Air Pollution
Burning fuels such as petrol, diesel, coal, and gas releases pollutant gases into the atmosphere. These pollutants can cause harm to humans, the environment, and contribute to global issues like acid rain and smog.
Where do air pollutants come from?
- Incomplete combustion of fossil fuels (when there’s not enough oxygen)
- Vehicle engines
- Power stations and factories
- Domestic heating and cooking
Main pollutants and their effects
Pollutant | How it’s formed | Harmful effects |
Carbon monoxide (CO) | Incomplete combustion of fuels | Toxic gas – binds to haemoglobin, prevents oxygen transport |
Particulates | Unburnt fuel or soot from diesel engines | Cause lung damage and global dimming |
Sulfur dioxide (SO₂) | Sulfur in fuels reacts with oxygen | Causes acid rain, irritates lungs |
Nitrogen oxides (NOₓ) | High temp in engines (N₂ + O₂ → NOₓ) | Causes acid rain and respiratory problems |
Carbon dioxide (CO₂) | Complete combustion of fossil fuels | Greenhouse gas – contributes to global warming |
Key terms explained
- Incomplete combustion: not enough oxygen → CO and particulates
- Acid rain: formed when SO₂ or NOₓ mix with rainwater to form acidic solutions
- Global dimming: particulates reflect sunlight, reducing light that reaches Earth
Reducing air pollution
- Use cleaner fuels (e.g. low-sulfur petrol or electric vehicles)
- Fit catalytic converters in cars to remove CO and NOₓ
- Renewable energy to replace coal/oil power stations
- Government policies and emission regulations
Questions
- What gas is formed by incomplete combustion and is toxic?
- What causes acid rain?
- Name one health problem caused by particulates.
- What is global dimming?
- How can vehicle emissions be reduced?
Summary
- Air pollution is caused by burning fossil fuels
- Main pollutants include CO, SO₂, NOₓ, particulates, and CO₂
- CO is toxic, particulates cause health problems and global dimming
- SO₂ and NOₓ cause acid rain
- Air pollution can be reduced by using cleaner fuels, catalytic converters, and renewable energy