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Air Pollution                                                                                                         

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Presentation on theme: "Air Pollution                                                                                                         "— Presentation transcript:

1 Air Pollution                                                                                                         

2 Sources of Pollution Point Sources Non-Point Sources
Primary Pollutants Secondary Pollutants Natural Sources Larger than anthropogenic sources

3 Thermal Inversions Warm air on top of a layer of cool air near surface
Prevents pollutants from rising & dispersing

4 Major Categories of Air Pollutants: Regulated by the Clean Air Act
Carbon Monoxide Nitrogen Oxides Sulfur Oxides Ozone Lead Suspended Particulate Matter Volatile Organic Compounds

5 Carbon Monoxide Source: burning fossil fuels
Replaces oxygen in blood stream Bonds to hemoglobin Only dangerous in high concentrations

6 Nitrogen Oxides: Photochemical Smog
Source: Automobiles (burning gasoline) NO2 + UV  O3 + Nitrates Yellow-brown color, sweet smell

7 Sulfur Oxides: Industrial Smog
Source: Coal-fired industry, electric SO2 + UV  O3 + Sulfates Gray-air smog, colored by soot

8 Sulfur & Nitrogen Oxides: Acid Rain
Source: Coal-fired industry, electric Normal Rain pH 5.6 CO2 + H2O  H2CO3 (normal) NO2 + H2O  HNO3 (contributes) SO2 + H2O  H2SO4 (strong acid) Secondary pollutant Limestone acts as a buffer: neutralize acid

9 Effects of Acid Deposition
Human respiratory illness Leach toxic metals from pipes to water Damage building materials Lakes – acid shock Release Al3+ into water – asphyxiate fish Dissolve nutrients - reduce algal growth Plants and soils Weakens trees, competition with mosses Acids leach minerals from soil

10 Ground-level Ozone Source: burning fossil fuels Secondary Pollutant!
Formed from rxns with UV Health Effects Chest pain, coughing, throat irritation, congestion Worsen respiratory disease (bronchitis, asthma, etc.) Environmental Damage Damage leaves, reduce crop yields

11 Lead Source: industry, waste incinerators
Regulations removed lead from gasoline Toxicant, accumulates in bones Neurological, kidney, immune and reproductive systems

12 Particulate Matter Source: dust, fires, volcanoes, fossil fuels
Regulated PM10 and PM2.5 Smaller than 10 um (thickness of one hair strand) Health effects Lung irritation, reduced visibility, altered nutrient balance, damage to crops

13 Reducing Pollution Carbon Monoxide Nitrogen Oxides Sulfur Oxides Ozone
CO detectors in homes Nitrogen Oxides Catalytic converters and regulations on vehicles Sulfur Oxides Scrubbers on smokestacks Ozone Lead Unleaded gasoline, removed from paints Particulates Spray mines and construction with water

14 Clean Air Act 1970, ammended 1977 & 1990
Comprehensive regulations on 6 common air pollutants: CO, NOx, SOx, O3, PM10, lead Addressed acid rain, toxic emissions, ozone depletion, automobile exhausts Created NAAQS (National Ambient Air Quality Standards) Gave enforcement authority: mainly controlled and enforced by state governments

15 Air Quality Index                                                                                                                                                                                                    

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