What is air pollution?
Air pollution is the release of harmful substances into the air. These substances are called pollutants. They may be gases, tiny solid particles or droplets. Most air pollution comes from human activities, although volcanoes and forest fires also add pollutants naturally.
Main pollutants and their sources
- Carbon monoxide (CO) — from incomplete combustion in vehicle engines; poisonous.
- Sulfur dioxide (SO₂) — from burning fuels containing sulfur; causes acid rain.
- Carbon dioxide (CO₂) — from burning fossil fuels; adds to the greenhouse effect.
- Smoke and dust particles — from factories, open burning and vehicles.
Key idea
A pollutant is any substance that harms living things or the environment when it enters the air. Main effects: breathing problems, acid rain and a warmer climate.
Effects and control
Air pollution can cause coughing, asthma and lung disease. Acid rain damages plants, buildings and rivers. Extra carbon dioxide traps heat and warms the Earth. We can reduce air pollution by using public transport, filtering factory smoke, using cleaner energy such as solar power, and stopping open burning.
Remember
- Vehicles and factories are major sources of air pollution.
- Sulfur dioxide leads to acid rain.
- Planting trees helps clean the air.