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Wildfire Smoke and Your Health - FAQ

The following information has been informed by wildfire smoke evidence reviews conducted by the BC Center for Disease Control (BCCDC).

Why is wildfire smoke bad for my health?
Wildfire smoke is a complex mixture of particles and gasses.  Gases released by wildfires, such as carbon monoxide, are mainly a risk to people (like firefighters) who work near smoldering areas. Fine particles, which are in 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 overall health, play a role in determining if you will experience smoke- related health problems.
If you are experiencing serious medical problems for any reason, seek medical attention immediately.


What is particulate matter?
The particulate matter (also called “PM”) in wildfire smoke poses the biggest risk to the health of the public. 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 (PM10) 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 symptoms such as coughing or may worsen existing heart and lung conditions.  PM concentrations and forecast duration is most useful to inform decisions on how to protect public health.

Health Effects of Wildfire Smoke

Who is most likely to have health effects from wildfire smoke exposure?
Wildfire smoke affects people differently. Smoke may worsen symptoms for people who have pre-existing health conditions and those who are particularly sensitive to air pollution. These people are of primary risk and concern.
Sensitive groups include:
• people with existing respiratory conditions such as lung cancer, asthma or chronic obstructive pulmonary disease (COPD), including chronic bronchitis and emphysema;
• people with existing heart conditions including angina, previous heart attack, congestive heart failure or irregular heartbeat;
• infants and young children;
• people over 65 years of age; and
• Pregnant women.


How can I tell if wildfire smoke is affecting me or my family?
Smoke can hurt your eyes, irritate your respiratory system, and worsen chronic heart and lung diseases. Some of the common symptoms include:
• watery or dry eyes;
• persistent cough, phlegm, wheeze, scratchy throat or irritated sinuses;
• headaches;
• shortness of breath, asthma attack or lung irritation;
• irregular heartbeat, chest pain or fatigue.


What should I do if I am having a health problem from smoke?
Sensitive groups should take specific precautions during conditions of moderate and high smoke:
• People with heart or lung conditions should watch for any change in symptoms. 
• People with asthma or other chronic illness should activate their asthma or personal care plan.
• If any symptoms are noted, take steps to reduce exposure to smoke by moving to cleaner air and, if necessary, see your physician.
• Maintain good overall health to prevent health effects resulting from short-term exposure.

People with symptoms should go to their health care provider, walk in clinic or emergency department depending on severity of symptoms.

For general information about smoke contact HealthLink BC available toll free, 24 hours a day, 7 days a week at 8-1-1, or via the web at:


What about risks to wildfire crews?
This FAQ is not intended to address occupational or worker exposures. Risk to firefighters or wildfire crews are different than the public because of the proximity to fires and heavy smoke, and the duration of their exposures. WorksafeBC should be consulted.

Strategies to Reduce Smoke Exposure

How can I protect myself and my family from the harmful effects of smoke?
Limit your exposure to the smoke:
• Stay indoors with the doors and windows closed;
• Reduce outdoor physical activity;
• Use a home or community clean air shelter;
• Use a high-efficiency (HEPA) air-cleaning filter for your home, if available;
• When driving in a vehicle, keep windows closed with air conditioning or fans set to recirculate;
• Drink plenty of water to help reduce symptoms of scratchy throat and coughing.
• Leaving the area of thick smoke may be best if you or a family member has health conditions that put you at higher risk. Ensure you check the air quality of any other regions before you go to ensure it is not the same or worse.


Why is reducing physical activity important?
During physical activity, the volume of air intake increases up to ten times, therefore increasing the amount of smoke exposure.


What is a home clean air shelter (home-CAS)?
A home-CAS is your home, or room of your home, with filtration that is suitable for reducing smoke exposure. Use may be part-time or full-time for residents who are unable to achieve cleaner air within their home. For further guidance on clean air shelters, please see the Clean Air Shelter FAQ. In cases of extreme heat, additional precautions may be needed to reduce impacts of heat stress.


What is a community clean air shelter (community-CAS)?
A community-CAS is a building, or area of a building, with filtration that is suitable for reducing smoke exposure. Use may be part-time or full-time for residents who are unable to achieve cleaner air within their home. FNHA EHOs can work with communities to identify suitable community-CAS. For further guidance on clean air shelters, please see the Clean Air Shelter FAQ.


Do air-purifying machines help remove smoke particles inside buildings?
Portable air cleaners with HEPA filters and/or electrostatic precipitators (ESP) can reduce indoor particle levels. They are beneficial in creating a home or community clean air shelter.
Air cleaners using ozone will not remove particles unless they also use HEPA filters and/or ESP technology. Humidifiers or dehumidifiers are not air cleaners and will not be effective.


How can I reduce smoke levels in my car?
Keep the windows closed and use the air conditioner or cool fan on the recirculate setting.


Should I attend outdoor events?
Organizers of outdoor events may consider canceling events to help reduce exposures. To be effective, people should seek cleaner air instead of remaining outdoors. If events are not cancelled, organizers could make clean air shelters available. Participants should monitor their health and seek cleaner air if symptoms arise.


What can commercial buildings do?
Every non-residential building has a uniquely designed ventilation system. Any changes, even temporary ones, can affect building occupants and indoor air quality. In some cases, outside air intakes can be closed to minimize entry of smoke into the building. Special ventilation systems designed to eliminate indoor pollutants, such as chemicals, should consult a heating, ventilation and air- conditioning professional or someone who knows your special ventilation needs. 


Should I wear a N95 respirator?
A physician should be consulted on the individual health suitability and need for the use of N95 respirators. N95 respirators are filter masks that fit over the nose and mouth. When properly fitted by a professional, a N95 respirator is effective for fine smoke particles but do not filter toxic gases and vapors. Respirators may be useful for workers who must remain outdoors during smoke events, provided that they have professional fit testing and training in proper use. For the general public, use is less feasible because professional fit and appropriate use is difficult to achieve.

The respirator will provide little if any protection if not professionally fitted, and may offer a false sense of security. Respirators are not suitable for certain people, such as children and adults with facial hair, because proper sizing, fit, and seal cannot be achieved.

N95 respirators can create further medical complications for individuals with pre-existing respiratory problems because breathing is more strenuous, leading to increased breathing and heart rates. Even healthy adults may find that the increased effort required for breathing makes it uncomfortable to wear a respirator for long periods of time.


What is the difference between an N95 respirator and a dust mask?
N95 respirators are tested and certified by the National Institute for Occupational Safety and Health (NIOSH) for use in filtering at least 95% of airborne particles. If an employer requires an employee to wear a respirator, the employee must be trained and professionally fitted to wear a NIOSH-approved respirator.
Dust masks and surgical masks that are not NIOSH certified to remove particles are not effective and should not be used.


Will a wet towel or bandana provide any help?
No. A wet towel or bandana may stop large particles, but not the fine particles that reach the lungs.


Should the community be evacuated due to the smoke?
Air quality is often poor in surrounding communities, and smoke patterns can change quickly. Community evacuations have significant potential to cause harm due to the disruption of normal activity, social and economic ties, and health care access.

Ensure you are accessing any available community clean air shelters, or consider temporarily relocating to an area with cleaner air. Identify whether you have family or friends in other areas where the air quality may be better and make arrangements to stay with them where possible.


What can communities do if they are prone to wildfire smoke events?
Communities that are likely to experience regular wildfire smoke events can plan and prepare for these events by:
• Identifying susceptible populations in the community;
• Identifying and existing community clean air shelters, or equipping buildings to be CAS;
• Creating home clean air shelters, particularly for susceptible populations;
• Creating community messaging to ensure that community members are well-informed of air quality and measures that they can take; and
• Developing an approach to managing outdoor events.

You can monitor general air quality conditions at: 

BC Air Quality Health Index:

Western Canada Smoke Forecast:

For more information, contact:

1) For general information about smoke contact HealthLink BC available toll free, 24 hours a day, 7 days a week at 8-1-1, or via the web at: 
2) Your local Environmental Public Health Office 


Adapted from: Alberta Health Services: Wildfire Smoke and Your Health

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