Download Indoor Air Pollution

Brodnax
Concept 18-1: The atmosphere is structured in layers, including the troposphere, which supports life,
and the stratosphere, which contains the protective ozone layer.
Atmosphere Video
Troposphere
75–80% of the earth’s air mass
Closet to the earth's surface
Chemical composition of air
Rising and falling air currents:
weather and climate
Involved in chemical cycling
Stratosphere
Concept 18-2: Pollutants mix in the air to form industrial smog, mostly the
result of burning coal, and photochemical smog, caused by motor vehicle,
industrial, and power plant emissions.
Air Pollution comes from natural and human
sources
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Air pollution: the presence of chemicals in the
atmosphere in concentrations high enough to harm
organisms, ecosystems, or human-made materials

Natural sources
• Dust blown by wind
• Pollutants from wildfires and volcanoes
• Volatile organics released by plants

Human sources: mostly in industrialized and/or urban areas
• Stationary sources: power plants, industrial sources
• Mobile sources: cars

Primary pollutants: harmful chemicals emitted directly into
the air from natural processes & human activities

Secondary pollutants: new harmful chemicals that are
formed once IN the atmosphere when primary pollutants
react with one another and with the basic components of air
Is our global sunscreen
Similar composition to the
troposphere, with 2 exceptions
o Much less water
o Contains the ozone layer,
which filters UV radiation
AQ Index Video
Concept 18-4: The most threatening indoor air pollutants are smoke and soot from wood and coal cooking
fires (a hazard found mostly in developing countries) and chemicals used in building materials and products.
Indoor Air Pollution
Who is at the greatest risk
from indoor air pollution?
 Developing countries
o Indoor burning (wood, dung, charcoal, crop residues, coal,
fuels) = high levels of particulates
o Poor suffer the greatest risk
 Developed countries
o Indoor air pollution > outdoor air pollution
o Why?
1. 11 of the common air pollutants are higher inside
than outside
2. Greater in vehicles than outside
3. Health risks magnified: people spend 70–98% of their
time indoors
Indoor Pollutant
Sources
Children under 5
The elderly
Sick people
Pregnant women
People with respiratory disorders or
heart problems
Smokers
Factory workers
Human Health Risks
Tobacco Smoke
Smoking
Lung cancer, respiratory ailments,
heart disease
Formaldehyde
Furniture stuffing, paneling,
particleboard, foam insulation
Irritation of eyes, throat, skin &
lungs; nausea; dizziness
Radioactive Radon222 gas
Underground rock deposits
(seeps in through cracks in
foundation or walls)
Pollen, pet dander, dust mites,
cooking particles, fungal spores
Lung cancer
Very Small Particles
Irritated lungs, asthma, itchy eyes,
runny nose, lung disease
Indoor Air Pollutants Video
Major Outdoor Pollutants
Pollutant
“Name”
Natural
Sources
Human Sources
Human Health Impact
Environmental Impact
Carbon
Monoxide
Burning of
forests and
grasslands
Auto exhaust,
tobacco smoke,
inefficient
stoves/heaters
Reacts with hemoglobin and
reduces oxygen transport;
headache, nausea, drowsiness,
coma, death
Contributes to smog and
ground-level ozone
Carbon
Dioxide
Animal
respiration
Burning fossil fuels,
cutting down forests
Dizziness, headaches,
unconsciousness
Global warming and
climate change
Nitrogen
Compounds
Lightening,
soil bacteria
Auto engines, coalburning plants
Irritation to the eyes, nose and
throat; cause asthma and
bronchitis
Suppress plant growth
and reduce visibility
Sulfur
Compounds
Volcanic gases
Industrial power
plants, oil refining
Respiratory and cardiovascular
illness
Precursor to acid rain,
which damages lakes,
rivers and trees
Particulates
Dust,
wildfires, sea
salt
Coal-burning power,
industrial plants,
motor vehicles,
plowed fields, road
construction,
tobacco smoke, etc.
Irritate nose and throat, damage
lungs, aggravate asthma and
bronchitis, shorten lifespan,
cause mutations, reproductive
problems and cancer
Reduce visibility,
corrode metals, discolor
clothes and paints
Ozone (O3)
Formed from
reaction of
nitrogen
oxides and
VOCs
Good ozone is in the
stratosphere. Bad
ozone is the
troposphere. Human
activities are
decreasing the good
and increasing the
bad ozone.
Aggravate lungs and heart,
irritate eyes, nose and throat,
coughing, breathing problems
Smog precursor, reduce
crop production and
forest growth, damage
plants
VOCs
(Volatile
Organic
Chemicals)
Methane
emissions
from plants,
wetlands and
termites
Methane: Landfills,
rice paddies, cow
belching, Other
VOCs: industrial
solvents, dry
cleaning liquids, gas,
plastics, rubber, etc.
Eye and skin irritation, nausea,
headaches, cancer, blood
disorders, immune damage
Smog precursor
Burning Coal Produces Industrial Smog
Sunlight plus Cars Equals Photochemical Smog
Industrial smog consists of sulfur dioxide,
droplets of sulfuric acid, and suspended solid
particles. This smog is “gray smog.”

•
Reduction of this smog in urban cities of the
United States

China and smog
•
“Brown Air Smog” (yellow)
Exhaust from morning vehicles release
large amounts of NO and VOCs into the
air of a city. NO is converted to NO2.
When exposed to UV rays from the sun,
the NO2 reacts in complex ways with
VOCs. The resulting smog is a chemical
brew called photochemical oxidants
because they can oxidize certain
compounds in the atmosphere and in
your lungs.
• Chemical composition:
VOCs + NO2 + Heat + Sunlight yields
• Ground level O3 and other
photochemical oxidants
• Aldehydes
• Other secondary pollutants
Hotter days lead to higher levels of O3
•
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Photochemical Smog
Asian Brown Cloud Video
Human deaths – 981 per day
In China, if 400 million people are
driving gas-powered cars by 2050, the
resulting photochemical smog could
cover the entire Western Pacific,
extending to North America.
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Factors that increase it
Factors that decrease it
Urban buildings slow
winds and reduce dilution
Hills and mountains
reduce air flow
High temperatures
promote p. smog
formation
Emissions of VOCs from
certain trees and plants
promote p. smog
Grasshopper effect (see
below)
Temperature inversions
(see below)
•
Outdoor
Pollution
•
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Settling of particles
due to gravity
Rain and snow
cleanse the air
Salty sea spray from
the ocean wash out
pollutants
Winds sweep
pollutants away and
bring in cleaner air
Chemical reactions
can remove
pollutants (ex. Acid
rain)
Photochemical Smog in Santiago, Chile
Grasshopper Effect
Occurs when volatile air pollutants are transported by
evaporation and winds from tropical and temperate
areas through the atmosphere to the earth’s polar
areas, where they are deposited. This happens mainly
in winter.
This explains why arctic polar bears, sharks, and
other top carnivores and native peoples have high
levels of toxic pollutants in their bodies.
Temperature Inversions
Temperature inversions can cause pollutants to
accumulate in high levels.
During the day, the sun warms the air near the earth’s
surface. Normally, this warm air and most of the
pollutants it contains rise to mix and disperse with the
cooler air above it. Under certain atmospheric
conditions, a layer of warm air can temporarily lie atop
a layer of cooler air nearer the ground. This is called a
temperature inversion.
Because the cooler air is denser than the warmer air
above it, the air near the surface does not rise and mix
with the air above. This allows pollutants to build up in
the stagnant layer of cool air near the ground.
Temp. Inversion Video
Concept 18-3: Acid deposition is caused mainly by coal-burning power plants and motor vehicle emissions, and in
some regions, threatens human health, aquatic life and ecosystems, forests, and human-built structures.
Acid Deposition
Acid deposition – the falling of acidic compounds
(pH < 5.6) from the atmosphere to the earth’s
surface
 Acid rain refers to the wet deposition
consisting of acid rain, snow, fog and cloud
vapor
o Occurs within 4-14 days in distant,
downwind areas from the emission
source
 Dry deposition consists of dry acidic particles
o Occurs within 2-3 days near the
emission sources
Acid Rain Formation
Acid rain is caused by a chemical reaction that
begins when compounds like sulfur
dioxide and nitrogen oxides are released
into the air (from coal-burning power plants,
industrial plants, and vehicle emissions).
These substances can rise very high into the
atmosphere, where they mix and react with
water, oxygen, and other chemicals to form
more acidic pollutants, known as acid rain.
Tall smokestacks of coal-burning power plants reduce local air pollution but can increase regional air
pollution downwind. The primary pollutants (sulfur dioxide and nitrogen oxides) emitted high into the
troposphere may be transported as far as 1,000 kilometers (600 miles) by prevailing winds.
Acid Rain Video
Regions where acid
deposition is now a
problem and regions with
the potential to develop
this problem
What are the conditions
where we live?
Air Pollution NG Video
Areas with soils that
have basic compounds
such as calcium
carbonate or limestone
can neutralize, or
buffer, acid deposition.
Typical
precipitation in the
eastern United
States is at least
10 times more
acidic than normal
precipitation
Prevailing winds
can carry acid
deposition across
country borders.
Acidic emissions
from the UK blow into
Norway and Austria.
China is world’s top emitter of
SO2 because they get 70% of
their total energy and 80% of
their electricity from burning
coal. The acid rain is
damaging crops in China,
Japan, and North and South
Korea.
 Major contributor of the
Asian Brown Cloud
Harmful Effects of Acid Deposition
 Human respiratory disorders

Asthma, bronchitis, lung cancer, etc.
 Aquatic ecosystems affected

Fish cannot survive in pH below 4.5

Metal ions can clog their gills and
suffocate them
 Leaching of soil nutrients and release of toxic
metals

Leaches calcium and magnesium from
soils and releases aluminum, lead and
mercury which are toxic to the trees
 Loss of crops and trees

Reduce plant productivity when soil
drops below 5.1 pH
 Damage to buildings, statues, cars, and
monuments
The U.S. Clean Air Act of 1970
Federal Law implemented to protect public
health and welfare from different types
of air pollution caused by a diverse array of
pollution sources known to be hazardous to
human health.
Since 1970,
The six commonly found air pollutants
have decreased by more than 50%
Air toxins from large industrial sources,
such as chemical plants, petroleum
refineries, and paper mills have been
reduced by nearly 70%
New cars are more than 90% cleaner and
will be even cleaner in the future
Production of most ozone-depleting
chemicals has ceased.
Concept 18-5: Air pollution can contribute to asthma, chronic bronchitis, emphysema, lung
cancer, heart attack, and stroke.
Your body has natural mechanisms to
protect you from air pollutants, but
they can be easily overwhelmed with
pollutants
 Nose hairs filter out large particles
 Sticky mucus lining your upper respiratory
tract captures small particles; coughing and
sneezing expels the particles
 Cilia also lines your upper respiratory tract
and traps particles; sends trapped particles
to your throat where they are swallowed or
expelled
According to the WHO:
3 million people worldwide (most of them in
Asia) die prematurely each year from the effects
of air pollution (8,200 per day)
73% of these result from indoor air pollution,
typically from heart attacks, respiratory diseases
and lung cancer related to daily breathing of
polluted air.
According to the EPA:
In the US, annual deaths related to air pollution
range from 150,000 – 350,000
More than 125,000 Americans (96% in urban
areas) get lung cancer from breathing soot-laden
diesel fumes from buses, trucks, bulldozers, etc.
Airway Comparative
Air Pollution and Health Video
Concept 18-6: Legal, economic, and technological tools can help to clean up air pollution, but much
greater emphasis should be focused on preventing air pollution.
Laws and Regulations can reduce outdoor
air pollution

United States
• Clean Air Acts: 1970, 1977, and 1990

EPA (Environmental Protection Agency)
• National ambient air quality standards (NAAQs)
for 6 criteria outdoor pollutants
• CO, NOX, SO2, SPM, O3, Pb
• National emission standards for 188 hazardous
air pollutants (HAPs)
• Mostly chlorinated hydrocarbons, VOCs &
toxic metals
• Toxic Release Inventory (TRI)
• Industries must tell how much
they released and how they deal
with waste management
Problems:
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We rely on cleanup more than prevention of pollution
Airports are exempt from many regulations
No regulation of greenhouse gas emissions
No regulation of ultrafine particles
Urban O3 levels are too high
Laws don’t deal with indoor air pollution
Need better enforcement of the Clean Air Act
We Can Use the Marketplace to
Reduce Outdoor Air Pollution

Emission trading or cap-and-trade
program; already being used in 110
polluting power plants in Eastern
and Midwestern US
 Gives power plants & industries a
certain number of pollution credits
o If you emit less, you can use
them or sell them
 Uses: another plant that
is not in compliance,
use it to expand your
factory
 Buyers: other polluting
factories, private
citizens &
environmental groups
 Mixed reactions to program; need
more careful monitoring for accurate
results
 Critics believe that air pollutants are
just getting moved around without
actually reducing overall air quality
 SO2 emissions down by 53%
 NO2 will be tried in the future
Cap and Trade Video