2 The Atmosphere as a Resource Atmospheric composition:Nitrogen = 78%Oxygen = 21%Argon = 0.93%Carbon dioxide = 0.04%
3 The Atmosphere as a Resource Name the 4 major gaseous components of the earth’s atmosphere.Describe 2 ecosystem services that the atmosphere provides.
4 Air Pollution What do you know? What is outdoor air pollution? What do you think causes outdoor air pollution?Where does air pollution come from?Have you ever seen air pollution? How do you know?Is air pollution a solid, liquid or a gas?Do you think humans are affected by air pollution? How?
5 Air PollutionWhat else do you think might be affected by air pollution?How do we get rid of air pollution?Have you heard of ozone? Is it good or bad? Explain.Have you heard about particle pollution before?Do you think particles floating in the air affect humans? How?How do particles get into the air?
6 Types of Air PollutionAir Pollution – various substances added to the atmosphere by natural events and human activities in high enough concentrations to cause harm to humans, other organisms, or materialsPrimary air pollutant – a substance emitted directly to the atmosphereSecondary Air Pollutant – a substance formed in the atmosphere as a result of reactions involving primary pollutants
7 Types and Sources of Air Pollution Primary and Secondary Air Pollutants
8 Types and Sources of Air Pollution Major Classes of Air PollutantsParticulate matterNitrogen oxidesSulfur oxidesCarbon oxidesHydrocarbonsOzoneLeadOzone damage
9 Types and Sources of Air Pollution Major Air Pollutants
10 Types and Sources of Air Pollution Learning Objective: 1. Describe the difference between a primary and secondary air pollutant and give examples of each.
11 Types of Air PollutionParticulate Matter – solid and liquids suspended in the atmosphere.Soil, Soot, lead, asbestos, sea salt, sulfuric acid dropletsReduces visibilityCorrodes structuresLeaves residue on surfacesCan absorb other toxic substances
12 Types of Air Pollution Nitrogen oxides- NO, NO2, N2O Produced by the reaction at high temperatures between N2 and O2Inhibit plant growthAggravate respiratory conditionsInvolved in the production of photochemical smogN2O is a greenhouse gas and is involved in ozone depletionCorrode metals and textiles
13 Types of Pollution Sulfur oxides – SO2, SO3 formed mainly when sulfur containing fuels are burned (mainly coal)Dissolve in water to form sulfuric acid (acid rain), which damages plants and structuresDamage plantsRespiratory irritants
14 Types of Pollution Carbon Monoxide – CO Produced by the incomplete combustion of hydrocarbonsPoisonous gas
15 Types of Pollution Hydrocarbons-compounds containing H and C Wide variety of compoundsInvolved in the production of photochemical smog.Some are toxic (respiratory irritants, cancerous)Some are involved in ozone depletionMethane (CH4) is a potent greenhouse gas.
16 Types of Pollution Ozone – O3 Essential component of the stratosphere that blocks UV light waves from the sunHarmful component of photochemical smog in the troposphere.A secondary pollutant formed by reactions between nitrogen oxides and hydrocarbons, initiated by sunlightReduces visibility and causes health problems; damage to plants
17 Effects of Air Pollution Damages organismsReduced visibilityCorrodes materialsEspecially harmful to the respiratory systems of humansReduction in crop productivityLeads to acid depositionGlobal climate changeStratospheric ozone depletion
18 Effects of Air Pollution Air Pollution and Human HealthAir Toxics – a variety of hazardous air pollutants; it is estimated that 360 out of 1 million Americans die of cancer every year as a result of air toxics.
19 Effects of Air Pollution Effects of air pollution on children:Air pollution can restrict lung development in children making them more susceptible to respiratory and heart problems later in life.Children have a higher metabolic rate, meaning they breathe in more air than adults.
20 Controlling Air Pollution in the United States Clean Air ActEmissions in the US, 1970 vs. 2000
21 Controlling Air Pollution Energy efficiency and conservation are importantSmokestacks are equipped with electrostatic precipitators, scrubbers, filters, etc. to remove particulates, sulfur oxides, and nitrogen oxidesControlling the fuel/air ratio and lowering combustion temperatures leads to the production of less nitrogen oxidesModifications to furnaces and combustion engines to provide more complete combustion eliminates carbon monoxide and hydrocarbon emissions.
22 Controlling Air Pollution in the United States Turned OFFControlling Air PollutantsTurned ONElectrostatic precipitator
23 Controlling Air Pollution in the United States Turned OFFControlling Air PollutantsTurned ONElectrostatic precipitator
24 Controlling Air Pollution Clean Air Actpassed in 1970; amended in 1977 and 1990Administered by the EPAStates pass laws which must be as stringent as the federal lawFocuses on six air pollutants (lead, particulates, sulfur dioxide, carbon monoxide, nitrogen oxides, ozone)
25 Controlling Air Pollution in the United States US Urban Areas with Worst Air Quality, 2002
26 Controlling Air Pollution Clean Air ActAreas which do not meet regulatory requirements for the six pollutants are designated as nonattainment areas1977 and 1990 amendments required stricter controls on automobile emissions.1990 amendments also focused on regulation of air toxics; required a 90 % reduction in emissions of 189 toxic chemicals