1. Air and Noise Pollution
Chapter 22 (pgs )

2. Section 22.1 The Air Pollution Problem
Objectives:
Describe air pollution.
Explain the historical background of air pollution.
Identify common air pollutants.
Think Critically
In 1976, 35 American Legion members died mysteriously at a convention center in Philadelphia.
Doctors had no idea what was causing the people to die.
How do you think they were able to determine the cause?

3. Air Pollution Problem Air is a mixture of gases – 78% nitrogen,
21% oxygen, and small amounts of argon,
CO2, and water vapor
Air pollution – harmful materials that enter
the environment and released into the atmosphere
Pollutants can be from natural sources (sandstorms, volcanic eruptions), or from human activity
Human caused air pollution
Air pollution became a big problem during the industrial revolution during the 1700’s
Huge amounts of coal and wood were burned and human health effects were devastating

5. Outdoor Pollutants Air Pollutants can be gases or particulates
Air particulates – tiny solids
suspended in the atmosphere
(ash, dust, soot, liquid droplets, trace metals, pesticides, fertilizer dust, etc)
Particulates are dangerous because they are so small and are easily inhaled and get trapped in people’s lungs
Gaseous Pollutants – most are oxides (compounds of oxygen and another element like carbon, sulfur, or nitrogen) released when fossil fuels are burned

6. Outdoor Pollutants Photochemical Smog – a
yellow-brown haze formed when
sunlight reacts with pollutants
produced by cars
Develops in cities with heavy automobile traffic (L.A. New York)
Contains:
Ozone – (O3) very corrosive and breaks down rubber and synthetic fibers. High concentrations are poisonous to plants and animals
Nitrogen Dioxide - (NO2) brown gas that gives smog its color

7. Outdoor Pollutants Hydrocarbons – made of hydrogen and carbon
Methane – most common – produced by certain bacteria, livestock, and by rotting plant and animal matter
Chlorofluorocarbons – (CFC’s) compounds of carbon, chlorine, and fluorine once used in refrigerators, air conditioners, aerosol cans, and in the production of Styrofoam

9. Indoor Pollutants
Air inside of buildings can often contain high levels of pollutants
Home products such as plastics, insulation, and cleaners can give off harmful fumes
Air circulation in buildings is poor – especially in winter
Most people spend hours/day inside
Indoor air can contain:
Cigarette smoke – dangerous to smokers and nonsmokers
Microorganisms – bacteria and fungus
Radon –colorless, odorless, radioactive gas from natural breakdown of radium. Radon gas enters the soil and then your basement. Can cause lung cancer.

10. Section 22.2 Air Pollution and Living Things
Objectives:
Identify the effects of air pollution on human health
Describe the effects of air pollution on plants and animals
Think Critically
The number one cause of death in the U.S. is heart disease.
Heart disease is responsible for about 750,000 deaths annually.
Do you know what the leading cause of heart disease is?

11. Health Effects Carbon Monoxide – dangerous
because it takes the place of oxygen
on your red blood cells. High
concentrations can stress the heart,
cause headaches and dizziness,
and even cause death
Ozone and Oxides of Sulfur and Nitrogen – irritate the eyes and respiratory tract, trigger asthma and allergy attacks, cause bronchitis and emphysema
Emphysema – disease in which tiny air sacs in the lungs break down
Particulates – can cause cancer – a disease in which cells grow abnormally and without restraint.

12. Plants and Animals Plants : Animals: Affected by ozone and sulfur
oxides
Causes stems to be brittle and
leaves to develop spots
Affected millions of Ponderosa Pines in L.A.
Also damages agricultural crops
Animals:
Loss of plants – no food for animals
Eye and lung irritation, bronchitis, and cancer
Industrial air pollutants (lead and zinc) can contaminate rangeland
and make grazing animals sick

13. Section 22.3 Global Effects of Air Pollution
Objectives:
Identify the effects of acid precipitation and ozone depletion
Explain the greenhouse effect and global warming
Think Critically
You have all heard the political talk about global warming.
What does global warming mean to us?
Do you think it is something to worry about?

14. Pollution Pollution can threaten ecosystems and even the entire planet
Three major air pollution problems threatening the global environment:
Acid precipitation
Ozone depletion
Global warming

15. Acid Precipitation Rain or snow that is more acidic than normal
Normal precipitation has a pH of 5.6
Carbon dioxide mixes with water in the air and forms carbonic acid
Burning fossil fuels releases:
sulfur into the air which mixes with water to form sulfuric acid
nitrogen into the air which mixes with water to form nitric acid
Acid rain:
falls in forests and hurts the trees
falls into lakes and hurts the fish
Falls on buildings/statues and deteriorate them

16. Ozone Layer At earth’s surface, ozone is a poisonous gas
At km above earth, it forms a protective layer around earth
The ozone layer absorbs almost all of the ultraviolet (UV) radiation given off by the sun
This prevents the UV rays from reaching earth and harming living things.

17. Hole in the Sky
1980’s – scientists discovered a hole in the ozone layer over both the South Pole and the North Pole
Damage to the ozone layer could greatly increase the amount of UV radiation that reaches earth
In humans this can cause:
Sunburn
Blindness
Skin cancer
Can also cause severe
crop damage

18. Causes of Ozone Depletion
CFC’s – main cause of ozone
depletion – used in refrigerators,
air conditioners, and aerosol sprays
CFC’s are OK in the lower atmosphere, but when they reach the stratosphere they are exposed to UV radiation
UV radiation causes CFC’s to break down and release chlorine and fluorine atoms
Chlorine and fluorine atoms destroy ozone

20. Global Warming
Greenhouse Effect – the trapping of radiated heat by gases in the atmosphere
Light energy from the sun enters the atmosphere and is absorbed by earth’s surface
Once absorbed, light energy is changed to heat
Earth radiates this heat back into space in the form of infrared radiation
Some of the infrared radiation gets trapped and warms the air in the lower atmosphere
Without the greenhouse effect, life on earth would not be possible!

22. Greenhouse Gases Atmospheric gases that trap heat:
Carbon dioxide (CO2)
Methane
Sulfur and nitrogen oxides
CFC’s
Water vapor
Amounts of greenhouse gases are increasing because of pollution caused by human activities
Burning fossil fuels releases CO2 into the air
Ice cores are used to determine the levels from many years ago

24. Global Warming An increase in earth’s average
surface temperature caused by
an increase in greenhouse gases
Another large increase in atmospheric
carbon dioxide occurred at the end of
the last ice age (14,000 years ago)
Scientists think there is the same link between increased carbon dioxide and temperature now
As the temperature rises, water in the oceans will expand, polar ice caps will begin to melt and flooding will occur

27. Issues – Assault on the Past
Read page 363 in your textbook
Answer decision questions on a sheet of paper and hand it in before you leave class.

28. Section 22.4 Controlling Air Pollution
Objectives:
Describe natural processes that help
control air pollution.
Explain human efforts to control air pollution.
Identify federal legislation for curbing air pollution.
Think Critically
We know of ways to decrease air pollution.
Most of these ways cost money.
Would you be willing to pay more for products to have cleaner air?

29. Natural Air Pollution Control
Precipitation is the most effective
natural method of removing particulates
and aerosols from the air
But, removing pollutants from the air
means putting them somewhere else – land, water
Carbon dioxide is removed from the air 2 ways:
Biological activity – plants remove CO2 to make sugars (photosynthesis) – it plants get buried, we get fossil fuels
Ocean water – depends on temperature. If temperatures rise due to global warming, the ocean will begin to release CO2

30. Human Air Pollution Control
Automobiles – major source of air pollution
States have set strict emission control standards
Cars equipped with catalytic converters
Cars designed for better gas mileage
Look for other means of fueling cars (electricity)
Power Plants – major source of pollution
Design ways of cleaning the emissions – scrubbers
Can be very expensive

31. Section 22.5 Noise Pollution
Objectives:
Describe the problem of noise
pollution.
Explain measures and legislation
for controlling noise pollution.
Think Critically
Concerts can be as loud as 120 dB.
This can cause physical pain and serious hearing damage.
Would this make you not attend a concert?

32. Noise Pollution Can cause annoyance, stress, and hearing damage
Sources are airplanes, machines,
and concerts
Sound intensity is measured in decibels (dB)
Softest sounds are around 0 dB
Annoying sounds are around dB
Damaging sounds are around dB
1972 – Congress passed the Noise Control Act – set standards for maximum noise levels
Industries have also tried to reduce sources and levels of noise pollution in the workplace
Don’t listen to very loud music and wear earplugs if you will be in a noisy area!!