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A Climate Change with Matt Matern
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Staying Safe From Air Pollution: What Is an Air Quality Alert?

air quality alert

According to one study, 73% of Americans are aware that air pollution from fossil fuels poses a direct threat to human health. Yet, only 55% can name one specific condition that this issue causes. 

The reality is that polluted air can catalyze a range of health concerns, including breathing difficulties and a heightened risk of respiratory infections. Sustained exposure can lead to lung cancer, heart disease, and chronic respiratory diseases, among other conditions. 

Education and awareness can help you stay safe. State and local agencies monitor the Air Quality Index (AQI) around the clock, issuing an Air Quality Alert when the AQI exceeds safe levels. 

Knowing how to read and respond to these alerts is critical to protecting your health. Today, we’re sharing what they mean and why they’re important. 

What Is the Air Quality Index?

The  U.S. Environmental Protection Agency (EPA) first created a national index for air quality back in 1976. The goal was to create a report that local agencies could update every day, following a format that’s consistent from one state to the next. 

To streamline efforts, the EPA created the AQI in 1999. The values on this index run from 0 to 500.

When they’re high, this means there’s a greater amount of ozone and particle pollution in the outdoor air. It also means health concerns are more significant. 

In general, AQI values under 100 are considered satisfactory. When they creep above this threshold, the air quality is deemed unhealthy. Levels right at or above 100 are most concerning for sensitive groups of people, such as the elderly.

At levels above 150, the air quality is unsafe for everyone. 

air quality indexAQI Categories 

There are six categories in the AQI, and each one corresponds to a specific level of concern. Local agencies update their AQI color daily depending on nearby conditions. Let’s take a look at the categories. 

Green: AQI 0 to 50

When the AQI is green, the level of concern is Good. This means that the air quality is satisfactory and pollutants do not pose a significant risk. 

Yellow: AQI 51 to 100

A yellow AQI means the level of concern is Moderate. The air quality is generally acceptable, but certain people may be at risk. This includes anyone who’s unusually sensitive to air pollution. 

Orange: AQI 101 to 150

If the AQI is orange, the level of concern is Unhealthy for Sensitive Groups. While the general public isn’t likely to be affected, sensitive groups may experience health effects. This includes anyone with heart or lung disease, as well as older adults, children, and teenagers.

Red: AQI 151 to 200

A red AQI means the level of concern is Unhealthy. There are some members of the general public who may experience health effects, and these effects could be more severe for members of sensitive groups. 

Purple: AQI 201 to 300

When the AQI is purple, the level of concern is Very Unhealthy. At this point, agencies will issue an official Health Alert. Everyone is susceptible to increased health effects. 

Maroon: ACI 301 and Higher

A Maroon AQI means the level of concern is Hazardous. There will be a Health Warning that details emergency conditions. Everyone is at risk of being affected. 

AQI Color Coding

Why are AQI levels color-coded? This makes it easy for residents to quickly understand the air quality in their local area. This way, they can make informed decisions on when to go out, and how to stay protected. 

The AQI expands upon the basic traffic light protocols we’ve all known since childhood. Green means go, yellow means slow down, and red means stop. 

How to Use the AQI

Air quality is different all around the world. When you check the AQI for your local area, you learn valuable information, including:

  • Which level the air quality is at today
  • Which groups of people may be affected
  • Steps you can take to limit your exposure to air pollution 

In addition, reporters also use the AQI as a basis for air quality forecasts. Any metro area within the U.S. that has a population of more than 350,000 is required to share a daily AQI report. However, there are many smaller areas that choose to voluntarily share the report as a public service. 

Places you can find the daily AQI for your area include:

  • On the EPA’s designated air quality website “Air Now”
  • On your state and local agency websites 
  • Via smartphone alerts

In all, more than 4,000 monitoring stations across the country report daily on air quality levels. In addition to checking the AQI, it’s also helpful to review other environmental resources that explain what’s going on with the world and how to stay safe.  

What Are the Major Pollutants?

Under the Clean Air Act, the EPA is required to set National Ambient Air Quality Standards (NAAQS) for five major air pollutants. Found all over the U.S., these pollutants pose a risk to human health, property and the environment. 

They include: 

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

Air quality levels are determined by assessing both ground-level ozone levels and particle pollution. Let’s review how these differ.

Ground-Level Ozone

Also called tropospheric ozone, ground-level ozone doesn’t emit directly into the air. Rather, it’s created when chemical reactions occur between volatile organic compounds (VOC) and oxides of nitrogen (NOx). Common contributors include cars, industrial boilers, and power plants.

When these entities release pollutants in the presence of sunlight, it can trigger a chemical reaction. Breathing in ground-level ozone can cause chest pain, congestion, and throat irritation. It can also exacerbate respiratory conditions and reduce lung function. 

Particulate Matter

Particulate matter includes a range of industrial and automotive emissions, such as cigarette smoke and fossil fuel combustion. It also occurs when organic matter burns, which explains why air quality suffers in the event of a wildfire. 

These particles can be solid or liquid, and their size ranges significantly. Some are so small they can only be detected by an electron microscope. Others, such as dirt, soot, or smoke, are larger and darker. 

When inhaled, they can cause serious health problems, traveling deep into your lungs and even into your bloodstream. 

What Is an Air Quality Alert?

When AQI levels reach a certain threshold, local air pollution control agencies may issue an Air Quality Alert. This occurs when an area’s AQI reaches an unhealthy range.

The EPA calls these “Action Days” and each agency can decide when to announce them.

Many agencies will call an Action Day when the AQI reaches Code Orange (Unhealthy for Sensitive Groups) or above. This means that anyone who’s sensitive to air pollution should reduce their exposure to outdoor air and limit heavy exertion outdoors.

Sometimes, agencies will declare an Action Day when the AQI is Code Yellow (Moderate). This is especially the case if they suspect that the level will soon reach Code Orange levels. The more proactive and informative an agency can be, the earlier local residents can take protective action.  

Almost all agencies will issue an Air Quality Alert when the AQI is forecasted to be Code Red (Unhealthy). When pollutant levels are this high, everyone should limit their time outdoors. 

What to Do When You Receive an Air Quality Alert

Did you receive an Air Quality Alert when you woke up this morning? If your local area is experiencing moderate to high levels of air pollution, here are a few steps you can take to minimize and control your exposure.

Stay Indoors

Naturally, the best way to respond to an Air Quality Alert is to simply stay indoors as much as you can while pollutant levels are elevated. Keep your windows closed and your exterior doors shut. Opening them for even a brief period of time can bring polluted air into your home. 

Avoid Exercising Outdoors

If possible, try to keep your workout indoors. If you need to take it outside, try to schedule it strategically.

Avoid exercising outdoors during certain times of day when pollution levels are highest, such as during rush hour. It’s also helpful to work out in green spaces, such as parks, rather than beside busy city streets.

When ozone levels are up, conditions will be worse in the afternoon and early evening. Try to exercise in the morning when they’re at their lowest point. 

Turn on the Air Conditioning

Whether you’re at home or traveling in your car, turn on the air conditioning. When you’re driving, make sure the AC is set to recirculate so it won’t draw in the outside air. 

Wear a Mask

If you can’t avoid being outside when the air quality in your area reaches an unhealthy level, you need to wear a mask that covers your nose and mouth. An N95 mask will offer the most thorough protection. This covering will keep dangerous air particulates from entering your airways. 

Learn More About Air Pollution Today

The more you know about air pollution, including how to respond to an Air Quality Alert, the safer you can be. On our show, we seek to educate the general public about issues that affect the environment, giving listeners actionable tools they can use to respond. 

Air pollution won’t go away overnight, but we can all do our part to lessen the emissions we put out into the world. To learn how you can lower your carbon output and help reverse the effects of climate change, be sure to subscribe to our podcast.

You can find us on Apple Podcasts, Spotify, and iHeart Radio. Check out our latest episodes today to catch up and get started!


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