Humans and other mammals have lungs which they use to breathe; we breath in the outside air into our lungs.
Air is a mixture of different gases. An important gas in air is oxygen. When we breathe in the air into our lungs, the oxygen from the air goes into our bodies and is carried around the body by the blood, which is pumped around the body by the heart. This happens continuously. If the air didn’t have oxygen humans or animals would not be able to survive. So, the air we breathe is very important.
You may have heard or seen the terms “poor air quality” or “air pollution”. This means that there is “pollution” in the air, think “dirty” air. What do we mean when we say the air is polluted? When the air is polluted, it means there are gases and particles in the air which might be bad for our health. These gases and particles can affect us when we breathe in the air and cause us health problems. They can also be harmful to animals and plants.
So, what causes air pollution? Well, we do. Humans change the environment because they are trying to make life better. For example, we drive cars to get to places more quickly and we build homes, so everyone has somewhere to live. When we do these things without planning carefully, we can change our environment in a negative way.
The things that cause air pollution are known as “pollutants”. There are different types of pollutants, and you can find out more about them on the “Types of pollution” page. Some pollutants can be seen; others are invisible to the human eye. Perhaps you’ve seen smoke come out the chimney on a cold day? That’s air pollution. Some pollutants are smelly; others have no smell at all. Have you smelt a strong smell from traffic? That’s also air pollution. The one thing that they all have in common is that they're bad for us and bad for the animals and plants that share our planet with us. The good news is that our air is getting better, but we still have a long way to go. Read our page on what you and your family can do to help improve air quality.