GEOG 3000 Resource Management Urban Air Pollution and Impacts

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GEOG 3000 Resource ManagementUrban Air
Pollution and Impacts

• M.D. Lee CSU Hayward Winter 2004

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Air as a resource Clean air

• We take air for granted but it is an important
  resource in itself and has many indirect resource
  benefits. Principally
• It is our source of life-giving oxygen (this
  function appears not at risk virtually
  perpetual).
• It regulates the temperature and processes of our
  climate (undergoing change - conditional).
• It protects us from harmful UV-rays from the sun
  (undergoing change conditional).
• It accepts, dilutes and removes harmful
  pollutants from our immediate environment
  (thresholds are easily passed - conditional).

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Background conditions

• Humans and most other species have evolved under
  conditions of remarkable stability in the
  chemistry of air, which is predominantly nitrogen
  (4/5) and oxygen (1/5) and a variety of minor
  but important other gases with relatively rapid
  cycles.
• Atmospheric fall-out (gravity), photosynthesis,
  adsorption and the solvent action of
  precipitation help to regulate the ambient
  chemistry of air in a steady equilibrium.
• However, natural assimilative processes can be
  overwhelmed by human decisions to use the air
  resource intensively as a sink for waste.

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 Air - A commons resource

• The air is a commons resource - shared by all,
  owned by none.
• Individual property owners may sell or lease the
  rights to the air above their property for the
  construction of wind farms or high rise
  buildings, and nations have sovereign control of
  the air space above their territories.
• Although rights are assigned to air-space,
  these are not physical boundaries and air, and
  the pollutants that enter it, moves freely from
  one geographical location to another, often with
  relatively consistent patterns.
• Pollution can thus be exported and the off-site
  effects (the fall out) of a particular resource
  decision can create major conflicts and
  externalities via the air masses.

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The concept of airsheds

• It is possible to recognize theoretical airsheds
  - the locations over which a given pollutant will
  probabilistically be distributed from a given
  source, given prevailing wind patterns.
• Airsheds are not topographically fixed like
  watersheds but help us to understand the
  distributed nature of air resource issues and
  problems.
• Airsheds and the fate of pollutants are a
  function of wind speeds and directions, measured
  by anemometers and plotted out on wind roses (a
  circular graph with its (0,0) at the center and
  360 degree lines radiating out as axes for
  plotting).

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A Theoretical Air Shed
Predominant Wind Direction
Pollution Point Source
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Clean air - A modern resource goal

• Air pollution has been with us since humans first
  experimented with fire.
• The importance of air and its pollution as a
  resource issue has grown with increasing
  urbanization and industrialization, and
  especially with the intensive combustion of
  fossil fuels.
• Clean air is particularly important for human
  health, for the productivity of biotic resources,
  for aesthetic resources, and for the hydrological
  cycle.

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Important impacts

• Health impacts - from breathing in solids and
  chemicals that directly affect the surface of the
  lungs, enter the bloodstream or irritate the skin
  and mucus membranes or cause secondary effects
  such as heart-failure from reduced lung
  performance

• Aesthetic impacts - reductions in visibility and
  clarity in areas of outstanding scenic beauty
• Ecological impacts - changes to water and soil
  chemistry, damage to food webs, genetic
  modifications (esp. from UV radiation increased
  by ozone depletion and the changes it causes to
  DNA)

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Important impacts

• Physical impacts - mechanical or chemical damage
  to the surface of buildings, vehicles, and other
  human structures
• Agricultural impacts - damages the photosynthetic
  or reproductive capabilities of vegetation
  through leaf or bud damage
• Climate impacts - changes to global heat budget,
  UV radiation levels, weather patterns and
  ultimately sea levels

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Unclean air - scale effects

• The loss of clean air manifests itself at a range
  of nested, interrelated scales with a variety of
  impacts.
• Local hot-dry photochemical (LA) and cold-wet
  (London) smogs, chemical and particulate haze,
  dust storms and domes.
• Regional - acid deposition/precipitation,
  non-point source water pollution.
• Global - atmospheric warming, climatic and hazard
  frequency/intensity changes, sea level change (a
  key land issue), UV radiation increases.

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Air regulations

• Air quality in the US is regulated by the EPA
  through the Clean Air Act of 1970 and subsequent
  amendments and this sets national ambient air
  quality standards or NAAQS.
• Six Criteria Air Pollutants are controlled by
  this act suspended particles (PM10 or dust microns), sulfur oxides, carbon monoxide,
  nitrogen oxides, ozone and lead.
• A seventh pollutant controlled by the act is
  actually a range of chemicals grouped under the
  term volatile hydrocarbons.
• The EPA has estimated in studies that the Clean
  Air Act costs the US some 20 billion per year
  but saves around 400 billion in avoided costs.

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Today's Big Five Primaries

• Particulates (soot, smoke, dusts and mists)
  they create problems of visibility, corrosion,
  irritation, etc. (especially those less than
  
• Nitrogen oxides (NOxs - NO and NO2) - from
  combustion creates problems of acidification,
  plant growth inhibition, and heat adsorption.
• Sulfur oxides - principally from coal creates
  problems of acidification, corrosion, lung
  irritation.
• Carbon monoxide (CO) from carbon fuels -
  poisonous.
• Hydrocarbons from solvents, unburned fuels,
  etc. creates problems of visibility,
  irritation, carcinogenic.
• Note that ozone is not a primary pollutant but a
  product of other pollutants introduced to the
  atmosphere.

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Current emissions in the United States of five
primary air pollutants, by source, for 1998. Fuel
combustion refers to fuels burned for electrical
power generation and for space heating. (Source
EPA Office of Air Quality, 2000.)
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Pollution and Respiration

• With every breath, we take in from 200 to 500 cm3
  (12 to 30 in3) of air depending on our anatomy
  and level of exertion.

• Thus, in our lifetime we will probably inhale
  between 126 and 315 million liters of air.
• Even if there is only one part per million of a
  pollutant in the air, that would mean breathing
  in between 126-315 kg over a lifetime or 275-700
  .
• Childrens lungs are much smaller than adults,
  with smaller bronchioles that are easily blocked,
  irritated or damaged (why asthma is a common
  childhood illness).
•  

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Air Quality Standards

• Establishing standards is a tricky subject - the
  science is not clear on the effects of short and
  long term exposure to low or high concentrations
  of different pollutants.
• Air quality standards are expressed as an average
  concentration over a specific time period (e.g.
  an hour, a day, or a year).
• Concentrations are expressed in parts per million
  (ppm) or micrograms of pollutant per cubic meter
  of air (µg/m³), e.g. ozone might be measured as
  0.12 ppm averaged over 1 hour.
• Standards need to take into account the fact that
  air pollutants can have acute impacts
  (short-duration, high concentration) and chronic
  impacts (long duration, often small
  concentrations not causative of acute responses)

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The Clean Air Act

• Environmentalists think it is too weak,
  industrialists too strong.
• States are responsible for preparing and
  implementing "State Implementation Plans" to
  achieve and maintain the air quality standards
  within their borders.
• They divide into "Air Quality Control Regions."
  e.g. Bay Area Air Quality Management Board and
  establish individual requirements for controlling
  air pollution within each region since some are
  more problematic than others (e.g. Sacramento,
  Bay Area and LA in these regions a different
  gasoline formulation is required).
• Californias urban regions have been very strict
  in interpreting Clean Air regulations and have
  frequently been sued or petitions made to the
  federal courts to overturn standards (for
  example, the current battle in congress over CA
  emissions standards for lawnmowers).

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Why the Clean Air Act?

• The residents of the US top ten most polluted
  cities have a 15-17 higher risk of premature
  death from all causes than the people living in
  the top ten least polluted cities.
• In the US, air pollution causes an extra 30,000
  to 60,000 people per year to die prematurely -
  2-3 of all deaths in the country.
• Air pollution causes damage to trees, plants and
  agricultural crops (estimated up to 5.4 b per
  year).
• It damages buildings, cars, statues and other
  exterior surface materials (estimated at 5b per
  year).

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Battling the Clean Air Act

• The Clean Air Act has done a good job at reducing
  most of the regulated pollutants (although
  nitrogen dioxide has been problematic)
• Carol Browner (EPA - Clinton Admin.) tried to
  significantly beef up standards for PM-10s and
  ozone but the EPA has been repeatedly taken to
  court over CAA amendments.
• New regulations were drafted in 1997 to reduce
  acceptable ozone levels from 0.12 to 0.08 ppb and
  further reduce PM-10 levels.
• A consortium of business groups challenged these
  changes as being too costly and unscientific and
  won their case in 1999.

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Air Quality and Automobiles

• Gasoline powered internal combustion engines are
  key sources of smog, acid precipitation and
  global warming causing pollutants.
• Todays cars are 60-80 less polluting than they
  were in the 1960s, however, they are used to a
  greater degree.
• In the US in 1970, we collectively drove our
  motor vehicles 1,000,0000,000 miles and today we
  drive over 4,000,000,000 wiping out any pollution
  efficiency gains.
• Buses and trucks have not significantly cleaned
  up their diesel engines since the 1970s, although
  they will have to by 2007 because of legislation
  signed during the Clinton administration.

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US Trends in Major Pollutants
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Clean Air Act Elements

• The act required the use of catalytic converters
  the metallic lining of the converters react
  with exhaust gases to reduce CO and NOx outputs
  for at least the first 100,000 miles of a car.
• Cleaner fuels are now required with oxygenates to
  promote more complete combustion and less
  pollution (but this has back-fired by choosing
  MTBE).
• Industries have to implement toxic release risk
  analyses and develop prevention plans and also
  must control normal release of over 100 listed
  toxics e.g. benzene.
• High risk states are required to implement
  vehicle inspection programs (smog tests) and
  require repairs to be made.

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Market-Based Approaches

• The EPA has been implementing offset programs for
  pollutants such as sulfur dioxide since 1990.
• Permits have been issued to large polluters (for
  example, power stations or refineries) in
  particular management districts (non-attainment
  areas) and they can be bought and sold.
• Thus polluters who cannot meet the pollution
  reduction targets can buy the permits of others
  who have managed to exceed reduction targets, the
  effect being an overall reduction in emissions,
  theoretically in an economically optimum way.
• A similar program has been contemplated for
  carbon dioxide and other greenhouse gases, but at
  a global scale (one country buying carbon rights
  from others).