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Healthy Lifestyle

How air quality affects lung health and what you can do

Multiracial adults practicing yoga outside.

06/23/2025

Breathing in polluted air can affect your lungs and overall respiratory health. Here’s how to protect yourself and your family on days with poor air quality.

By Amy Ahasic, MD, Chief of Pulmonary and Critical Care Medicine at Norwalk Hospital, part of Northwell Health

If you’ve ever had a cough that won't quit, found it harder to breathe on humid days or noticed a change in how things smell or taste, air quality might be to blame. Poor air quality can impact people of all ages, especially those with asthma, allergies or other respiratory conditions.

Air quality matters more than ever. Recently, Canadian wildfires have sent waves of smoke into the U.S., creating hazy skies and triggering air quality alerts in Connecticut, New York and beyond. On the flip side, frequent rainstorms can help clean the air temporarily. Humidity also plays a role, sometimes trapping pollutants close to the ground.

Let’s break down what all this means for your lungs and overall health.

What is the air quality index?

The air quality index (AQI) is a scale that tells you how clean or polluted the air is. It ranges from 0 to 500, with higher numbers indicating worse air quality. The U.S. Environmental Protection Agency (EPA) uses this scale to report daily air quality.

0–50: Good — Air quality is considered satisfactory.

51–100: Moderate — Air quality is acceptable but may affect people who are unusually sensitive to air pollution.

101–150: Unhealthy for sensitive groups — Older adults, young children and those with lung disease should limit time outdoors.

151–200: Unhealthy — Everyone may begin to experience health effects; sensitive groups could experience more serious effects.

201–300: Very unhealthy — Health alert: Everyone may experience more serious effects.

301–500: Hazardous — Health warnings of emergency conditions.

You can check your local AQI at AirNow.gov.

What level of air quality is harmful?

Air quality becomes a concern when the AQI goes above 100. While a few hours of exposure may not cause harm to healthy individuals, those with existing respiratory issues should limit outdoor activity. Long-term or repeated exposure — even to moderate AQI levels — can cause damage over time.

Short-term exposure to poor air quality may lead to coughing or irritation, but long-term exposure is associated with an increased risk of respiratory and cardiovascular disease, according to the American Lung Association.

Does bad air quality affect your lungs?

Yes, polluted air can irritate and inflame your airways. Over time, this can impair lung function and exacerbate conditions like asthma or chronic obstructive pulmonary disease (COPD).

Chronic exposure to pollutants is linked to:

Decline in lung function: Breathing may become harder over time.

Development of asthma: Especially in children or at-risk populations.

Worsening of existing respiratory illnesses: May result in more frequent flare-ups or hospital visits.

Increased hospitalizations: Particularly during poor air quality events.

Why is the air quality worse on some days?

Several factors contribute to daily changes in air quality:

Weather patterns like stagnant air or inversions (when warm air traps cool air near the ground) can trap pollutants near the ground.

High traffic increases emissions from vehicles.

Industrial activity and fossil fuel use add airborne pollutants.

Wildfires can introduce massive amounts of smoke and fine particulate matter into the air. PM2.5 is particulate matter with a size of 2.5 micrometers or less; these particles are so small they can reach deep into the lungs when inhaled.

Seasonal allergens like pollen may also worsen air quality and respiratory symptoms.

Why do fires that are far away affect air quality near me?

Smoke from wildfires can travel hundreds or thousands of miles due to wind and atmospheric conditions. Even if you can’t see or smell smoke, microscopic particles (PM2.5) can be present in the air, which can penetrate deep into the lungs and even enter the bloodstream, increasing health risks. That’s why a wildfire in Canada can affect air quality in Connecticut and New York.

How does the weather affect the quality of the air?

Weather can impact air quality in the following ways:

Rain helps clear pollutants from the air, including clearing pollen off trees and plants, improving short-term air quality.

Humidity can trap pollutants and exacerbate respiratory symptoms. Humidity also commonly affects the subjective sense of air flow (“mugginess” or “stagnant” air), contributing to sensation of shortness of breath, particularly in patients with existing lung disease.

Temperature inversions can prevent pollutants from dispersing.

Even after heavy rain, a warm, humid day may cause pollutants to build up quickly.

How do you tell if air quality is affecting you?

Common symptoms of air quality issues include:

Coughing or wheezing, especially in people with asthma or COPD.

Shortness of breath after mild physical exertion.

Eye, nose or throat irritation, including redness, burning or itchiness.

Fatigue or headache.

Some people may also notice their allergies or sinus symptoms worsen on poor air quality days.

Need a doctor? Find a Nuvance Health Medical Practice provider near me.

Are you protected from bad air quality in your house or car if you have the air conditioner on?

At home

Air conditioners can help filter the air, especially if you use a HEPA (high efficiency particulate air) or MERV-13 filter. Keep windows closed and ensure your filters are clean. Air conditioners also help to control indoor humidity.

Portable air purifiers can also improve indoor air quality in bedrooms or high-use areas.

In your car

Set the system to “recirculate” air instead of pulling it in from outside. This minimizes exposure while driving through polluted areas.

What should you do if the air quality affects you?

You don’t need to stay inside all the time, but when the AQI is high:

Limit time outdoors, especially doing strenuous activities like running or yard work.

Stay indoors in well-ventilated, filtered spaces.

Use an N95 mask outdoors to filter fine particles if it’s comfortable for you. Some people with more severe lung disease may not tolerate wearing N95 masks.

Monitor symptoms. If you experience chest pain or difficulty breathing, call your doctor.

If you take medications for a lung disease, such as inhalers, check with your doctor on whether your medications may be part of your strategy to tolerate poor air quality days.

Short-term exposure on a bad air quality day is generally not dangerous for healthy people, especially if you’re taking steps to reduce exposure. But if you experience symptoms, it’s a sign to rest and seek fresher air.

How can you keep your lungs healthy to better handle poor air quality?

Keeping your lungs strong helps your body better handle environmental stressors:

Don’t smoke and avoid secondhand smoke or vaping.

Exercise indoors or in areas with clean air.

Keep vaccinations up to date; flu, COVID-19, RSV and pneumonia shots, all help prevent respiratory complications. Check with your doctor on whether you are eligible for vaccines.

Talk to your doctor if you have asthma, COPD or frequent respiratory infections.

Does poor air quality affect your taste and smell?

Yes, air pollution can impact your ability to detect odors and flavors. Research shows long-term exposure to fine particles (PM2.5) can damage the olfactory system, reducing your sense of smell and, by extension, taste. Small airborne particles can irritate and inflame the olfactory lining in your nose, making it harder to detect aromas from foods and the environment.

However, short-term exposure to moderate air pollution typically doesn’t cause permanent loss of smell or taste. If you experience temporary changes, they should resolve once the air quality improves. To protect your senses:

Check the AQI and limit exposure on days when PM2.5 is high.

Wear a well-fitted N95 mask outdoors during poor air quality days, if able.

Avoid heavy exercise or prolonged exposure until the air improves.

The bottom line: Poor air quality is becoming more common, but that doesn’t mean you have to stay inside all summer. Check the AQI, understand how your body reacts, and take steps to limit exposure on bad days. With the right habits, you can protect your respiratory health and keep doing the things you love safely.