air pollution Flashcards
What are the layers of the atmosphere (from lowest to highest)?
Troposphere
Stratosphere
Mesosphere, Thermosphere
Exosphere
What is the composition of Earth’s atmosphere?
78% nitrogen,
21% oxygen
1% argon
CO₂, water vapor, and trace gases
What is the difference between ‘good’ ozone and ‘bad’ ozone?
Good ozone is in the stratosphere and blocks UV rays;
bad ozone is in the troposphere and contributes to smog.
Why is the stratosphere called Earth’s ‘global sunscreen’?
The ozone layer absorbs harmful UV radiation from the sun.
Name common outdoor air pollutants and their sources.
CO, NOx, SO₂, O₃, PM, lead – from vehicles, industry, burning fossil fuels.
Name common indoor air pollutants and their sources.
Radon (soil), formaldehyde (furniture), VOCs (cleaners), CO (heaters)
What are the health effects of indoor air pollution?
Respiratory issues, cancer, headaches, organ damage
What are VOCs?
Volatile Organic Compounds – chemicals that vaporize easily and can harm health
What is a primary pollutant? Give examples.
Emitted directly into the air. Examples: CO, SO₂, NO
What is a secondary pollutant? Give examples.
Forms in the atmosphere. Examples: ozone, smog, acid rain
What does the Clean Air Act regulate?
It regulates six criteria pollutants: CO, NO₂, SO₂, lead, ozone, and PM
How do wet scrubbers reduce air pollution?
They use mist to trap and remove pollutants from gas emissions.
How do electrostatic precipitators work?
They use electric charges to remove particles from smokestack emissions.
What does a catalytic converter do?
Converts converts harmful pollutants (CO, NOx, and hydrocarbons) into less harmful substances (CO₂, N₂, and H₂O.)
What is photochemical smog and when does it form?
Brown smog formed from sunlight + NOx + VOCs. Happens in warm, sunny, polluted areas.
What is a temperature inversion and how does it affect pollution?
Warm air traps cooler air below, causing pollutants to accumulate near the ground.
How does acid deposition occur?
SO₂ and NOx (from burning fossil fuels) react with water, oxygen, and other chemicals in the atmosphere, forming acidic compounds that fall to the earth as wet (rain, snow) or dry deposition (gases and particles
What is the EPA’s acid rain pH threshold?
Below pH 5.6
How can acid deposition be reduced?
Use scrubbers, cleaner fuels, and reduce emissions.
What are the four most dangerous indoor air pollutants?
Tobacco smoke, formaldehyde, radon, particulates
What are National Ambient Air Quality Standards (NAAQS)?
Legal limits for major air pollutants to protect health/environment
What chemical reactions cause ozone depletion?
catalytic cycles involving chlorine and bromine atoms, which are released from chlorofluorocarbons (CFCs) and other halogen source gases in the stratosphere. These atoms react with ozone, breaking it down into oxygen molecules, and then are regenerated to continue destroying ozone
What is noise pollution and what causes it?
Harmful sound levels from traffic, industry, and construction
What are health effects of noise pollution?
Hearing loss, stress, sleep issues, high blood pressure
