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Ch. 20 Air Pollution. Earth’s Atmosphere know the difference!! Outdoor air pollution - troposphere Outdoor air pollution - troposphere Global Warming.

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Presentation on theme: "Ch. 20 Air Pollution. Earth’s Atmosphere know the difference!! Outdoor air pollution - troposphere Outdoor air pollution - troposphere Global Warming."— Presentation transcript:

1 Ch. 20 Air Pollution

2 Earth’s Atmosphere know the difference!! Outdoor air pollution - troposphere Outdoor air pollution - troposphere Global Warming Global Warming troposphere troposphere stratosphere stratosphere Ozone Depletion Ozone Depletion mostly stratosphere mostly stratosphere

3 Naturally occurring Pollutants VOC’s – trees (terpenes & isoprenes), animal waste (aldehydes, methanol, acetone) CH 4 -- metabolic activity in organisms, decaying swamp vegetation SO 2 -- volcanoes, sea spray, decaying vegetation H 2 S – geysers/hot springs, decay in bogs (hydrogen sulfide) Particulates – volcanoes(ash), forest fires (ash), trees (pollen), dust storms (dirt) CO -- forest fires CO 2 -- respiration of organisms N 2 O -- soil denitrification by bacteria (nitrous oxide) NOx – decaying organic matter & ammonia in fertilizer O 3 – lightning (in the troposphere)

4 Air Pollution Sources Point Source -–from a controlled site (smokestacks, vents, etc) Non-Point Sources – burning leaves, road dust, dust from construction site, Fugitive Sources – open areas exposed to wind processes – dirt roads, construction sites, farmland, surface mines, etc. Fugitive Sources – open areas exposed to wind processes – dirt roads, construction sites, farmland, surface mines, etc. Mobile Sources – emitters that move from place to place – autos, trucks, buses, aircraft, ships, trains Mobile Sources – emitters that move from place to place – autos, trucks, buses, aircraft, ships, trains

5 Primary Air Pollutants : SO2 SO2 NO NO NO2 NO2 CO CO CO2 CO2 PM-10 PM-10 VOC’s (including hydrocarbons) VOC’s (including hydrocarbons)

6 Anthropogenic (man-made) sources: SO 2 - burning fossil fuels (mostly coal) NO & NO 2 (NOx) - fossil fuel burning (mostly car exhaust) CO - fossil fuel burning (mostly car exhaust) PM-10 - fly ash, carbon black (soot), smoke (tobacco, oil), industrial fumes, agricultural practices (insecticide/pesticide, plowing) VOC’s - industrial processes (solvents, dyes, finishes– ( CFCs and HCs, i.e. benzene)

7 Health Effects of Primary Pollutants: lung irritant aggravates (asthma, bronchitis, emphysema) - NOx/SO black lung disease - SPM carcinogens - VOCs Headaches, dizziness - CO

8 Photochemical/Industrial Smog

9 Photochemical Smog Yellowish- Brown/NOx fig. 20.5 VOCs + NOx + heat + sunlight  VOCs + NOx + heat + sunlight  Ground level O3 Ground level O3 brownish haze brownish haze Irritates respiratory tract Irritates respiratory tract Worse on hot days Worse on hot days Trees contribute – VOCs isoprene Trees contribute – VOCs isoprene

10 Industrial Smog Gray smog/SO 2 fig. 20.6 mixture of SO 2 + droplets of H 2 SO 4 + PM-10 - coal (soot) mixture of SO 2 + droplets of H 2 SO 4 + PM-10 - coal (soot) PM – 10 fine less than 10 microns PM – 10 fine less than 10 microns Worse (ultra fine <2.5) Worse (ultra fine <2.5) Respiratory disease Respiratory disease gray smog gray smog

11 Factors influencing the formation of Smog: climate climate topography topography population density population density the amount of industry the amount of industry

12 Thermal Inversions fig. 20.7 layer of cool air trapped beneath warm air layer of cool air trapped beneath warm air prevents air currents from dispersing pollutants prevents air currents from dispersing pollutants Where Where Valley surrounded by mountains Valley surrounded by mountains City – 3 sides mountains, 1 side ocean City – 3 sides mountains, 1 side ocean

13 Acid Deposition fig. 20.8 Sulfur dioxide Sulfur dioxide Nitrogen oxides Nitrogen oxides Acidic rain, snow, fog Acidic rain, snow, fog US pH 4.4 - 4.8 US pH 4.4 - 4.8 CaCO 3 (calcium carbonate buffers soil) CaCO 3 (calcium carbonate buffers soil)

14 Effects of Acid Deposition: Reduces visibility Reduces visibility Plants – causes chlorosis,(yellowing of leaves & needles) - destroy the chlorophyll, inhibit growth Plants – causes chlorosis,(yellowing of leaves & needles) - destroy the chlorophyll, inhibit growth Leaches nutrients (Ca 2+, Mg 2+ ) from topsoil, plants susceptible to disease/pests Leaches nutrients (Ca 2+, Mg 2+ ) from topsoil, plants susceptible to disease/pests Inorganic mercury + acidic water  methyl mercury,bioaccumulates in fish, bioaccumulates in these who eat fish causing brain damage or neurological disorders. Inorganic mercury + acidic water  methyl mercury,bioaccumulates in fish, bioaccumulates in these who eat fish causing brain damage or neurological disorders.

15 Acidifies lakes and streams killing aquatic life (fish, macroinvertebrates, phytoplankton) when the pH is 4.5 and less Acidifies lakes and streams killing aquatic life (fish, macroinvertebrates, phytoplankton) when the pH is 4.5 and less Dissolves buildings, statues, and bridges that contain limestone or marble. (Concrete contains limestone) Dissolves buildings, statues, and bridges that contain limestone or marble. (Concrete contains limestone) Promotes acidic moss growth -drowns trees, kill mycorrhizal fungi that help roots absorb nutrients Promotes acidic moss growth -drowns trees, kill mycorrhizal fungi that help roots absorb nutrients Slows decomposition of forest floor plant material - acid destroys the microbial decomposers Slows decomposition of forest floor plant material - acid destroys the microbial decomposers Effects of Acid Deposition:

16 Factors increasing air pollution urban buildings – reduce wind speed urban buildings – reduce wind speed Hills/mountains – reduce air flow Hills/mountains – reduce air flow high temperatures - increase secondary air pollutants high temperatures - increase secondary air pollutants

17 Indoor Air Pollutants 4 most dangerous 4 most dangerous Cigarette smoke Cigarette smoke Formaldehyde Formaldehyde Radiactive radon-222 gas Radiactive radon-222 gas Very small fine/ultrafine particles Very small fine/ultrafine particles Developing countries Developing countries Burning wood, coal, drop residues Burning wood, coal, drop residues

18 Indoor air pollutant fig. 20.13 Asbestos Asbestos Nitrogen oxides Nitrogen oxides Trichloroethane Trichloroethane Chloroform Chloroform Para-dichlorobenz Para-dichlorobenz tetrachloroethylene tetrachloroethylene Formaldehyde Formaldehyde Styrene Styrene radon radon Study source and threat

19 Your respiratory system protects you! fig. 20.15 Nasal hairs Nasal hairs Upper respiratory sticky mucus Upper respiratory sticky mucus Sneezing/coughing Sneezing/coughing Cilia in air passages Cilia in air passages

20 Prevention Clean Air Act – set regulations for key pollutants Clean Air Act – set regulations for key pollutants NAAQS – national ambient air quality standards NAAQS – national ambient air quality standards HAPS – hazardous air pollutants standards HAPS – hazardous air pollutants standards TRI – toxic release inventory TRI – toxic release inventory

21 7 provisions of the Clean Air Act Establish - NAAQS (National Ambient Air Quality Standards) – Establish - NAAQS (National Ambient Air Quality Standards) – 6 pollutants CO, SO2, NO2, PM-10, Pb, O 3 6 pollutants CO, SO2, NO2, PM-10, Pb, O 3 monitor outdoor air on a daily basis monitor outdoor air on a daily basis Prevent air quality deterioration Prevent air quality deterioration Set national emission standards –toxic industrial emissions Set national emission standards –toxic industrial emissions Require coal-burning power plants to cut SO 2 emissions Require coal-burning power plants to cut SO 2 emissions Require mobile sources to reduce NO 2 emissions Require mobile sources to reduce NO 2 emissions Require oil companies to sell cleaner burning gasoline Require oil companies to sell cleaner burning gasoline Allow an Emissions Trading Policy (pollution credits) for SO 2 Allow an Emissions Trading Policy (pollution credits) for SO 2

22 Reducing Emissions Removes particulates & SO2


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