1. Air Quality Section 15-4

2. Sources of Pollution Pollutants – harmful substances in the air, water or soil. Natural sources – fires, soil erosion, dust storms, volcanoes, mold, and pollen Human Activity – farming, construction, burning fossil fuels

3. Smog and Acid Rain London-type smog – smoke from factories and fog polluted London Photochemical smog – formed by the action of sunlight on pollutants such as hydrocarbons and nitrogen oxides

4. Acid Rain Acid rain – rain that is more acidic than normal. Moisture in air mixes with nitrogen oxides or sulfur oxides Damages buildings, statues. Kills animals and plants

5. Environmental Protection Agency EPA – government agency that monitors air pollution in the US.