PUBLIC HEALTH DIVISION
Wildfire Smoke and Your Health
When smoke levels are high, even healthy people may have symptoms or health problems.
The best thing to do is to limit your exposure to smoke. Depending on your situation, a
combination of the strategies below may work best and give you the most protection from
wildfire smoke. The more you do to limit your exposure to wildfire smoke, the more you’ll
reduce your chances of having health effects.
The Oregon Smoke blog
has information about air
quality in your community:
Frequently asked questions about
wildfire smoke and public health
Q: Why is wildfire smoke bad for my health?
A: Wildfire smoke is a mixture of gases and
fine particles from burning trees and other
plant material. The gases and fine particles
can be dangerous if inhaled. In wildfires,
carbon monoxide is mainly a risk to people
(like firefighters) who work near smoldering
areas. Smoke can irritate your eyes and your
respiratory system, and worsen chronic heart
and lung diseases. The amount and length
of smoke exposure, as well as a person’s
age and degree of susceptibility, play a role
in determining if someone will experience
smoke-related health problems. If you are experiencing serious medical problems for any
reason, seek medical attention immediately.
Q: Why is everyone talking about particulate matter?
A: The particulate matter (also called “PM”) in wildfire smoke poses the biggest risk to the
public’s health. The potential health effects vary based on the type of plants burning,
atmospheric conditions and, most importantly, the size of the particles. Particles larger than
10 micrometers usually irritate only the eyes, nose and throat. Fine particles 2.5 micrometers
or smaller (PM2.5) can be inhaled into the deepest part of the lungs, and may cause greater
Health effects of wildfire smoke
Q: Who is most likely to have health effects from wildfire smoke exposure?
A: Smoke may worsen symptoms for people who have pre-existing health conditions and those
who are particularly sensitive to air pollution. Sensitive groups include:
• Persons with asthma or other chronic
• Persons with cardiovascular disease
• Persons ≥ 65 years of age
• Infants and children
• Pregnant woman
• Smokers, especially those who have
smoked for several years
Q: How can I tell if wildfire smoke is affecting me or my family?
A: Wildfire smoke can cause the following:
• Watery or dry eyes
• Persistent cough, phlegm, wheeze,
scratchy throat or irritated sinuses
• Shortness of breath, asthma attack or
• Irregular heartbeat, chest pain or fatigue
• Nonfatal and fatal heart attacks
People with chronic heart disease or lung disease such as asthma and chronic
obstructive pulmonary disease (COPD) may be more likely to have serious health effects
from wildfire smoke.
Q: What should I do if I am having a health problem from smoke?
A: If you have a medical emergency from smoke, you should call 911 or go to the hospital
emergency room immediately. Contact your healthcare provider for advice on how to prevent
and treat symptoms from exposure to wildfire smoke.
Strategies to reduce smoke exposure
Q: How can I protect myself and my family from the harmful effects of smoke?
A: Limit your exposure to the smoke:
• Stay indoors whenever possible with the
doors and windows closed.
• Reduce other sources of indoor air
pollution such as smoke from
tobacco, wood-burning stoves and
• Use high-efficiency (HEPA) air-cleaning
filters, if available.
• Avoid vacuuming, which can stir up dust.
• When driving in a vehicle, keep
windows closed with air conditioning
set to recirculate.
• Drink plenty of water to help
reduce symptoms of scratchy throat
Leaving the area of thick smoke may be best for those with health conditions that put them at
higher risk for illness from wildfire smoke.
Q: What can I do to deal with eye irritation from wildfire smoke?
A: Wildfire smoke can cause burning, redness and tearing in the eyes. To relieve the symptoms,
you can use over-the-counter artificial tear drops and drink enough water. Running a
humidifier may also provide relief. Consult with a healthcare provider if symptoms last longer
than several days. If you are in an area where there is a lot of ash or fine dust, consider
Q: Should I wear a dust mask or N95 respirator?
A: N95 respirators are filter masks that fit over the nose and mouth. When properly fitted, an
N95 respirator can filter 95% of smoke particles. However, N95 respirators do not filter toxic
gases and vapors.
Most people will find it difficult to correctly use N95 respirators. It is important that the
respirator fits properly and air does not leak around the sides. If it does not fit properly, the
respirator will provide little if any protection, and may offer a false sense of security. Proper fit
testing requires special equipment and training.
N95 respirators can make breathing more difficult and lead to increased breathing and heart
rates. Respirator use by those with heart and respiratory diseases should only be done under a
healthcare provider’s supervision.
Even healthy adults may find that the increased effort required for breathing makes it
uncomfortable to wear a respirator for long periods of time. Decisions on whether to use
respirators or masks as personal protection should be made on a case-by-case,
Q: What is the difference between an N95 respirator and a dust mask?
A: N95 respirators are tested and certified by the National Institute for Occupational Safety and
Health (NIOSH) for use in certain work places. N95 respirators are tested to ensure they filter
at least 95% of airborne particles. If an employer requires an employee to wear a respirator,
the employee must be trained and fitted to wear a NIOSH-approved respirator. Voluntary use
of respirators by employees does not eliminate all employer responsibilities under Oregon
Dust masks and surgical masks that are not NIOSH certified are not tested for filtration
effectiveness and may not offer a consistent level of protection from particles. This means that
they may offer little protection.
Q: Will a wet towel or bandana provide any help?
A: Probably not. A wet towel or bandana may stop large particles, but not the fine, small ones
that can get down into the lungs. They will likely provide little protection.
Q: What should I do about closing up my house when it is so hot in there?
A: Make sure you don’t get overheated if you live without air conditioning and have the doors and
windows closed. Consider visiting family members, neighbors or public buildings that have air
conditioning and air filtration. Leaving the area of thick smoke may be best for those with health
conditions that put them at higher risk for illness.
Q: I’ll probably need to go out some time.
Is there a time of day when smoke is
less of a problem?
A: This varies depending on the fire and
the conditions. Check the Department of
Environmental Quality (DEQ) Air Quality
Index. If there is an air quality monitor near
you, the website can give you information
about what time of day the smoke levels are
lowest. The DEQ Air Quality Index can be
found on the Oregon Smoke Blog:
Q: What should I do if I must drive to work?
A. You can reduce smoke exposure by keeping
the windows closed and using the air
conditioner on the recirculate setting. This
can reduce exposure to particles, but not to
the toxic gases in wildfire smoke.
Q: Do air-purifying machines help remove
smoke particles inside buildings?
A: Portable air cleaners with HEPA filters and/or electrostatic precipitators (ESP) can reduce
indoor particle levels, but most are not effective at removing gases and odors. Air cleaners
using ozone will not remove particles unless they also use HEPA filters and/or ESP technology.
Also, humidifiers or dehumidifiers are not air cleaners and will not do much to reduce the
amount of particles in the air during a smoke event.
Q: I operate a nonresidential building with outside air intakes. Should I close the outside
air intakes during a wildfire smoke event?
A. Every nonresidential building has a uniquely designed ventilation system, and any changes,
even temporary ones, can affect building occupants and indoor air quality. If your building is
strictly an office environment, it may be wise to cut back or eliminate outside intake into the
building during a wildfire smoke event. If the building has labs or special ventilation systems,
it may not be wise to reduce outside air flow if ventilation is needed to prevent the build up
of chemicals in the building. We recommend you consult with a heating, ventilation and airconditioning
professional or someone who knows your special ventilation needs for guidance
on this issue.
Q. Where can I find information about ongoing wildfires in Oregon?
A. The Oregon Smoke Blog has more information about wildfires in Oregon:
Q: Where can I find information about air quality in my community?
A. Check the local air quality index (AQI) on the Oregon DEQ’s website:
Q: Our community has an outdoor event scheduled for this evening. Should we cancel it?
A. It depends on the level of smoke exposure. Check with your local health department.
Q: Is climate change affecting wildfires?
A. Hotter, drier weather may increase the likelihood of bigger and more destructive wildfires. The
total area burned, number of fires and size of the fires are all increasing across the western
United States, including Oregon. It is not certain this is due to “climate change,” but it is
happening. As forest fires increase, so does exposure to wildfire smoke.
Q: How does wildfire smoke affect pets and livestock?
A. The effects of smoke are similar for humans and animals. High levels of smoke may irritate
your animal’s eyes and respiratory tract. Strategies to reduce animals’ exposure to smoke are
also similar to those for humans: reduce the time spent in smoky areas, provide animals with
plenty of water, limit activities that will increase breathing and reduce exposure to dust or
other air pollutants. If your pet or livestock is coughing or having difficulty breathing, contact
Q. How can wildfires affect drinking water quality?
A. Wildfires destroy plants that stabilize soil. By burning ground cover, fires also release
chemicals such as nitrates and phosphates that affect water quality. Erosion and release of
these chemicals into surface water can decrease the quality of drinking water. Nitrates and
phosphates can also promote growth of harmful algae. Flame retardants used by firefighters
may find a way to drinking water sources. Water suppliers can monitor the drinking water
source upstream of the intake to determine if unhealthy chemicals are in the raw water. Public
drinking water systems can take steps to protect drinking water quality by applying post-fire
erosion control techniques in the watershed.
This document can be provided upon request in an alternate format for individuals with disabilities or in a language other
than English for people with limited English skills. To request this publication in another format or language, contact the
Public Health Division at 971-673-1222, 971-673-0372 for TTY.