Air Quality and Asthma: Protecting Yourself in the City and During Wildfires

Visit Quebec summers have changed. Urban smog, smoke from wildfires, heat waves : Air quality has become a recurring public health issue, particularly for people living with a chronic respiratory disease [1][2]. Understanding the Air Quality Index (CAS) and to know adapt its activities makes a real difference. This article explains the index, its effects on asthma and COPD, best practices during episodes of air pollution, the importance of an action plan, and resources available in Quebec.

On this page

• The Air Quality Index (CAS)
• Effects on Asthma and COPD
• What to Do When Pollution Levels Are High
• Have an asthma action plan
• Particularly Vulnerable Individuals
• Indoor air quality matters, too
• Special Case: Smoke from Forest Fires
• Myths and Misconceptions
• Frequently asked questions
• Sources

The Air Quality Index (CAS)

Visit Air Quality Rating is a Canadian index on a scale from 1 to 10+ that combines the concentrations of several pollutants: PM2.5 fine particulate matter, ozone (O₃) and nitrogen dioxide (NO₂) [1]. The higher the index, the more the health risk is increasing, especially among vulnerable groups.

Levels and Recommendations

• 1 to 3 — Low risk : normal activities
• 4 to 6 — Moderate risk : Reduce or adjust activities if symptoms occur
• 7 to 10 — High risk : Reduce the burden on vulnerable groups when they are outside
• 10+ — Very high risk : Avoid prolonged physical exertion for everyone
• Visit CAS is updated several times a day by Environment and Climate Change Canada
• It is available online, in weather reports, and through several mobile apps

Key Takeaways

• Visit Air Quality Rating is a simple tool to consult before outdoor activities [1]
• Visit fine particulate matter (PM2.5) are primarily responsible for the effects of wildfire smoke
• L’ozone is higher in the afternoon on hot, sunny days
• People with asthma, COPD, heart disease, children, pregnant women, and the elderly are the most vulnerable
• A asthma action plan A written plan, developed with their doctor, is essential for managing flare-ups
• L’indoor air Also includes: HEPA filters, ventilation, and air conditioning
• In the event of heavy smoke, a N95 mask A well-fitting one is useful, even for healthy adults

Effects on Asthma and COPD

Visit pollutants in the air have a direct effect on the respiratory tract. The fine particles penetrate deep into the bronchi and can trigger inflammation, bronchospasm and acute exacerbation [3].

What Happens in the Bronchi

• Visit PM2.5 and finer particles (PM1) pass through the airways' defenses
• They reach the lung alveoli, or even blood circulation
• They trigger a inflammatory response local and systemic
• Spasm the smooth muscles of the bronchi (bronchospasm)
• Overproduction mucus, cough, chest tightness
• Worsening of the’asthma, chronic bronchitis, emphysema
• Cardiovascular effects are also possible (arrhythmias, heart attacks, strokes)

What We're Seeing in Quebec

• Increase emergency room visits and hospitalizations in the days following pollution peaks or episodes of smoke from wildfires [2]
• Increase in visits for acute asthma, especially in children and young adults
• Decompensations cardiac and respiratory problems in older adults
• Delay from a few hours to several days between the peak of pollution and the onset of clinical symptoms
• Cumulative effects in the event of repeated occurrences (summer 2023, for example)

Symptoms That Should Raise a Red Flag

• Shortness of breath more pronounced than usual
• Cough dry or productive, and becoming more intense
• Chest tightness, wheezing
• Need more common emergency bronchodilator
• Alarm Clocks nighttime episodes associated with respiratory symptoms
• Decrease tolerance to the usual level of exertion
• Headaches, fatigue, burning sensation in the eyes and throat
• All worsening A patient who no longer responds to standard medications should seek medical attention

What to Do When Pollution Levels Are High

A few simple habits help to reduce exposure and to protect the respiratory tract on tough days.

Monitor and Anticipate

• View Environment Canada's Air Quality Index every morning
• ’S’"subscribe email or app alerts
• Take into account Forest Fire Smoke Forecasts (Natural Resources Canada, MELCCFP)
• Anticipate outings (sports, gardening) depending on the forecast
• Plan alternative indoor activities

At home

• Close windows during a severe episode
• Air conditioning if possible, with an appropriate filter (central air conditioning set to recirculation mode, when properly filtered, can help)
• Use a HEPA filter or an air purification unit in the bedroom and main rooms
• Avoid lighting a candle, a fireplace, or an outdoor fire, or smoking indoors during episodes
• Ventilate briefly during breaks in the clouds, referring to the CAS
• Limit activities internal physiological responses that increase breathing when indoor air quality is poor

Outside

• Limit physical activity outdoors, especially in the afternoon (when ozone levels peak)
• Prioritize in the early morning hours, if the tide is lower
• Avoid high-traffic roadways
• Choose parks and green spaces rather than busy streets
• To have one's emergency inhaler within easy reach
• N95 Mask Worn properly during periods of heavy smoke (also useful for healthy adults)
• Drink enough’water, without, however, believing that it «cleanses» the respiratory tract (a common misconception)
• Monitor Children: They don't always mention when they're short of breath

At work

• Visit outdoor workers are among those most at risk (construction, agriculture, gardening, delivery)
• Visit employers must adjust work arrangements based on specific situations (LSST, CNESST)
• Adapter schedules, pace, protective equipment depending on the rating
• Raise awareness teams responding to warning signals
• Plan for a procedure if you experience respiratory symptoms at work

Have an asthma action plan

A asthma action plan a document, prepared in consultation with his doctor, is the go-to tool to manage the disease and its flare-ups [4]. It reduced significantly reduce hospitalizations and emergency room visits.

What Makes a Good Deal

• Which medications Take daily (inhaled corticosteroid, combined bronchodilator if needed)
• When increase Doses in the event of warning signs (yellow zone)
• When to use the rescue bronchodilator
• When view at a clinic or in the emergency room (red zone)
• How recognize signs of worsening symptoms (shortness of breath, wheezing, nighttime cough, decreased peak expiratory flow rate if a peak flow meter is used)
• What to Do in the Event of a’exhibition a trigger (smoke, pollen, a viral infection, intense exercise)
• The plan is custom and reviewed periodically

The Three Zones (Traffic Light Model)

Zone	Signs	Action
Green (controlled asthma)	Few or no symptoms, normal sleep, normal activities	Continue the basic treatment
Yellow (alert)	New or more frequent symptoms, increased need for medical assistance, disturbed sleep	Increase the dosage as planned; consult a doctor if necessary
Red (emergency)	Severe shortness of breath, ineffective first aid, bluish lips, slurred speech	Call 911 or go to the emergency room

For COPD

• A COPD Action Plan There is also one based on the same principle
• Identify the exacerbations early (increased sputum production, change in color, marked shortness of breath)
• Plan for a antibiotic therapy and a oral corticosteroid at home in certain cases (prescription «emergency plan»)
• Importance of the maintenance flu, pneumococcal, and COVID-19 vaccinations
• Visit smoking cessation remains the most effective treatment
• Visit pulmonary rehabilitation improves quality of life and exercise tolerance

Do you have asthma or COPD and don't have a written action plan? Omicron Clinic offers asthma and COPD management, prescribes action plans, and provides evaluations during exacerbations at our locations in Quebec, with teleconsultations available for treatment reviews. Make an appointment or opt for the teleconsultation.

Particularly Vulnerable Individuals

Groups at Increased Risk

• People with asthma, COPD, pulmonary fibrosis, bronchiectasis
• People with heart disease (angina, heart failure, history of heart attack, arrhythmias)
• Pregnant women (increased risk of obstetric complications with high levels of exposure)
• Children (developing respiratory system, increased breaths per minute, outdoor play)
• Older Adults (often multiple chronic conditions)
• Outdoor Workers (extended exhibition)
• People living in poverty or in poorly ventilated housing
• People with diabetes or obesity, who are more susceptible to cardiovascular effects

Recommended Additional Measures

• Limit more outdoor activities during episodes
• To have a action plan up-to-date, shared with the family
• Check the emergency inhaler, its expiration date, and how to use it correctly
• Anticipate the need to renew a prescription before a vacation or a trip
• Make sure to have an air-conditioned or cooled room during heat waves
• Identifier the nearest emergency room or clinic in advance
• Useful Phone Numbers Save this information: Info-Santé 811, option 1; emergency: 911

Indoor air quality matters, too

On average, we spend 80 to 90 % of his time inside. The indoor air quality has a significant impact on respiratory health and either amplifies or mitigates the effects of outdoor pollution.

The Main Enemies at Home

• Smoke Tobacco and Vaping
• Fireplaces wood-burning stoves and poorly ventilated appliances
• Candles, incense, scented sprays
• Products strong-smelling household products (aerosols, sprays, bleach)
• Mold and excessive humidity (above 50 %)
• Mites dust and pet dander
• Vapors of paintings, varnishes, adhesives
• Cooking without a proper range hood (especially when using gas)

Good Habits at Home

• Ventilate on a regular basis, except in the event of a critical external situation
• Use a range hood that vents to the outside
• Maintain a humidity level between 30 and 50 %
• Clean air conditioning and ventilation filters
• Use a HEPA filter in the most frequently used rooms
• Avoid smoking or vaping indoors
• Minimize scented products and harsh chemicals
• Limit rug and heavy fabrics in the bedroom of people with allergies
• Detector Mandatory carbon monoxide detectors in Quebec for various residential settings

Special Case: Smoke from Forest Fires

Since the’Summer 2023, Quebec has experienced episodes of thick smoke related to forest fires that are sometimes far away. These situations require specific reflexes [2].

What Makes Smoke from Fires Particularly Harmful

• Very high concentration in PM2.5 and PM1
• Presence of volatile organic compounds (VOCs)
• Carbon monoxide in areas very close to traffic lights
• Effects high notes in the respiratory tract within a few hours
• Possible persistence several days, sometimes several weeks
• Cardiovascular Effects documented
• Health Effects mental (anxiety, stress, sleep disorders)

Specific Measures to Be Taken

• Limit limit outdoor activities as much as possible during the episode
• Create a «clean room» At home: a room with closed windows and a HEPA filter
• Use a N95 mask Perfectly suited for essential outings
• Visit surgical masks and cloth masks are not very effective against PM2.5
• Check local resources (evacuation procedures, shelters with filtered air)
• Monitor especially young children, pregnant women, and the elderly
• Anticipate prescription refills before the scheduled appointment
• Take into account fatigue and stress related to the situation

Myths and Misconceptions

«Drinking plenty of water cleanses the lungs.»

False. Hydration is beneficial for many reasons, but it does not «wash out» the respiratory tract. Protecting the lungs involves reduction in exposure, medication management, and a healthy indoor environment.

«A cloth mask is enough to protect against smoke»

False. Cloth or surgical masks only partially block fine particles. For forest fire smoke and heavy smog, a a well-fitting N95 mask is more effective. A proper fit (no leakage from the sides) is essential.

«Air conditioning spreads pollution»

Not necessarily. In mode recirculation, With a good filter, air conditioning helps protect indoor air quality. Without a proper filter—or when set to draw in outside air—it can actually bring pollution into the home. The key is the quality of the filter and the operating mode used.

«Intense exercise “cleanses” the lungs»

False and risky. During an episode of air pollution, intense exercise increases ventilation and’inhalation of pollutants. This can trigger flare-ups, especially in people with asthma. It is best to postpone or move the activity indoors to a healthy environment.

«My asthma is under control; I don't need an action plan.»

False. Even well-controlled asthma can to lose control quickly during a major pollution episode, a viral infection, or a specific exposure. The written action plan exists precisely for those moments when it’s harder to react instinctively.

Frequently asked questions

How often should you check the Air Quality Index?

Daily during high-risk seasons (summer smog, episodes of smoke from wildfires), especially in the morning before outdoor activities and in the afternoon (when ozone levels peak). Several mobile apps and weather reports include the index. The vulnerable people can enable automatic notifications.

Should children stay indoors during a storm?

If the score is high (7 or higher) or very high (10+), then yes: reduce or avoid outdoor activities, especially vigorous play that increases breathing rate. Children with asthma are particularly at risk. Schools and daycare centers generally adapt their activities in accordance with official advisories and guidelines from the MSSS.

Do you need to wear an N95 mask every time you go out?

No. The N95 is useful during periods of heavy smoke or very high pollution levels, especially for vulnerable individuals and during extended outings. For short walks at a moderate pace, it is not essential. A proper fit is more important than wearing it all the time.

Which air purifiers should you choose?

Prioritize the HEPA units, sized appropriately for the room's square footage. Check the «CADR» (Clean Air Delivery Rate) and the filter replacement schedule. Avoid filterless units (ionizers, ozone generators), as some may produce irritants. A single air purifier, properly placed in the bedroom, is often better than several that are poorly maintained.

Is it safe to exercise indoors during wildfire smoke?

Yes, provided that indoor air quality is maintained (windows closed, air conditioning with a good filter or HEPA purifier). Well-ventilated sports centers and swimming pools are often a good alternative to outdoor activities during such episodes. Adjust the intensity if symptoms appear.

When Should You Go to the Emergency Room?

As soon as severe shortness of breath no longer responds to the rescue bronchodilator, or if the person has bluish lips, slurred speech, unusual drowsiness, or chest pain. If in doubt, call 911 or go to the emergency room. Call 811, option 1 (Info-Santé) for help in quickly assessing the situation.

Sources

1. Environment and Climate Change Canada. Air Quality Index (CAS) and Adaptation Tips.
2. Health Canada. Air Quality, Wildfire Smoke, and Health.
3. INSPQ — Quebec National Institute of Public Health. Air Pollution and Respiratory Health in Quebec.
4. Asthma Canada. Asthma Action Plans and Management.
5. Quebec Lung Association. Asthma, COPD, and Air Quality.
6. Ministry of the Environment, Climate Change, Wildlife, and Parks. Air Quality Monitoring in Quebec.
7. Canadian Paediatric Society. Effects of Air Pollution on Children.

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