# Wildland Fire Smoke, Air Quality, and Health

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URL: https://www.frixlaw.com/law-library/documents/crs%3AIN12730

## Record

- **Collection:** Congressional research report
- **Document type:** Insight
- **Published:** August 13, 2026
- **Citation:** IN12730

## Text

INSIGHTi

Wildland Fire Smoke, Air Quality, and Health
August 13, 2026
Wildland fire smoke is a complex mixture of gases and fine particles produced by burning materials
during wildland fire events that temporarily degrades air quality over long distances, creating health
concerns and decreasing visibility. Wildland fire smoke affects the public and fire personnel, and may
impose a disproportionate risk on sensitive populations such as children, older adults, and those with
certain chronic conditions. During 2023 and 2026, weather conditions transported Canadian wildfire
smoke hundreds of miles into the United States, driving responses from the public and some Members of
Congress.

Wildland Fire Smoke and Health
Particulate matter is the principal pollutant of concern from wildland fire smoke. Wildland fire smoke,
including smoke from prescribed burns (planned fires burning under supervision) and wildfires
(unplanned fires and escaped prescribed burns), releases fine particles (less than 2.5 microns, or
“PM2.5”). The U.S. Environmental Protection Agency’s (EPA’s) National Emissions Inventory identifies
wildland fires as a major contributor of these fine particles and other pollutants. Fine particles can
penetrate deeply into the lungs and may contribute to a range of health effects, including eye irritation,
sore throat, coughing, breathing difficulties, worsening of preexisting heart and lung disease, and
increased premature mortality.
Wildland fire smoke also includes carbon monoxide, hazardous air pollutants, and emissions that
contribute to the formation of ground-level ozone, a lung and airway irritant. The chemical composition
of smoke depends on various factors, including burn conditions (e.g., fire temperature) and type of
materials burned (e.g., vegetation or structures).
Research links wildland fire smoke exposure to health complications, including respiratory,
cardiovascular, and potential pregnancy impacts; reduced lung function in subsequent years; and
increased risk of respiratory infections in exposed infants and influenza across age groups. While smoke
may affect the health of any exposed individual, sensitive populations—children, people who have
chronic conditions, pregnant women, and the elderly—are more vulnerable.
Wildland firefighters are regularly exposed to pollutants in wildland fire smoke, including carcinogens.
Less is known about cumulative and long-term exposure to wildland fire smoke. In 2026, the U.S. Forest
Service within the U.S. Department of Agriculture and the U.S. Wildland Fire Service within the U.S.
Congressional Research Service
https://crsreports.congress.gov
IN12730
CRS INSIGHT
Prepared for Members and
Committees of Congress

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Department of the Interior updated policies in an effort to reduce smoke exposure for wildland fire
personnel.

Air Quality Requirements and Wildland Fires
The Clean Air Act (CAA) is the principal statute addressing air quality concerns. The CAA requires EPA
to establish minimum national air quality standards to protect health. EPA has set and periodically revised
national ambient air quality standards (NAAQS) for six “criteria” air pollutants, including some that are
in wildland fire smoke. Under the CAA, states have primary responsibility for assuring compliance with
NAAQS and establishing state implementation plans intended to meet these standards. Measurements
from a national network of air quality monitoring stations, in combination with modeling analyses, inform
NAAQS compliance determinations.
The national monitoring network may detect smoke from wildland fires, sometimes exceeding the
NAAQS. The CAA allows EPA to exclude air quality data from regulatory decisions if air quality is
demonstratively influenced by “exceptional events,” such as wildland fires and certain natural events (42
U.S.C. §7619(b)). To exclude prescribed burn-impacted air quality data from regulatory decisions,
individuals and agencies that conduct prescribed burns must adhere to the exceptional events rule by
demonstrating appropriate smoke management procedures.

Wildland Fire Smoke Response
Wildland fire smoke response strategies include air quality monitoring, smoke forecasting, timely
communication of air quality conditions and related health risks, and measures to avoid smoke. Federal,
tribal, state, and local agencies contribute to these tasks.
EPA and other agencies have developed tools to measure air quality conditions and alert the public. For
example, EPA manages AirNow, a multiagency website that reports air quality based on monitoring data
received on a regular basis from state, local, and federal agencies. AirNow reports air quality information
using the color-coded Air Quality Index (AQI), a nationally uniform index. EPA calculates the AQI for a
criteria pollutant based on the ambient concentration of that pollutant. The higher the AQI, the greater the
pollution level. EPA’s AirNow mobile app can send phone alerts when AQI exceeds a user-chosen
threshold, and its EnviroFlash service provides email alerts. The National Weather Service issues air
quality alerts when the AQI is unhealthy. States and local agencies may share alert information with local
media outlets.
To help protect health near wildland fires, the Forest Service’s Interagency Wildland Fire Air Quality
Response Program (IWFAQRP) may deploy trained specialists called Air Resource Advisors (ARAs) to
monitor and forecast local air quality conditions and help develop smoke management strategies. ARAs
also use computer modeling to estimate pollution levels. The IWFAQRP and EPA lend smoke particulate
monitoring kits to ARAs and firefighting agencies to monitor wildland fire emissions. In 2026, the
program had more than 70 ARA deployments. EPA also lends supplemental and educational air quality
monitors.
The federal government provides other resources to help individuals and local officials who encounter
wildland fire smoke. For example, EPA publishes resources online, including a guide for public health
officials. EPA collaborated with the American Society of Heating, Refrigerating, and Air-Conditioning
Engineers (ASHRAE) to develop guidelines and best practices for building design and operation to
reduce smoke impacts. EPA also provides assistance to certain nonfederal entities for projects that seek to
improve public health protection during wildland fire smoke events through its Wildfire Smoke
Preparedness in Community Buildings grant program.

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Issues for Congress
The federal government currently engages in measures to protect the public from wildland fire smoke
through air quality monitoring, public communications, financial and technical assistance, and other
means. Congress may consider options for maintaining or improving air quality monitoring networks,
smoke models, and public communications to help inform smoke management and public health
responses. Congress could clarify the eligibility of prescribed burns as exceptional events and reduce the
burden and cost to demonstrate an event. Congress may also consider supporting research into fields
related to smoke and health, such as respiratory protection devices, building technologies, medical
research, or other topics.

Author Information
Alicyn R. Gitlin
Analyst in Natural Resources Policy

Omar M. Hammad
Analyst in Environmental Policy

Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff
to congressional committees and Members of Congress. It operates solely at the behest of and under the direction of
Congress. Information in a CRS Report should not be relied upon for purposes other than public understanding of
information that has been provided by CRS to Members of Congress in connection with CRS’s institutional role.
CRS Reports, as a work of the United States Government, are not subject to copyright protection in the United
States. Any CRS Report may be reproduced and distributed in its entirety without permission from CRS. However,
as a CRS Report may include copyrighted images or material from a third party, you may need to obtain the
permission of the copyright holder if you wish to copy or otherwise use copyrighted material.

IN12730 · VERSION 1 · NEW

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Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/crs%3AIN12730. Public record. Not legal advice.
