Transcript Honnors Pollution

Pollution
Pollution defined as
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Something that is unwanted that
interferes with the environment and
an organisms self sustaining
processes in a negative wayThe texts
A change in the physical chemical
and biological characteristics of air
water and food that adversely effects
the survival of organisms.
Basic Toxicology
Basic Toxicology
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Toxin=Damages a living
organism by ingesting or
absorbed.
Toxicity=the degree which a
toxin harmful.
Any thing in high enough
quantities may be harmful
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Ex water
Factors to consider
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Dosage
Amount of exposure
Size and age or organism
Ability of organism to detoxify
Sensitivity to substance
Synergistic/Antagistic effects
Dose response analysis
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2 tests
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LD 50 when 50% die
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Poisons-LD50= 50 mg or less
Threshold dose=when a negative effect
occurs
Types of effects
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Acute-Short exposure to a high
level of toxin
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Ex snake bite
Chronic-Long term exposure to
a low level toxin.
Risk
assessment/management
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Assessment calculations of the
risk taken
Management=strategies taken
to reduce risk
Air Pollution
Air Pollution
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2 sources human and natural
Natural=volcano
 Car=man The majority of the
pollution today is from man and
occurred after the industrial
revolution.
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Beijing is one of the most
polluted cities
Sources
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Primary pollutants released
directly into the lower
atmosphere and are toxic.
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Ex mercury coal burning
Secondary-toxins formed in the
atmosphere from multiple
primary pollutants.
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SO2 from coal +H2O
H2SO4
EPA
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Environmental Protection Agency
Regulates pollution
Regulates 6 “Criteria Pollutants”
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Carbon monoxide CO-combustion-60% car
Lead Pb-from coal and smelting
Ozone O3-good in stratosphere-bad in
troposphere-from combustion.
Nitrogen Dioxide NO2-car engines forms nitric
acid
Sulfur dioxide SO2 coal and diesel–sulfuric acid
Particulates
Changes
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Since 1970 CO and lead have
decreased
New concerns=VOC volatile
organic compounds.
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Toxic organic compounds from
manufacturing, dry cleaning,
industrial solvents, form O3
Smog
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Fog=natural water vaper
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2 types industrial and
photochemical
Smog=Toxic gas
Industrial Smog
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Industrial (grey) smog- formed from
the burning of coal common 19001950.
CO2 combines with particulate matter.
 Problems=Sulfuric acid lead particulate
matter.
 Lead to- pneumonia, tuberculosis,heart
failure, bronchitis, whooping cough.
1952 killed 4000 in London
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Photochemical smog
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Photochemical Smog.
The brown cloud found on sunny
days.
 Caused by car combustion and
industrial combustion.
 VOC, NOx, O3 combine,
catalyzed by sunlight, to form a
toxic gas.
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Common in baltimore
Inversion
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Air is trapped by warmer layers
of air in low places.
Climate change
Caused By
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Increasing CO2 and other green
house gasses cause the green
house effect.
1900-1950 25% caused by
combustion 75% by reducing
biomass.
1950-today 75% by combustion
25% by reduction in biomass.
IPCC (Intergovernmental panel on
climate change) report
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1-Climate change is occurring
There is a correlation between
temperature and CO2 levels
(greater than 90%)
CO2 1950 280ppm 2006
380ppm
Methane 1950 715ppm 2005
1774ppm
NOx 270-319
Rise in CO2
Effects
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Additive effect decrease in ice
caps= increased temperatures.
Increased heat = increased H2O
gas=increased heat.
Increased temp=less
permafrost=more Co2 released
from the permafrost.
Increased temp= decreased
land= less biota and more CO2
Impact
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Higher levels of water-maryland
4th most at risk
Decreasing glaciers=less
drinking water
Increased storms
Ozone depletion
Ozone depletion
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Ozone –in stratosphere is a
toxin but in the stratosphere
provides a defense from UV
radiation.
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Formation
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3O2 + UV sunlight
2O3
Ozone depletion
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Occurs during the summer
months.
Caused by Chloroflurocarbons
(CFCs) And other compound
compounds used in
propellants, fire extinguishers,
and hair spray.
Reaction
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CFCs break down to Chlorine
gas and reacts with ozone
Cl + O3
O2+ClO
is stored in ice crystals over the
winter.
In the spring the crystals melt
and continue to react
ClO+O
Cl+O2
Results
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26 million square Km zone of
thinness (hole).
Chronic Exposure= eye
cataracts, skin cancer,
weakening of immune system.
Kill phytoplankton,-primary
producers.
Acid rain
Acid rain:
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Formed from SO2 and NOx and
water into sulfuric and nitric
acids
pH=range from 5.4-2.3
Caused by coal and auto
emmissions
Environmental effects
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Mineral leaching
Sulfur and nitrogen buildup in
soil/lakes
Increased aluminum buildup
Leaching of calcium from conifers
Lowering of pH in lakes
Human respiratory irritation
Dissolving stone-monuments
buildings exc.
2 types
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Dry acidic particle depositiondrops few days after
Wet deposition-drops 4-14 days
1990 Clean air Act reduced SO2
and NOx levels.