Transcript Distribution of national total emissions estimates by source category for specific pollutants, 2010 www.epa.gov/air/airtrends/2011/index.html.

Distribution of national total emissions estimates
by source category for specific pollutants, 2010
www.epa.gov/air/airtrends/2011/index.html
Air Pollution – Components
IV.
A.
Particulate Matter
1.
Sources
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2.
Combustion of fossil fuels, especially coal
Mobile sources – Cars, trucks
Stationary sources – Power plants, industrial furnaces,
wood stoves
Dust production – Agriculture, unpaved roads
Effects
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By the 1950s, air quality in London had deteriorated so
much that incidences of death due to pollution weren’t
uncommon
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1952 – “Killer Smog” in London  4000+ deaths
Health – Respiratory impairment, lung damage, lung
cancer
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Especially children, elderly, people with chronic
respiratory problems
Acidic PM can damage structures, reduce visibility
LA - 1943
NYC - 1963
Beijing
IV. Air Pollution – Components
A.
Particulate Matter
3.
Trends
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EPA Standards
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Pre-1987 – TSP (Total Suspended Particulates)
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Post-1987 – PM10 (Particles < 10 μm)
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Post-1997 – PM2.5 (Particles < 2.5 μm)
NAAQS for PM10
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Annual average = 50 μg m-3 (revoked Dec 2006)
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Daily peak = 150 μg m-3
NAAQS for PM2.5
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Annual average = 15 μg m-3
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Daily peak = 35 μg m-3
PM10
1990-2010:
Direct PM10 emissions down 67%
PM2.5
1990-2010:
Direct PM2.5 emissions down 55%
http://www.epa.gov/air/airtrends
Air Pollution – Components
IV.
B.
Carbon Monoxide
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Colorless, odorless gas
Produced by incomplete combustion of fossil fuels
(too little O2 supplied in a normally tuned engine)
Sources
1.
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About 56% of CO emissions nationwide from motor
vehicles
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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
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Produces hazardous amounts of heat
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Combustion temperature can be lowered using
catalyst
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Chemical catalysts poisoned by lead
IV. Air Pollution – Components
B.
Carbon Monoxide
2.
Effects
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CO binds to hemoglobin in place of oxygen
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Affinity for CO ~ 200x higher than for O2
Continued exposure can lead to
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Impairment of vision
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Difficulty estimating time
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Reduced manual dexterity
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Poor learning ability
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Difficulty performing complex tasks
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Greater risk of heart attacks in people with
certain forms of heart disease (e.g. angina)
Contributes to formation of ground-level ozone
Carbon Monoxide
1990-2010:
CO emissions down 60%
1990-2010: Vehicle miles traveled increased 40%
Air Pollution – Components
IV.
C.
Nitrogen Oxides (NOx)
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Principally NO2
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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
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Forms from FF combustion at high temperatures
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Mobile – Cars & trucks (56%)
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Stationary – Power plants (33%), home heaters, gas
stoves, industrial plants (11% total)
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Formation could be controlled by using pure
oxygen for combustion (impractical and dangerous)
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Formation reduced by low-temperature combustion
Denver
Air Pollution – Components
IV.
C.
Nitrogen Oxides (NOx)
2.
Effects
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Strong oxidizing agent
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Reacts readily in air to form nitric acid and nitrates
Health
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Irritates lungs and lower resistance to respiratory
infections
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Lung damage
Environment
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Damages plant foliage, impairs growth
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Precursor of ground-level ozone, PM, smog
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Contributes to acid rain
- Leaching of minerals from soil
- Acidification of lakes and waterways
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Contributes to eutrophication of lakes & waterways
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Contributes to global warming (N2O)
NO2
1990-2010:
NOx emissions down 48%
IV. Air Pollution – Components
D.
Ground-Level Ozone (O3)
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Primary constituent of photochemical smog
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1.
Secondary pollutant (ground-level ozone)
Formed from NOx and volatile organic chemicals
(VOCs) in the presence of heat and sunlight
Sources
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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
IV. Air Pollution – Components
D.
Ground-Level Ozone (O3)
2.
Effects
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2010 – 35% of US population lived in counties with
ozone levels above EPA standards
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Worst city = Los Angeles
Health
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Respiratory inflammation
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Reduction of lung function
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Chest pain, coughing, nausea, pulmonary
congestion
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Permanent lung damage from repeated
exposure
Phoenix
Taj Mahal
Air Pollution – Components
IV.
D.
Ground-Level Ozone (O3)
2.
Effects
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2010 – 35% of US population lived in counties with
ozone levels above EPA standards
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Worst city = Los Angeles
Health
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Respiratory inflammation
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Reduction of lung function
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Chest pain, coughing, nausea, pulmonary
congestion
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Permanent lung damage from repeated exposure
Environment
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Impair plant growth
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Damage plant foliage
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Ozone causes several billion dollars in agricultural
crop loss each year
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Damage to forest ecosystems
1990-2010: VOC emissions down 52%
IV. Air Pollution – Components
E.
Sulfur Oxides (SOx)
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Mostly SO2 but some SO3
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Reactive gases
Important in the formation of photochemical
smog and acid rain
Sources
1.
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Formed when fuel containing sulfur (mainly coal
and oil) is burned
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Electricity generation (84%)
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Metal smelting (3%)
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Paper manufacturing
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Other industrial processes (9% total)
Air Pollution – Components
IV.
E.
Sulfur Oxides (SOx)
2.
Effects
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Major precursor to PM2.5
Combine with water to form sulfuric acid
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Major component of acid rain
Health
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Temporary breathing impairment
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Respiratory illness
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Aggravation of cardiovascular disease
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Especially harmful to elderly and children
Environment
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Damage to structures and objects
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Leaching of minerals from soil
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Damage to plants/foliage
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Acidification of lakes and waterways
SO2
1990-2010:
SO2 emissions down 65%
IV. Air Pollution – Components
F.
Lead (Pb)
1.
Sources
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Formerly motor vehicles
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Transition to unleaded gasoline virtually
eliminated this source
Industrial plants
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Smelters
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Battery manufacturers
Human exposure mostly through inhalation of lead
in air and dust
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Food
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Paint
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Water