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