Summary
Introduction of harmful substances into air, water or soil, such as plastics and chemicals.
In depth
Types: air (particulates, ozone), water (nutrients, chemicals, plastics), soil and noise or light pollution. Effects on health and ecosystems. Controls: regulation, cleaner technology, treatment.
Pollutants may be point source or non-point. Persistent organic pollutants travel long distances. Cleanup is often costly compared with prevention.
Example: lead removal from petrol lowered children's blood lead levels.
Pollution is the introduction of harmful substances or energy into the environment faster than it can be absorbed or broken down. Pollutants are classified by medium (air, water, soil) and by form: chemicals, nutrients, plastics, heavy metals, radioactive waste, noise, heat and light.
Sources can be point (a factory pipe) or non-point (farm runoff). Some pollutants bioaccumulate in organisms and biomagnify up food chains, such as DDT and mercury. Effects range from respiratory disease in people to dead zones in seas. Control measures include regulation, cleaner technology, treatment and reduction at source.
Example: lead in petrol was phased out, lowering blood lead levels.
Remember: prevention is cheaper than clean-up.
Frequently asked questions
What is Pollution?
Introduction of harmful substances into air, water or soil, such as plastics and chemicals.
Which area of biology covers Pollution, and how advanced is it?
Pollution is one of the 54 topics in Marine & Environmental Biology. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Environmental Toxicology, Plastic Pollution, Sustainable Agriculture.
Can you give an example of Pollution?
The Clean Air Act reduced lead and sulfur dioxide.
What should I learn before Pollution?
Pollution is a Beginner topic, so no earlier topic is required. Other Beginner topics in Marine & Environmental Biology that pair well with it include Oceans, Ocean Zones, Plankton.
What topics are related to Pollution?
The closest topics to Pollution are Environmental Toxicology, Plastic Pollution, Sustainable Agriculture, One Health. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Pollution?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Pollution. To practise the whole of Marine & Environmental Biology, use the Marine & Environmental Biology quiz.
How is Pollution different from Environmental Toxicology?
Pollution: Introduction of harmful substances into air, water or soil, such as plastics and chemicals. Environmental Toxicology: Studies how pollutants, such as heavy metals and pesticides, harm organisms and ecosystems. Read both side by side and note what each one explains.
How should I study Pollution step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Environmental Toxicology and explain the difference aloud. Finally, take the Marine & Environmental Biology quiz and come back to this page for any question you miss.