APES UNIT 7

1. Primary vs. Secondary Pollutants

• Q: What is the difference between primary and secondary pollutants?

• A: Primary pollutants are emitted directly from a source (e.g., CO, NOx, SO2). Secondary pollutants form when primary pollutants react in the atmosphere (e.g., ozone, acid rain).

2. Major Air Pollutants

• Q: Name the six criteria air pollutants regulated by the Clean Air Act.

• A: NO2 (Nitrogen Dioxide), O3 (Ozone), SO2 (Sulfur Dioxide), CO (Carbon Monoxide), PM (Particulate Matter), Pb (Lead).

3. Photochemical Smog

• Q: How does photochemical smog form?

• A: It forms when NOx (nitrogen oxides) and VOCs (volatile organic compounds) react in the presence of sunlight, creating tropospheric ozone (O3) and other pollutants.

4. Industrial Smog

• Q: What causes industrial smog, and where is it most common?

• A: Burning coal releases SO2, which reacts with water to form sulfuric acid and particulates. Common in China, India, and areas with heavy coal use.

5. Thermal Inversions

• Q: What is a thermal inversion, and how does it worsen air pollution?

• A: A layer of warm air traps cooler air below it, preventing pollutants from dispersing, leading to higher concentrations of smog and pollutants.

6. Acid Deposition

• Q: What are the primary causes of acid rain?

• A: SO2 and NOx react with water in the atmosphere, forming sulfuric acid (H2SO4) and nitric acid (HNO3), which fall as precipitation.

7. Effects of Acid Rain

• Q: List three environmental effects of acid deposition.

• A: 1) Lowers pH of water bodies, harming aquatic life.

2. Leaches nutrients from soil, affecting plant health.

3. Erodes buildings and monuments, especially limestone structures.

8. Particulate Matter (PM10 & PM2.5)

• Q: What is the difference between PM10 and PM2.5?

• A: PM10 (larger particles) can cause respiratory irritation. PM2.5 (smaller, finer particles) can penetrate deep into the lungs and bloodstream, causing severe health issues.

9. Carbon Monoxide (CO) Poisoning

• Q: Why is carbon monoxide (CO) dangerous?

• A: It binds to hemoglobin in red blood cells, preventing oxygen transport, leading to dizziness, unconsciousness, and even death.

10. Ozone Layer vs. Ground-Level Ozone

• Q: What’s the difference between stratospheric and tropospheric ozone?

• A: Stratospheric ozone protects from UV radiation (good ozone), while tropospheric ozone is a secondary pollutant and a component of smog (bad ozone).

11. Indoor Air Pollutants

• Q: Name three common indoor air pollutants.

• A: 1) Radon (Rn) – a radioactive gas from soil that causes lung cancer.

2. Formaldehyde – found in furniture, causes respiratory irritation.

3. Carbon monoxide (CO) – from incomplete combustion, leads to poisoning.

12. Noise Pollution

• Q: What are the effects of noise pollution?

• A: Hearing loss, stress, high blood pressure, and disruption of animal communication.

13. Clean Air Act (1970, 1990 Amendments)

• Q: What is the purpose of the Clean Air Act?

• A: Regulates air pollutants, establishes NAAQS (National Ambient Air Quality Standards), and reduces emissions from industries and vehicles.

14. Reducing Air Pollution

• Q: Name three ways to reduce air pollution from vehicles.

• A: 1) Catalytic converters (reduce NOx, CO, and hydrocarbons).

2. Public transportation and carpooling (reduce emissions).

3. Electric vehicles and cleaner fuels.

15. Controlling Industrial Pollution

• Q: How can industries reduce emissions?

• A: 1) Scrubbers (remove SO2).

2. Electrostatic precipitators (remove particulates).

3. Baghouse filters (trap pollutants before they escape).

16. Global Efforts to Reduce Pollution

• Q: What was the Montreal Protocol’s main achievement?

• A: It banned CFCs (chlorofluorocarbons) to protect the ozone layer.

17. The Role of Trees in Air Quality

• Q: How do trees help reduce air pollution?

• A: Absorb CO2, filter particulates, and produce oxygen.

18. Volatile Organic Compounds (VOCs)

• Q: What are VOCs, and where do they come from?

• A: VOCs are chemicals that evaporate easily, found in paints, gasoline, and cleaning products, contributing to smog formation.

19. Sulfur Dioxide (SO2) Sources

• Q: What are the main sources of SO2 pollution?

• A: Burning coal and oil, industrial processes, and volcanic eruptions.

20. Lead (Pb) in the Atmosphere

• Q: What was the main source of lead air pollution before regulation?

• A: Lead-based gasoline, which was phased out by the Clean Air Act.