Almost all living creatures on Earth breathe in some way, even trees and plants. While breathing is something all people have in common, unfortunately we don’t all breathe clean air. Human activity and some natural forces allow toxic materials into our atmosphere, which is the layer of gases that surrounds our planet. This air pollution can threaten our health and quality of life.
The U.S. Environmental Protection Agency (EPA) created a tool called the Air Quality Index (AQI) to inform the public of the level of air pollution and the risks it can pose to our health. Air quality can change very quickly, and the AQI allows people to stay on top of current air conditions in their area, just like the weather forecast.
Below, we’ll discuss how to use the AQI to understand air quality in your community and what you can do to keep you and your loved ones safe when the air quality is poor.
What is air quality?
The average human takes about 22,000 breaths every day, supplying our body with the oxygen it needs to function. Clean, oxygen-rich air is essential for our health, but the air around us can also contain harmful substances, called pollutants. Air quality refers to the level of pollutants in the air.
Good air quality means the air is relatively clean and there are few or no pollutants present that day.
Bad (or poor) air quality means the air contains one or several pollutants in amounts that are hazardous to our lungs and overall health.
What causes bad air quality?
Poor air quality is polluted air, and there are many sources that contribute to air pollution:
- Human industry: Our cities, agricultural areas, power plants, factories and oil refineries pump pollutants into the air in the form of smoke, soot and smog.
- Transportation: Cars, buses, airplanes, trains and any machine with a combustion engine put pollution into the air through the exhaust they produce.
- Nature: The smoke and microscopic matter from forest fires, dust storms and volcanic activity can pollute our air, while wind and geographic features – like valleys – determine where many pollutants end up.
Air quality is more of a concern during the summer months, when the combination of pollutants in the air and heat creates dangerous conditions that can negatively affect everyone’s health.
Who is most at risk from poor air quality?
Air pollution isn’t good for anyone, but it’s especially bad for the very young and very old, people with certain health conditions, and people who spend a lot of time outside. Those most at risk of experiencing negative health effects in bad air quality are considered “sensitive groups.” This category includes:
- People who have cardiovascular or lung disease, including asthma, COPD and lung cancer
- Adults aged 65 and older
- Children and teenagers
- Pregnant women
- People who frequently exercise outside
- People living in poverty
- People who smoke tobacco or who live with someone that does
- People who live and work close to major roadways or industrial areas
- People who work outside
For some of these groups, it’s not a current health condition that makes them more sensitive to poor air quality, but other ongoing factors that increase their level of risk in air pollution, as well as their vulnerability if they were to develop an illness.
What is the air quality index (AQI)?
In 1970, the EPA established the Clean Air Act, a set of laws that restricts and regulates the amount of pollutants allowed in the air in the United States. The Air Quality Index (AQI) was created soon after. The AQI notifies the public of the air quality around where they live and work, and empowers them to make assessments of the individual health risks involved in venturing outside that day.
The AQI measures the following five pollutants:
- Airborne particles (solid matter)
- Ground level ozone
- Carbon monoxide
- Sulfur oxide
- Nitrogen dioxide
Most of these pollutants are invisible to the naked eye, colorless and odorless, and this makes air pollution hard to detect on our own. That’s why these substances are monitored by the EPA, which has determined a safe range for each. When any one of them surpasses their safe range, an air quality alert is triggered.
What is an air quality alert?
The AQI is divided into five categories, based on the level of pollutants in the air and the corresponding health risk they pose. As a measurement tool, the AQI spans from 0 to 500. An AQI of 50 and below means the air quality is good. The AQI increases with the amount of air pollution to reflect the rising health risk, first for select groups of people, and then for everyone.
An AQI of 200 and above means the amount of pollution in the air has reached dangerous levels for everyone, regardless of their current health or planned outdoor activities.
The Air Quality Index reads as follows:
0-50: Good (green)
The air is clean and clear, and pollutants are mostly absent. It is safe for everyone to be outdoors.
51-100: Moderate (yellow)
There are some pollutants in the air, but they are still within a safe range. However, people with certain health conditions that make them more sensitive to air quality should watch for symptoms.
101-150: Unhealthy for sensitive groups (orange)
One or more pollutants in the air have surpassed their safe range. People in sensitive groups may want to limit outside exercise, while everyone else can continue outdoor activities with caution.
151-200: Unhealthy (red)
People in sensitive groups should avoid extended or vigorous exercise in the outdoors. Everyone else should plan to shorten outdoor exercise or reschedule it for the morning when pollution can be lower.
201-300: Very unhealthy (purple)
Health alerts are triggered. People in sensitive groups should avoid any outdoor exertion. Everyone else should avoid extended or vigorous exercise, and plan to move all activities indoors.
301 and up: Hazardous (maroon)
Everyone should avoid all outdoor activities.
Why air pollution is a health risk
If you spend time outside on a day when the AQI is high, the air pollution can make you feel unwell very quickly, but this is usually temporary. However, breathing polluted air for months or years can result in long-lasting or permanent health impacts. The length of your exposure determines the repercussions to your health.
Short-term exposure to air pollution can cause:
- Trouble breathing
- Nose, throat, eye or skin irritation
- Recurring pneumonia and bronchitis
Long-term exposure to air pollution can cause:
- Damage to the cardiovascular system
- Diminished lung capacity and function, leading to chronic wheezing, coughing and shortness of breath
- New chronic lung conditions like asthma, emphysema and lung cancer
- The worsening of existing lung conditions like COPD and asthma, with more frequent asthma attacks
- A shortened lifespan
What to do when the air quality is bad
If you’re wondering about the air quality where you live or work, go to airnow.gov and enter your city or zip code. It will tell you the current AQI for the area, the forecasted AQI for the next three days and more.
Follow the tips below to stay safe on those days when the air quality is very unhealthy (purple) or hazardous (maroon):
- Avoid spending any time outdoors and keep children from playing outside
- Limit activities that cause you to breathe heavily
- Keep windows and doors closed to prevent outdoor air pollution from spreading through your home or workplace
- If it’s a hot day, turn on the air conditioner, but only if your AC model has a filter and doesn’t draw from outside air – if you don’t have air conditioning, try to go somewhere that does
- If you have to go outside, wear a N95, KN95 or P100 mask to protect yourself from inhaling pollutants
Indoor air quality
Good air quality in your home and workplace is just as important to your health and well-being as the air quality outside. In the U.S., we spend a lot of time indoors, so indoor air is the majority of what we breathe. And when the air quality outside is poor, you should be able to have an indoor space where you can safely stay until conditions improve.
Some common sources of indoor air pollution include:
- Household features and appliances that burn fuel like stovetops, furnaces and fireplaces
- Biological matter like mold, mildew and bacteria
- Household products that contain asbestos like insulation, ceiling and floor tiles, roofing shingles and vinyl materials
- Lead-based paint or pipes
- Secondhand tobacco smoke
- Wood furniture or flooring with stains or finishes containing formaldehyde
- Volatile organic compounds (VOCs) found in carpet, varnishes, glues and adhesives, upholstery, air fresheners and other products
Ways to improve indoor air quality
With so many potential sources, it’s easy to become overwhelmed at the thought of eliminating indoor air pollution. However, knowing there’s a problem is the first step to fixing it. And you can preserve your health and the health of your home by taking just a few steps to clear the air.
- Address air pollution directly by sealing, enclosing or removing any sources of pollution (including harsh cleaning solutions)
- Increase indoor ventilation by opening windows whenever possible and using ceiling fans
- Purchase an air filtering device that continuously pulls in dirty air and emits clean, filtered air
- Keep your home clean – dust, wipe down and vacuum surfaces often (in that order, to prevent the vacuum from kicking up too much debris) to get rid of dust and other irritants, and opt for cleaning products with natural ingredients, like vinegar.
Exercising during an air quality alert
Before going outside to exercise, it’s a good idea to check the current AQI, just like you would the weather. If the air quality is poor that day, consider:
- Your health history and current medical conditions
- The type, duration and intensity of the exercise you plan to do
Those in sensitive groups can exercise outside when the AQI is 150 or below, but should plan for a short, easy workout and watch out for symptoms. People who are not in a sensitive group can exercise outside when the AQI is below 200, but should also keep exertion mild and to a minimum.
Keep in mind that, no matter the AQI level, exercising near busy, congested roadways can expose you to high levels of vehicle emissions. Plan a different route for your run or bike ride that follows mostly residential streets, trails and parks.
Air quality in Minnesota and the Upper Midwest
The air quality across the state of Minnesota has been improving since 2003, and much of the Upper Midwest benefits from good air quality. However, as wildfires become larger and more frequent in western states and southern Canada, the Upper Midwest could experience increasing air pollution from smoke. Additionally, our increasingly warmer and drier summers allow for higher levels of harmful ozone pollution.
But not everyone in the Upper Midwest gets to enjoy good air quality. Low-income communities and communities of color in urban areas are disproportionately impacted by air pollution. This is typically the result of proximity to major highways and industrial areas. Air pollution will continue to be a problem until all of us can breathe clean air.
Care to help you breathe easier
It’s important to keep yourself and your loved ones safe during periods of poor air quality for long-term health and well-being. If you have concerns about air quality in your area, talk to your primary care doctor about what you can do to protect your lungs and your overall health.
For more information on air pollution and to get up-to-date air quality conditions in your area, visit airnow.gov.