Air Pollution Sources

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• Air Pollution Sources Effects
• Most local air pollution associated with cities,
  esp. large cities and industrial centers
• Average concentration of airborne particles in
  urban areas 10x concentration in rural areas
• Major cities air pollution causes thousands of
  deaths each year
• Los Angeles 6000
• New York 4000
• Detroit 2000
• Mexico City Air quality so severe that some
  people estimate breathing is equivalent to
  smoking two packs of cigarettes a day
• Many air pollutants are hygroscopic
• Combine with water and promote fog formation
• Particulate matter can affect local precipitation
• Boulder, CO Power plant produced fly ash
  aerosols and induced snowfall

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• Air Pollution Components
• Primary
• Problematic in the form in which theyre produced
• Ex Lead, carbon monoxide
• Secondary
• Require modification
• Ex Ozone
• Many are components of photochemical smog
  (react chemically with light)
• Legislation addressing air pollution requires
  consideration of both primary and secondary
  pollutants
• Clean Air Act 1970
• Clean Air Act Amendments 1990
• EPA NAAQS for six criteria pollutants

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• Air Pollution Components
• Particulate Matter
• Sources
• Combustion of fossil fuels, especially coal
• Mobile sources Cars, trucks
• Stationary sources Power plants, industrial
  furnaces, wood stoves
• Effects
• By the 1950s, air quality in London had
  deteriorated so much that incidences of death due
  to pollution werent uncommon
• 1952 Killer Smog in London ? 4000 deaths
• Health Respiratory impairment, lung damage,
  lung cancer
• Especially children, elderly, people with chronic
  respiratory problems
• Acidic PM can damage structures, reduce
  visibility

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LA - 1943
NYC - 1963
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• Air Pollution Components
• Particulate Matter
• Trends
• EPA Standards
• Pre-1987 TSP (Total Suspended Particulates)
• Post-1987 PM10 (Particles lt 10 µm)
• Post-1997 PM2.5 (Particles lt 2.5 µm)
• NAAQS for PM10
• Annual average 50 µg m-3 (revoked Dec 2006)
• Daily peak 150 µg m-3
• NAAQS for PM2.5
• Annual average 15 µg m-3
• Daily peak 35 µg m-3

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http//www.epa.gov/oar/particlepollution/basic.htm
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http//www.epa.gov/air/airtrends
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• Air Pollution Components
• Carbon Monoxide
• Colorless, odorless gas
• Produced by incomplete combustion of fossil fuels
  (too little O2 supplied in a normally tuned
  engine)
• Sources
• About 56 of CO emissions nationwide from on-road
  motor vehicles (22 from non-road vehicles)
• In cities, 85-95 of CO from motor vehicles
• Diesel engines typically produce less CO but more
  PM than gasoline engines
• Alternative to complete combustion of fuel is
  combustion of exhaust
• Produces hazardous amounts of heat
• Combustion temperature can be lowered using
  catalyst
• Chemical catalysts poisoned by lead

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• Air Pollution Components
• Carbon Monoxide
• Effects
• CO binds to hemoglobin in place of oxygen
• Affinity for CO 200x higher than for O2
• Continued exposure can lead to
• Impairment of vision
• Difficulty estimating time
• Reduced manual dexterity
• Poor learning ability
• Difficulty performing complex tasks
• Greater risk of heart attacks in people with
  certain forms of heart disease (e.g. angina)
• Contributes to formation of ground-level ozone

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1993-2002 Vehicle miles traveled increased 23
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• Air Pollution Components
• Nitrogen Oxides (NOx)
• Principally NO2
• Highly reactive reddish-brown gas
• Play a major role in the formation of ozone, PM,
  haze and acid rain
• Important component of photochemical smog
• Sources
• Forms from FF combustion at high temperatures
• Mobile Cars trucks (55)
• Stationary Power plants (22), home heaters,
  gas stoves, industrial plants (22 total)
• Formation could be controlled by using pure
  oxygen for combustion (impractical and dangerous)
• Formation reduced by low-temperature combustion

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Denver
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• Air Pollution Components
• Nitrogen Oxides (NOx)
• Effects
• Strong oxidizing agent
• Reacts readily in air to form nitric acid and
  nitrates
• Health
• Irritates lungs and lower resistance to
  respiratory infections
• Lung damage
• Environment
• Damages plant foliage, impairs growth
• Precursor of ground-level ozone, PM, smog
• Contributes to acid rain
• - Leaching of minerals from soil
• - Acidification of lakes and waterways
• Contributes to eutrophication of lakes
  waterways
• Contributes to global warming (N2O)

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• Air Pollution Components
• Ozone (O3)
• Primary constituent of photochemical smog
• Secondary pollutant (ground-level ozone)
• Formed from NOx and volatile organic chemicals
  (VOCs) in the presence of heat and sunlight
• Sources
• Gasoline vapors (gas tanks, gas cans)
• Chemical solvents (chemical plants, factories,
  refineries, commercial products)
• Fossil fuel combustion (motor vehicles)
• Precursor gas emissions may be concentrated in
  one area, but gases may be carried far from
  sources before forming ozone

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• Air Pollution Components
• Ozone (O3)
• Effects
• 1994 20 of US population lived in counties
  with ozone levels above EPA standards
• Worst city Los Angeles
• Health
• Respiratory inflammation
• Reduction of lung function
• Chest pain, coughing, nausea, pulmonary
  congestion
• Permanent lung damage from repeated exposure

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Phoenix
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Taj Mahal
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• Air Pollution Components
• Ozone (O3)
• Effects
• 1994 20 of US population lived in counties
  with ozone levels above EPA standards
• Worst city Los Angeles
• Health
• Respiratory inflammation
• Reduction of lung function
• Chest pain, coughing, nausea, pulmonary
  congestion
• Permanent lung damage from repeated exposure
• Environment
• Impair plant growth
• Damage plant foliage
• Ozone causes several billion dollars in
  agricultural crop loss each year
• Damage to forest ecosystems

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• Air Pollution Components
• Sulfur Oxides (SOx)
• Mostly SO2 but some SO3
• Reactive gases
• Important in the formation of photochemical smog
  and acid rain
• Sources
• Formed when fuel containing sulfur (mainly coal
  and oil) is burned
• Electricity generation (67)
• Metal smelting (3)
• Paper manufacturing
• Other industrial processes (18 total)

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• Air Pollution Components
• Sulfur Oxides (SOx)
• Effects
• Major precursor to PM2.5
• Combine with water to form sulfuric acid
• Major component of acid rain
• Health
• Temporary breathing impairment
• Respiratory illness
• Aggravation of cardiovascular disease
• Especially harmful to elderly and children
• Environment
• Damage to structures and objects
• Leaching of minerals from soil
• Damage to plants/foliage
• Acidification of lakes and waterways

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• Air Pollution Components
• Lead (Pb)
• Sources
• Formerly motor vehicles
• Transition to unleaded gasoline virtually
  eliminated this source
• Industrial plants
• Smelters
• Battery manufacturers
• Human exposure mostly through inhalation of lead
  in air and dust
• Food
• Paint
• Water

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• Air Pollution Components
• Lead (Pb)
• Effects
• Not readily excreted by body
• Accumulates in tissues, especially kidneys,
  liver, nervous system, bones
• Health
• Anemia
• Kidney disease
• Reproductive disorders
• Neurological problems (seizures, mental
  retardation, behavioral disorders)
• Birth defects (CNS damage, retarded growth)
• High blood pressure ? heart disease
• Environment
• Deposition on leaves of plants is hazardous to
  grazing animals and humans (ingestion of meat)

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Comparison of growth measures and emissions,
1980-2006
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Estimated county-level cancer risk from the 1999
National Air Toxics Assessment (NATA99)