public health air pollution

1.) what is the significance of air pollution in global mortality rates; and what are the relative contributions of indoor air quality and ambient air pollution to this?

• Major health risk: Air pollution is a leading environmental cause of premature deaths worldwide, linked to diseases like chronic obstructive pulmonary disease, stroke, lung cancer, and ischemic heart disease.

• Global burden: Millions of deaths each year are attributed to exposure to polluted air.

• Contributors:
  

  • Ambient (outdoor) air pollution — from vehicles, industries, and power generation.

  • Indoor air pollution — often from burning fuels like wood or coal for cooking/heating, especially in low-income regions.

• Significance: Reducing air pollution can save millions of lives and improve global public health.

1.) what are the primary medical causes of premature mortality from poor air quality (either indoor or ambient)?

• Cardiovascular diseases
  

  • ischemic heart disease (major cause)

  • stroke (often triggered or worsened by long-term exposure)

• Respiratory diseases
  

  • chronic obstructive pulmonary disease

  • lung cancer

  • lower respiratory infections (especially in children and elderly)

• Other impacts: Exacerbation of asthma, reduced lung function, and increased hospitalizations.

✅ Poor air quality is a major contributor to global premature deaths, especially in vulnerable populations.

what is the general life cycle of air pollutants (source, transport, chemical reaction or loss, deposition); and what is the role of temperature inversion in air pollution events?

• Source: Emitted from natural (e.g., wildfires, dust) and human activities (e.g., vehicles, industry).

• Transport: Carried by wind and atmospheric circulation.

• Chemical reaction/loss: Pollutants can react in the atmosphere to form secondary pollutants or break down.

• Deposition: Removed from the air by settling (dry deposition) or precipitation (wet deposition).

• Temperature inversion: A warm air layer traps cooler air at the surface, preventing vertical mixing. This traps pollutants near the ground, causing smog and worsening air quality.

✅ Temperature inversions intensify pollution episodes by limiting dispersion.

1.) what are the most important ambient air pollutants regulated by NAAQS? 2.) for each know trends in each of these pollutants- which have decreased dramatically and which are still challenges for U.S air quality; characteristic sources (or sectors) for ambient air pollutant; primary or secondary pollutant?

• Pollutants regulated by National Ambient Air Quality Standards:
  

  1. Ozone (O₃) – secondary; from NOₓ + VOCs (transportation, industry); still a major challenge.

  2. Particulate Matter (PM₂.₅ & PM₁₀) – primary & secondary; from combustion, industry; improving but remains a concern.

  3. Carbon Monoxide (CO) – primary; from vehicles; decreased greatly.

  4. Sulfur Dioxide (SO₂) – primary; from power plants; major reduction.

  5. Nitrogen Dioxide (NO₂) – primary & secondary; from transportation & industry; improved but contributes to ozone.

  6. Lead (Pb) – primary; mainly from past vehicle emissions & industry; dramatically decreased.

✅ Biggest remaining challenges: ozone and fine particulate matter.

for particulate matter; know critical size ranges and the reasons this matters, and atmospheric “sink” or how particles are removed from the atmosphere

• Critical size ranges:
  

  • PM₂.₅ (fine particles): ≤ 2.5 µm → penetrate deep into lungs, cause serious health effects (e.g., cardiovascular disease, chronic obstructive pulmonary disease).

  • PM₁₀ (coarse particles): ≤ 10 µm → affect upper respiratory tract.

  • Smaller particles stay suspended longer and travel farther.

• Why it matters: Smaller particles are more toxic, have longer atmospheric lifetimes, and can cross into the bloodstream.

• Atmospheric “sinks” / removal processes:
  

  • Gravitational settling (large particles fall out of the air)

  • Wet deposition (rain, snow)

  • Dry deposition (impaction on surfaces)

  • Chemical transformation (into less harmful compounds).

✅ Key idea: Particle size determines both health risk and atmospheric lifetime.

what factors contribute to elevated ozone levels in the atmosphere? how do VOCs contribute to this and what else is needed to cause a high ozone AQI?

• Key factors:
  

  • High levels of volatile organic compounds (VOCs) and nitrogen oxides (NOₓ)

  • Strong sunlight (drives photochemical reactions)

  • Warm temperatures and stagnant air (less dispersion)

  • Limited vertical mixing (e.g., temperature inversion traps pollutants near the surface).

• Role of VOCs:
  

  • VOCs react with NOₓ in sunlight to form tropospheric ozone, a major component of photochemical smog.

• Additional conditions for high AQI:
  

  • Urban emissions (traffic, industry)

  • Prolonged sunny, hot weather.

✅ Ozone is a secondary pollutant — it forms in the atmosphere rather than being emitted directly.

what are health impacts of each of the criteria air balloons plus hazardous air pollutants. know general mechanism of toxicity, sensitive populations symptoms. what is an example of air quality as an environmental justice issue?

• Criteria pollutants: (regulated under United States Environmental Protection Agency standards)
  

  • Particulate matter (PM): lung & heart disease, asthma, premature death.

  • Ground-level ozone: respiratory irritation, reduced lung function, worsened asthma.

  • Nitrogen dioxide (NO₂): airway inflammation, increased infection risk.

  • Sulfur dioxide (SO₂): bronchoconstriction, breathing difficulties.

  • Carbon monoxide (CO): reduced oxygen delivery → headaches, dizziness, heart strain.

  • Lead: neurological damage, developmental issues (especially in children).

• Hazardous air pollutants (HAPs):
  

  • Often carcinogenic or neurotoxic (e.g., benzene, formaldehyde, mercury).

  • Long-term exposure can affect organ systems and increase cancer risk.

• Sensitive populations: children, elderly, people with preexisting conditions, low-income communities, and those near pollution sources.

• Mechanism of toxicity: pollutants can trigger inflammation, oxidative stress, impaired oxygen transport, or direct cellular damage.

• Environmental justice example:
  

  • Communities located near highways, power plants, or industrial zones often face higher exposure and worse health outcomes due to inequitable pollution burdens.

✅ Air quality is both a public health and social equity issue.

what are some of the common sources of indoor air pollution in common air balloon balloons, both in the developed and developing world?

• Developing countries:
  

  • Burning solid fuels (wood, coal, crop waste, dung) for cooking and heating.

  • Poor ventilation in homes → buildup of smoke and particulates.

  • Use of kerosene lamps and stoves.

• Developed countries:
  

  • Emissions from gas stoves and heaters.

  • Tobacco smoke and secondhand smoke.

  • Off-gassing from building materials, cleaning products, and furniture (e.g., Formaldehyde, Volatile organic compounds).

  • Mold, dust, pet dander, and indoor allergens.

  • Inadequate ventilation increasing pollutant concentrations.

✅ Indoor air pollution is often higher than outdoor levels, especially in homes with poor ventilation or heavy fuel use.

what is the air quality index and what does it communicate? At what level (color or number) should most people be concerned and change their behavior?

Tells how polluted the air is and possible health risks.

• 0–50 Green: Good

• 51–100 Yellow: Moderate

• 101–150 Orange: Sensitive groups at risk

• 151–200 Red: Unhealthy

• 201–300 Purple: Very unhealthy

• 301+ Maroon: Hazardous
  ⚠ People should limit activity starting at Orange (101+).

What are actions of people can take to reduce their exposure to air pollutants particularly particulate matter? What about other air pollutants? What can be done beyond the individual level to reduce health harm from air pollution?

✅ Individual actions:

• Stay indoors on high pollution days

• Use air purifiers and wear masks (e.g., N95)

• Avoid heavy outdoor exercise when AQI is high

• Keep windows closed and use filtered ventilation

🏙 Community/Policy actions:

• Stricter emission standards

• Expand clean energy and public transit

• Urban green spaces and air monitoring

• Stronger environmental regulations

know some links between climate change and ambient air pollution also of indoor air pollution. How does climate change worse in air pollution? How do air pollutants (other than the primary long live greenhouse gas as we studied- carbon dioxide methane nitrous oxide) contribute to (or reduce) global warming?

🌍 Links:

• Climate change ↑ temperature → worsens air pollution (e.g., more ozone, wildfire smoke, stagnant air).

• Air pollution can also worsen climate change (e.g., black carbon warms atmosphere).

💨 Pollutants’ role:

• Warming: black carbon, ozone → trap heat.

• Cooling: sulfate aerosols reflect sunlight but harm health.

🏠 Indoor & outdoor: heat waves and wildfires increase indoor and ambient pollution.