Air quality - What is air?
Air quality is the term that is used to describe how clean the air is.
View a beginners guide to Air Quality (PDF) [1MB] for more information.
Our air is made up of gases - 78% nitrogen, 21% oxygen and 1% of other gases like argon, carbon dioxide, carbon monoxide, hydrogen, methane, helium, ozone, nitrous oxide and neon.
Air also holds water vapour (as part of the water cycle) and lots of tiny particles like dust, sea salt and pollen.
It is important because all humans, animals and plants need to breathe. Humans and animals breathe in air and use the oxygen within it and breathe out carbon dioxide. Plants use carbon dioxide and sunlight to make food and grow, as part of this process they give off oxygen (this part of the oxygen cycle is called photosynthesis).