Air Pollution

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Air Pollution

• Major Air Pollutants
• Clean Air Act EPA

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Air Pollution

• During the 1950s and 1960s, most factories
  looked like this

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Air Pollution

• The term Smog (smoke and fog) was first used in
  1905 to describe sulfur dioxide emission
• In 1952, severe pollution took the lives of 5000
  people in London
• It isnt pollution thats harming the
  environment. Its the impurities in our air and
  water that are doing it.
  
  Former U.S. Vice President Dan Quayle

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Air Pollution

• Natural sources of air pollution are often made
  worse by human activity.
• Land use policies
• Slash and burn agriculture
• Build up of fuel wood from fire suppression in
  U.S. national forests

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Air Pollution

• Anthropogenic (human caused) air pollution
• Point sources
• Coal-fired power plants smokestack
• Non-Point sources
• Automobiles

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Air Pollution

• Primary air pollutants
• Come directly out of a smokestack or exhaust pipe
• Carbon monoxide
• Carbon dioxide
• Sulfur dioxide
• Nitrous oxides
• Most suspended particulate matter
• Secondary air pollutants
• Have undergone chemical change or transformation
  in the presence of sunlight with water or with
  oxygen in the atmosphere
• Sulfuric acid
• Ozone

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Where do the air pollutants come from?
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Major Sources of Primary Pollutants

• Stationary Sources
• Combustion of fuels for power and heat Power
  Plants
• Other burning such as Wood crop burning or
  forest fires
• Industrial/ commercial processes
• Solvents and aerosols
• Mobile Sources
• Highway cars, trucks, buses and motorcycles
• Off-highway aircraft, boats, locomotives, farm
  equipment, RVs, construction machinery, and lawn
  mowers

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Human Impact on Atmosphere

• Refining petroleum and burning fossil fuels and
  manufacturing
• Adds CO2 and O3 to troposphere
• Climate Change
• Produces Acid Rain
• Releases SO2 into troposphere
• Releases toxic heavy metals (Pb, Cd, and As) into
  troposphere
• Using Nitrogen fertilizers and burning fossil
  fuels
• Releases NO, NO2, N2O, and NH3 into troposphere
• Produces acid rain

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Where are we at today?

• There are six criteria air pollutants established
  by the EPA
• Carbon Oxides
• Nitrogen Oxides
• Particulate matter
• Lead
• Sulfur Oxides
• Tropospheric Ozone (ground)

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Major Air Pollutants

• Carbon oxides
• Properties
• colorless, odorless, heavier than air, 0.0036 of
  atmosphere
• highly toxic gas that forms during the incomplete
  combustion of carbon-containing materials.
• Sources
• incomplete combustion of fossil fuels 60 - 95
  from auto exhaust
• Carbon monoxide (CO) is a 93 of carbon dioxide
  (CO2) in the troposphere occurs as a result of
  the carbon cycle.
• 7 of CO2 in the troposphere occurs as a result
  of human activities (mostly burning fossil
  fuels).
• Effects
• binds tighter to Hgb than O2
• Impairs mental functions and visual acuity, even
  at low levels
• EPA Standard 9 ppm
• 5.5 billion tons enter atmosphere/year

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Mobile Source Emissions - CO
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Major Air Pollutants

• Suspended particulate matter (SPM)
• Properties
• Consists of a variety of solid particles and
  liquid droplets small and light enough to remain
  suspended in the air.
• The most harmful forms of SPM are fine particles
  (PM-10, with an average diameter lt 10
  micrometers) and ultrafine particles (PM-2.5).
• Sources
• Burning coal or diesel
• Volcanoes
• Asbestos
• PCBs, dioxins, pesticides
• unpaved roads, plowing, burning fields
• lint, pollen, spores
• Effects
• lung damage,
• mutagenic, carcinogenic, teratogenic
• EPA Standard 50 ug/m3 (annual mean)
• SPM is responsible for about 60,000 premature
  deaths a year in the U.S.

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Mobile Source Emissions Fine Particulate Matter
(PM2.5)
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Major Air Pollutants

• Nitrogen oxides
• Properties
• Reddish brown gas
• NO reacts with air to form NO2.
• NO2 reacts with water vapor in the air to form
  nitric acid (HNO3) and nitrate salts (NO3-) which
  are components of acid deposition.
• Sources
• lightening and certain soil bacteria.
• fossil fuels combustion at high temperatures
• power plants, forest fires, volcanoes, bacteria
  in soil
• Effects
• acid rain
• lung and heart problems
• decreased visibility (yellow haze)
• suppresses plant growth
• EPA Standard 0.053 ppm

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Mobile Source Emissions Nitrogen Oxides
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Major Air Pollutants

• Lead
• Properties
• Heavy metal
• Effects
• Is a powerful neurotoxin.
• accumulates in tissue
• affects kidneys, liver and nervous system
  (children most susceptible)
• mental retardation
• possible carcinogen
• 20 of inner city kids have high levels
• Sources
• particulates, smelters, batteries
• Was removed from gasoline over three decades ago
• Concentrations in the air have declined
  precipitously
• Mercury from coal fired power plants is now of
  greater concern than lead
• EPA Standard
• 1.5 ug/m3
• 2 million tons enter atmosphere/year

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Major Air Pollutants

• Volatile organic compounds (VOCs)
• Properties
• Most are hydrocarbons emitted by the leaves of
  many plants and methane
• Organic compounds that evaporate easily, usually
  aromatic
• Benzene
• Chlorofluorocarbons (CFCs
• Sources
• Vehicles (largest source), evaporation of
  solvents or fossil fuels, aerosols, paint
  thinners, dry cleaning
• About two thirds of global methane emissions
  comes from human sources.
• Other VOCs include industrial solvents such as
  trichlorethylene (TCE), benzene, gasoline, paint
  thinner, and vinyl chloride.
• Effects
• Long-term exposure to benzene can cause cancer,
  blood disorders, and immune system damage.
• eye and respiratory irritants
• Carcinogenic
• Liver, CNS, or kidney damage
• Damages plants
• Lowered visibility due to brown haze
• Global warming

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Major Air Pollutants

• Sulfur dioxide (SO2)
• Properties
• colorless gas with irritating odor
• Sources
• About one-third of SO2 in the troposphere occurs
  naturally through the sulfur cycle.
• Two-thirds come from human sources, mostly
  combustion (S O2 ? SO2) of sulfur-containing
  coal and from oil refining and smelting of
  sulfide ores, paper manufacture
• Effects
• produces acid rain (H2SO4),
• breathing difficulties,
• eutrophication due to sulfate formation (lichen
  and moss are indicators)
• EPA Standard 0.3 ppm (annual mean)

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Major Air Pollutants

• Ozone (O3)
• Properties
• colorless, unpleasant odor
• highly reactive gas
• major component of photochemical smog
• Sources
• Created by sunlight acting on NOx and VOC
• Photocopiers, chemical solvents
• Cars
• Industry
• Incomplete fuel combustion products
• Effects
• Lung irritant
• Cause and aggravate respiratory illness
• Can aggravate heart disease
• Eyes
• Damage plants, rubber in tires, fabrics, and
  paints
• 0.1 ppm can lower PSN by 50
• 10,000 to 15,000 people in US admitted to
  hospitals each year due to ozone-related illness

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Mobile Source Emissions Hydrocarbons
Precursors to Ozone
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Sunlight plus Cars Equals Photochemical Smog

• Mexico City is one of the many cities in sunny,
  warm, dry climates with many motor vehicles that
  suffer from photochemical smog.

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Sunlight plus Cars Equals Photochemical Smog

• Photochemical smog is a mixture of air pollutants
  formed by the reaction of nitrogen oxides and
  volatile organic hydrocarbons under the influence
  of sunlight.

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Clean Air Act of 1963

• Congress found
• Most people now live in urban areas
• Growth results in air pollution
• Air pollution endangers living things
• It decided
• Prevention and control at the source was
  appropriate
• Such efforts are the responsibility of states and
  local authorities
• Federal funds and leadership are essential for
  the development of effective programs

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Clean Air Act

• Originally signed 1963
• States controlled standards
• 1970 Uniform Standards by Federal Govt.
• Standards were stricter
• Limits on emissions
• New funding
• Pollution control research
• Citizens could sue
• Criteria Pollutants
• Primary Human health risk
• Secondary Protect materials, crops, climate,
  visibility, personal comfort

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Clean Air Act

• 1990 version
• Strengthened regulations pertaining to air
  quality standards
• Set nation wide standards for emissions of the
  six criteria pollutants
• Left it up to the States to regulate and monitor
• Emissions trading program introduced (Cap and
  Trade)
• Total emissions have declined by 60 despite
  substantial increases in energy consumption,
  miles traveled by vehicles and gross domestic
  product

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Clean Air Act

• 1990 Policy changes and developments
• Catalytic converters - Required on all new U.S.
  autos since 1975
• Scrubbers use a combination of air and water
  that separates and removes particulates and SO2
  before they are emitted from smokestacks
• Leaded gasoline phase out caused U.S. lead
  emissions to plummet by 93 in the 1980s alone
• Electrostatic precipitators installed in
  smokestacks use an electrical charge to make
  particulates coalesce to that they can be
  physically removed

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Clean Air Act

• 1997 version
• Reduced ambient ozone levels
• Cost 15 billion/year -gt save 15,000 lives
• Reduce bronchitis cases by 60,000 per year
• Reduce hospital respiratory admission 9000/year

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Clean Air Act

• 2007
• U.S. Supreme Court ruled that carbon dioxide
  should be considered an air pollutant under the
  Clean Air Act
• 2009
• EPA proposed that it should be considered an air
  pollutant at some point in the future

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General Status of Global Air Quality

• Some pollutants are not declining, some new air
  pollutants are emerging and green house gas
  emissions continue to rise
• CO2 rose 44 from 1970 to 2008
• Industrializing nations such a China and India
  are suffering increasing air pollution problems
• China has fueled its rapid industrial development
  with its abundant reserves of coal.
• Brown Cloud
• Rural issue great deal of air pollution
  emanates from feedlots (dust, methane, hydrogen
  sulfide, ammonia

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South Asias Massive Brown Cloud

• A huge dark brown cloud of industrial smog,
  caused by coal-burning in countries such as China
  and India, stretches over much of southeastern
  Asia.
• In areas beneath the cloud, photosynthesis is
  reduced interfering with crop development.
• Fine particles and droplets in the cloud appear
  to be changing regional climates (including
  rainfall).
• May have contributed to floods in 2002 and 2005
  which killed thousands of people.

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• Hopefully Not The End