The air we breathe is a mixture of different gases. The most important gas to humans and animals is oxygen, which we all need to survive.
Humans and other mammals have lungs, which we use to breathe. When we breathe air into our lungs, the oxygen from the air goes into our bodies. It is then carried around our body by the blood, which is pumped around by our heart. This happens 24 hours per day and 365 days per year! If the air didn’t have oxygen, neither humans nor animals would be able to survive. This makes the air we breathe really important.
Some days, you may hear on the news that there is “poor air quality”. This means that there is “pollution” in the air. We say the air is “polluted”. So, what is air pollution?
When we say the air is polluted, we mean that it has become dirty. The sorts of things that make our air dirty are gases, dust, fumes or smoke that have been let out into the air around us. These things can be harmful to humans, animals or plants.
Perhaps you have seen smoke coming out of a chimney on a cold day? That is one sort of air pollution. Or, maybe you have seen smoke coming out of the exhaust pipe of a car or truck. Sometimes, there’s a strong smell from the traffic too. That is air pollution too.
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 “Pollutant Fact Files” page. Some pollutants can be seen; others are invisible. Some pollutants are smelly; others have no smell at all. 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.