Transcript chapter 18- Air pollution

Chapter 18
Air Pollution
Fig. 18.3
The Atmosphere
Atmospheric pressure (millibars)
0
120
110
Altitude (kilometers)
800
1,000
75
Pressure
65
Thermosphere
90
 Greenhouse effect
600
Temperature
100
 Ozone layer
400
55
Mesopause
80
Heating via ozone
Mesosphere
70
45
60
Stratopause
50
Stratosphere
25
40
Tropopause
30
Ozone “layer”
20
0
15
Heating from the earth
Troposphere 5
10
(Sea
Level)
35
Altitude (miles)
 78% N, 21% O
200
–80
–40
0
40
80
Temperature (˚C)
120
Pressure = 1,000
millibars at
ground level
AIR POLLUTION
• Some primary air pollutants may react with one another
or with other chemicals in the air to form secondary air
pollutants.
Figure 18-4
Major Air Pollutants
• Suspended particulate matter (SPM):
– Consists of a variety of solid particles and liquid
droplets small and light enough to remain
suspended in the air.
– The most harmful forms of SPM are fine particles
(PM-10, with an average diameter < 10
micrometers) and ultrafine particles (PM-2.5).
– According to the EPA, SPM is responsible for
about 60,000 premature deaths a year in the U.S.
Your Body’s Natural Defenses Against Air Pollution
Can Be Overwhelmed
• The respiratory system protects from air pollutants through:
– Hair
– Cilia
– Mucus
• Effects of smoking and prolonged air pollution exposure
– Chronic bronchitis
– Emphysema
Major Components of the Human
Respiratory System
Major Air Pollutants
• Ozone (O3):
– Is a highly reactive gas that is a major component
of photochemical smog.
– It can
• Cause and aggravate respiratory illness.
• Can aggravate heart disease.
• Damage plants, rubber in tires, fabrics, and paints.
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 inversions.
Figure 18-11
ACID DEPOSITION
• Acid deposition consists of rain, snow, dust, or
gas with a pH lower than 5.6.
Figure 18-12
Acid Deposition and Humans
 Respiratory diseases
 Toxic metal leaching
 Decreased visibility
 Damage to structures, especially
containing limestone
 Decreased productivity of fisheries,
forests, and farms
Acid Deposition and Aquatic Systems
 Fish declines
Water
boatman
Whirligig
 Undesirable
species
 Acid shock
Yellow perch
Lake trout
Brown trout
Salamander
(embryonic)
Mayfly
Smallmouth
bass
Mussel
6.5
6.0
5.5
5.0
pH
4.5
4.0
3.5
Air Pollution Damage to Trees
Acid Deposition, Plants, and Soil
 Nutrient
leaching
 Heavy metal
release
 Weakens trees
Fig. 18-14
Some Important Indoor Air
Pollutants
INDOOR AIR POLLUTION
• Indoor air pollution usually is a greater threat to
human health than outdoor air pollution.
• According to the EPA, the four most dangerous
indoor air pollutants in developed countries are:
–
–
–
–
Tobacco smoke.
Formaldehyde.
Radioactive radon-222 gas.
Very small fine and ultrafine particles.
Air Pollution is a Big Killer
• Each year, air pollution prematurely kills about
3 million people, mostly from indoor air
pollution in developing countries.
– In the U.S., the EPA estimates that annual deaths
related to indoor and outdoor air pollution range
from 150,000 to 350,000.
Air Pollution is a Big Killer
• Spatial distribution of premature deaths from air
pollution in the United States.
Figure 18-21
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 18-18
Solutions
 Clean Air Act -1970,1977, 1990
 Primary and secondary
standards (limits)
 6 major outdoor air pollutants
 Carbon monoxide, nitrogen
dioxide,
 sulfur dioxide, SPM, ozone,
lead.
Solutions
• National emission standards for 188 hazardous
air pollutants.
• Toxic Release Inventory (1990)
– 20,000 refineries, power plants, factories
– Report releases and waste management methods
for 667 toxic chemicals.
– Available on Internet
Since implemented emissions have dropped
Solutions
• 2012: Coal-burning power plants build after
2013 keep carbon dioxide emissions below a
specified level.
• Result will be less new coal plants constructed
because of costly equipment.
Using the Marketplace to
Reduce Outdoor Air Pollution
• To help reduce SO2 emissions, the Clean Air Act
authorized and emission trading (cap-and-trade)
program.
– Enables the 110 most polluting power plants to buy
and sell SO2 pollution rights.
– Between 1990-2002, the emission trading system
reduced emissions.
We Can Use the Marketplace to Reduce
Outdoor Air Pollution
• Emission trading or cap-and-trade program
– Success depends on:
• How low initial cap is set
• How often it is lowered
Solutions
What else can be done?
– Improve fuel efficiency standards for motor vehicles
– Better regulation of emissions from motorcycles and
two-cycle gas engines like chainsaws, lawnmowers,
scooters.
• A gas power riding lawn mower (1 hour)= 34 cars for 1
hour.
– Stricter regulations for oceangoing ships and airports.
Solutions
• 2013 EPA proposed stricter motor vehicle
emissions standards.
– Savings $7 health care costs for every $1 spent to
implement new standards.
Solutions
• There are a of number of ways to prevent and
control air pollution from motor vehicles.
– Because of the Clean Air Act, a new car today in the
U.S. emits 75% less pollution than did pre-1970 cars.
– There is and increase in motor vehicle use in
developing countries and many have no pollution
control devices and burn leaded gasoline.
What Can You Do?
Indoor Air Pollution
• Test for radon and formaldehyde inside your home and take corrective
measures as needed.
• Do not buy furniture and other products containing formaldehyde.
• Remove your shoes before entering your house to reduce inputs of dust,
lead, and pesticides.
• Test your house or workplace for asbestos fiber levels and for any
crumbling asbestos materials if it was built before 1980.
• Don't live in a pre-1980 house without having its indoor air tested for
asbestos and lead.
• Do not store gasoline, solvents, or other volatile hazardous chemicals inside
a home or attached garage.
• If you smoke, do it outside or in a closed room vented to the outside.
• Make sure that wood-burning stoves, fireplaces, and kerosene- and gasburning heaters are properly installed, vented, and maintained.
• Install carbon monoxide detectors in all sleeping areas.
• Emissions of sulfur dioxide down 49%
since 1970.
• LA 1976-1990 average 150 days in
violation in 2004 is was 27 days.
• End chapter 18