Though you may not notice it, the air around you holds many things besides the mixture of gases you breathe. It holds water vapor, dust, pollen, and sometimes — pollutants. Pollutants are things that are in our environment that may be harmful to us. Where do pollutants come from? Air pollution can be smoke from a forest fire or chemicals released from a factory smokestack. It is the exhaust from our cars, trucks, boats, buses, planes, and even lawn mowers! It can be chemicals right out of your house like paint, varnish, or turpentine fumes. Chemical pesticides sprayed on crops pollute the air. So do methane gases from rotting garbage in landfills.

Air pollution can affect your health. It can also affect the health of crops, forests, and animals. It can even damage the protective ozone layer in our atmosphere. Air pollution can make a haze in the sky so thick that you cannot see nearby mountains.

“Natural” Pollution

Not all pollution is man-made. Sometimes natural events can cause air pollution, like a volcano erupting, natural gas — like radon escaping into the air — or a lightning strike setting off a forest fire. Even dust blown off dry land can be an air pollution hazard. All these things are natural to our environment but still make air pollution that can harm us.