1. Composition of clean air
1.1. Nitrogen
1.1.1. 79%
1.2. Oxygen
1.2.1. 20%
1.2.1.1. High amount of oxygen in the might contribute to more combustion such as more frequent forest fires.
1.2.1.2. Low amount of oxygen might not be enough for the demand for organisms to respire.
1.3. Other gases
1.3.1. 1%
1.3.1.1. Carbon dioxide
1.3.1.1.1. 0.03%
1.3.1.2. Argon
1.3.1.3. Neon
1.3.1.4. Helium
1.3.1.5. Water vapour
2. Pollutants
2.1. Carbon monoxide
2.1.1. Effects
2.1.1.1. CO reacts with haemoglobin in blood to form carboxyhaemoglobin.
2.1.1.2. As a result, haemoglobin cannot transport oxygen to the rest of the body
2.1.1.3. Causes
2.1.1.3.1. Headaches
2.1.1.3.2. Fatigue
2.1.1.3.3. Breathing difficulties
2.1.1.3.4. Death!
2.1.2. Source
2.1.2.1. Incomplete combustion of fossil fuels such as pertrol
2.1.3. Features
2.1.3.1. odourless
2.1.3.2. colourless
2.1.3.3. poisonous gas
2.2. Sulphur dioxide
2.2.1. Source
2.2.1.1. volcanic eruption
2.2.1.2. combustion of
2.2.1.2.1. coal
2.2.1.2.2. fossil fuels
2.2.1.2.3. crude oil
2.2.1.2.4. natural gas
2.2.2. Effects
2.2.2.1. irritates eyes
2.2.2.2. irritates the lungs to cause breathing problems
2.2.2.3. may cause bronchitis
2.2.2.4. acid rain
2.2.2.4.1. reacts with rain water to form acid rain
2.3. Oxides of nitrogen
2.3.1. Source
2.3.1.1. exhaust fumes
2.3.1.2. lightning
2.3.2. Effects
2.3.2.1. similar to