Transcript Air Pollution

Human
caused air
pollution is
mainly in the
Troposphere
(CO2, ozone,
Sox, Nox)
Stratospheric
ozone layer =
GOOD
Presence of chemicals in the atmosphere that
affect climate, human health, and animal
health
 Outdoor air pollution and indoor air pollution
 2 Main Types of Pollutants:

› Primary Pollutants: emitted directly into atmosphere
in harmful form (soot and CO2)
› Secondary Pollutants: new pollutants that form
when primary pollutants react with air molecules
(Sox, Nox)

1 out of every 6 people on earth live in areas
with unhealthy air
Pollutant
Description
Source
Health Effects
Carbon Monoxide
Colorless, odorless gas
Fossil fuel burning
(vehicles), cigarette
smoke
Reduces O2 transport
in body, can cause
lung problems and
death
Reddish brown gas
(gives smog its color)
Fossil fuel burning
(vehicles and industry)
Lung problems:
bronchitis and asthma
*Acid deposition
Colorless gas
Coal burning (industry)
Breathing problems:
asthma
*Acid Deposition
Suspended
Particulate Matter
(SPM)
Particles and droplets
Coal burning, vehicle
emissions
Throat irritation, lung
damage
Ozone
O3
Irritating gas, has bad
odor
Reaction with VOCs,
Car emissions
Breathing problems,
coughing, lung
diseases
Lead
Solid toxic metal
Paint, smelting,
batteries
Nervous system
damage
CO
Nitrogen Dioxide
NO2
Sulfur Dioxide
SO2

Not classified as an air pollutant
according to the EPA
› Most scientists think it should be:
 High concentrations in atmosphere
 Humans have been adding to this by cutting
down forests, which would normally absorb
CO2
 Considerable evidence that global warming is
influenced greatly by human-released CO2

Formed when NOXs (nitrous oxides) and
VOCs (volatile organic compounds)
react with the help of UV rays
› Mix of more than 100 primary and secondary
pollutants
 Ground-level ozone, nitric acid, aldehydes
Hotter days=more photochemical smog
 Car emissions and industry are biggest
causes


Mixture of Sox, sulfuric acid,
and particulates emitted
from burning coal and oil
› Particles include salts and
carbon causing it to have a
gray color.

Can be easily reduced with
pollution controls like
scrubbers and precipitators
› Common in China, India,
Ukraine
 Lots of coal burning with few
pollution controls used
Reducing Smog
 Rain and snow:
Increasing Smog
 Buildings
› “clean” the air
› Dry cities more
susceptible to smog

reduce dilution

Salt Spray (oceans)
› “Wash” air and
remove pollutants

› Slow winds and
› Reduce air flow

High Temperatures
› Promote smog-
Winds
forming chemical
reactions
› Dilute pollutants and
sweep them away
Hills/mountains

Grasshopper Effect
› Moves pollution to
earth’s poles

Layer of warm air sitting on top of a layer of
cool air near the ground
› Susceptible areas:
 Valleys surrounded by mountains that have cold,
cloudy weather during parts of the year
 Large cities (millions of people) with low winds,
sunny days, ocean on one side and mountains on
the other (Los Angeles)

Can cause pollutants to concentrate near
the surface
› This can cause breathing problems and
coughing, and has been known to be deadly in
some instances

Industrial smog stretching
from India to China, and
even into the ocean
› Reduces solar energy
getting to the earth’s
surface by as much as 15%
 Leads to food harvest
reductions
› Increase in respiratory
disease in these areas

Both China and India are
beginning to take steps to
reduce their pollution
levels

Yes, there is indoor air pollution and…
› Levels of pollutants are much higher inside than
outside!!!
 Buildings: 2-5 times higher
 Cars: 100 times higher

Much greater threat to human health than
outdoor pollution
› People spend 70-98% of their time indoors

Sick Building Syndrome: pollutants indoors
leading to health problems like:
› Sneezing, headaches, dizziness, nausea, fatigue,
flu-like symtoms
Causes the most problems indoors for
people in developed countries
 Used to manufacture many households
goods

› Plywood, particle-board, paneling, flooring,
cabinets, furniture, insulation, nail polish

20-40 million Americans have issues from
daily exposure to formaldehyde
› 1/5000 people living in manufactured homes for
10 years or more develops cancer from
formaldehyde exposure

Radioactive gas found in soil and rocks
› Can seep into houses
› Increase risk of lung cancer
Enters buildings through cracks in the
foundations and walls, openings in sump
pumps, and through concrete blocks
 EPA recommends all households test for
radon gas at some point ($20-$100)


Asthma: allergic reaction
causing muscle spasms in
bronchial walls
› Asthma in children
increased by 160%
between 1980-1994
Chronic Bronchitis:
continual inflammation of
bronchi and bronchioles
 Emphysema: irreversible
damage to air sacs
causing extreme shortness
of breath


Clean Air Act:
› 1970, 1977, 1990
› Directed EPA to establish national air quality
standards
 Included maximum allowable levels for 188
HAP (Hazardous Air Pollutants)
› Requires companies to submit toxic release
inventories

Combined emissions have decreased 48%
› Lead: down 93%
› CO: down 41%
› VOCs: down 40%
› SPM: down 34%
› SOx: down 33%
› NOx: down 15%

The bad news:
› Mercury and dioxin releases have increased
 Both are toxic at low levels
Allows the most polluting power plants in
the US to buy and sell Sox emissions
rights, Nox emissions, and VOC emissions
 Part of the Clean Air Act of 1990
 Cap and Trade approach to Sox
emissions

› Helped reduce SOx emissions by 40%
› Not well regulated: abusing program, not
reducing emissions as much as planned

Coal Burning Industry:
› Cleaner burning technology: fluidized beds
› Emissions filtration: scrubbers, electrostatic
precipitators

Vehicle Pollution:
› Get rid of old, high polluting vehicles and replace
with hybrid vehicles
› use zeolites to remove sulfur from gasoline

Indoor Air Pollution:
› Cover AC ducts
› Limit formaldehyde emissions
› Limit hazardous substance use in homes and
businesses