About Air Pollutants

Table of Contents

Breaking Down Air Pollution

Air pollution can be categorized based on the source or composition of pollutants. 

Particulate Matter

Particulate matter is commonly abbreviated as “PM,” and it is a mix of tiny particles and droplets that are hard to see. PM is at times visible in the form of haze, or cloud-like smoke, dust, or other small particles in the air. These particles come from lots of places, most commonly from cars, fires, power plants, and other industries. PM is also particularly damaging to our environment as it contributes to acid rain.  

“PM” is usually followed by a number in subscript: PM10 or PM2.5. This number is how big the particulate matter is in diameter. PM10 is 10 microns in diameter, and PM2.5 is 2.5 microns in diameter. For reference, a human hair is 70 microns in diameter. So, PM2.5  is 30 times smaller than a single human hair!

Health Effects

Particulate matter (PM) is easily absorbed into the body through inhalation and ingestion. Communities that live in environments with high levels of PM are impacted by air respiratory illnesses at higher rates. Be aware of the following health symptoms and problems:

  • premature death in people with heart or lung disease
  • nonfatal heart attacks
  • irregular heartbeat
  • aggravated asthma
  • decreased lung function
  • irritation of the airways 
  • coughing 
  • difficulty breathing

High levels of PM2.5 aggravate during wildfires. Wearing a N95 mask outdoors and filtering your indoor air can help protect your respiratory health and that of your loved ones.


Check out your area’s PM levels by visiting airnow.gov, and learn if local schools and community centers have a flag program to alert you of the day’s air quality. 


Ozone is created when different types of gas emissions react with other chemicals in the air. The chemical reaction is exacerbated by sunlight, which means that our air is more susceptible to ozone in warm summer months. We often see ozone in the form of smog, or ground level ozone. Large cities are commonly referenced for their smog due to higher levels of gas emissions released via vehicle, factory, and other industrial activities. 

Health Effects

Ground level ozone can negatively impact one’s health. People, especially children and older age groups, with asthma or other respiratory problems necessitate additional resources and precautions when ozone pollution is high. These precautionary steps include the use of K95 masks, personal air filters, or limited industrial activity. Overexposure to ozone can cause the following symptoms:

  • Coughing
  • Sore, itchy throat
  • Pain when taking deep breaths
  • Trigger asthma attacks
  • Infection in lungs

Even at low levels ozone can cause respiratory problems, and it is one of many causes of developing asthma.


You can check the ozone levels in your community as easily as checking the weather forecast. Take a look at the air quality forecast by visiting www.airnow.gov

When the local air quality is a concern, EnviroFlash, a free service, may alert you by email.

You can sign up on www.enviroflash.info.

Nitrogen Oxides

Nitrogen oxides (NOx) get released into the air from the burning of fuels, specifically through electric power, transportation, and industrial combustion processes

Nitrogen oxide (NO) and nitrogen dioxide (NO2) are common indicators of nitrogen oxides in our air. When atmospheric oxygen interacts with nitrogen in high flame temperatures, nitrogen oxides are formed. NO2 and other types of NO can also contribute to the formation of particulate matter and ozone in the air.

Health Effects

High concentrations of NOx in the air can result in respiratory health issues. When inhaled, NOx can irritate respiratory pathways in the body and can lead to the following health symptoms and chronic illnesses: 

  • Difficulty breathing
  • Coughing
  • Wheezing
  • Asthma
  • Other respiratory infections

Carbon Monoxide

Carbon monoxide (CO) is a colorless, odorless gas that is created from the incomplete burning of natural gas or products containing carbon. It is harmful to both our health and the environment. 

This pollutant is a result of burning fuel in appliances including stoves, lanterns, grills, fireplaces, gas ranges, and furnaces. Carbon monoxide pollutes our outdoor air as well. It is produced by cars, trucks, and other machinery or equipment that burns fossil fuels. 

Health Risks

Breathing high levels of carbon monoxide indoors can cause sudden illness or death. 

High levels of carbon monoxide are likely to occur in closed spaces and are harmful to both people and animals. How much is breathed in matters. Signs to look out for are:

  • Chest Pain
  • Headaches
  • Nausea
  • Dizziness
  • Confusion
  • Unconsciousness
  • Fatal at high levels

Carbon Monoxide prevents organs like your heart and brain from receiving the amount of oxygen it needs. 

What can you do?

  • Be aware of carbon monoxide poisoning. It claims hundreds of lives each year.
  • Check your CO detectors to make sure they are working properly.
  • Have your furnace inspected every year.
  • Generators should never be used inside or in a garage (even if doors and windows are open).

More Resources

Learn about how air quality has a direct impact on our collective and individual wellbeing.
Check out the air quality in your area!
There are three easy steps to improve your air, and the reason it is important.