Air pollution

What happened in Donora, PA in 1948?

A temperature inversion trapped smog for 4 days → 20 deaths, 6,000 illnesses

What was the Great London Smog of 1952?

Cold front + pollution trapped by inversion → 5 days of smog, ~4,000 deaths

What is a temperature inversion?

A layer of cold air traps warm air and pollutants near the ground, worsening air quality

What are health effects of air pollution?

Asthma, bronchitis, heart disease, lung infections, cancer, and up to 2–3% of U.S. deaths.

What are environmental effects of air pollution?

Crop damage, tree death, reduced visibility, acid rain, and global warming.

How does air pollution affect property?

Paint corrosion, rubber cracking, metal rusting, and damage to cultural monuments.

Name two economic effects of air pollution.

Increased health care costs and decreased worker productivity.

Natural vs, manmade pollutants

wildfires/ power plants

What was the Clean Air Act of 1963?

Created a national air pollution program and established emissions standards.

What were the major additions in the 1990 Clean Air Act amendments?

• Created NAAQS

• Tightened auto emissions

• Introduced reformulated gasoline

• Controlled acid rain

• Required pollution permits

What are national ambient air quality standards (NAAQS)

National standards for allowable pollutant levels to protect public and environmental health.

What is the goal of a primary NAAQS standard?

Protect human health, including sensitive populations.

What is the goal of a secondary NAAQS standard?

Protect property, crops, livestock, and the environment.

Name the six criteria pollutants NAAQS

Ozone, Lead, Particulate Matter, Sulfur Dioxide, Nitrogen Oxides, Carbon Monoxide.

What are the health effects of Carbon Monoxide (CO)

Limits oxygen in blood → headaches, dizziness, nausea, even death.

What are sources and effects of Nitrogen Oxides (NOx)

Cars and power plants; cause respiratory irritation and smog.

What are sources and effects of Sulfur Dioxide (SO₂)?

Coal-burning plants; causes asthma, bronchitis, and acid rain.

Why is Particulate Matter dangerous?

PM2.5 penetrates deep into lungs → heart/lung disease, cancer, visibility loss.

What is a primary pollutant?

Directly emitted into the air (e.g., CO, SO₂).

What is a secondary pollutant?

Forms in the atmosphere through chemical reactions (e.g., ozone, acid rain).

What causes acid rain?

SO₂ and NOx react with water in the atmosphere → sulfuric and nitric acid.

Name five effects of acid rain.

1. Acidifies lakes/streams

2. Damages forests

3. Deteriorates buildings

4. Reduces visibility

5. Aggravates asthma and bronchitis

What are the top greenhouse gases?

Carbon Dioxide (CO₂), Methane (CH₄), Nitrous Oxide (N₂O)

What is the main source of CO₂?

Burning fossil fuels (oil, gas, coal)

What are key effects of climate change?

• Rising temperatures

• Melting glaciers

• Sea level rise

• Biodiversity loss

• Changes in agriculture

• More frequent extreme weather

What is a mega city?

A city with over 10 million people.

What is the “urban penalty”?

The decline in health and quality of life for people migrating to rapidly growing cities.

Name three problems from rapid urbanization.

• Overcrowded slums/shanty towns

• Inadequate sanitation and water

• Air and water pollution