Introduction: Air Pollution

Question 1

What are the Problems with Air Pollution?

Answer 1

• A person inhales ~20,000 L (~35 pounds) of air each day [Roughly 6X more than the amount of food or water consumed per day]
• Breathing is continuous
• There are sources all around us
• Many of our exposures are involuntary

Question 2

What are other Problems with Air Pollution?

Answer 2

• adverse human health effects
• damage trees, crops, other plants, lakes, and animals
• damage to buildings, monuments, and statues
• impaired by visibility (if a lot of smog)
• ozone layer depletion
• global warming

Question 3

How do the Lungs work?

Answer 3

• oxygen essential for all cells
• air that enters lungs in rich in oxygen
• lungs help put oxygen into bloodstream; heart circulates the oxygen-rich blood around the body
• cells use oxygen and make carbon dioxide as a waste product
• blood comes back to lungs with carbon dioxide, lungs remove it and exhale it

Exchange of Air( Oxygen-> Lungs -> Blood Stream)

Question 4

How do Air Pollutants affect our Respiratory System?

Answer 4

• nose filters out bigger particles
• tiny hairs called cilia line the airways and move gently to keep mucus and dirt out of the lungs
• airways are covered by a liquid layer of mucus. Particles and pathogens are trapped in this mucus are coughed up or swallowed.
• Immune system cells (e.g., macrophages) patrol the lungs and remove particles or pathogens.
• On high air pollution days, our lungs’ defenses may be overwhelmed. Pollutants can cause damage from inflammation, irritation. Toxic substances can enter our bloodstream and travel to other organs.

Question 5

What are Acute health effects of air pollution?

Answer 5

• loss of lung function (absenteeism, increased need for medication, increased emergency room visits, hospitalization)
• increased mortality rate/ premature death (respiratory and cardiovascular deaths)
• irritation/cough
• asthma attacks

Question 6

What are Chronic health effects of air pollution?

Answer 6

• Asthma

  - disease that inflames and narrows the airways
  - leading cause of hospitalizations and school absences in children in U.S.
   - 1 in 10 children and 1 in 12 adults have asthma

• Impaired lung growth
• Accelerated lung aging
• Cardiovascular disease
• Cancer

Question 7

What are Factors determining Air pollutants?

Answer 7

• Sources
• Weather
      - Wind, speed and direction
      - Temperature
• Land patterns
      - Mountains
      - Valleys

Question 8

Explain Normal Conditions of Air

Answer 8

• Higher altitude= temp goes down

- Lower altitude= temp goes up

Question 9

Temperature Inversion

Answer 9

Calm winds and the inversion result in poor air quality.

1. The winter sun, low in the sky supplies less warmth to the Earth’s surface.
2. Warmer air aloft acts as a lid and holds cold air near the ground.
3. Pollution of wood fires and cars are trapped by the inversions.
4. Mountains can increase the strength of valley inversions.

Question 10

What is Marine Inversion?

Answer 10

Warm Air from Land on top of Cool Marine Air

Question 11

What is Inversion?

Answer 11

Air flows over an obstacle such as an mountain range or blows from a high plateau and descends into a lower basin overlying a colder air at the surface.

Question 12

What are some cities that experience inversions?

Answer 12

• Los Angeles
• Denver

(pollutants get trapped along with cool air)

Question 13

What are Sources of Air Pollutants?

Answer 13

1. Natural vs. Manmade
   - smoke from forest fires ( West part of U.S.)
   - Volcanic ash
2. Biological
   - Pollen
   - Some VOCs
3. Anthropogenic
   - Industrial emissions
   - Automobile emissions
   - Fossil fuel combustion
4. Stationary: fixed source (e.g., Co2 from fossil fuel burning, smoke stack factories)
5. Mobile: Motor vehicles, engines, and equipment that move (e.g., diesel exhaust, cars,, any transportation)

Question 14

What are Types of Air Pollutants?

Answer 14

1. Primary: directly emitted (volatile organic chemicals)
   example: tail pipe
2. Secondary: product of chemical reactions (ozone)
   example: nitrogen oxide and sunlight
3. Particulate matter (solid or liquid)
   - Solid or aqueous particles, including dust, dirt, soot, smoke and liquid droplets
   - Can be suspended in the air for long periods of time
   - 0.01um to 100um aerodynamic diameter
4. Gases and vapors
   examples: oxides of sulfur and nitrogen, combustion products

Question 15

What is Global Fossil Fuel Use?

Answer 15

• China’s fossil fuel use and pollution heads to the U. S.

- On occasion, ~25% of LA pollution can be attributed to Asia (EPA)