approaches; Atmos. Environ. 2016, 140, 539-554.6. Baker, K.; Woody, M.; Valin, L.; Szykman, J.; Yates, E.; Iraci, L.; Choi, H.; Soja, A.; Koplitz, S.; Zhou, L. Photochemical model evaluation of 2013 California

wild fire air quality impacts using surface, aircraft, and satellite data; Sci. Total Environ. 2018, 637, 1137-1149.7. Zhou, L.; Baker, K.R.; Napelenok, S.L.; Pouliot, G.; Elleman, R.; O’Neill, S.M.; Urbanski, S. P.; Wong, D.C. Modeling crop residue burning experiments to

evaluate smoke emissions and plume transport; Sci. Total Environ. 2018, 627, 523-533.8. Kelly, J.T.; Koplitz, S.N.; Baker, K.R.; Holder, A.L.; Pye, H.O.; Murphy, B.N.; Bash, J.O.; Henderson, B.H.; Possiel, N.C.; Simon, H. Assessing PM2.5 model per-

formance for the conterminous US with comparison to model performance statistics from 2007-2015; Atmos. Environ. 2019, 214, 116872.9. Improving Emission Inventories for Effective Air Quality Management Across North America: A NARSTO Assessment; NARSTO Emission Inventory Assess-

ment Team, 2005; http://www.4cleanair.org/Oldmembers/members/committee/modeling/NARSTOEIAcomplete_10_01_04_draft.pdf.10. 2017 National Emissions Inventory (NEI) Technical Support Document (TSD); U.S. Environmental Protection Agency, 2020; https://www.epa.gov/sites/pro-

duction/files/2020-02/documents/nei2017_tsd_27feb2020.pdf. 11. Raffuse, S.; Pryden, D.A.; Sullivan, D.C.; Larkin, N.K.; Strand, T.; Solomon, R. SMARTFIRE Algorithm Description, Sonoma Tech Memo STI-905517- 3719.

Prepared for U.S. Environmental Protection Agency by Sonoma Technology, Inc., 2009.12. Larkin, N.K.; O’Neill, S.M.; Solomon, R.; Raffuse, S.; Strand, T.; Sullivan, D.C.; Krull, C.; Rorig, M.; Peterson, J.; Ferguson, S.A. The BlueSky smoke modeling

framework; International Journal of Wildland Fire 2010, 18 (8), 906-920.13. Larkin, N.S.R.; Huang, S.; Pavlovic, N.; Rao, V. The Comprehensive Fire Information Reconciled Emissions (CFIRE) Inventory: Wildland Fire Emissions Devel-

oped for the 2011 and 2014 U.S. National Emissions Inventory (in press); J. Air & Waste Manage. Assoc. 2020.14. Baker, K.; Koplitz, S.; Foley, K.; Avey, L.; Hawkins, A. Characterizing grassland fire activity in the Flint Hills region and air quality using satellite and routine

surface monitor data; Sci. Total Environ. 2019, 659, 1555-1566.

K.R. Baker, V. Rao, J. Vukovich, and S. Koplitz are all with U.S. Environmental Protection Agency (EPA), Office of Air Quality Planning& Standards, Research Triangle Park, NC; J. Beidler is with General Dynamics Information Technology, Research Triangle Park, NC; and L.Avey is with EPA Region 7, Lenexa, KS.

The 2020 Critical Review1 focuses on the topic of fire and air quality. Several factors

have recently combined to make this one of the most important topics in environmental

science. These factors include our changing climate, the increase presence of humans

in forests and wildlands, the increase in population at the wildland–urban interface,

and the role of historical fire management. As a result, wildfires—and the resulting air

pollution impacts—are on the rise across the United States. This Critical Review team

of authors includes the leading experts on these topics and will cover a full range of

issues across the fire/air quality/health perspectives to provide a Critical Review of key

uncertainties and unknowns. The full-length review paper appears in the June 2020

issue of the Journal of the Air & Waste Management Association (JA&WMA). A brief

summary follows.

50th Annual A&WMA Critical Review:Wildfire and Prescribed

Burning Impacts on Air Qualityin the United States

by Daniel A. Jaffe, Susan M. O’Neill, Narasimhan K. Larkin, Amara L. Holder, David L. Peterson, Jessica E. Halofsky, and Ana G. Rappold


A Summary of the 50th Annual A&WMA Critical Review by Daniel A. Jaffe, et al.



Air quality impacts from wildfires have been dramatic inrecent years, with millions of people exposed to elevatedand sometimes hazardous fine particulate matter concentra-tions for extended periods. Fires emit particulate matter andgaseous compounds that can negatively impact humanhealth and reduce visibility. While the overall trend in U.S. air quality has been improving for decades, largely due toimplementation of the U.S. Clean Air Act, seasonal wildfiresthreaten to undo this in some regions of the United States.Our understanding of the health effects of smoke is growingregarding respiratory and cardiovascular consequences andmortality. The costs of these health outcomes can exceed thebillions already spent on wildfire suppression. In this CriticalReview, the authors examine each of the processes that in-fluence wildland fires and the effects of fires, including thenatural role of wildland fire, forest management, ignitions,emissions, transport, chemistry, and human health impacts.The authors highlight key data gaps and examine the com-plexity and scope and scale of fire occurrence, estimatedemissions, and resulting effects on regional air quality acrossthe United States. The goal is to clarify which areas are wellunderstood and which need more study. The authors con-clude with a set of recommendations for future research.

Large wildfires in the United States are becoming increas-ingly common, and smoke from these fires is a national concern. Figure 1 shows impacts from large wildfires thatburned in the western United States in summer of 2017.These fires generated smoke plumes that were transported

across North America, resulting in measured PM2.5 (particu-late matter with aerodynamic diameter <2.5 micrometers)concentrations that reached “unhealthy to hazardous” levelsin many areas, based on U.S. National Ambient Air QualityStandard definitions.

Fires emit PM directly along with hundreds of gaseous com-pounds. The gaseous compounds include nitrogen oxides(NOx), carbon monoxide (CO), methane (CH4), and hun-dreds of volatile organic compounds (VOCs), includingmany oxygenated VOCs (OVOCs). This chemical complex-ity makes wildfire smoke very different from typical industrialpollution. A key challenge for understanding fire impacts onair quality is the large variability from fire to fire in both thequantity and composition of emissions. Emissions can varyas a function of the amount and type of fuel (Prichard et al.,2019a), meteorology, and burning conditions. These varia-tions give rise to large uncertainties in the emissions from individual fires (Larkin et al., 2012). Once emitted, wildfiresmoke undergoes chemical transformations in the atmos-phere, which alters the mix of compounds and generatessecondary pollutants, such as ozone (O3) and secondary organic aerosol (SOA).

Figure 2 shows the progression of fire in the United Statesthroughout the year 2017 as seen by satellite detections. Inwinter, fires are found mainly in the Southeast, typically asprescribed low-intensity understory burns to maintain longleafpine and other forest savanna systems. As spring approaches,

Get the latest information on new guidance, technology, and solutions on vapor intrusion!

Advancements in Vapor Intrusion and Emerging Contaminant Air Quality Issues

September 23-24, 2020 • Chicago, IL

Pre-conference courses on Optimizing Vapor Intrusion Mitigation System Design and Indicators/Tracers will be o�ered on Tuesday, September 22.

Make your plans now to sponsor and attend. Learn more at www.awma.org/vapor.

Building o� the momentum gathered during the nine previous meetings, this year’s vapor intrusion specialty conference will bring together internationally-recognized scientists, engineers, regulators, and attorneys to share research and solutions on the latest developments in the investigation and mitigation of the vapor intrusion (VI) pathway, including indicators and tracers, toxicology, risk assessment, sampling and laboratory analysis, as well as the newly-added topic of emerging contaminants.

Technical sessions will cover:

• VI Attenuation Factors

• Innovative VI Investigative Techniques

• Advancement in VI Modeling and Screening Techniques

• All Things PFAS

• Vapor Intrusion Mitigation

High level panels cover these timely topics:

• The Latest Investigative Tools: Tracers and Indicators

• The Importance of Sewers as Preferential Pathways

• A Regulator’s Perspective

Humans have a profound influence on both the use andsuppression of wildland fire. It is difficult to separate humaninfluence from the natural occurrence of fire on the land-scape (Pyne, 1997). For example, Native Americans usedfire as a tool for agriculture and to manage wildlife habitatand hunting grounds. These frequent, low-intensity fires mayhave substantially affected the landscape across the UnitedStates, but modern management practices, especially fire



fire detections move north, with increased prescribed fire activity across the central United States in many rangelands. In summer, wildfire season peaks, especially in the westernUnited States. Late fall can also be a time of many fires in California and the Southeast. This progression of fire through-out the seasons and ecosystems across the United States hasimplications for the overall quantity and specific chemistry ofthe emitted smoke.

Figure 1. Observed smoke on September 4, 2017. (Top) NASA Worldview (https://worldview.earth-data.nasa.gov/) image showing fire hotspot detections from the VIIRS and MODIS satellite instruments,along with visible satellite imagery from the VIIRS instrument between 12:00–14:00 local time. Brightwhite areas are clouds; grayer areas are smoke. (Bottom) 24-hr average PM2.5, shown as the correspon-ding Air Quality Index (AQI) level category colors, based on surface PM sensors collected in the EPA’sAirNow system (https://www.airnow.gov/).



suppression efforts, probably have been more important inchanging the forest structure (Ryan et al., 2013). The resultthrough the 1900s has been less fire on the landscape thanin pre-settlement times (Leenhouts, 1998), and therefore,likely less smoke in the air (Brown and Bradshaw, 1994). Recent episodes of smoke across extensive landscapes,driven by large wildfires, may therefore to some extent be a return to pre-suppression levels.

Several studies have documented the importance of climatechange on the increasing frequency and size of fires in thewestern United States. Large fires are increasing in the West (Dennison et al., 2014). Rising temperatures affect fuelaridity and the length of the fire season (Abatzoglou andWilliams, 2016), the amount of snow, the timing ofsnowmelt (Westerling, 2016), and relative humidity, whichhas been related to the increasing trend of area burned inCalifornia (Williams et al., 2019). However, the relationship between climate and human influences is complex and notall fires should be attributed to climate change. For example,Mass and Ovens (2019) suggested that the 2017 WineCountry fires in northern California likely had little influencefrom recent climate change. Littell et al. (2009) found thatthe effect of climate change on area burned can vary withthe ecosystem and fuels.

Complicating the role of climate change are the effects ofinvasive species (Fusco et al., 2019) and direct human ignitions. These ignitions are estimated to be responsible for over 80% of wildfires, excluding prescribed and management fires (Balch et al., 2017). Human ignitionsources include on-road vehicles, construction equipment,

power lines, fireworks, camping, and arson. However, in theIntermountain West, lightning appears to be the dominantcause for ignitions (Balch et al., 2017).

In recent years, smoke from large fires has caused extremeconcentrations of PM2.5 and O3, especially in the westernUnited States (Gong et al., 2017; Laing and Jaffe, 2019; Massand Ovens, 2019). The highest PM2.5 concentrations ever observed in many western cities were seen in the summers of2017 or 2018, due to wildfires, with some daily PM2.5 valuesof over 500 µg/m3. The United States has made steadyprogress in reducing air pollution from industrial and vehicleemissions, but the recent increase in wildland fires has slowedor even reversed this progress in some parts of the country(McClure and Jaffe, 2018).

Although much of the recent attention on wildfires has focused on the western United States, large fires also burnin the southeastern United States. In November 2016, largewildland fires burned in Tennessee, North Carolina, SouthCarolina, and Georgia, generating PM2.5 concentrations exceeding 100 µg/m3 in many cities. The smoke and elevated PM2.5 persisted across the region for weeks.

As smoke plumes move overpopulated areas, they can elevate PM2.5 and/or O3 levels over health standards. Largeand extended wildfires can be associated with respiratory issues and premature mortality (e.g., Liu et al., 2015a; Reidet al., 2019). The plumes can affect regions directly and/ormix with other urban pollutants. In the United States, theClean Air Act of 1963 was enacted to protect public healthand welfare. In 1970, the U.S. Environmental Protection

Figure 2. Progression of fires throughout the year using 2017 MODIS hotspot fire detections. Source: U.S. Forest Service.



Attend the 50th Annual A&WMA Critical Review Livestream PresentationWildfire and Prescribed Burning Impacts on Air Quality in the United Statesby Daniel A. Jaffe

Thursday, July 2, 2020

For more details and to register for this livestream event, go to www.awma.org/ace2020registration.

Following Dr. Jaffe's presentation, a panel of invited experts will critique the presentation and offer their own views on the topic. This year’s invited discussants are:

• Merlyn L. Hough, P.E., BCEE — Director of the Lane Regional Air Protection Agency in Springfield-Eugene, Oregon, responsible for the overall direction of the regional air quality agency for Lane County — has been invited to address regulatory perspectives; • Fernando Garcia Menendez, Ph.D. — Assistant Professor in the Department of Civil, Construction, and Environmental Engineering at North Carolina State University, uses computational modeling and data analysis to explore interdisciplinary questions related to air pollution, climate change, and environmental policy — has been invited to discuss air quality and public health impacts of ildland fire in the Southeastern United States; • Charles Thomas (Tom) Moore, Jr. — Air Quality Program Manager for the Western Regional Air Partnership (WRAP) and for the Western States Air Resources Council (WESTAR), the association of state air quality agencies for 15 western states, has led numerous regional air pollution studies and analysis projects — has been invited to address visibility issues;• Luke P. Naeher, Ph.D. — Professor of Environmental Health Science in the College of Public Health at the University of Georgia, has led multiple exposure assessments and epidemiological studies — has been invited to address health effects; and • Qi Zhang, Ph.D. — Professor in the Department of Environmental Toxicology at the University of California, Davis, focuses her research on understanding the chemical and physical properties, emission sources, lifecycle processes, and health impacts of atmospheric particulate pollutants — has been invited to discuss fine and ultrafine particulates.

Comments will be solicited from written submissions to the Critical Review Committee Chair. The Chair will then synthesize these pointsinto a Discussion Paper that will be published in the October 2020 issue of JA&WMA. Comments should be submitted in writing toSamuel L. Altshuler, Critical Review Committee Chair, at [email protected] by no later than August 1, 2020.

Merlyn L. Hough,P.E., BCEE

Fernando GarciaMenendez, Ph.D.

Charles Thomas(Tom) Moore, Jr.

Luke P. Naeher,Ph.D.

Qi Zhang, Ph.D.

About the Lead Author/PresenterDr. Daniel A. Jaffe is a Professor of Atmospheric Chemistry at the University of Washington in the Department of Atmospheric Sciences and in the School of STEM at the University of Washington (UW) Bothell Campus. He isalso Chair of the Physical Sciences Division in the School of STEM at UW Bothell. He is an expert on atmosphericchemistry, mercury, ozone, urban and regional smog, and long-range transport of pollutants, and the author ofmore than 150 peer-reviewed publications on these topics. Dr. Jaffe is widely recognized as an expert on global

transport of pollutants, especially transport from Asia to the United States and has several papers on the influence of background sourceson regional and urban air quality. Dr. Jaffe’s work has received much recognition, including being named to the National Academy of Sciences’ panel on “Global Sources of Air Pollutants” and receiving the UW Bothell’s first Distinguished Research Award. He started andis the Principal Investigator for the Mt. Bachelor Observatory in Central Oregon, which is the only high elevation research station on theWest Coast. His research has been supported by the NSF, NOAA, EPA, NASA, NPS, EPRI, API, and other organizations.



in British Columbia (Laing and Jaffe, 2019). These same fireswere associated with smoke transport to Europe and strongthunderstorm activity, which injected smoke into the strato-sphere (Baars et al., 2019). Large fires in Quebec have sig-nificantly affected air quality in the northeast United States(DeBell et al., 2004), fires from Mexico and Central Ameri-can can impact Texas (Mendoza et al., 2005; Kaulfus et al.,2017), and even large fires in Siberia can affect surface airquality in the United States (Jaffe et al., 2004; Teakles et al.,2017).

In this Critical Review, the authors examine the current capabil-ities for observing and quantifying smoke, what is knownabout wildland fire emissions, the development of models forsmoke plumes and transport, and the chemical makeup andtransformations of smoke. They also examine current under-standing of modeling smoke impacts, understanding of effectsof smoke on health, and the state of air quality regulations in-volving smoke, all with an emphasis on the continental UnitedStates. The authors conclude by looking at future U.S. nationalfire patterns and trends and suggest a set of recommendationsfor future research. em

Agency (EPA) established the U.S. National Ambient AirQuality Standards (NAAQS) for six criteria pollutants. Thecriteria pollutants most relevant to wildland fire emissions arePM2.5, O3, and CO.

For daily average PM2.5, the current primary standard is 35µg/m3 at the 98th percentile, averaged over three years. ForO3, the current primary standard is 0.070 parts per million(ppm) for the annual fourth-highest daily maximum 8-hrconcentration (MDA8), averaged over three years. For CO,the current primary standards are 9 ppm for an 8-hr averag-ing time, and 35 ppm for a 1-hr averaging time, not to beexceeded more than once per year. Although CO from firesis rarely a concern to the public, it can affect wildland fire-fighters, and recent work analyzes exposure in terms of Na-tional Institute of Occupational Safety and Health (NIOSH)standards (Henn et al., 2019).

Most smoke in the United States is associated with wildlandfires in the United States, but fires outside the country canalso have major impacts on U.S. air quality. In 2017, highPM2.5 in the Pacific Northwest was associated with large fires

Reference1. Jaffe, D.A., et al. 2020 Annual A&WMA Critical Review: Wildfire and Prescribed Burning Impacts on Air Quality in the United States; J. Air & Waste Manage. Assoc. 2020, 70 (6): 583-615.[Editor’s Note: Please refer to the full-length published paper for all other in-text citations and sources.]

In Next Month’s Issue…Climate Change PolicyThe July issue of EM will consider several policy questions relating to climate change, including what have the United States, China, and Indiaaccomplished to date, and what is their climate commitment for the future? In addition, this issue will include a report from the representativeswho served as A&WMA’s Official Observers at last year’s United Nations’COP meeting in Spain on what they observed and how future climate policy might affect A&WMA members.

Lead Author: Dr. Daniel A. Jaffe, Professor & Chair of Physical Sciences Division, University of Washington, School of STEM and Department of Atmospheric Sciences

Contributing Authors: Susan M. O’Neill, Pacific North West Research Station, U.S. Forest Service; Narasimhan K. Larkin, Pacific Wildland Fire Sciences Laboratory, U.S. Forest Service; Amara L. Holder, U.S. Environmental Protection Agency, Office of Research and Development;David L. Peterson, University of Washington, School of Environmental and Forest Sciences; Jessica E. Halofsky, University of Washington, School of Environmental and Forest Sciences; and Ana G. Rappold, U.S. Environmental Protection Agency, National Healthand Environmental Effects Research Lab.

Acknowledgments: The authors acknowledge editing, analysis, and/or graphics assistance from Dee Ann Lommers-Johnson (UW Bothell),Amy Marsha (USFS), Patti Loesche (USFS), Jonathan Callahan (Mazama Science), and Aranya Ahmed (Oak Ridge Associated Universities).Partial support was provided by the NASA Health and Air Quality Applied Sciences Team (HAQAST) (grant #NNH16AD18I) for remotely-sensed data processing under the direction of S. O’Neill.

Disclaimer: The views expressed in this publication are those of the authors and do not represent the policies or opinions of any U.S. government agency.


Waste Management Corner by Pete Roos and Ben Losby

Landfill gas emissions are a known cause of odor nuisance and are known to be a principal source of methane emissions, a potent greenhouse gas. The U.S. Environmental Protection Agency (EPA) regulates landfill gas (LFG) emissions, including arequirement for monitoring methane emissions from landfills. Until recently, both the technology and costs associated with detecting and quantifying methane emissions have been viewed by many landfill operators as less than optimal. This article describes a new landfill methane-monitoring technology intended to make landfill methane measurements more comprehensive, more accurate, and less costly.

Drones Save Landfill OperatorsTime and Money with

Advanced Emissions Measurements

Gas Mapping LiDAR drone (top) and manned aircraft (bottom) versions. Copyright: Bridger Photonics, Inc.

Waste Management CornerNew for 2020, EM is expanding its content coverage of waste management issues with a special section of waste-themed articlesin every issue, called Waste Management Corner. In this month’s article, Pete Roos and Ben Losby describe a new landfillmethane-monitoring technology.



Landfill Methane EmissionsLandfill emissions have an impact on both a local and globalscale. At the local level, while methane itself is odorless, it isoften accompanied by other gases emitted by landfills thatare odorous. As a result, landfill owners and operators canfind and mitigate odor sources by locating methane “hotspots” with surface emissions monitoring (SEM) technology.SEM is required by EPA for controlled landfills that haveLFG collection and control systems installed. Currently, SEMis performed at landfills using expensive and time-consum-ing foot patrols equipped with handheld sensors. These footpatrols cost landfill operators an EPA-estimated US$10,400per year on average.1 Anecdotal industry information, suchas for a 53-acre Kansas landfill incurring a cost of aroundUS$12,000 per year, support this estimate.2

On a global scale, methane is a potent greenhouse gas.Landfills are a significant emitter of methane. Accordingly,EPA also regulates whole-landfill emissions (i.e., the amountof methane emitted from an entire landfill over time).3 Inthese cases, if modeled emissions of methane from a landfillexceed EPA’s applicable threshold, then EPA requires a LFGcollection system. However, whole-landfill emissions are cur-rently only estimated based on mathematical models ratherthan measured empirically. Unfortunately, the model inputs,such as waste material composition and age, moisture con-tent, soil content, landfill topology, temperature, and otherconditions, are notoriously difficult to accurately determineand the models’ predictive capabilities are often poor.4 A re-cent study found that “the models consistently overestimatedannual methane emissions by a factor ranging from 4−31.”4

As a result, many landfill owners unnecessarily pay for reme-diation based on incorrectly high regulatory tiers.

Gas Mapping LiDARRecent advances in light detection and ranging (LiDAR) are transforming the way methane emissions are detected,quantified, and managed. Over the past four years, a smallcompany in Bozeman, Montana, Bridger Photonics, Inc., hasdeveloped an advanced airborne remote sensor technology

called Gas Mapping Lidar™ (GML) that images and quanti-fies methane emissions. While GML was initially developedfor the oil and gas industry to detect, locate, and quantifymethane leaks throughout the entire natural gas value chain,Bridger has recently investigated applying the technology tothe solid waste industry. GML determines gas concentrationby measuring the amount of laser light absorbed bymethane gas. The laser beam is rapidly scanned over thelandscape to generate sensitive gas concentration maps thatare geo-registered using GPS and a whole host of othersensors, and then overlaid onto satellite imagery.

Figure 1 shows an example GML data product for the oiland gas industry where multiple simultaneous methaneleaks are imaged. Bridger’s technology applies advanced analytics to the plume imagery to identify the source of theleak (to equipment-level precision) and to quantify the emissions rate (gas flux), among other data products. With this information, oil and gas operators know preciselywhere the leak sources are and how much gas is being lostby each leak so they can deploy their mitigation resourcesmost efficiently.

For landfills, the emissions sources may be spatially distrib-uted area sources rather than point sources, but similar principles apply. Figure 2 shows imagery from a landfill fly-over using a helicopter-mounted GML sensor. The light blueswaths represent the areas interrogated by the sensor’s laser,the white lines represent the aircraft flight path, and thecolor map represents the methane concentration map. “Hot spots” of methane emissions may be determined fromthe concentration map (and signified by red dots in theimage). Landfill owners may choose to focus odor remedia-tion efforts on these regions. Importantly, by scanning theentire landfill, and applying advanced analytics, the whole-landfill methane emissions can be determined. However,challenges remain, and the process is long, to secure EPAapproval for using GML to replace existing approved meth-ods. Neverthe-less, the technology already provides neededinformation in a more efficient manner.

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on several factors, including the size andlocation of the landfill.

Successful TestsBridger’s GML technology has beentested in blind field tests for methane detection on oil well pads at the MethaneEmissions Test and Evaluation Center(METEC) in Colorado, using both mast-mounted and drone versions of the sen-sor. METEC is an undertaking of TheEnergy Institute at Colorado State Univer-sity, and the testing was conducted on behalf of the oil and gas industry. DuringRound 1 of testing, GML detected 17 of17 leaks (plus one null); it located all leaksources to within a three-foot radius; andit quantified the flow rates of all leaks towithin 50% of the METEC uncertainty, asshown in Figure 3. While the blind testingwas performed under ideal and controlledscenarios, it validates the fundamentalprinciples of the GML technology.

Current StatusIn early 2019, Bridger’s GML was com-mercially deployed surveying oil and gasassets in both the United States andCanada. In just its first year of deploy-ment, Bridger surveyed tens of thousandsof oil and gas well sites and natural gaspipeline miles. As a result of these surveys,operators have been able to repair thou-sands of leaks, significantly reducing theiremissions profiles. GML was recently (inOctober 2019) recognized by R&D World magazine as one of the top 100 innova-tions worldwide.

Bridger received funding from the Environ-mental Research and Education Foundation(EREF), a consortium of waste management

industry leaders, to demonstrate the capabilities of GML forboth SEM and whole landfill emissions determination. Thosestudies are ongoing, and results will be available throughEREF. Bridger is currently capable of deploying GML com-mercially to scan landfills via helicopter to identify hot spotsand is seeking a waste management service provider partnerin the longer-term for drone deployment.

Whether capturing methane emissions at your landfill is thehighlight of your day professionally, or the bane of your professional existence, it is an increasingly important part oflandfill management. The first step in addressing methaneemissions is knowing where a facility stands. To do that,managers need auditable coverage to know that their landfill



Bridger has developed GML sensors suitable for bothmanned aircraft and drone deployment (see graphic on firstpage of this article). Airborne deployment can achieve signif-icant time and cost savings relative to foot patrols. Bridger’sdrone-based sensor can scan an average landfill (50 acres)in less than two hours, compared to more than three daysusing conventional foot patrols. With a helicopter, the time to scan the same landfill is reduced to less than 10 minutesbecause the helicopter can cover so much more ground somuch faster. Due to line-of-site restrictions currently placedon the operation of drones by the U.S. Federal Aviation Administration (FAA), both manned and drone deploymentrequires a human operator or observer. As a result, the eco-nomics of drone versus manned aircraft are heavily dependent

Figure 1. GML results for the oil and gas industry showing emissions quantification (1 lpm = 2.08 scfh). Copyright: Bridger Photonics, Inc. Figure 1 was enabled by funding and site accessprovided by the Alberta Upstream Petroleum Research Fund. Measurements were acquired in collaboration with Lidar Services International and Z-Air.

Figure 2. GML imagery from a landfill fly-over. Copyright: Bridger Photonics, Inc.



facility, in its entirety, has been inventoried for its LFG emissions. With that comprehensive LFG emissions data inhand, landfill managers can make informed decisions re-garding methane emissions-reduction requirements. Inmany cases, having a full picture of a site’s emission profilewill result in a significant savings in landfill operational costsvia a reduction in the regulatory tier under which the facility falls, thus eliminating the requirement for LFG

control. Significant savings in landfill operating costs can also result because new technology reduces the cost of surface emissions monitoring for LFG emissions. As methaneemissions continue to be a dominant topic of conversation in relation to climate impacts, landfill managers have the opportunity now to be proactive in their emission reductionefforts. New and exciting technology is making it easier toget ahead of the curve. em

Figure 3. Data from blind testing of GML at the METEC research facility in Colorado.Copyright: Bridger Photonics, Inc.

References1. See EPA Outreach Briefing: https://www.epa.gov/sites/production/files/2015-09/documents/appendix-c-sbarpanel-landfills.pdf.2. Green, J. Change in landfill gas monitoring requirement hikes cost; The Hutchinson News, Dec. 20, 2016.3. CFR 40 accessed through: Sullivan, P. New Rules for Landfills; MSW Management, Nov.-Dec. 2016; 30-32.4. De la Cruz, et al. Comparison of Field Measurements to Methane Emissions Models at a New Landfill; Environ. Sci. Technol. 2016, 50 (17); 9432-9441.

Pete Roos and Ben Losby are both with Bridger Photonics, Inc., Bozeman, MT.

Now in its 38th year, this conference provides a forum for the discussion of state-of-the-art technical information, regulations, and public policy on thermal treatment technologies and their relationship to air emissions, greenhouse gases, and climate change. Sessions will focus on technology advances, regulatory issues, waste-to-energy applications, greenhouse gas inventories, residuals treatment, climate change, and related topics including how these a�ect public perception and developing governmental policies.

Be a part of the premier conference on thermal treatment technologies!

Topics include, but are not limited to:

Sponsorship and exhibit opportunities available. Find the full Call for Abstracts and details online at www.awma.org/IT3.

38TH INTERNATIONAL CONFERENCE ON THERMAL TREATMENT TECHNOLOGIES & HAZARDOUS WASTE COMBUSTORS

January 27-28, 2021 • West Palm Beach, FL

• Practical Applications and Industry Best Practices

• Established and Emerging Markets for Incineration

• Thermal Treatment Case Studies — Municipal and Industrial

• Waste-to-Energy, Renewable Energy, and Biomass

• Greenhouse Gas Management and Sustainability

• Permitting and Regulatory Policy Issues

• Research and Development (R&D) — All Areas

• Plant Level Operational Issues• Pollution Control Technologies;

VOC and Odor Management• Medical and Biohazardous

Waste Treatment

Call for Abstracts open through July 27, 2020.

New topics added for 2021 include PFAS sampling, methods, and laboratory analysis, waste/compliance impacts of health pandemics and natural disasters, plastics to energy/closed loop processing, and comprehensive performance testing (CPT).

Share your knowledge and submit abstracts of 250 words or less to [email protected].

Health Effects of Fine Particulate Air

Pollution: Lines that Connect

C. Arden Pope III

Department of Economics, Brigham Young University, Provo, UT

Douglas W. Dockery

Department of Environmental Health, Harvard School of

Public Health, Boston, MA

ABSTRACT

Efforts to understand and mitigate the health effects of

particulate matter (PM) air pollution have a rich and

interesting history. This review focuses on six substantial

lines of research that have been pursued since 1997 that

have helped elucidate our understanding about the effects

of PM on human health. There has been substantial

progress in the evaluation of PM health effects at different

time-scales of exposure and in the exploration of the

shape of the concentration-response function. There has

also been emerging evidence of PM-related cardiovascular

health effects and growing knowledge regarding intercon-

nected general pathophysiological pathways that link PM

exposure with cardiopulmonary morbidity and mortality.

Despite important gaps in scientific knowledge and con-

tinued reasons for some skepticism, a comprehensive

evaluation of the research findings provides persuasive

evidence that exposure to fine particulate air pollution

has adverse effects on cardiopulmonary health. Although

much of this research has been motivated by environ-

mental public health policy these results have important

United States reported apparent health effects at unex-

pectedly low concentrations of ambient PM. These efforts

included: (1) a series of studies that reported associations

between daily changes in PM and daily mortality in sev-

eral cities17–24; (2) the Harvard Six Cities and American

Cancer Society (ACS) prospective cohort studies that re-

ported long-term PM exposure was associated with respi-

ratory illness in children25 and cardiopulmonary mortal-

ity in adults26,27; and (3) a series of studies in Utah Valley

that reported particulate pollution was associated with a

wide range of health end points, including respiratory

hospitalizations,28,29 lung function and respiratory symp-

toms,30–32 school absences,33 and mortality.20,34 Compa-

rable results were also reported in studies from the United

States,35–37 Germany,38 Canada,39 Finland,40 and the

Czech Republic.41 Although controversial, the conver-

gence of these reported findings resulted in a critical mass

of evidence that prompted serious reconsideration of the

health effects of PM pollution at low-to-moderate expo-

sures and motivated much additional research that con-

tinues to this day Since the early 1990s numerous re

Douglas W. Dockery

C. Arden Pope III

2006 CRITICAL REVIEW

ISSN 1047-3289 J. Air & Waste Manage. Assoc. 56:709–742

Copyright 2006 Air & Waste Management Association


This year, we celebrate 50 years of A&WMA’s Annual Critical Review. For half a century, A&WMAhas solicited and published in the Journal of the Air& Waste Management Association (JA&WMA) an Annual Critical Review on a topic of critical impor-tance to the air and waste management fields. Eachyear, the review author presents the Annual CriticalReview at a special session held during A&WMA’sAnnual Conference & Exhibition. Each month in this space, we will take a moment to look back at asingular review of critical significance from the past50 years.

Back In Time

This month, we spotlight the 2006 Critical Review, whichis consistently one of the most heavily cited and top-rankingdownloaded papers of all the past critical reviews.

Suspended particulate matter (PM) has adverse effects onvisibility, climate, ecosystems, and, along with other pollu-tants, human health. Of these effects, human health is ofgreatest concern and has been addressed in several criticalreviews. This topic was of special interest in 2006 becausethe U.S. Environmental Protection Agency (EPA) proposedrevisions to the PM National Ambient Air Quality Standards(NAAQS). These revisions proposed to retain the annual average level for PM2.5, averaged over 3 years, but lowerthe 24-hr PM2.5 level from 65 µg/m3 to 35 µg/m3 (98thpercentile averaged over 3 years); and proposed to replacethe PM10 standards of 50 µg/m3 annual average and 150µg/m3 24-hr average with a coarse particle indicator (PM10-

2.5; the difference between collocated PM10 and PM2.5 massconcentrations) applicable only in urban areas with popula-tions exceeding 100,000.

EPA’s proposal was at odds with its Clean Air Science Advisory Committee’s (CASAC) recommendation of a PM2.5annual average in the range of µg/m3 and PM10–2.5 monitor-ing in both urban and rural communities. The disagreementhighlights the controversy that often accompanies air qualitystandards owing to uncertainties in measuring size-specificPM and its chemical components, PM toxicity, human exposure, dosage, and relevant health end points.

The 36th Annual A&WMA Critical Review addressed theepidemiological evidence for the effects of PM on humanhealth indicators, specifically sickness (morbidity) and death

(mortality). The review identified and built on previous reviews and documented substantial progress in all areas of understanding, with notable advances in the areas ofshort-term exposure and mortality; long-term exposure and mortality; time-scales of exposure; the shape of the concentration-response function; cardiovascular disease; and biological plausibility.

The authors, Drs. Arden Pope and Douglas Dockery, observed that more than 100 studies published over thedecade leading up to this review, using many different studydesigns and data analysis methods, consistently showed statistically significant associations between cardiopulmonarymortality and daily PM concentrations. They described substantial progress in understanding the biological andchemical mechanisms that cause PM to adversely affectpublic health. Despite the additional science, Drs. Pope andDockery identified several knowledge gaps that needed tobe addressed: better defining susceptible populations; determining the relative effects of specific compositions,physical properties, and sources of pollutants; and evaluatingthe importance of co-pollutants such as sulfur dioxide, nitrogen dioxide, and ozone.

At the time of its publication, Drs. Pope and Dockery wereamong the premier air pollution epidemiologists in theworld. Dr. Pope, a professor of economics at Brigham Young University in Provo, UT, had published more than 70 articles on epidemiology and public health. Dr. Dockery,a professor of environmental epidemiology in the Depart-ment of Environmental Health at the Harvard School ofPublic Health, had published more than 100 articles on airpollution epidemiology. em

‘Those who ignore history are bound to repeat it.’

Past Critical ReviewsA complete list of A&WMA’s past Critical Reviews is available online at http://pubs.awma.org/journal/A&WMA%20Critical%20Reviews.pdf. To read and download any of the past Critical Reviews, log onto JA&WMA Online atwww.tandfonline.com/loi/uawm.

2006 Annual Critical Review: Health Effects of Fine Particulate Air Pollution: Lines that Connect by C. Arden Pope III and D. Dockery


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EM, a publication of the Air & Waste Management Association, is published monthly with editorial and executive offices at The Koppers Building, 436 Seventh Ave., Ste. 2100, Pittsburgh, PA 15219, USA. ©2020 Air & Waste Management Association(www.awma.org). All rights reserved. Materials may not be reproduced, redistributed, or translated in any form without prior written permission of the Editor. A&WMA assumes no responsibility for statements and opinions advanced by contributors to this publication. Views expressed in editorials are those of the author and do not necessarily represent an official position of theAssociation. A&WMA does not endorse any company, product, or service appearing in third-party advertising.

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