IGCSE Biology glossary
Pollution
Biology editorial review is supported by the named review panel. Reviewer participation may vary by guide. Checked against Cambridge IGCSE Biology 0610 (2026–2028); last reviewed August 2026.
Definition
The introduction of harmful substances or excessive energy into the environment, causing damage to living organisms and ecosystems. Pollution can affect air (e.g. Sulfur dioxide, carbon monoxide), water (e.g. Sewage, fertiliser runoff) or land (e.g. Pesticides, landfill waste).
What to include in an exam answer
In pollution questions, always state the pollutant, its source and its effect. Common examples: fertiliser runoff causing eutrophication, sulfur dioxide causing acid rain, CFCs damaging the ozone layer.
Example in context
Describe the effects of water pollution caused by sewage entering a river (3 marks): Sewage provides nutrients that cause algal bloom. The algae block light, killing aquatic plants. Decomposing bacteria increase in number, using up dissolved oxygen. Fish and other aquatic organisms die due to lack of oxygen (eutrophication).
Related syllabus topic
Human influences on ecosystems