When we burn fuels, chemicals called ’sulphur‘ and ’nitrogen‘ are released into the air. Once in the air, they mix with water in the air – rain, snow, etc – and are transformed into different chemicals called ’sulphur dioxide‘ and ’nitrogen oxides‘, which can be very dangerous for plants, animals and people. Most of the ’sulphur‘ comes from power stations, which make electricity, and also from volcanoes. Most of the ’nitrogen oxides‘ come from car and truck exhausts.
We call ‚air pollution‘ the bad gases that we produce and release in the air. ‚Sulphur dioxide‘ and ’nitrogen oxides‘ are the most important causes of acid rain.