Air Pollution

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SOURCES of pollution an analogy

Point sources Non-point sources

Easy to point out : Hard to point at just one

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Point Sources• Like giants

– big– easy to spot– e.g. factories– e.g. power plants

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Example of a point source(There it is!)

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Examples of non-point sources (Where?—All over.)

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What are non-point sources?• Like ants

– small– all over the place, often

moving– so many of them it is hard

to POINT OUT all of them– e.g. cars– e.g. houses– e.g. construction sites– e.g. farms– e.g. fires

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air pollutants—Most result from burning fuels

• excess carbon dioxide: CO2 ----sooo much more than natural

• Ozone: ground level O3 (the bad ozone)

– in urban smog; destroys our lungs; ozone alert days in summer (but our lives depend on good ozone way up in the stratosphere!)

• Carbon monoxide: CO– reduces blood’s ability to carry O2 – product of incomplete combustion (bad old cars)

• Nitrogen oxides: NOx • Sulfur Dioxide: SO2

– precursor to acid rain along with NOx• Particulate Matter– respiratory disorders

CFCs—a success story? –maybe

• Chlorofluorocarbons (CFCs) --an unreactive gas, seemed perfect as propellant

• plastic foam• refrigerator equipment (old)• old spray cans

• Eventually reached the ozone layer– destroyed good ozone --- ozone in the stratosphere.

• Banned several years ago– too late? Is too much damage done?– the replacement chemicals—Are they ok?

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Natural Air Pollutants• Natural air pollutants can include:– Smoke from wild fires– Volcanic eruptions–Methane released from livestock

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here!here!

not here

Consequences of Air Pollution

• decreased quality of life!• breathing sicknesses (asthma, emphysema)• acid rain• increased greenhouse effect, which leads to

GLOBAL WARMING

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The Greenhouse Effect– a natural process, greatly exaggerated by

us humans

11How is the greenhouse effect related to global warming?

Acid Rain: Its effect on trees

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A smoggy city

WAYS TO reduce AIR POLLUTION

and global warming• Everyone pollutes. • You can’t stop it, but you can reduce it.• What can you do? What are you willing to do? Some

ideas:– Transportation: Walk, ride a bike, use public transportation,

use cars less, get a more energy-efficient car– Buy only energy-efficient appliances– Re-use materials– Recycle newspaper, aluminum, others– Plant trees in urban areas– Don’t purchase products that contain CFCs– Support much stricter clean air laws– Support enforcement of international treaties to reduce ozone

depletion and slow global warming–Don’t buy so much stuff! 13

Air Pollution Guided NotesAnswer these.1. Compare non-point sources and point sources of

air pollution.2. Give examples.3. Which do you think cause worse problems in North

Carolina? Why?4. Do giants and ants really pollute the air?5. Why are giants and ants referred to in the lesson

on pollution?6. Name 7 air pollutants caused by humans and tell

what each pollutant does.7. Name three air pollutants that are not caused by

humans.8. How is the greenhouse effect related to global

warming?9. Name ≥5 ways that you or your family could

reduce air pollution. Be specific. Which ones are you willing to try?