Common Pollutants from Combustion and Their Effects — AQA GCSE Chemistry
Burning fuels releases gases and particles into the atmosphere that can harm health and the environment.
The pollutants
| Pollutant | Source | Effect |
|---|---|---|
| Carbon dioxide (CO₂) | complete combustion | greenhouse gas → global warming |
| Carbon monoxide (CO) | incomplete combustion | toxic — reduces oxygen carried by the blood; colourless and odourless |
| Soot (particulates) | incomplete combustion | breathing problems; global dimming; dirties buildings |
| Sulfur dioxide (SO₂) | sulfur impurities in fuels | acid rain; respiratory problems |
| Oxides of nitrogen (NOₓ) | high temperatures in engines | acid rain; respiratory problems |
Carbon monoxide
Carbon monoxide is especially dangerous because it is colourless and odourless, so it cannot be detected easily. It binds to haemoglobin, reducing the blood's ability to carry oxygen.
Acid rain
Sulfur dioxide and oxides of nitrogen dissolve in rainwater to form acid rain, which damages buildings, trees, and lakes/rivers (harming aquatic life).
Reducing pollution
Removing sulfur from fuels before burning, and using catalytic converters in cars, reduce these pollutants.
Exam tips
- Learn each pollutant with its source and effect.
- Carbon monoxide = toxic, from incomplete combustion, reduces oxygen transport.
- Sulfur dioxide and nitrogen oxides cause acid rain.
- Soot causes breathing problems and global dimming.