Air PollutionAir Pollution

The air we breatheThe air we breathe

Clean air consists of:Clean air consists of: Nitrogen Nitrogen Oxygen Oxygen Very small amounts of Very small amounts of

argon, carbon dioxide and argon, carbon dioxide and water vapor.water vapor.

We breathe 3,000 gallons We breathe 3,000 gallons of air each day.of air each day.

When harmful substances When harmful substances reach unhealthy levels we reach unhealthy levels we call this “air pollution.”call this “air pollution.”

Layers of Earth’s atmosphereLayers of Earth’s atmosphere

Troposhere: provides us Troposhere: provides us with the air we breathe. with the air we breathe. Extends 7 miles high. Extends 7 miles high. Responsible for weatherResponsible for weather

Stratosphere: 7-31 miles. Stratosphere: 7-31 miles. Contains the ozone layer. Contains the ozone layer. Stratosheric ozone scatters Stratosheric ozone scatters UV radiationUV radiation

Mesosphere: 31-56 miles Mesosphere: 31-56 miles highhigh

Thermosphere: top layer, Thermosphere: top layer, extends to 300 milesextends to 300 miles

Thermal InversionThermal Inversion In the troposphere warm In the troposphere warm

air rises, mixes with air rises, mixes with cooler air and pollution cooler air and pollution dissipatesdissipates

In mountain valleys In mountain valleys slopes block morning slopes block morning sun, air at ground level sun, air at ground level remains coolremains cool

Warm air at altitude traps Warm air at altitude traps pollutants near the pollutants near the groundground

Ex: Los Angeles, Mexico Ex: Los Angeles, Mexico City, Rio de Janeiro, Sao City, Rio de Janeiro, Sao PauloPaulo

The London Smog of 1952The London Smog of 1952 In 1952, London In 1952, London

abandoned their electric abandoned their electric tramcars in favor of diesel tramcars in favor of diesel buses.buses.

This added to pollution This added to pollution already coming from already coming from burning coalburning coal

December 1952 was cold December 1952 was cold and foggy.and foggy.

The air pollution was The air pollution was trapped by an inversion trapped by an inversion layer abovelayer above

An estimated 4,000 people An estimated 4,000 people died from respiratory died from respiratory problemsproblems

Air PollutionAir Pollution

Most air pollution is man-made.Most air pollution is man-made. Natural air pollution includes volcanic ash, Natural air pollution includes volcanic ash,

dust, pollen, and spores.dust, pollen, and spores. Primary Pollutant:Primary Pollutant: one that is put directly into one that is put directly into

the air by human activity ex. Soot, COthe air by human activity ex. Soot, CO Secondary Pollutant: Secondary Pollutant: forms when two primary forms when two primary

pollutants interact, or when one combines with pollutants interact, or when one combines with a naturally occurring substance ex. ground a naturally occurring substance ex. ground level ozone, Sulfuric acidlevel ozone, Sulfuric acid

The Clean Air Act (1970)The Clean Air Act (1970)

The Clean Air Act gave the federal The Clean Air Act gave the federal government authority to clean up air government authority to clean up air pollution.pollution.

EPA set maximum limits on pollutants that EPA set maximum limits on pollutants that can be in the air (National Ambient Air can be in the air (National Ambient Air Quality Standards)Quality Standards)

EPA limits emissions from industryEPA limits emissions from industry EPA regulates vehicle emissions and EPA regulates vehicle emissions and

required the gradual elimination of lead from required the gradual elimination of lead from gasolinegasoline

Clean Air Act of 1990Clean Air Act of 1990

Strengthened regulations on:Strengthened regulations on: Auto emisionsAuto emisions Toxic air pollution (188 pollutants incl. Toxic air pollution (188 pollutants incl.

mercury, benzene)mercury, benzene) Acid rainAcid rain Stratospheric ozone pollutionStratospheric ozone pollution Emissions trading for SOEmissions trading for SO22

Criteria Air PollutantsCriteria Air Pollutants

Carbon MonoxideCarbon Monoxide Nitrogen OxidesNitrogen Oxides Sulfur Dioxide (SOSulfur Dioxide (SO22))

Particulate MatterParticulate Matter Troposheric (ground level) ozoneTroposheric (ground level) ozone LeadLead

Carbon monoxide (CO)Carbon monoxide (CO)

Odorless, colorless, Odorless, colorless, poisonouspoisonous

Produced by the Produced by the incomplete burning of incomplete burning of fossil fuelfossil fuel

Sources include vehicles, Sources include vehicles, burning propane or natural burning propane or natural gas indoors, faulty gas indoors, faulty furnacesfurnaces

500 Americans die each 500 Americans die each year from accidental CO year from accidental CO poisoningpoisoning

Affects blood’s ability to Affects blood’s ability to carry oxygen. carry oxygen.

http://www.epa.gov/cgi-bin/broker?_service=data&_debug=0&_program=dataprog.dw_do_all_emis.sas&pol=225&stfips=19

Nitrogen Oxides (NONitrogen Oxides (NOXX))

Foul smelling, reddish Foul smelling, reddish brown gasbrown gas

From vehicle exhausts, From vehicle exhausts, coal burning power coal burning power plants, industryplants, industry

Contributes to smog Contributes to smog and acid rainand acid rain

Makes your body Makes your body vulnerable to respiratory vulnerable to respiratory disease and cancerdisease and cancer

http://www.epa.gov/air/emissions/nox.htm

Sulfur Dioxide (SOSulfur Dioxide (SO22))

Colorless gas with pungent odorColorless gas with pungent odor Produced by interactions between sulfur and Produced by interactions between sulfur and

oxygenoxygen Comes from burning of coal and oil which Comes from burning of coal and oil which

contain sulfurcontain sulfur Contributes to acid rain as sulfuric acidContributes to acid rain as sulfuric acid Harms plants and irritates human respiratory Harms plants and irritates human respiratory

systemsystem

http://www.epa.gov/air/emissions/so2.htm#so2loc

Particulate Matter (PM)Particulate Matter (PM)

Particles of liquid or solid small enough to be Particles of liquid or solid small enough to be suspended in the atmospheresuspended in the atmosphere

Fine particles come from vehicles, coal Fine particles come from vehicles, coal burning power plants. Coarse particles come burning power plants. Coarse particles come from cement plants, mining and agriculturefrom cement plants, mining and agriculture

Can form clouds that reduce visibility.Can form clouds that reduce visibility. Can cause a variety of respiratory problems Can cause a variety of respiratory problems

and cancer.and cancer.

http://www.epa.gov/air/emissions/pm.htm#pmloc

Troposheric (ground level) ozoneTroposheric (ground level) ozone

Ozone Ozone (O3) is a gas composed of three oxygen atoms. (O3) is a gas composed of three oxygen atoms. Not usually emitted directly into the air (secondary Not usually emitted directly into the air (secondary

pollutant)pollutant) Created by a chemical reaction between oxides of Created by a chemical reaction between oxides of

nitrogen (NOx) and volatile organic compounds (nitrogen (NOx) and volatile organic compounds (VOCVOC) ) in the presence of sunlight.in the presence of sunlight.

OO33 is unstable. It readily releases an O atom producing is unstable. It readily releases an O atom producing OO22 and free O atom. and free O atom.

Free O can damage living tissues and cause Free O can damage living tissues and cause respiratory problemsrespiratory problems

This is the pollutant that most often exceeds EPA This is the pollutant that most often exceeds EPA NAAQS.NAAQS.

Ozone: good up high, bad nearby!Ozone: good up high, bad nearby!

High Altitude (stratosperic) High Altitude (stratosperic) ozone protects life on ozone protects life on Earth from harmful UV Earth from harmful UV rays.rays.

Man-made chemicals, Man-made chemicals, such as CFC’s, have such as CFC’s, have depleted our ozone layer.depleted our ozone layer.

Since 1987 we have Since 1987 we have practically eliminated the practically eliminated the use of ozone depleting use of ozone depleting substancessubstances

Our ozone layer is Our ozone layer is recoveringrecovering

Health Effects of Ground level ozoneHealth Effects of Ground level ozone

Airway irritation, coughing, and pain when taking a Airway irritation, coughing, and pain when taking a deep breath; deep breath;

Wheezing and breathing difficulties during Wheezing and breathing difficulties during exercise or outdoor activities; exercise or outdoor activities;

Inflammation, which is much like a sunburn on the Inflammation, which is much like a sunburn on the skin;  skin; 

Aggravation of asthma and increased Aggravation of asthma and increased susceptibility to respiratory illnesses like susceptibility to respiratory illnesses like pneumonia and bronchitispneumonia and bronchitis

Permanent lung damage with repeated exposures. Permanent lung damage with repeated exposures.

LeadLead

Heavy metal found as a particulateHeavy metal found as a particulate Once found in gasoline Once found in gasoline Lead was found to enter the food chain, Lead was found to enter the food chain,

accumulate in tissues, causes central accumulate in tissues, causes central nervous system damagenervous system damage

Today’s sources: industrial metal smeltingToday’s sources: industrial metal smelting Lead paintLead paint

Volatile Organic Compounds (VOC)Volatile Organic Compounds (VOC)

Organic compounds that easily become Organic compounds that easily become toxic gastoxic gas

Vehicles are a major source, also found in Vehicles are a major source, also found in household products (paint, varnish, dry household products (paint, varnish, dry cleaned clothing, air freshener)cleaned clothing, air freshener)

Contribute to smog formationContribute to smog formation Cause serious health problems including Cause serious health problems including

cancercancer

http://www.epa.gov/air/emissions/voc.htm

Air Pollution has decreased since Air Pollution has decreased since 19701970

Case Study - ChinaCase Study - China

China is building coal fired power plants at a China is building coal fired power plants at a rate of one each weekrate of one each week

According to the World Bank 16 of the worlds According to the World Bank 16 of the worlds 20 cities with the worst air are in China.20 cities with the worst air are in China.

http://www.youtube.com/watch?v=-http://www.youtube.com/watch?v=-1DNjJd2YfA1DNjJd2YfA

http://www.youtube.com/watch?http://www.youtube.com/watch?v=GsjANjFlK0M&feature=relatedv=GsjANjFlK0M&feature=related