Air Quality Index (AQI): What it Means for You

More than one in 13 people in the United States, or 25 million Americans, suffer from asthma. Even if you don't suffer from this debilitating respiratory condition, it's still important to monitor the quality of the air around you.

Thanks to the Air Quality Index (AQI), you have immediate access to that information. Yet, it can be easy to confuse what the AQI means and how to apply it to your daily life.

Today, we're explaining how to break down the ACI by component, so you can better understand its importance and use it as the decision-guiding tool it was meant to be. Ready to learn more? Let's get started.

What is the Air Quality Index?

In 1970, Congress designed and issued the Clean Air Act. Since its inception, the goal of this act has been to spread information and awareness about different forms of pollution and their effect on public health and welfare.

Under this act, the Environmental Protection Agency (EPA) was required to create a nationally-uniform AQI that accurately reported on the current state of the country's air quality. In 1976, the EPA created the index, then known as the Pollutant Standards Index.

Now, the AQI is a go-to resource for those seeking more information about the air in their local community and beyond. These reports reveal the level of pollutants in the air, along with any associated health effects you should be aware of over the next few days.

Measured Pollutants

Though there are many different chemicals that comprise air pollution, the Clean Air Act requires that the EPA categorize them into five groups, measuring a separate AQI for each one. The groups include:

  • Ground-level ozone
  • Particle pollution (or particulate matter)
  • Carbon monoxide
  • Nitrogen dioxide
  • Sulfur dioxide

Of these groups, the first two (ground-level ozone and airborne particles) pose the greatest threat to human health in the United States.

Understanding the AQI Scale

When you hear the numbers associated with the AQI, does your head start to spin? Is a higher number better or worse than a lower one and what do the figures even mean in the first place?

Let's take a look.

The AQI runs from 0 to 500. Higher numbers denote a higher percentage of air pollution while lower numbers signify the opposite. The same holds true for health concerns. An AQI of 50 poses a greater health risk than an AQI of 300.

In most cases, the national air quality standard for each pollutant group is set at an AQI value of 100. This means that values below 100 are satisfactory while those above 100 are considered unhealthy.

The only discrepancy to keep in mind? Values close to 100 might only pose a threat to certain people with respiratory sensitivities. However, the higher the number moves away from 100, the greater the health risk posed to the general population.

The Correlation Between Air Quality and Your Health

A report full of numbers is one thing, but what do these findings really mean? Specifically, what impact do they have on your health?

Understanding how to analyze and interpret the AQI starts with knowing what each part of it means. The index features six main categories that dictate the level of health concern associated with each AQI value.

The categories are as follows:

AQI Range: 0 to 50

This range means that the air quality is good, or satisfactory. It poses minimal or no risk and there are no health impacts anticipated.

AQI Range: 51 to 100

This range means that the air quality is moderate and acceptable.

However, there might be slightly heightened levels of some pollutants that can aggravate health concerns for a small population. For instance, people with ozone sensitivities might notice respiratory symptoms. These people should avoid prolonged periods of outdoor exertion.

AQI Range: 101 to 150

This range means that the air quality is unhealthy for sensitive groups. While most of the general public won't feel any negative effects, certain people with pre-existing respiratory conditions could be affected.

Specifically, the presence of ozone or other particles in the air could bother individuals with lung disease, senior adults and children. These people should avoid prolonged periods of outdoor exertion.

AQI Range: 151 to 200

This range means that the air quality is unhealthy. All population groups could experience negative health effects due to exposure. At the same time, members of more sensitive groups are at a greater risk of experiencing serious effects.

While at-risk populations should avoid prolonged periods of outdoor exertion, everyone else should limit their time outdoors.

AQI Range: 201 to 300

This range means that the air quality is very unhealthy for all groups. If the AQI reaches this range, the Centers for Disease Control and Prevention (CDC) will issue a public health alert issued to help inform the population about the serious health effects that could follow.

At-risk populations should avoid outdoor exertion altogether. Everyone else should limit their time outdoors.

AQI Range: 301 to 500

This range means that the air quality is hazardous. If the AQI reaches this range, the CDC will issue an emergency alert notifying the public about the health warning. To the greatest extent possible, everyone should avoid outdoor exertion.

Note that if the AQI range exceeds 500, you should follow all of the recommendations listed for hazardous air quality conditions. A range this high means that there is a dangerous level of microscopic particulate matter (PM) in the atmosphere with a diameter of fewer than 2.5 micrometers (PM2.5).

A few of the steps you can take to reduce your exposure during this time include:

  • Stay indoors in a room with filtered air
  • Purchase an air cleaner if you live in an area with a high PM2.5 concentration
  • Reduce your activity levels
  • Avoid burning anything indoors (fires, candles, gas logs)
  • Don't vacuum unless necessary
  • Don't smoke
  • Ensure your HVAC system is up to par and isn't spreading harmful particulates or disrupting humidity levels

Understanding AQI Color Codes

In addition to numbers, you'll also find colors on the AQI. However, these colors aren't merely aesthetic additions to the index. Rather, each shade signifies a different AQI range and its associated health concern (if any).

The EPA assigned a color to each AQI category to make it easier for the general public to understand and use the tool. This way, there's no calculation or analysis involved. They can simply look at the chart and know in seconds whether the air quality in their region is about to reach an unhealthy level!

Next, let's review what each color means and which category it correlates to.

  • Green: AQI range of 0 to 50, good air quality
  • Yellow: AQI range of 51 to 100, moderate air quality
  • Orange: AQI range of 101 to 150, air quality is unsafe for sensitive groups
  • Red: AQI range of 151 to 200, unhealthy air quality
  • Purple: AQI range of 201 to 300, very unhealthy air quality
  • Maroon: AQI range of 301 to 500, hazardous air quality

Where Can I Find Information on the Air Quality Near Me?

Naturally, the air quality in one location will vary from the air quality in another location. As such, it's important to know where to look when you want specific information localized for your region.

Thankfully, the Natural Weather Service (NWS) makes this step a cinch.

When you visit the NWS home page and enter your zip code on the lefthand menu, you'll notice a link that reads "Local Air Quality." When you click it, you'll find up-to-date information on the air quality forecasts in your area, including a link to your Air Quality Index Statement from the NWS.

This report will break your region up by area, listing the following details for each one:

  • AQI number
  • Color code
  • Primary pollutant
  • Significance and steps to take

Especially if you're a member of an at-risk population, it's important to check this forecast on a regular basis. This way, you know what to expect and you can take steps to proactively safeguard yourself from relevant health concerns.

Improve the Air Quality in Your Home

You might not be able to control the Air Quality Index or constantly monitor the air outside of your front door. However, there are many steps you can take to breath more easily at home.

It all starts with making sure your HVAC system is in top condition.

A well-designed system doesn't just deliver hot or cold air to keep you comfortable. It also works hard to filter pollutants from the outside air before it heats and cools your spaces. At the same time, it helps your home maintain a steady temperature to keep indoor air as fresh and clean as possible.

In need of a new HVAC system or a repair on your existing unit? That's where we come in.

Our team of reliable and experienced HVAC technicians is ready to provide a full range of HVAC support, from initial installation to ongoing maintenance. Contact us today and make your home the safe haven it's meant to be.

Give our team a call for the most dependable HVAC repairs in your area.

Let us keep your system humming throughout the seasons! Call the number below to schedule a service with one of our experienced HVAC technicians. If you don't have time to call us now, and would like to send us a message, fill in the contact form here.

(512) 284-3412

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