Air Pollution

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Air Pollution

• Ch 12

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Review Atmosphere Structure
Stratospheric ozone layer GOOD
Human caused air pollution is mainly in the
Troposphere (CO2, ozone, Sox, Nox)
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What is Air Pollution

• Presence of chemicals in the atmosphere that
  affect climate, human health, and animal health
• Outdoor air pollution and indoor air pollution
• 2 Main Types of Pollutants
• Primary Pollutants emitted directly into
  atmosphere in harmful form (soot and CO2)
• Secondary Pollutants new pollutants that form
  when primary pollutants react with air molecules
  (Sox, Nox)
• 1 out of every 6 people on earth live in areas
  with unhealthy air

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Main Outdoor Air Pollutants
Pollutant Description Source Health Effects
Carbon Monoxide CO Colorless, odorless gas Fossil fuel burning (vehicles), cigarette smoke Reduces O2 transport in body, can cause lung problems and death
Nitrogen Dioxide NO2 Reddish brown gas (gives smog its color) Fossil fuel burning (vehicles and industry) Lung problems bronchitis and asthma Acid deposition
Sulfur Dioxide SO2 Colorless gas Coal burning (industry) Breathing problems asthma Acid Deposition
Suspended Particulate Matter (SPM) Particles and droplets Coal burning, vehicle emissions Throat irritation, lung damage
Ozone O3 Irritating gas, has bad odor Reaction with VOCs, Car emissions Breathing problems, coughing, lung diseases
Lead Solid toxic metal Paint, smelting, batteries Nervous system damage
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Carbon Dioxide

• Not classified as an air pollutant according to
  the EPA
• Most scientists think it should be
• High concentrations in atmosphere
• Humans have been adding to this by cutting down
  forests, which would normally absorb CO2
• Considerable evidence that global warming is
  influenced greatly by human-released CO2

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Photochemical Smog

• Formed when NOXs (nitrous oxides) and VOCs
  (volatile organic compounds) react with the help
  of UV rays
• Mix of more than 100 primary and secondary
  pollutants
• Ground-level ozone, nitric acid, aldehydes
• Hotter daysmore photochemical smog
• Car emissions and industry are biggest causes

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Industrial Smog (Gray-Air Smog)

• Mixture of Sox, sulfuric acid, and particulates
  emitted from burning coal and oil
• Particles include salts and carbon causing it to
  have a gray color.
• Can be easily reduced with pollution controls
  like scrubbers and precipitators
• Common in China, India, Ukraine
• Lots of coal burning with few pollution controls
  used

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Factors Influencing Smog Formation

• Reducing Smog
• Rain and snow
• clean the air
• Dry cities more susceptible to smog
• Salt Spray (oceans)
• Wash air and remove pollutants
• Winds
• Dilute pollutants and sweep them away

• Increasing Smog
• Buildings
• Slow winds and reduce dilution
• Hills/mountains
• Reduce air flow
• High Temperatures
• Promote smog-forming chemical reactions
• Grasshopper Effect
• Moves pollution to earths poles

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Grasshopper Effect
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Temperature Inversions

• Layer of warm air sitting on top of a layer of
  cool air near the ground
• Susceptible areas
• Valleys surrounded by mountains that have cold,
  cloudy weather during parts of the year
• Large cities (millions of people) with low winds,
  sunny days, ocean on one side and mountains on
  the other (Los Angeles)
• Can cause pollutants to concentrate near the
  surface
• This can cause breathing problems and coughing,
  and has been known to be deadly in some instances

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Case Asias Brown Cloud

• Industrial smog stretching from India to China,
  and even into the ocean
• Reduces solar energy getting to the earths
  surface by as much as 15
• Leads to food harvest reductions
• Increase in respiratory disease in these areas
• Both China and India are beginning to take steps
  to reduce their pollution levels

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Indoor Air Pollution

• Yes, there is indoor air pollution and
• Levels of pollutants are much higher inside than
  outside!!!
• Buildings 2-5 times higher
• Cars 100 times higher
• Much greater threat to human health than outdoor
  pollution
• People spend 70-98 of their time indoors
• Sick Building Syndrome pollutants indoors
  leading to health problems like
• Sneezing, headaches, dizziness, nausea, fatigue,
  flu-like symtoms

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Formaldehyde

• Causes the most problems indoors for people in
  developed countries
• Used to manufacture many households goods
• Plywood, particle-board, paneling, flooring,
  cabinets, furniture, insulation, nail polish
• 20-40 million Americans have issues from daily
  exposure to formaldehyde
• 1/5000 people living in manufactured homes for 10
  years or more develops cancer from formaldehyde
  exposure

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Radon Gas (Radon-222)

• Radioactive gas found in soil and rocks
• Can seep into houses
• Increase risk of lung cancer
• Enters buildings through cracks in the
  foundations and walls, openings in sump pumps,
  and through concrete blocks
• EPA recommends all households test for radon gas
  at some point (20-100)

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Air Pollution Effects

• Asthma allergic reaction causing muscle spasms
  in bronchial walls
• Asthma in children increased by 160 between
  1980-1994
• Chronic Bronchitis continual inflammation of
  bronchi and bronchioles
• Emphysema irreversible damage to air sacs
  causing extreme shortness of breath

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Laws Air Pollution

• Clean Air Act
• 1970, 1977, 1990
• Directed EPA to establish national air quality
  standards
• Included maximum allowable levels for 188 HAP
  (Hazardous Air Pollutants)
• Requires companies to submit toxic release
  inventories

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Have We Made a Difference?

• Combined emissions have decreased 48
• Lead down 93
• CO down 41
• VOCs down 40
• SPM down 34
• SOx down 33
• NOx down 15
• The bad news
• Mercury and dioxin releases have increased
• Both are toxic at low levels

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Emissions Trading

• Allows the most polluting power plants in the US
  to buy and sell Sox emissions rights, Nox
  emissions, and VOC emissions
• Part of the Clean Air Act of 1990
• Cap and Trade approach to Sox emissions
• Helped reduce SOx emissions by 40
• Not well regulated abusing program, not
  reducing emissions as much as planned

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Reducing Pollution

• Coal Burning Industry
• Cleaner burning technology fluidized beds
• Emissions filtration scrubbers, electrostatic
  precipitators
• Vehicle Pollution
• Get rid of old, high polluting vehicles and
  replace with hybrid vehicles
• use zeolites to remove sulfur from gasoline
• Indoor Air Pollution
• Cover AC ducts
• Limit formaldehyde emissions
• Limit hazardous substance use in homes and
  businesses