Air pollution happens when solid and liquid particles—called aerosols—and certain gases end up in our air. These particles and gases can be bad for the planet and for our health, so keeping track of them is important.
Where do aerosols come from?
Any particle that gets picked up into the air or is formed from chemical reactions in the air can be an aerosol. Many aerosols enter the atmosphere when we burn fossil fuels—such as coal and petroleum—and wood. These particles can come from many sources, including car exhaust, factories and even wildfires. Some of the particles and gases come directly from these sources, but others form through chemical reactions in the air.
Aerosols can come from other places, too, such as ash from an erupting volcano. Dust, pollen from plants and mold spores are also examples of aerosols.
