Describe four sources of atmospheric pollutants produced by human activities. In your answer, name each pollutant and its source.

1. Carbon dioxide – produced by burning fossil fuels such as coal, oil or gas in power stations, cars and factories.
2. Sulphur dioxide – released when fossil fuels containing sulphur impurities are burnt in power plants and industrial processes.
3. Methane – emitted from the digestive tracts of livestock (especially cattle) and from the decay of organic waste in landfill sites.
4. Carbon particulates (soot) and carbon monoxide – formed by incomplete combustion of fossil fuels in engines, boilers and open fires.