Transcript Man-made pollutants - West Branch Schools

Air and Air Pollution
Chapter 6
What is Air?
•
•
•
•
Air is made up of the following gases:
Nitrogen – 78 %
Oxygen – 21%
Other gases: 1% (Argon, Carbon dioxide,
and water vapor)
• Air can contain other particles of pollution
from both natural and man-made sources
Natural Air Pollution:
•
•
•
•
•
Dust
Pollen
Spores
Bacteria
Volcanic activity
Man-made pollutants:
Man-Made
Pollutants
Ozone
• Ground level ozone = Pollution
• Created when oxygen combines with
VOCs, pollutants, and ultraviolet light
• Not to be confused with upper level
atmospheric ozone, which is beneficial
• How does Mahoning County score in air
pollution? American Lung Association
Website
The Clean Air Act
• Regulated by the EPA (Environmental
Protection Agency)
• Passed in 1970
• Amended in 1990
• Over the last 20 years, total emissions of
the six principal air pollutants have
decreased by more than 41 percent
(EPA)
Smog
• Smoke and fog
• Caused when sunlight, nitrogen oxides, and
hydrocarbons combine
• Major problem in sunny cities with many
vehicles
Health problems due
to Air Pollution:
•
•
•
•
Bronchitis
Asthma
Emphysema
Lung cancer – non
smoking city dwellers
are 3 to 4 times as
likely to develop
cancer than a person
living in a rural area
Bhopal, India 1984
• One of the worst cases of industrial pollution
in history
• 27 tons of methyl isocyanate (MIC) gas leaked
from a Union Carbide plant in India
• MIC was used to make the pesticide, SEVIN
• Over 6,000 people died in the area
• Hundreds of thousands have been injured or
suffer long-term genetic and carcinogenic
effects
• Cause? Poor maintenance or sabotage?
Bhopal, India 1984
Indoor Air Pollution
• Caused by natural
and man-made
pollutants
• Intensified by
highly insulated
and sealed homes
• Sick building
syndrome
• Bacteria, pollen,
mold, black mold,
dust, mites
• VOCs from paint,
plastics, carpet (newcar smell)
• Asbestos from old
insulation and tiles
• Radon gas from
radioactive particles
of uranium seeping
into basements
Acid Rain
• Normal rain
pH is 5.6
• Acid rain’s
pH is below
5.0
• Caused by
the burning
of fossil fuels
( Source: http://fli.hws.edu/sos/images)
Acid Rain Effects
Atmosphere and Climate
Chapter 7
Earth’s Early Atmosphere
• Very little oxygen
existed
• Oxygen was only
formed after the
evolution of
photosynthetic
bacteria
• Provided oxygen for
more advanced life
forms
Layers of the atmosphere:
Link
What is the difference between
climate and weather?
• Weather – what is happening in the
atmosphere at a particular place in a
particular time
• Climate – average weather over a long
period of time. Determined by:
• Temperature, humidity, wind, precipitation,
lattitude, air circulation, ocean currents, and
local geography
Air Currents Affect Climate
Ocean Currents Affect Climate
• Is it good or bad for the Earth?
• GOOD – we must have this atmosphere to
help retain the heat from the sun
• Helps regulate Earth’s temperatures
Greenhouse gases:
• Water vapor
• Carbon dioxide
• CFCs –
chlorofluorocarbons
• Methane
• Nitrous oxide and
other gases
• Experiments and
models show that
increasing these
gases causes more
heat to be trapped
• What natural events
increase greenhouse
gases?
• What man-made
activities increase
greenhouse gases?
Is our climate changing?
• Yes! Ice core
samples go back
Thousands of
years, showing
fluctuation in
temperature and
carbon dioxide
• Did humans
cause this?
Is our climate changing?
• Have
humans
caused this
change over
time?
Is our climate changing?
• Did humans
cause this
change?
• Why is this
not an easy
answer?
• Short
amount of
time
Is our climate changing?
• This graph raises questions about the relationship
between carbon dioxide and temperature
• What will the future temperature look like?
Is climate change accelerated
by human activity?
• Two groups:
• 1. Name 5-10 consequenses if the scientists
who say that humans ARE significantly
increasing global warming are correct and we
DO NOT take steps to halt it?
• 2. Name 5-10 consequences if the scientists
who say that humans are NOT significantly
increasing global warming are correct and we
DO take steps to halt it?
Temperature increases:
• Affect weather
patterns –
increased storm
intensity and
hurricanes,
droughts, increased
snow
• Agriculture changes
– planting seasons,
regions
• Rising sea levels
• Change in ocean
currents
• Decrease polar ice
• Changes in animal
migrations and cycles
Ozone Depletion
• Ozone layer blocks a portion of the sun’s
ultraviolet rays
• Depleted by man-made chemicals such as
chlorofluorocarbons (propellants) and methyl
bromide (pesticides)
• If UV increases: rise in cataracts, aging,
wrinkles, skin cancer, weakened immune
system, decreased crop yields, kills plankton in
the ocean
• Concentrated over Antarctica...NOW..
Ozone hole