Transcript air quality - School District of La Crosse

AIR QUALITY
Consider:
An oxygen tank costs $20.
1,000,000 Americans wouldn’t need 2 tanks
per week for emphysema/bronchitis if air
pollution is decreased.
A savings of $2 billion dollars yearly.
Why do you care?
Insurance/Taxes
The Atmosphere
 Whole mass of air around the earth
Components:
78% N2, 21% O2
Water, Carbon dioxide (0.03%), helium,
etc. make up the remainder.
Realize- earth’s circumference is 24,800
miles. Atmosphere is FINITE!!!
Layers of the Atmosphere
DID YOU KNOW?
Mexico City has some of the worst air quality
in the world. Over 22 million people in a
valley 7575 ft above sea level.
Cars are less efficient, pollutants are trapped
in valley, little air quality legislation for
business all result in “bad air”.
Air Pollution

any substance in the air that causes harm
to living organisms.
TWO TYPES:
1. Natural—volcanoes, pollen, forest fire
smoke, salt
2. Human Activity—produced by US!!!
2. Human Activity cont.
Two forms of Pollution Due to Human Activity
a. Primary—released directly into the
atmosphere as a pollutant.
Includes: soot, CO, NOx, SOx, VOC’s
(volatile organic compounds), CO2
Human Activity cont.
b. Secondary—primary pollutants combine
with other compounds to produce pollutants
Includes:
*Smog—smoke + fog
*Ozone—UV light + exhaust + Oxygen
*Acid ppt—SOx + NOx + H2O vapor
Temperature Inversions
 Cold, cloudy weather in a valley surrounded
by mountains can trap air pollutants (left).
 Areas with sunny climate, light winds,
mountains on three sides and an ocean on
the other (right) are susceptible to
Figure 19-5
inversions.
Sunlight plus Cars Equals
Photochemical Smog
 Mexico City is one
of the many cities
in sunny, warm,
dry climates with
many motor
vehicles that suffer
from
photochemical
smog.
Figure 19-4
Sunlight plus Cars Equals
Photochemical Smog
 Photochemical smog is a mixture of air
pollutants formed by the reaction of nitrogen
oxides and volatile organic hydrocarbons
under the influence of sunlight.
Acid Precipitation
 Cars/Factories/PowerPlants
 NOx + SOx + H2O  HNO3 + H2SO4
Kills plants by leaching nutrients into the soil, destroys
leaves. Kills fish, invertebrates by “suffocation”.
Destroys buildings, paint, etc.
ACID PRECIPITATION
 Acid deposition consists of rain, snow, dust,
or gas with a pH lower than 5.6.
Figure 19-6
Emissions
SO2
Acid H O
2 2
deposition
PANs
NOx
O3
Others
Reduced
photosynthesis
and growth
Direct damage to
leaves & bark
Tree death
Soil acidification
Leaching
of soil
nutrients
Acids
Release of
toxic metal
ions
Susceptibility
to drought,
extreme cold,
insects,
mosses, &
disease
organisms
Root
damage
Reduced nutrient
& water uptake
Lake
Groundwater
Fig. 19-9, p. 451
DID YOU REALIZE?
• 1/3 of air pollution comes from cars
• 2/3 sulfur oxides and 1/3 nitrogen oxides
come from electrical plants
• Companies buy/sell emission rights!!
DID YOU KNOW?
 The first Clean Air Law was designed in the
1200’s by King Edward I. He was tired of
the smell from burning low quality coal.
 He made it illegal and hung a violator in
1273!!!
 Moral of the Story—don’t burn stinky stuff!!
CLEAN AIR ACT
 1970 and 1990—EPA regulations for air quality.
 Reduced carbon, nitrogen and sulfur oxides as well as
particulates.
 Cut lead pollution by 98% by 1997.
-got rid of leaded gasoline,
mandated catalytic converters
Catalytic Converter- Reduced vehicular pollutants 20X!!!!
 32% less pollutants in air than in 1997.
 Problem – 220 million Americans still breathe air 100X
more polluted than desired.
Chloroform
Para-dichlorobenzene
Tetrachloroethylene
Formaldehyde
1, 1, 1Trichloroethane
Styrene
Nitrogen
Oxides
Benzo-a-pyrene
Particulates
Tobacco
Smoke
Asbestos
Carbon Monoxide
Radon-222
Methylene Chloride
Fig. 19-11, p. 453
Case Study: Radioactive Radon
 Radon-222, a
radioactive gas
found in some
soils and rocks,
can seep into
some houses and
increase the risk
of lung cancer.
Sources and paths of entry
for indoor radon-222 gas.
Figure 19-13