Chapter 18Air Pollution

Alyssa Weibe

4/28/14

What is the nature of the atmosphere

• The two innermost layers of the atmosphere are the

troposphere, which supports life, and the stratosphere, which

contains the protective ozone layer.

• South Asia had this massive thick set of clouds hover over

called “brown clouds” and the clouds contained small

particles of dust, smoke, and ash resulting from drought and

the clearing and burning of forests for planting crops. These

brown clouds do not stay put, they move across continents

within three to four days.

• The atmosphere consists of several layers. We live under a thin blanket of

gases

• The lower layers have more gases in them than upper layers do

• the air we breathe at sea level has a higher density than the air we would

inhale on top of a high mountain

• About 99% of the volume of air you inhaled consists of two gases: nitrogen

(78%) and oxygen (21%).

• The UV filtering effect of ozone in the lower stratosphere allows us and

other forms of life to exist on land and helps to protect us from sunburn,

skin and eye cancers, cataracts, and damage to our immune systems

• Rising and falling air currents, winds, and concentrations of CO2 and other

greenhouse gases in the troposphere play a major role in the planet’s

short-term weather and long-term climate.

Vocabulary

• Atmospheric pressure- the force, or mass,

per unit area of a column of air

• Troposphere- the atmospheric layer

closest to the earths surface

• Stratosphere- atmospheres second layer

What are the major outdoor air pollution

• Pollutants mix in the air to form

industrial smog, primarily as a result

of burning coal, and photochemical

smog, caused by emissions from

motor vehicles, industrial facilities,

and power plant

• Air pollution comes from natural and human sources

• Natural sources include wind-blown dust, pollutants from wildfires and

volcanic eruptions, and volatile organic chemicals released by some

plants.

• almost any chemical in the atmosphere can become a pollutant if it

occurs in a high enough concentration

• Some pollutants in the atmosphere combine to form other pollutants

• high concentrations of cars and factories, urban areas normally have

higher outdoor air pollution levels than rural areas have

• There is no place on the planet that has not been affected by air

pollution caused mostly by the burning of forests and the use of fossil

fuels

• Carbon monoxide can combine with hemoglobin in

red blood cells, which prevents the normal binding of

oxygen with hemoglobin molecules

• This can contribute to human health problems such

as heat exhaustion and to the reduction of food

supplies in some areas, while causing water

shortages, prolonged drought, or excessive flooding

in other areas.

• About one- third of the SO2 in the atmosphere comes

from natural sources as part of the sulfur cycle

What is acid deposition and why is it a problem?

• Acid deposition is caused mainly by

coal- burning power plants and motor

vehicle emissions, and in some

regions it threatens human health,

aquatic life and ecosystems, forests,

and human-built structures

• Most coal-burning power plants, ore smelters, and other industrial

facilities in more-developed countries use tall smokestacks to vent the

exhausts from burned fuel, which contain sulfur dioxide, suspended

particles, and nitrogen oxides, high into the atmosphere where wind

can dilute and disperse them

• Most dry deposition occurs within 2–3 days of emission, fairly near the

industrial sources, whereas most wet deposition takes place within 4–14

days in more distant downwind areas.

• Acid deposition is mostly a regional air pollution problem in areas that

lie downwind from coal-burning facilities and from urban areas with

large numbers of cars

• In the United States, older coal-burning power and industrial plants

without adequate pollution controls, mostly located in the Midwest,

emit the largest quanti- ties of SO2 and other pollutants that cause acid

depo- sition

• Acid deposition damages statues and buildings, contributes to

human respiratory diseases, and can leach toxic metals from

soils and rocks into lakes used as sources of drinking water.

• Acid deposition often along with other air pollutants such as

ozone can harm crops, especially when the soil pH is below

5.1.

• You can prevent acid deposition by, reducing coal use, burn

low-sulfur coal, an tax emissions of SO2

• According to the U.S. National Emissions Inventory, between

1980 and 2008, air pollution laws in the United States helped

to reduce sulfur dioxide emissions from all sources in the

United States by 56% and nitrogen oxide missions by 40%.

What are the major indoor air pollution problems

• The most threatening indoor air

pollutants are smoke and soot from the

burning of wood and coal in cooking fires

(mostly in less-developed countries),

cigarette smoke, and chemicals used in

building materials and cleaning products.

• Indoor air pollution is a serious problem

• The most threatening air pollutant are smoke and

soot from the burning of wood, and chemicals

• A serious problem in developed areas because of the

chemicals used in the building materials and products

• Living organisms and their excrements can also

pollute indoor air

• Another living source of indoor air pollution is toxic

airborne spores of fungal growths such as molds and

mildew that can cause headaches and allergic

reactions and aggravate asthma and other respiratory

diseases.

• When radon gas from such deposits seeps

upward through the soil and is released

outdoors, it disperses quickly in the air and

decays to harmless levels.

• About 90% of radon-related lung cancers

occur among current or former smokers

• 1 of every 5,000 people who live in

manufactured homes for more than 10 years

are likely to develop cancer from

formaldehyde exposure

What are the health effects of air pollution

• Air pollution can contribute to

asthma, chronic bronchitis,

emphysema, lung cancer, heart

attack, and stroke.

• Your body’s natural defenses against air

pollution can be overwhelmed

• Your respiratory system (Figure 18-21)

has a number of ways to help protect

you from air pollution.

• Prolonged or acute exposure to air

pollutants, including tobacco smoke, can

overload or break down these natural

defenses

• Air pollution is a big killer

• at least 2.4 million people worldwide die

prematurely each year from the effects of air

pollution

• According to recent EPA studies, each year,

more than 125,000 Americans get cancer from

breathing soot-laden diesel fumes emitted by

buses and trucks

How should we deal with air pollution

• Legal, economic, and technological

tools can help us to clean up air

pollution, but the best solution is to

prevent it.

•

• Laws and regulations can reduce outdoor air pollution

• The TRI law passed and required power plants, mines,

factories, and chemical manufacturers to report release

and waste management

• We can use the market place to reduce outdoor air

pollution

• reducing pollutant emissions has been to allow

producers of air pollutants to buy and sell government

air pollution allotments in the marketplace.

• There are many ways to reduce outdoor air pollution

• You can prevent motor vehicle air pollution by walking, a

bike, or mass transit

• Reducing indoor air pollution should be a priority

• Little effort has been devoted to reducing indoor air

pollution even though it poses a much greater threat

to human health than does outdoor air pollution.

• In more-developed countries, where VOCs present the

greatest indoor air pollution threats, houseplants may

provide some relief

• You can prevent indoor air pollution by ban indoor

smoking, prevent radon infiltration, and use less

polluting cleaning agents, paints, and other products

3 big ideas

• Outdoor air pollution, in the forms of industrial smog,

photochemical smog, and acid deposition, and indoor

air pollution are serious global problems.

• Each year, at least 2.4 million people die prematurely

from the effects of air pollution; indoor air pollution,

primarily in less-developed countries, causes about

two-thirds of these deaths.

• We need to put our primary emphasis on preventing

outdoor and indoor air pollution throughout the world.