Chapter 19 Air Pollution. Core Case Study: South Asias Massive Brown Cloud

Chapter 19Chapter 19

Air PollutionAir Pollution

Core Case Study: Core Case Study: South Asia’s Massive Brown CloudSouth Asia’s Massive Brown Cloud

Case Study: Case Study: South Asia’s Massive Brown CloudSouth Asia’s Massive Brown Cloud

A huge dark brown cloud of A huge dark brown cloud of industrial smogindustrial smog, , caused by caused by wood fireswood fires, , carscars, and , and coal-burningcoal-burning in countries such as China and India, in countries such as China and India, stretches over much of southeastern Asia.stretches over much of southeastern Asia. In areas beneath the cloud, In areas beneath the cloud, photosynthesis is photosynthesis is

reducedreduced interfering with crop development. interfering with crop development. Fine particles and droplets in the cloud appear to Fine particles and droplets in the cloud appear to

be be changing regional climateschanging regional climates (including rainfall). (including rainfall).• May have contributed to floods in 2002 and 2005 May have contributed to floods in 2002 and 2005

which killed thousands of people in India & which killed thousands of people in India & BangladeshBangladesh



China


India

Chapter Overview QuestionsChapter Overview Questions

What What layerslayers are found in the atmosphere? are found in the atmosphere? What are the major What are the major outdoor air pollutantsoutdoor air pollutants, ,

and where do they come from?and where do they come from? What are What are twotwo types of smog types of smog?? What is What is acid depositionacid deposition, and how can it be , and how can it be

reduced?reduced? What are the What are the harmful effectsharmful effects of air pollutants? of air pollutants? How can we How can we preventprevent and and control control air air

pollution?pollution?

Case Study: Case Study: When Is a Lichen Like a Canary?When Is a Lichen Like a Canary?

Lichens can warn Lichens can warn us of bad air us of bad air because they because they absorb itabsorb it as a as a source of source of nourishment.nourishment.

Figure 19-1Figure 19-1

Core Case Study: Core Case Study: When Is a Lichen Like a Canary?When Is a Lichen Like a Canary?

Some lichen species are sensitive to specific Some lichen species are sensitive to specific air-polluting chemicals.air-polluting chemicals.

After the After the Chernobyl Chernobyl nuclear power plant nuclear power plant explosion (1986), more than explosion (1986), more than 70,000 reindeer70,000 reindeer had to be killed because they ate highly had to be killed because they ate highly radioactive lichensradioactive lichens..

Because lichens are Because lichens are widespreadwidespread, , long-livedlong-lived, , and and anchored in placeanchored in place, they can help track , they can help track pollution to its source.pollution to its source.

STRUCTURE AND SCIENCE OF STRUCTURE AND SCIENCE OF THE ATMOSPHERETHE ATMOSPHERE

The atmosphere The atmosphere consists of several consists of several layers with different layers with different temperaturestemperatures, , pressurespressures, and , and compositionscompositions..


Fig. 19-2, p. 440

Atmospheric pressure (millibars)

Temperature

•Thermosphere

Pressure

Mesopause

Heating via ozone

• Mesosphere

Stratopause

Alt

itu

de

(kil

om

eter

s)

• Stratosphere

Alt

itu

de

(mil

es)

Tropopause

Ozone “layer”

Heating from the earthHeating from the earth

• Troposphere

Temperature (˚C)

Pressure = 1,000 millibars at ground level

(Sea level)

•Exosphere

STRUCTURE AND SCIENCE OF STRUCTURE AND SCIENCE OF THE ATMOSPHERETHE ATMOSPHERE

The atmosphere’s innermost layer The atmosphere’s innermost layer (troposphere)(troposphere) is made up mostly of nitrogen is made up mostly of nitrogen (78%) and oxygen (21%), with smaller (78%) and oxygen (21%), with smaller amounts of argon (0.93%) and amounts of argon (0.93%) and

COCO2 2 (0.038% = 380 ppm), plus 0.01% to 4% (0.038% = 380 ppm), plus 0.01% to 4% water vapor.water vapor.

Ozone (0Ozone (033) in the atmosphere’s second layer ) in the atmosphere’s second layer (stratosphere)(stratosphere) filters out 95% of the sun’s filters out 95% of the sun’s UV radiation that is harmful to us and most UV radiation that is harmful to us and most other species.other species.

AIR POLLUTIONAIR POLLUTION

Some Some primary primary air pollutants may react with one air pollutants may react with one another or with other chemicals in the air to form another or with other chemicals in the air to form secondarysecondary air pollutants (see below). air pollutants (see below).


Fig. 19-3, p. 442

Primary Pollutants

CO CO2

Secondary Pollutants

SO2 (NO & NO2)

Most hydrocarbonsSO3

Most suspended particlesHNO3

H2O2 O3 PANs

Most NO3– and SO4

2– salts

3 Sources:

Natural

Stationary

Mobile

H2SO4

NOx

Major Air PollutantsMajor Air Pollutants

Carbon oxidesCarbon oxides: : Carbon monoxideCarbon monoxide (CO) is a (CO) is a highly toxic gashighly toxic gas that that

forms during the forms during the incomplete combustionincomplete combustion of of carbon-containing materials (such as…?)carbon-containing materials (such as…?)

93%93% of carbon dioxide (CO of carbon dioxide (CO22) in the troposphere ) in the troposphere

occurs as a result of the occurs as a result of the natural carbon cyclenatural carbon cycle.. 7%7% of CO of CO22 in the troposphere occurs as a result in the troposphere occurs as a result

of of human activitieshuman activities (mostly burning fossil fuels). (mostly burning fossil fuels).• It is not regulatedIt is not regulated as a pollutant under the U.S. Clean as a pollutant under the U.S. Clean

Air ActAir Act..

Carbon DioxideCarbon Dioxide COCO22 Concentration Concentration

280 ppm 280 ppm prior to the Industrial Revolution prior to the Industrial Revolution

(about 275 years ago)(about 275 years ago)

384 ppm 384 ppm in 2007in 2007

Increasing exponentially, currently by 2 ppm per Increasing exponentially, currently by 2 ppm per yearyear

Major Air PollutantsMajor Air Pollutants Nitrogen oxides Nitrogen oxides andand nitric acid nitric acid: :

Nitric oxideNitric oxide (NO) forms when nitrogen and oxygen (NO) forms when nitrogen and oxygen gas in air react at the gas in air react at the high-combustion high-combustion temperaturestemperatures in in automobile enginesautomobile engines and and coal-coal-burning plantsburning plants. NO can also form from lightning . NO can also form from lightning and certain soil bacteria.and certain soil bacteria.• NO reacts with ONO reacts with O2 2 in the air to form NOin the air to form NO22..

• NONO2 2 reacts with water vapor in the air to form reacts with water vapor in the air to form nitric acidnitric acid

(HNO(HNO33) and ) and nitrate saltsnitrate salts (NO (NO33--) which are components of ) which are components of

acid deposition.acid deposition.

• Together, NO (primary) and NOTogether, NO (primary) and NO2 2 (secondary)(secondary) are are

generically labeled as NOgenerically labeled as NOxx


Sulfur dioxide (SOSulfur dioxide (SO22)) andand sulfuric acidsulfuric acid:: About About one-thirdone-third of SO of SO22 in the troposphere occurs in the troposphere occurs

naturally through the sulfur cycle.naturally through the sulfur cycle. Two-thirdsTwo-thirds come from human sources, mostly come from human sources, mostly

combustion of sulfur-containing coalcombustion of sulfur-containing coal

(S+ O(S+ O22 SO SO22) and from ) and from oil refiningoil refining and and smelting smelting

of sulfide ores. of sulfide ores. SOSO2 2 in the atmosphere can be converted to in the atmosphere can be converted to sulfuric sulfuric

acidacid (H (H22SOSO44) and ) and sulfate saltssulfate salts (SO (SO442-2-) that return to ) that return to

earth as a component of earth as a component of acid deposition.acid deposition.


Suspended particulate matter (SPM)Suspended particulate matter (SPM)::

Consists of a variety of Consists of a variety of solid particlessolid particles and and liquid liquid dropletsdroplets small and light enough to remain small and light enough to remain suspended in the airsuspended in the air..

The The most harmfulmost harmful forms of SPM are forms of SPM are fine particlesfine particles ((PM-10)PM-10), with an average diameter < 10 , with an average diameter < 10 micrometers, and micrometers, and ultrafineultrafine particles ( particles (PM-2.5PM-2.5).).


Suspended particulate matter (SPM)Suspended particulate matter (SPM):: According to the EPA, SPM is responsible for According to the EPA, SPM is responsible for

about about 60,00060,000 premature deaths a year in the premature deaths a year in the U.S.U.S.

SPM can: irritate nose and throat, damage lungs, SPM can: irritate nose and throat, damage lungs, and aggravate asthma and bronchitisand aggravate asthma and bronchitis

Toxic particles of lead, cadmium, and PCBs can Toxic particles of lead, cadmium, and PCBs can cause mutations, birth defects, and cancercause mutations, birth defects, and cancer


Ozone (OOzone (O33)):: Is a highly reactive gas that is a major Is a highly reactive gas that is a major

component of component of photochemical smogphotochemical smog.. ““Ground level” ozone is a strong oxidizer and Ground level” ozone is a strong oxidizer and

damages living tissue when breathed.damages living tissue when breathed. It can It can

• Cause and aggravate respiratory illness.Cause and aggravate respiratory illness.• Can aggravate heart disease.Can aggravate heart disease.• Damage plants, rubber in tires, fabrics, and paints. Damage plants, rubber in tires, fabrics, and paints.


Volatile organic compounds (VOCs)Volatile organic compounds (VOCs):: Most are hydrocarbons emitted by the leaves of Most are hydrocarbons emitted by the leaves of

many plants, and many plants, and methanemethane (CH (CH44).). About About two thirdstwo thirds of global methane emissions of global methane emissions

comes from comes from human sourceshuman sources.. Other VOCs include Other VOCs include industrial solventsindustrial solvents such as such as

trichlorethylene (TCE), benzene, and vinyl trichlorethylene (TCE), benzene, and vinyl chloride.chloride.• Long-term exposure to benzene can cause cancer, Long-term exposure to benzene can cause cancer,

blood disorders, and immune system damage.blood disorders, and immune system damage.


Radon (Rn)Radon (Rn):: RadonRadon occurs naturally when Uranium-238 occurs naturally when Uranium-238

undergoes undergoes radioactive decayradioactive decay..

Some types of soil and rock, such as granite, are Some types of soil and rock, such as granite, are relatively high in U-238relatively high in U-238

Radon can seep into homes and buildings sitting Radon can seep into homes and buildings sitting above these deposits of U-238 containing rocks.above these deposits of U-238 containing rocks.

URBAN OUTDOOR AIR POLLUTIONURBAN OUTDOOR AIR POLLUTION

Industrial smogIndustrial smog (“gray smog”) is a mixture of (“gray smog”) is a mixture of sulfur dioxidesulfur dioxide, droplets of , droplets of sulfuric acidsulfuric acid, and a , and a variety of variety of suspended solid particlessuspended solid particles emitted emitted mostly by mostly by burning coalburning coal.. In In most developed countriesmost developed countries where coal and where coal and

heavy oil is burned, heavy oil is burned, industrial smog is not a industrial smog is not a problemproblem due to reasonably good pollution control due to reasonably good pollution control or with tall smokestacks that transfer the pollutant or with tall smokestacks that transfer the pollutant to rural areas.to rural areas.

Sunlight plus Cars Equals Sunlight plus Cars Equals Photochemical SmogPhotochemical Smog

Photochemical smogPhotochemical smog is a mixture of air is a mixture of air pollutants formed by the reaction of pollutants formed by the reaction of nitrogen nitrogen oxidesoxides (NO (NOxx) and ) and volatile organic volatile organic hydrocarbonshydrocarbons (VOCs) under the influence of (VOCs) under the influence of sunlightsunlight..

Sunlight plus CarsSunlight plus Cars Equals Equals Photochemical SmogPhotochemical Smog

Mexico City is one Mexico City is one of the many cities of the many cities in in sunny, warm, drysunny, warm, dry climates with climates with many many motor vehiclesmotor vehicles that that suffer from suffer from photochemical photochemical smog.smog.


Factors Influencing Levels of Factors Influencing Levels of Outdoor Air PollutionOutdoor Air Pollution

Outdoor air pollution can be Outdoor air pollution can be reduced byreduced by:: settling out, precipitation, sea spray, winds, and settling out, precipitation, sea spray, winds, and

chemical reactions. chemical reactions.

Outdoor air pollution can be Outdoor air pollution can be increased byincreased by:: urban buildings (slow wind dispersal of urban buildings (slow wind dispersal of

pollutants), mountains (promote temperature pollutants), mountains (promote temperature inversions), and high temperatures (promote inversions), and high temperatures (promote photochemical reactions).photochemical reactions).

Temperature InversionTemperature Inversion

Smoke rising in Lochcarron, Scotland is stopped by an overlying layer of warmer air.

http://en.wikipedia.org/wiki/Lochcarron

http://en.wikipedia.org/wiki/Scotland

Temperature InversionTemperature Inversion

Fig. 19-5, p. 447

Cooler air

Descending cold air mass

Inversion layer Inversion layer

Sea breezeIncreasing altitude

Decreasing temperature

Denver:

Cold, cloudy, surrounded by mountains

LA:

Hot, sunny, ocean on one side, mountains on 3 other sides

Temperature InversionsTemperature Inversions

Cold, cloudy weather in a valley surrounded by Cold, cloudy weather in a valley surrounded by mountains can trap air pollutants (left).mountains can trap air pollutants (left).

Areas with sunny climate, light winds, Areas with sunny climate, light winds, mountains on three sides & an ocean on the mountains on three sides & an ocean on the other (right) are also susceptible to inversions.other (right) are also susceptible to inversions.


ACID DEPOSITIONACID DEPOSITION

These trees look bad, but…


……the worst threat of acid deposition is to the worst threat of acid deposition is to human healthhuman health, when , when toxic metalstoxic metals such as such as lead & mercurylead & mercury are are leachedleached from soils into from soils into the water supply, where they threaten:the water supply, where they threaten: Drinking waterDrinking water Food supplies via biomagnificationFood supplies via biomagnification


Primary pollutants:Primary pollutants: Sulfur dioxides Sulfur dioxides (SO (SO22), ),

nitrogen oxidesnitrogen oxides (NO (NOxx), and ), and particulatesparticulates can can

react in the atmosphere to produce… react in the atmosphere to produce…

Secondary pollutants:Secondary pollutants: acidic chemicals acidic chemicals that that can travel long distances before returning to can travel long distances before returning to the earth’s surface.the earth’s surface. HH22SOSO44,, HNOHNO33, and SO, and SO44

2-2- and NO and NO33- - saltssalts

Tall smokestacksTall smokestacks reduce local air pollution but reduce local air pollution but can increase regional air pollution.can increase regional air pollution.


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


Fig. 19-6, p. 448

WindTransformation to sulfuric acid (H2SO4) and nitric acid (HNO3)

Windborne ammonia gas and particles of cultivated soil partially neutralize acids and form dry sulfate and nitrate salts

Wet acid deposition (droplets of H2SO4 and HNO3 dissolved in rain and snow)

Nitric oxide (NO)Sulfur dioxide (SO2) and NO

Dry acid deposition (sulfur dioxide gas and particles of sulfate and nitrate salts)

Acid fogFarm

OceanLakes in deep Lakes in deep

soil high in soil high in limestone are limestone are

bufferedbuffered

Lakes in shallow Lakes in shallow soil low in limestone soil low in limestone

become acidicbecome acidic


pH measurements in relation to major coal-pH measurements in relation to major coal-burning and industrial plants.burning and industrial plants.


Effects of Acid Deposition…Effects of Acid Deposition…

Dead or Severely Damaged Forests and Lakes,

(especially in the Northeast US and Canada)

More Acid Deposition DamageMore Acid Deposition Damage

SO2

NOx

H2SO4

HNO3

Sulfuric AcidNitric Acid

Acid Rain in the USAcid Rain in the US

Specific Effects of Acid Deposition in a Vermont Lake

Acid Deposition in Western EuropeAcid Deposition in Western Europe

Effects of Effects of Acid Rain on Acid Rain on

Stone Stone SculptureSculpture

This photo, from 1910, shows the effect of 400 years of weathering on a grotesque which decorates Lincoln Cathedral in England.

In 1984, only 74 years later, acid rain and other atmospheric pollution have worn the figure to a barely recognizable remnant.


Contributes to Contributes to chronic respiratory diseasechronic respiratory disease Can Can leach toxic metalsleach toxic metals (such as lead and (such as lead and

mercury) from soils and rocks into acidic mercury) from soils and rocks into acidic lakes used as sources for drinking water.lakes used as sources for drinking water.




Air pollution is Air pollution is one of several one of several interacting interacting stresses that can stresses that can damage, damage, weaken, or kill weaken, or kill treestrees and pollute and pollute surface and surface and groundwatergroundwater..


Fig. 19-9, p. 451

Emissions

SO2 NOxAcid deposition

H2O2 O3

Others

Direct damage to leaves & bark

Reduced photo-synthesis and growth

Susceptibility to drought, extreme cold, insects, mosses, & disease organisms

Soil acidification

Tree death

Leaching

of soil nutrients

Release of toxic metal ions

Root damage

Reduced nutrient & water uptakeAcids

Lake

Groundwater

PANs

Fig. 19-10, p. 452

Solutions

Acid Deposition

Prevention Cleanup

Reduce air pollution by improving energy efficiency

Add lime to neutralize acidified lakes$$$$$$$$$$$$$!

Reduce coal use

Add phosphate fertilizer to neutralize acidified lakes$$$$$$$$$$$$$!

Increase natural gas use

Increase use of renewable energy resources

Burn low-sulfur coal

Remove SO2 particulates & NOx from smokestack gases (scrubbers)

Remove NOx from motor vehicular exhaust

Tax emissions of SO2

INDOOR AIR POLLUTIONINDOOR AIR POLLUTION Indoor air pollution usually is a Indoor air pollution usually is a greater threatgreater threat

to human health than outdoor air pollution.to human health than outdoor air pollution. According to the EPA, the According to the EPA, the four most four most

dangerousdangerous indoor air pollutants in indoor air pollutants in developed developed countriescountries are: are: Tobacco smoke.Tobacco smoke. Formaldehyde (upholstery, paneling, particle Formaldehyde (upholstery, paneling, particle

board, carpet, and foam insulation)board, carpet, and foam insulation) Radioactive radon-222 gas (natural- must be Radioactive radon-222 gas (natural- must be

vented)vented) Very small fine and ultrafine particles.Very small fine and ultrafine particles.

Chloroform

Benzo--pyrene

Styrene

Radon-222

Methylene Chloride

Tobacco Smoke

Carbon Monoxide

Asbestos

Nitrogen Oxides

1, 1, 1-Trichloroethane

Particulates

FormaldehydeTetrachloroethylene TCE

Para-dichlorobenzene

See p. 484

INDOOR AIR POLLUTIONINDOOR AIR POLLUTION

Household Household dust mitesdust mites that feed on human skin that feed on human skin and dust, live in and dust, live in materials such as materials such as bedding and furniture bedding and furniture fabrics.fabrics. Can cause asthma Can cause asthma

attacks and allergic attacks and allergic reactions in some reactions in some people.people.


Case Study: Radioactive RadonCase Study: Radioactive Radon Radon-222, a Radon-222, a

radioactive, radioactive, carcinogenic gascarcinogenic gas found in some soils found in some soils and rocks, can seep and rocks, can seep into some houses into some houses and increase the risk and increase the risk of of lung cancerlung cancer..

Radon comes from Radon comes from the radiactive decay the radiactive decay of of Uranium-238Uranium-238Sources and paths of entry Sources and paths of entry

for indoor radon-222 gasfor indoor radon-222 gas.NextNext

Fig. 19-13, p. 454

Outlet vents for furnaces and dryers

Open window

Openings around pipes

Cracks in wall

Slab joints

Wood stove

Cracks in floorClothes

dryerSump Sump pumppumpFurnace

Slab Radon-222 gas

Uranium-238

Soil

HEALTH EFFECTS OF AIR HEALTH EFFECTS OF AIR POLLUTIONPOLLUTION

Your respiratory system can help protect you Your respiratory system can help protect you from air pollution, but some air pollutants can from air pollution, but some air pollutants can overcome these defenses.overcome these defenses. Figure 19-14Figure 19-14

Fig. 19-14, p. 455

Epithelial cellCilia

Nasal cavity

Oral cavity

Goblet cell (secreting mucus)

Pharynx (throat)

MucusTrachea (windpipe)

BronchusBronchioles

Right lung

Bronchioles

Alveolar sac (sectioned)

Alveoli

Alveolar duct

HEALTH EFFECTS OF AIR HEALTH EFFECTS OF AIR POLLUTIONPOLLUTION

Normal human lungs (left) and the lungs of a Normal human lungs (left) and the lungs of a person who died of emphysema (right).person who died of emphysema (right).

Air Pollution is a Big KillerAir Pollution is a Big Killer

Each year, air pollution prematurely kills Each year, air pollution prematurely kills about about 3 million people3 million people, mostly from , mostly from indoor air indoor air pollution in developing countriespollution in developing countries..

In the U.S., the EPA estimates that annual deaths In the U.S., the EPA estimates that annual deaths related to indoor and outdoor air pollution range related to indoor and outdoor air pollution range from 150,000 to 350,000.from 150,000 to 350,000.

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

Air Pollution is a Big KillerAir Pollution is a Big Killer

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


PREVENTING AND REDUCING AIR PREVENTING AND REDUCING AIR POLLUTIONPOLLUTION

The Clean Air ActThe Clean Air Act (1970, ’77, ‘90) in the (1970, ’77, ‘90) in the United States have greatly reduced outdoor United States have greatly reduced outdoor air pollution from air pollution from six major pollutantssix major pollutants:: Carbon monoxideCarbon monoxide COCO Nitrogen oxidesNitrogen oxides NONOxx

Sulfur dioxidesSulfur dioxides SOSO22

Suspended particulate matter (less than PM-10)Suspended particulate matter (less than PM-10) LeadLead PbPb Ozone Ozone OO33


Environmental scientists point out several Environmental scientists point out several deficienciesdeficiencies in the Clean Air Act: in the Clean Air Act: The U.S. continues to rely on The U.S. continues to rely on cleanup rather than cleanup rather than

prevention.prevention. The U.S. Congress has failed to The U.S. Congress has failed to increase fuel-increase fuel-

efficiency standards for automobiles.efficiency standards for automobiles. Regulation of emissions from Regulation of emissions from motorcycles and motorcycles and

two-cycle engines remains inadequatetwo-cycle engines remains inadequate.. There is little or no regulation of air pollution from There is little or no regulation of air pollution from

oceangoing shipsoceangoing ships in American ports. in American ports.

PREVENTING AND REDUCING AIR PREVENTING AND REDUCING AIR POLLUTION- POLLUTION- DeficienciesDeficiencies in the Clean Air in the Clean Air

Act of 1970Act of 1970 Airports Airports are exempt from many air pollution are exempt from many air pollution

regulations.regulations.

The Act does not regulate the greenhouse gas The Act does not regulate the greenhouse gas COCO22..

The Act has failed to deal seriously with The Act has failed to deal seriously with indoor air indoor air pollution.pollution.

There is a need for There is a need for better enforcementbetter enforcement of the of the Clean Air Act.Clean Air Act.


Executives of companies claimExecutives of companies claim that that correcting these deficiencies would:correcting these deficiencies would:

cost too muchcost too much

harm economic growthharm economic growth

and cost jobs.and cost jobs.

Using the Marketplace to Reduce Using the Marketplace to Reduce Outdoor Air PollutionOutdoor Air Pollution

To help reduce SOTo help reduce SO22 emissions, the Clean Air emissions, the Clean Air

Act authorized an Act authorized an emission trading (cap-and-emission trading (cap-and-trade) programtrade) program.. Enables the 110 most polluting power plants to Enables the 110 most polluting power plants to

buy and sell SObuy and sell SO22 pollution rights. pollution rights. Between 1990-2002, the emission trading system Between 1990-2002, the emission trading system

reduced emissionsreduced emissions.. In 2002, the EPA reported the cap-and-trade In 2002, the EPA reported the cap-and-trade

system system produced less emission reductionsproduced less emission reductions than than were projected.were projected.

Solutions: Solutions: Reducing Outdoor Air PollutionReducing Outdoor Air Pollution

There are a number of ways to prevent and control There are a number of ways to prevent and control air pollution from coal-burning facilities.air pollution from coal-burning facilities.

Electrostatic precipitatorElectrostatic precipitator: are used to : are used to attract negatively attract negatively charged particlescharged particles in a smokestack into a collector. in a smokestack into a collector.

Wet scrubberWet scrubber: : fine mists of water vapor trapfine mists of water vapor trap particulates particulates and convert them to a sludge that is collected and and convert them to a sludge that is collected and disposed of usually in a landfill.disposed of usually in a landfill.

Fig. 19-18a, p. 460

Clean gas out

Negatively charged electrode

Positively charged precipitator wall

Dirty gas (smoke) in

Dust falls off into collector

Taken to landfill

Electrostatic Precipitator

Electrostatic PrecipitatorElectrostatic Precipitator Can remove 99% of Can remove 99% of

particulate matterparticulate matter Does not removeDoes not remove

hazardous ultrafine hazardous ultrafine particles.particles.

Produces toxic dustProduces toxic dust that must be safely that must be safely disposed of.disposed of.

Uses Uses large amounts large amounts of electricityof electricity


Fig. 19-18b, p. 460

Clean gas out

Separator

Liquid water in

Dirty gas (smoke) in

Polluted liquid (sludge) out

Wet Scrubber

Wet ScrubberWet Scrubber

Can remove 98% of Can remove 98% of SOSO22 and and particulate particulate

mattermatter..

Not very effectiveNot very effective in in removing hazardous removing hazardous fine and ultrafine fine and ultrafine particles.particles.


Fig. 19-17, p. 459

Solutions

Stationary Source Air Pollution

Prevention

Burn low-sulfur coal

Disperse emissions above thermal inversion layer with tall smokestacks

Remove sulfur from coal

Convert coal to a liquid or gaseous fuel

Remove pollutants after combustion

Shift to less polluting fuels

Tax each unit of pollution produced

Dispersion or Cleanup


In 2003, fourteen states and a number of In 2003, fourteen states and a number of U.S. cities U.S. cities sued the EPAsued the EPA to block new rules to block new rules that would allow older coal-burning power that would allow older coal-burning power plants to plants to modernizemodernize without having to install without having to install the most advanced air pollution controlsthe most advanced air pollution controls..


There are a number of ways to prevent and There are a number of ways to prevent and control air pollution from control air pollution from motor vehiclesmotor vehicles.. Because of the Because of the Clean Air ActClean Air Act, a new car today in , a new car today in

the U.S. emits 75% less pollution than did pre-the U.S. emits 75% less pollution than did pre-1970 cars.1970 cars.

There is an There is an increaseincrease in motor vehicle use in in motor vehicle use in developing countriesdeveloping countries and many have and many have no pollution no pollution control devices and burn leaded gasolinecontrol devices and burn leaded gasoline..

Fig. 19-19, p. 460

Solutions

Motor Vehicle Air Pollution

Prevention Cleanup

Emission control devices

Mass transit

Bicycles and walking

Less polluting engines

Less polluting fuels

Improve fuel efficiency

Car exhaust inspections twice a year

Get older, polluting cars off the road

Give buyers large tax write-offs or rebates for buying low-polluting, energy efficient vehicles

Stricter emission standards

Indoor Air PollutionIndoor Air Pollution

Little effortLittle effort has been devoted to reducing has been devoted to reducing indoor air pollution even though it poses a indoor air pollution even though it poses a much greater threat to human health than much greater threat to human health than outdoor air pollution.outdoor air pollution.

Environmental and health scientists call for Environmental and health scientists call for us to focus on us to focus on preventingpreventing air pollution air pollution (especially indoor) in developing countries.(especially indoor) in developing countries.

Fig. 19-20, p. 461

Solutions

Indoor Air Pollution

Prevention

Cover ceiling tiles & lining of AC ducts to prevent release of mineral fibers

Use adjustable fresh air vents for work spaces

Increase intake of outside airBan smoking or limit it to well ventilated areas

Change air more frequently

Set stricter formaldehyde emissions standards for carpet, furniture, and building materials

Circulate a building’s air through rooftop green houses

Prevent radon infiltration Use exhaust hoods for stoves and appliances burning natural gasUse office machines in well

ventilated areas

Use less polluting substitutes for harmful cleaning agents, paints, and other products

Install efficient chimneys for wood-burning stoves

Cleanup or Dilution

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.

Fig. 19-22, p. 462

Solutions

Air Pollution

Outdoor Indoor

Improve energy efficiency to reduce fossil fuel use

Reduce poverty

Rely more on lower-polluting natural gas

Distribute cheap & efficient cookstoves or solar cookers to poor families in developing countries

Rely more on renewable energy (especially solar cells, wind, & solar-produced hydrogen) Reduce or ban indoor

smoking

Transfer technologies for latest energy efficiency, renewable energy, & pollution prevention to developing countries

Develop simple and cheap tests for indoor pollutants such as particulates, radon, and formaldehyde

Updates Online

The latest references for topics covered in this section can be found at the book companion website. Log in to the book’s e-resources page at www.thomsonedu.com to access InfoTrac articles.

• InfoTrac: Indoor air pollution. Eva Rehfuess, Carlos Corvalan, Maria Neira. Bulletin of the World Health Organization, July 2006 v84 i7 p508(1).

• InfoTrac: Risks of cleaning house disclosed. San Jose Mercury News (San Jose, CA), May 23, 2006.

• InfoTrac: Pollution From Chinese Coal Casts Shadow Around Globe. Keith Bradsher, David Barboza. The New York Times, June 11, 2006 pA1(L).

• American Industrial Hygiene Association: Do I Work in a Sick Building?• PBS: Deadly Smog• EPA: Toxic Air Pollutants

Video: Air Pollution

• This video clip is available in CNN Today Videos for Environmental Science, 2004, Volume VII. Instructors, contact your local sales representative to order this volume, while supplies last.

Video: Smog Pollution

• This video clip is available in CNN Today Videos for Environmental Science, 2004, Volume VII. Instructors, contact your local sales representative to order this volume, while supplies last.

How Would You Vote?

To conduct an instant in-class survey using a classroom response system, access “JoinIn Clicker Content” from the PowerLecture main menu for Living in the Environment.

• Should carbon dioxide be regulated as an air pollutant?– a. No. Because funds are limited, they should be

spent on regulating and reducing more toxic air pollutants, such as mercury.

– b. Yes. Carbon dioxide is a serious greenhouse gas and its emissions must be regulated and reduced.

How Would You Vote?

To conduct an instant in-class survey using a classroom response system, access the “Polls Clicker Questions” from the PowerLecture main menu.

• Should the 1990 U.S. Clean Air Act be strengthened?– a. No. Strengthening the Act would be too

expensive and would harm the economy.– b. Yes. Strengthening the Act would improve the

environment and people's health, save energy, and ultimately save money.

How Would You Vote?

To conduct an instant in-class survey using a classroom response system, access the “Polls Clicker Questions” from the PowerLecture main menu.

• Should emissions trading be used to help control emissions of all major air pollutants?– a. No. Emissions trading has no system for

verifying compliance and eliminating "hot spots" of air pollution.

– b. Yes. Emissions trading is an efficient and effective way of reducing air pollution.

How Would You Vote?

To conduct an instant in-class survey using a classroom response system, access “JoinIn Clicker Content” from the PowerLecture main menu for Living in the Environment.

• Should older coal-burning power and industrial plants have to meet the same air pollution standards as new facilities?– a. No. The private sector should not have to upgrade existing facilities

every time the regulations change.

– b. Yes. All facilities should comply with current regulations so that the environment and human health are effectively protected.

Documents

Chapter 19 Air Pollution. Core Case Study: South Asias Massive Brown Cloud