
♻️AP Environmental Science Review
AP Environmental Science Unit 7 - Atmospheric Pollution
♻️AP Environmental Science
Review
AP Environmental Science Unit 7 - Atmospheric Pollution
Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
APA
AP Environmental Science Pollution Review
Here's an organized outline for AP Environmental Science Unit 7 reviews. This outline has been adapted from the 2019 Course Description published by College Board. You can use this to build an AP Enviro Unit 7 study guide.

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Causes of Pollution
Human activities affect the quality of the air both indoors and outdoors.
- Burning fossil fuels releases nitrogen oxides into the atmosphere where they lead to the production of photochemical smog by producing ozone.
- Areas with large number of vehicles like cities often have more photochemical smog.
- Common indoor air pollutants include Volatile Organic Compounds (VOCs), formaldehyde and lead.
Air pollution can be in the form of gases or particulates in the atmosphere and be generated by both natural and human sources.
- CO2 appears naturally in the atmosphere from respiration, decomposition, and volcanic eruptions.
- CO2 concentrations in the atmosphere have increased from the burning of stored carbon (fossil fuels).
⚡ Watch: AP Environmental Science - 🎥 Air Pollution
Solving Pollution
Legislation has been put into place in order to protect air quality.
- The Clean Air Act regulates the use of lead in fuels, with the aim to decrease the amount of lead introduced into the atmosphere.
- The Environmental Protection Agency (EPA) use methods to reduce air pollutants including regulatory practices, conservation practices, and alternative fuels.
- To reduce air pollution generated by internal combustion engines in vehicles catalytic converters are required by most developed countries.
Introduction of pollutants to the atmosphere have created many large scale environmental and health consequences.
- Sulfur and nitrogen oxides form acid rain that can lead to acidification of soils and bodies of water including the ocean.
- Smog and particulates can be trapped close to the ground in a thermal inversion.
- Photochemical smog is formed when nitrogen oxides and volatile organic hydrocarbons react with heat and sunlight.
Unit 7 Vocab
- Acid rain
- Clean Air Act
- Effects of air pollutants
- Environmental Protection Agency (EPA)
- Indoor air pollutants
- Methods to reduce air pollutants
- Natural sources of CO2
- Noise pollution
- Photochemical smog
- Primary Air pollutants
- Secondary air pollutants
- Sources of air pollutants
- Thermal inversion
- Volatile Organic Compounds (VOCs)