We need a clear understanding of the EPA's Air Quality Index or AQI. Wildfires may not be at the door, but the smoke can sail thousands of miles, contaminating your air. You will want to get into action and this post guides you on what to look out for and when to start your wildfire smoke precautions.

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Wildfires may not knock on your door, but their far-reaching smoke can sail thousands of miles, contaminating the very air you breathe. This summer, an airborne invasion occurred, as smoke from Canada’s wildfires drifted into US cities across the East Coast, Northern Plains, and Midwest. In some areas, the air’s particulate matter rocketed to 100 times the safe limit. At the pinnacle of this pollution in June, New York City found itself gasping under the second-worst air quality in the world—an alarming Air Quality Index (AQI) of 405. Regardless of where we live, we all need a clear understanding of AQI and how it relates to airborne pollutants.


The AQI is an environmental communication tool that reports on common air pollutants, including ozone and particulate matter, and delivers crucial information about the potential health effects of breathing polluted air. Crafted by the Environmental Protection Agency (EPA), the AQI operates on a 0-500 scale. Higher values spell higher pollution levels and greater health concerns. An AQI value of 100 usually corresponds with the National Ambient Air Quality Standard’s daily limit. Values at or below 100 are generally deemed satisfactory. However, when AQI values soar above 100, air quality starts to become a concern for everyone—first for sensitive groups and then for the wider population.

The AQI is vital as it offers a public-facing illustration of the air quality and potential health implications. It becomes particularly relevant for sensitive groups such as children, older adults, and individuals with heart or lung diseases. High AQI levels often necessitate limiting outdoor activities, especially for these sensitive groups. In extreme cases, staying indoors and maintaining a clean room can help reduce exposure to pollutants.

Comparing AQI levels to smoking cigarettes isn’t a direct comparison due to different pollutant types. But a study by Berkeley Earth presents an intriguing equivalence—an AQI of 22 is akin to smoking one cigarette a day.

Your go-to resources for checking aqi

There are several resources available for checking the AQI.

  • An all-in-one source for air quality data. It showcases local air quality and offers extensive information about pollution levels.
  • AirVisual: A comprehensive AQI app for Android and iOS that lets you see quality levels and tracks pollution in 80 countries and over 10,000 cities.
  • IQAir AirVisual App: A trusted air quality app providing comprehensive air quality data.
  • BreezoMeter: This app offers real-time air quality information, enabling you to instantly check the pollution levels in your area.
  • EPA’s Outdoor Air Quality Data: A resource from the U.S. Environmental Protection Agency that offers data collected at outdoor monitors across the U.S.


AQI advisories serve to help individuals minimize their exposure to air pollution, particularly during high pollution periods. At high enough concentrations, microscopic airborne chemicals or smoke pollutants can enter our nose or mouth while we breathe. Once these particles enter the lungs where they can access the bloodstream and travel throughout the body.   

To understand this, think of it as:

Dose = ambient concentration (µg/m3) X volume of air breathed per minute (m3/min) X duration of exposure (min)

The inhaled “dose” of pollution depends on three factors: ambient pollution concentration, breathing rate, and exposure duration.

The AQI is divided into six categories, each corresponding to a different level of health concern and each having a specific color. Here's a description of each category: Green (Good): AQI values from 0 to 50. The air quality is satisfactory, and air pollution poses little or no risk. Yellow (Moderate): AQI values from 51 to 100. The air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution. Orange (Unhealthy for Sensitive Groups): AQI values from 101 to 150. Members of sensitive groups may experience health effects. The general public is less likely to be affected. Red (Unhealthy): AQI values from 151 to 200. Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects. Purple (Very Unhealthy): AQI values from 201 to 300. Health alert: The risk of health effects is increased for everyone. Maroon (Hazardous): AQI values from 301 and higher. Health warning of emergency conditions: everyone is more likely to be affected.
Image 1: Air Quality Index ranges from 0 to 100 and has six levels.

Ambient concentration refers to the contaminants in the air. Minute ventilation is how many breaths someone takes in 60 seconds. Whereas duration exposure is the amount of time spent in the presence of that specific air pollutant. By diminishing any of these three factors, you can lower your inhaled pollution dose. AQI advisories direct the public on how to achieve this, recommending less strenuous activities to lower breathing rates or advising limiting outdoor time during periods of high pollution.


Inhaling high pollutant levels can inflict both immediate and long-term health impacts. Short-term effects may manifest as eye, nose, and throat irritation, coughing, shortness of breath, and chest pain. Long-term effects include an elevated risk of chronic respiratory diseases, heart disease, and lung cancer, especially for individuals with pre-existing conditions and those exposed to high pollution levels over prolonged periods.

Keep in mind that reactions to air pollution can fluctuate based on factors such as age, health status, and exposure duration. Always heed local air quality reports and health advisories, especially during events like wildfires that can severely impact air quality.


Remember, AQI ranges from 0 to 500. Higher values correspond to higher air pollution levels and a greater health concern. Focus on limiting the amount of polluted air you breathe.

Wildfire smoke can wreak havoc on air quality due to the presence of smoke and fine particles. You will want to jump into action by ensuring you have a safe space to breathe clean air. This will include filtering the air and ventilating your space.. According to CDC wearing N95 masks when the AQI surpasses 100—an indication of unhealthy air quality. N95 masks can filter out 95% of airborne particles, including small particles prevalent in wildfire smoke. They are particularly recommended for vulnerable groups—children, the elderly, and individuals with pre-existing respiratory conditions—who are at a higher risk from smoke exposure. With an AQI of 151, even the most resilient among us may start feeling the effects, emphasizing the importance of N95 masks at these pollution levels. In cases where Volatile Organic Compound levels are high, respirators designed for filtration of VOCs may be necessary. 

Always stay informed about your local air quality, especially during wildfire events or other situations that could impact air quality. The air you breathe directly affects your health, performance, and quality of life. Equip yourself with knowledge, breathe cleaner, and strive for a healthier existence. Stay with us as we uncover more IAQ tips and tricks.



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This one page summary of our AQI post is a PDF with clickable links.


Our AQI chart is available for download and prints best on 8x10 paper.


A smaller version of our AQI chart perfect for Twitter posts.This image is 1600x900 pixels.

Wildfire Precautions

Prepare for wildfire season with us. We have an entire page dedicated to resources to help you avoid breathing in the smoke from these fires.


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