What is environmental pollution?
Environmental pollution is the release of harmful substances or energy – called pollutants – into the air, water or land, damaging living things and their surroundings. Human activities such as burning fuels, dumping waste and clearing forests are the main causes.
Main types
- Air pollution – gases and particles such as carbon dioxide, sulphur dioxide, nitrogen oxides and smoke.
- Water pollution – sewage, oil spills, factory chemicals and fertilisers washed into rivers and the sea.
- Soil / land pollution – rubbish, plastics, pesticides and toxic chemicals left on land.
- Thermal and noise pollution – hot water from factories and loud, continuous noise.
Key idea
Acid rain comes from sulphur dioxide and nitrogen oxides. Global warming comes from greenhouse gases such as carbon dioxide. Ozone-layer thinning comes from CFCs.
Effects and control
Pollution causes acid rain that damages plants and buildings, the greenhouse effect that warms the planet, and dirty water that spreads disease. Extra fertiliser in a river causes eutrophication, where algae bloom, block sunlight and use up oxygen so that fish die. Breathing polluted air can trigger asthma and lung disease, while heavy metals in water can poison people who eat contaminated fish. Pollution can be controlled by treating waste before it is released, fitting filters and catalytic converters, using cleaner and renewable energy, recycling, and enforcing environmental laws.
Example
During the dry season, open burning and forest fires create haze over Malaysia. The Air Pollutant Index (API) rises, and people with asthma are advised to stay indoors.
Remember
A pollutant can be a substance (like smoke) or a form of energy (like heat or noise). Reducing pollution protects both human health and the ecosystem.