What Are the Six Common Air Pollutants? 

The Clean Air Act requires EPA to set National Ambient Air Quality Standards for six common air pollutants. These commonly found air pollutants (also known as "criteria pollutants") are found all over the United States. They are particle pollution (often referred to as particulate matter), ground-level ozonecarbon monoxidesulfur oxidesnitrogen oxides, and lead. These pollutants can harm your health and the environment, and cause property damage. Of the six pollutants, particle pollution and ground-level ozone are the most widespread health threats. EPA calls these pollutants "criteria" air pollutants because it regulates them by developing human health-based and/or environmentally-based criteria (science-based guidelines) for setting permissible levels. The set of limits based on human health is called primary standards. Another set of limits intended to prevent environmental and property damage is called secondary standards.

What are the "Big Six" Air Pollutants all about?

Six Common Air Pollutants 

What is it? 
Where does it come from?

Particle Pollution
Tiny particles of liquid or solid in the air. 
Construction, agriculture, forestry, fires, cars and industries. 
Can reduce visibility, cause respiratory problems. 

 Ground-Level Ozone
 Primary constituent of smog.
 Motor vehicle exhaust, industrial emissions, gasoline vapors, chemical solvents.
 Airway irritation, aggravation of respiratory illnesses, lung damage with repeated exposure.

 Carbon Monoxide
 Colorless, odorless, poisonous gas.
 Incomplete burning of fossil fuels, motor vehicles and industry.
 Feeling lightheaded headaches, oxygen depravation.

 Sulfur Oxides
 Compounds made of sulfur and oxygen.
 Burning fossil fuels like coal.
 Can form acid rain and irritate respiratory system.

 Nitrogen Oxides
 A compound made of nitrogen and oxygen.
 Power plants, cars and industry. Also, burning at temperatures over 1,000 degrees.
 Can cause respiratory disease or lung cancer. Can form acid rain or smog.

 Lead Heavy, ductile, soft gray solid
 Lead-based paint, contaminated soil, dust.
 Can affect nervous system, kidney and blood. Particularly threatening to children.


What You Can Do At Home:

  • Open your windows! When it is a nice day outside, open the windows to increase ventilation in the house and get the added benefit of natural light! Circulating fresh air will help flush air pollutants out of your house.
  • Use natural cleaning agents. Baking soda can be used as a deodorizer, lemon juice fights bacteria, and corn starch can be used to clean windows and polish furniture. Check out for more tips on non-toxic cleaning! 
  • Avoid corrosive drain cleaners, oven cleaners and acidic toilet bowl cleaners. These can cause burning in the eyes and skin, and the fumes can lead to throat and lung damage (especially chlorine bleach and ammonia). You can find more information about the toxicity of various cleaning agents here: