Air PollutionAir Pollution

Chapter 20Chapter 20

Facts about AirFacts about Air

____% is Nitrogen (N____% is Nitrogen (N22)) ____% is Oxygen (O____% is Oxygen (O22)) ____% is Argon (Ar)____% is Argon (Ar) ____% is Carbon Dioxide (CO____% is Carbon Dioxide (CO22))

What services does the What services does the atmosphere provide for the atmosphere provide for the

earth?earth? 1.1. 2. 2. 3.3.

Definition of Air PollutionDefinition of Air Pollution

Gases, liquids and solids present in Gases, liquids and solids present in the atmosphere in high enough the atmosphere in high enough levels to harm organisms or levels to harm organisms or materialsmaterials

Primary air pollutants –Primary air pollutants –

Secondary air pollutants – Secondary air pollutants –

Major Classes of PollutantsMajor Classes of Pollutants

1.1. Particulate matter – solid and liquid Particulate matter – solid and liquid particles that are suspended in the particles that are suspended in the atmosphere.atmosphere.

• Solid particulate matter = Solid particulate matter = • Liquid particulate matter = Liquid particulate matter = • Effects – Effects –

Major classes of Air Pollutants Major classes of Air Pollutants (cont.)(cont.)

2. Nitrogen Oxides – gases produced by chemical 2. Nitrogen Oxides – gases produced by chemical interactions between nitrogen & oxygen when a interactions between nitrogen & oxygen when a source of energy produces high temperatures.source of energy produces high temperatures.- Group called NO- Group called NOxx & consists of nitric oxide (NO), & consists of nitric oxide (NO), nitrogen dioxide (NOnitrogen dioxide (NO22) and nitrous oxide (N) and nitrous oxide (N220) 0) -Effects -Effects inhibits plant growthinhibits plant growth aggravates health problemsaggravates health problems photochemical smog & acid depositionphotochemical smog & acid deposition corrodes metalscorrodes metals depletes stratosphere of ozone. depletes stratosphere of ozone.

Major classes of Air Pollutants Major classes of Air Pollutants (cont.)(cont.)

3.3. Sulfur oxides – produced by the chemical Sulfur oxides – produced by the chemical interactions between sulfur and oxygeninteractions between sulfur and oxygen

- Sulfur dioxide (SOSulfur dioxide (SO22) is an emitted air pollutant and ) is an emitted air pollutant and a primary pollutanta primary pollutant

- Sulfur trioxide (SOSulfur trioxide (SO33) is a secondary air pollutant ) is a secondary air pollutant that forms when sulfur dioxide reacts with Othat forms when sulfur dioxide reacts with O22 in the in the airair

- Reacts with HReacts with H220 to form sulfuric acid0 to form sulfuric acid- EffectsEffects

- Corrosion (acid deposition)Corrosion (acid deposition)- Irritate respiratory tractsIrritate respiratory tracts

Major classes of Air Pollutants Major classes of Air Pollutants (cont.)(cont.)

4.4. Carbon Oxides – including carbon Carbon Oxides – including carbon monoxide and carbon dioxidemonoxide and carbon dioxide

- Carbon monoxide is the largest Carbon monoxide is the largest quantity of pollutant except C02quantity of pollutant except C02

- Effects bloods ability to carry oxygen.Effects bloods ability to carry oxygen.- Carbon dioxide is a greenhouse gas.Carbon dioxide is a greenhouse gas.

Major classes of Air Pollutants Major classes of Air Pollutants (cont.)(cont.)

5.5. HydrocarbonsHydrocarbons- Compounds containing only hydrogen & carbonCompounds containing only hydrogen & carbon- Simplest form is methane (CHSimplest form is methane (CH44))- Smaller hydrocarbons are gases at room Smaller hydrocarbons are gases at room

temperature.temperature.- Medium hydrocarbons are liquid at room Medium hydrocarbons are liquid at room

temperature and many are volatiletemperature and many are volatile- Largest hydrocarbons are solids at room Largest hydrocarbons are solids at room

temperature.temperature.- EffectsEffects

- Part of photochemical smogPart of photochemical smog- Methane is a greenhouse gasMethane is a greenhouse gas

Major classes of Air Pollutants Major classes of Air Pollutants (cont.)(cont.)

6.6. Ozone – (O3) Ozone – (O3) - In the stratosphere – ozone present is In the stratosphere – ozone present is

good as it blocks the UV radiation good as it blocks the UV radiation emitted from sun.emitted from sun.

- In the troposphere – ozone reacts with In the troposphere – ozone reacts with sunlight, NOx, and hydrocarbons to sunlight, NOx, and hydrocarbons to form photochemical smogform photochemical smog

- Reduces visibility Reduces visibility - Stresses plantsStresses plants- Causes health problems. Causes health problems.

Major classes of Air Pollutants Major classes of Air Pollutants (cont.)(cont.)

7.7. Air toxics or pollutantsAir toxics or pollutants- Lots of other chemicals- Lots of other chemicals

What are the main sources of What are the main sources of primary air pollutants?primary air pollutants?

Transportation – mobile sourcesTransportation – mobile sources Industries - stationary sources, top 3 are Industries - stationary sources, top 3 are

chemical, metal and paper industries.chemical, metal and paper industries.

Mobile sources – Mobile sources –

Stationary sources – Stationary sources –

What is hydrocarbon What is hydrocarbon isoprene?isoprene?

It is hydrocarbons emitted from trees It is hydrocarbons emitted from trees at high temperatures at high temperatures

It is a natural pollutantIt is a natural pollutant

Effects of PollutionEffects of Pollution

Damages organismsDamages organisms Reduces visibilityReduces visibility CorrosionCorrosion Reduce crop plants productivityReduce crop plants productivity Harm respiratory tractsHarm respiratory tracts Acid depositionAcid deposition Global temperature changeGlobal temperature change Stratospheric ozone depletionStratospheric ozone depletion

Human effects of Air Human effects of Air PollutionPollution

Eye irritationEye irritation Respiratory tract inflammationRespiratory tract inflammation Suppress immune systemSuppress immune system Respiratory illness such as asthma Respiratory illness such as asthma

emphysema, & chronic bronchitisemphysema, & chronic bronchitis

What is smog?What is smog?

Smog is air pollution that reduces Smog is air pollution that reduces visibility.visibility.

Industrial smog –Industrial smog – Photochemical smog – Photochemical smog –

What are the ingredients of What are the ingredients of smog?smog?

Photochemical smog comes from :Photochemical smog comes from :

Thermal Thermal Inversion/Temperature Inversion/Temperature

InversionInversion Air near ground is colder than air at Air near ground is colder than air at

higher levelshigher levels Traps polluting gases and particulates Traps polluting gases and particulates

matter down near groundmatter down near ground Occurs often in valleys, near coasts, Occurs often in valleys, near coasts,

or leeward side of mountains.or leeward side of mountains. AnimationAnimation

Urban Heat IslandUrban Heat Island

Localized heat buildupLocalized heat buildup Increases number of thunderstormsIncreases number of thunderstorms Contribute to buildup of pollutants Contribute to buildup of pollutants

especially particulate matter (dust especially particulate matter (dust domes)domes)

Health Effects of Air Health Effects of Air PollutionPollution

Particulate MatterParticulate Matter Carbon MonoxideCarbon Monoxide OzoneOzone Children and air pollutionChildren and air pollution

How can we control air How can we control air pollution?pollution?

Fit smokestacks with electrostatic precipitators, Fit smokestacks with electrostatic precipitators, fabric filters, scrubbers to remove particulates.fabric filters, scrubbers to remove particulates.

Careful land excavating to keep dust down.Careful land excavating to keep dust down. Temperature reduction in autos & industry to Temperature reduction in autos & industry to

reduce NOreduce NOx x formationformation Use low sulfur fuels and alternative energy Use low sulfur fuels and alternative energy

sources.sources. Use no tillage practices & less nitrogen-based Use no tillage practices & less nitrogen-based

fertilizers used.fertilizers used. Catalytic afterburners to oxidize unburned Catalytic afterburners to oxidize unburned

gasses.gasses.

Air Pollution RegulationsAir Pollution Regulations

Clean Air ActClean Air Act Authorizes the EPA to set limit on amount Authorizes the EPA to set limit on amount

of specific air pollutants permitted.of specific air pollutants permitted. Focuses on lead, particulate matter, sulfur Focuses on lead, particulate matter, sulfur

dioxide, carbon monoxide, NOdioxide, carbon monoxide, NOxx, ozone , ozone with maximum allowed concentration. with maximum allowed concentration.

Sets levels for “attainment” and ranks Sets levels for “attainment” and ranks non-attainment areas as marginal to non-attainment areas as marginal to extreme.extreme.

Air Pollution Regulations Air Pollution Regulations (cont.)(cont.)

In California, air quality managed by In California, air quality managed by Air Air

Quality Management Districts.Quality Management Districts.

Ours is Bay Area Quality Ours is Bay Area Quality Management District (BAAQMD)Management District (BAAQMD)

What is Ozone Depletion?What is Ozone Depletion?

Stratospheric ozone – block UV radiation.Stratospheric ozone – block UV radiation. UV – A (320-400 nm) not blocked by ozoneUV – A (320-400 nm) not blocked by ozone UV – B (280-320 nm) partially blocked by UV – B (280-320 nm) partially blocked by

ozoneozone UV – C (200-280 nm) fully blocked by ozone.UV – C (200-280 nm) fully blocked by ozone.

Thinning of ozone in September over Thinning of ozone in September over Antarctica results in ozone holeAntarctica results in ozone hole

What are the causes of ozone What are the causes of ozone depletion?depletion?

Chlorine & bromine containing Chlorine & bromine containing substance catalyze ozone destructionsubstance catalyze ozone destruction

Primary substances Primary substances CFC (used in coolants, insulators)CFC (used in coolants, insulators) Methyl bromide (pesticides)Methyl bromide (pesticides) Carbon Tetrachloride (solvents)Carbon Tetrachloride (solvents) Methyl chloroform (solvents)Methyl chloroform (solvents)

http://http://www.epa.govwww.epa.gov/ozone/science//ozone/science/

Effects of Ozone DepletionEffects of Ozone Depletion

http://www.ucar.edu/learn/1_6_1.htmhttp://www.ucar.edu/learn/1_6_1.htm Excessive exposure to UV radiationExcessive exposure to UV radiation Causes health problems such as eye Causes health problems such as eye

cataracts, skin cancer, and weakened cataracts, skin cancer, and weakened immunityimmunity

Crops/forests damagedCrops/forests damaged Montreal ProtocolMontreal Protocol

Stipulated 50% reduction in CFC by 1998Stipulated 50% reduction in CFC by 1998

Acid DepositionAcid Deposition

Wet deposition – sulfuric and nitric acid in Wet deposition – sulfuric and nitric acid in precipitation.precipitation.

Dry deposition – dry sulfuric acid and nitric Dry deposition – dry sulfuric acid and nitric acid-containing particlesacid-containing particles

Acid Precipitation – rain, sleet, snow and fogAcid Precipitation – rain, sleet, snow and fog Sulfur dioxide and NOSulfur dioxide and NOxx reacts with water to reacts with water to

produce dilute solutions of sulfuric acid (Hproduce dilute solutions of sulfuric acid (H22SOSO44), ), nitric acid (HNOnitric acid (HNO33) & Nitrous Acid (HNO) & Nitrous Acid (HNO22))

Acid Rain animationAcid Rain animation

What are the effects of Acid What are the effects of Acid Deposition?Deposition?

CorrosionCorrosion Makes toxic metals more soluble Makes toxic metals more soluble

(aluminum)(aluminum) Weakens eggshells as calcium become Weakens eggshells as calcium become

unavailable due to increased acidityunavailable due to increased acidity Plants/forest declinePlants/forest decline Alters chemistry of soil which effects root Alters chemistry of soil which effects root

development & mineral dissolution & development & mineral dissolution & uptake.uptake.

Remediation of Acid Remediation of Acid DepositionDeposition

Reduce sulfur dioxide and NOx Reduce sulfur dioxide and NOx emissions by installing scubbersemissions by installing scubbers

Use cleaner fuels/alternative fuelsUse cleaner fuels/alternative fuels Reduction in auto emissions. Reduction in auto emissions.

Where is pollution the Where is pollution the worst?worst?

5 worst Cities for air pollution?5 worst Cities for air pollution? Mexico City, MexicoMexico City, Mexico Beijing, ChinaBeijing, China Shanghai, ChinaShanghai, China Tehran, IranTehran, Iran Calcutta, IndiaCalcutta, India

Air Pollution in Bay AreaAir Pollution in Bay Area

Pollutants do not stay in the Bay Pollutants do not stay in the Bay Area.Area.

Pollutants go to Central Valley, Pollutants go to Central Valley, Sierras, and can even head south.Sierras, and can even head south.

Air Quality IndexAir Quality Index

What compounds stay in the What compounds stay in the environment?environment?

Persistent compounds – these that do Persistent compounds – these that do not readily breakdown and accumulate not readily breakdown and accumulate in the environment.in the environment. Example – PCB, Dioxins, DDT, Pesticides, Example – PCB, Dioxins, DDT, Pesticides,

Global Distillation effect – volatile Global Distillation effect – volatile chemicals evaporate for land, are chemicals evaporate for land, are moved by winds to higher latitudes moved by winds to higher latitudes where they condense and fall to the where they condense and fall to the ground. ground.

Indoor Air QualityIndoor Air Quality

Common contaminants include:Common contaminants include: RadonRadon Cigarette smokeCigarette smoke Carbon monoxideCarbon monoxide FormaldehydeFormaldehyde Household pesticides & solventsHousehold pesticides & solvents OzoneOzone AsbestosAsbestos ParticulatesParticulates Viruses, bacteria, fungiViruses, bacteria, fungi Dust mitesDust mites PollenPollen

What is sick building What is sick building syndrome?syndrome?

The presence of air pollution inside a The presence of air pollution inside a building causing health effects such building causing health effects such as eye irritation, nausea, headaches, as eye irritation, nausea, headaches, fatigue, depression, colds.fatigue, depression, colds.

RadonRadon

Colorless, tasteless, naturally-occurring Colorless, tasteless, naturally-occurring radioactive gas resulting from radioactive gas resulting from radioactive decay of uranium in earth. radioactive decay of uranium in earth.

Emits alpha particles, a form of ionizing Emits alpha particles, a form of ionizing radiation that is very damaging to radiation that is very damaging to tissue but doesn’t penetrate very fartissue but doesn’t penetrate very far

Can cause cancer, mostly due to Can cause cancer, mostly due to inhalationinhalation