TOPIC 6 - AUDIO TO MEMORIZE SHIT

Air Pollution Sources

• Biogenic Sources:
  • Volcanoes
  • Wildfires
  • Livestock emissions
• Anthropogenic Sources:
  • Transportation
  • Combustion
  • Deforestation (man-made causes)

Types of Air Pollution

• Primary Pollutants:
  • Directly emitted into the atmosphere.
  • Examples: Wildfires, transportation combustion.
• Secondary Pollutants:
  • Created by chemical reactions in the atmosphere.
  • Example: Ozone (created by a chemical reaction with nitrogen oxides and sunlight).

Mechanisms of Harm of Air Pollution

• Particle Size:
  • Crucial in determining the effects on the respiratory system.
  • Smaller particles can penetrate deeper.
    • Above $5 \mu m$: Filtered in the nose, enter upper airways.
    • Between $2.5 \mu m$ and $5 \mu m$: Penetrate into the bronchi.
    • Below $2.5 \mu m$: Enter the alveoli.
    • Ultrafine particles: Enter the bloodstreams from the alveoli.
  • Impacts:
    • Asthma
    • Allergic rhinitis
    • General lung conditions
• Solubility in Water:
  • Chemical properties influence pollutant deposition.
    • High solubility: Permits dispersion, prevents reaching deeper lungs.
    • Low solubility: Permits reaching the alveoli, causing more damage.

Specific Pollutants

• Particulate Matter (PM):
  • Categorized by size:
    • Ultrafine PM
    • $PM_{10}$
    • $PM_{2.5}$
  • Sources: Biogenic and anthropogenic, seasonally dependent.
  • Health risks:
    • Irritation in the nose and throat
    • Asthma
    • Possible lung cancer (depending on particle size)
• Ozone ($O_3$):
  • Secondary pollutant (nitrogen oxides + sunlight).
  • Two types:
    • Good ozone: In the stratosphere, protective.
    • Bad ozone: Created as a secondary pollutant, harmful.
  • Health risks:
    • Air constriction
    • Reduced lung function
  • Most prevalent in sunny urban areas (high pollutant and sunlight levels).
• Nitrogen Oxides ($NO_x$):
  • Example: Nitrogen dioxide ($NO_2$)
    • Primary pollutant: Directly emitted from combustion and traffic.
    • Secondary pollutant: Reacts with sunlight to create ozone.
  • Health risks:
    • Low solubility in water: Reaches deeper lungs.
    • Respiratory irritation
    • Lung infections
    • Lung cancer
• Sulfur Dioxide ($SO_2$):
  • Sources: Industry, volcanic eruption, decomposition.
  • Highly soluble in water: Doesn't reach deep lungs.
  • Health effects:
    • Asthma
    • Cardiovascular diseases
• Carbon Monoxide (CO):
  • Source: Fossil fuel combustion.
  • Binds to hemoglobin: Forms carboxyhemoglobin, impairs oxygen delivery.
    • $Hb + CO \rightarrow HbCO$
  • Health effects:
    • Nausea
    • Can be fatal
  • Highly soluble in water (doesn't reach deep lungs).

Temperature Inversions

• Cold air and pollutants trapped by warm air above.
• Common in low-wind areas.
• Prevents pollutant dispersion, leads to accumulation.

Measuring Air Pollution

• Satellite data
• Air stations
• Personal monitors

Intervention Strategies

• Define the problem
  • Nature of the problem
  • Causes and consequences at all levels
• Identify modifiable factors
  • What can be changed, what cannot
• Decide on mechanisms of change
• Understand how changes will be delivered
• Test and adapt interventions
• Collect data to evaluate interventions