Air pollution occurs both outdoors and indoors, and it can affect human health, other living beings, and the environment. This lesson introduces the main types and sources of air pollution and explains how important pollutants behave.
Air pollution is the presence in the air of substances harmful to people, other organisms, or the environment. Pollutants may be gases, such as ozone and nitrogen oxides, or tiny solid and liquid particles, such as soot and dust. Air pollution may occur outdoors or inside buildings.
All flashcards
What is air pollution?
The presence of substances in the air that are harmful to humans, other living beings, or the environment.
What distinguishes primary from secondary pollutants?
Primary pollutants are emitted directly by a source. Secondary pollutants form in the atmosphere through reactions involving primary pollutants or other atmospheric components.
What does PM2.5 mean?
It describes fine particulate matter with a diameter smaller than 2.5 micrometers. These particles can reach deep into the lungs and may enter the bloodstream.
How does ground-level ozone form?
It forms mainly when nitrogen oxides and volatile organic compounds react in the presence of sunlight; heat often favors high concentrations.
Why are CFCs harmful to the ozone layer?
CFCs can reach the stratosphere, where ultraviolet light releases chlorine. Chlorine reacts with and destroys ozone, reducing protection from harmful ultraviolet radiation.
Quiz questions
Which description best defines air pollution?Answer: Harmful substances present in the air, affecting people, organisms, or the environment.
What conditions mainly contribute to the formation of ground-level ozone?Answer: Nitrogen oxides and volatile organic compounds reacting in sunlight.
What does an air quality index (AQI) communicate to the public?Answer: A simplified indication of air conditions and associated health risks.
What does the “shift” step in the avoid-shift-improve transport framework encourage?Answer: Moving journeys toward cleaner modes such as walking, cycling, and public transport.
What was a major outcome of the Montreal Protocol?Answer: The phaseout of many chemicals that deplete stratospheric ozone.
Based on the Wikipedia article Air pollution, licensed CC BY-SA 4.0. Adapted into a summary, flashcards and quizzes.