Chapter 19Chapter 19

Air Pollution

The AtmosphereThe Atmosphere

78% N, 21% O 78% N, 21% O

Ozone layer Ozone layer

Greenhouse effect Greenhouse effect

Pressure = 1,000Pressure = 1,000millibars atmillibars atground levelground level

Atmospheric pressure (millibars)Atmospheric pressure (millibars)

00 200200 400400 600600 800800 1,0001,000120120

110110

100100

9090

8080

7070

6060

5050

4040

3030

2020

1010

00(Sea(Sea

Level)Level)

––8080 ––4040 00 4040 8080 120120Temperature (˚C)Temperature (˚C)

Alt

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de

(k

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ters

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ud

e (

kil

om

ete

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Alt

itu

de

(m

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itu

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(m

ile

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7575

6565

5555

4545

3535

2525

1515

55

ThermosphereThermosphere

Heating via ozoneHeating via ozone

MesosphereMesosphere

StratosphereStratosphere

Ozone “layer”

Heating from the earthTroposphere

TemperatureTemperature

PressurePressure

MesopauseMesopause

StratopauseStratopause

Tropopause

Fig. 19.2

AIR POLLUTIONAIR POLLUTION

• Some primary air pollutants may react with one another or with other chemicals in the air to form secondary air pollutants.

Figure 19-3Figure 19-3

Major Air PollutantsMajor 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.

Major Air PollutantsMajor 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 InversionsTemperature 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 19-5Figure 19-5

Acid Deposition and HumansAcid Deposition and Humans

Respiratory diseases Respiratory diseases

Toxic metal leaching Toxic metal leaching

Decreased visibility Decreased visibility

Damage to structures, especially containing limestone

Damage to structures, especially containing limestone

Decreased productivity of fisheries, forests, and farms

Decreased productivity of fisheries, forests, and farms

ACID DEPOSITIONACID DEPOSITION

• Acid deposition consists of rain, snow, dust, or gas with a pH lower than 5.6.

Figure 19-6Figure 19-6

Acid Deposition and Aquatic SystemsAcid Deposition and Aquatic Systems

Fish declines Fish declines

Undesirable species

Undesirable species

Acid shock Acid shock

WaterWaterboatmanboatman

WhirligigWhirligig

Yellow perchYellow perch

Lake troutLake trout

Brown troutBrown trout

SalamanderSalamander(embryonic)(embryonic)

MayflyMayfly

SmallmouthSmallmouthbassbass

MusselMussel

6.56.5 6.06.0 5.55.5 5.05.0 4.54.5 4.04.0 3.53.5pHpH

Acid Deposition, Plants, and SoilAcid Deposition, Plants, and Soil

Nutrient leaching

Nutrient leaching

Heavy metal release

Heavy metal release

Weakens trees Weakens trees

Fig. 19-9

Acid Deposition in the USAcid Deposition in the US

Fig. 19-7

Chloroform

Benzo--pyrene

Styrene

Radon-222

Methylene Chloride

Tobacco Smoke

Carbon Monoxide

Asbestos

Nitrogen Oxides

1, 1, 1-Trichloroethane

Particulates

FormaldehydeTetrachloroethylene

Para-dichlorobenzene

Fig. 19-11, p. 453

INDOOR AIR POLLUTIONINDOOR 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 KillerAir 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.

– According to the EPA, each year more than 125,000 Americans get cancer from breathing diesel fumes.

Air Pollution is a Big KillerAir Pollution is a Big Killer

• Spatial distribution of premature deaths from air pollution in the United States.

Figure 19-16Figure 19-16

Case Study: Radioactive RadonCase 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 Sources and paths of entry for indoor radon-222 gasfor indoor radon-222 gas.

Figure 19-13Figure 19-13

Solutions: Preventing and Reducing Air PollutionSolutions: Preventing and Reducing Air Pollution

Clean Air ActClean Air Act

National Ambient Air Quality Standards (NAAQS)

National Ambient Air Quality Standards (NAAQS)

Primary and secondary standards

Emission Trading Policy

Primary and secondary standards

Emission Trading Policy

Using the Marketplace to Reduce Outdoor Air PollutionUsing 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.

– In 2002, the EPA reported the cap-and-trade system produced less emission reductions than were projected.

PREVENTING AND REDUCING AIR POLLUTIONPREVENTING AND REDUCING AIR POLLUTION• Environmental scientists point out several

deficiencies in the Clean Air Act:– The U.S. Congress has failed to increase fuel-

efficiency standards for automobiles.– Regulation of emissions from motorcycles and two-

cycle engines remains inadequate.– There is little or no regulation of air pollution from

oceangoing ships in American ports.

Solutions: Reducing Outdoor Air PollutionSolutions: Reducing Outdoor Air Pollution

• There are a 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.

Fig. 19-21, p. 461

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 gas-burning 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 19