1. Environmental Science
Chapter 6
Notes #1

2. Air Pollution
Definition: Harmful substances in the air at unhealthy levels
Substances can be Solids, Liquids, or gases
Mostly the result of human activities
Natural sources as well
Volcanoes, dust, spores, pollen

3. Air Pollution
In some areas there are “air pollution” days like we get “snow” days
Example – Mexico City
Birds sometimes drop dead out of the trees from too much air pollution
People and up with serious health problems

4. Air Pollution Primary Pollutant
Put directly into the air by human activity
Ex. Soot from smoke, CO, Sulfur and Nitrogen Oxides, VOCs, and particulate matter
See Page 152 and 153
Sources
Transportation, Fuel Burning, Industrial, Construction/agriculture

5. Air Pollution Secondary Pollutant
When primary pollutants come into contact with other chemicals, and a reaction takes place.
EX. Smog
Term combining words “smoke” and “fog”
Ozone

6. Air Pollution Over 1/3 of pollution comes from motor vehicles
Clean Air Act – gives the EPA the right to control automobile emissions
Eliminated lead from gas (reduced lead pollution by 78% in only 7 years)
Catalytic converters (clean gases before they exit the vehicle)
Car pooling also helps
Ethanol = corn/sugar based fuel for cars
Less polluting because the by-products are CO2 and H2O

7. Air Pollution Thermal Inversions General Fact- Warm air rises
In a thermal inversion – a layer of warm air traps cool air at the Earth – also trapping pollutants
Normally pollutants would rise up with the cooling air

8. Air Pollution Acid Rain Highly acidic precipitation A pH less than 5.6
pH scale -0 to 14, what does this mean?
Pop is about a 3.5 to 4.0
Mostly Caused by nitrogen and sulfur oxides
They form sulfuric and nitric acid in the air
Can cause leeching (of Al) and acid shock (when snow melts)
Both kill living things
Some areas spray powdered lime to counteract the effects of acid rain. Why would this work?