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Air Quality. Chapter 1 Section 2. Focus Questions. What are the main sources of air pollution? How do photochemical smog and acid rain form? What are two sources of air pollution that you see every day? How do natural conditions combine with human activities to create photochemical smog?.
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Air Quality Chapter 1 Section 2
Focus Questions • What are the main sources of air pollution? • How do photochemical smog and acid rain form? • What are two sources of air pollution that you see every day? • How do natural conditions combine with human activities to create photochemical smog?
Air Pollution • Pollutants – harmful substances in the air, water, or soil • Brown haze • Unpleasant smell • May lead to dizziness and headaches, allergies, cough, lung diseases, or chest pains
Air Pollution • Most air pollution is the result of burning fossil fuels such as coal, oil, gasoline, and diesel fuel. (human activities!) • cars and motor vehicles – approximately half of air pollution • Factories and power plants – approximately one fourth of air pollution
Particles • Air contains gases and particles • Particles in the air come from both natural and human activities
Particles • Natural Sources • Salt water splashing • Wind blowing (pollen and mold) • Erupting volcanos
Particles • Human Activities • Burning of fossil fuels (wood and coal, made mostly of carbon) • Farming • Construction
Smog • London-type smog – when particles in coal smoke combine with the water droplets in humid air • Photochemical smog – caused by the action of sunlight on chemicals • Brown haze seen in cities
Smog • High temperature of burning • Nitrogen in the air + oxygen • The nitrogen oxides, hydrocarbons, and other air pollutants then react with each other in the presence of sunlight to form a mix of ozone and other chemicals called photochemical smog
Checkpoint How do natural conditions combine with human activities to create photochemical smog? Turn – Talk - Share
Smog • The ozone in photochemical smog irritates breathing passages, harms plants, and damages rubber, paint, and some plastics.
Acid Rain • One result of air pollution • From the burning of coal that contains a lot of sulfur oxides • Acid rain forms when nitrogen oxides and sulfur oxides combine with water in the air to form nitric acid and sulfuric acid.
Acid Rain • Acid rain – when rain contains more acid than normal (normally rain is slightly acidic) • Harms plants, lakes, ponds…
Improving Air Quality • Laws and regulations • Generally improved in the USA over the last 30 years
Section 2 Review • How is most air pollution produced? • By the burning of fossil fuels
Section 2 Review 2. Name two natural and two artificial sources of particles in the atmosphere. Natural:Artificial: ocean salt burning of fossil fuels Molds / plant pollen farming Forest fires construction Soil erosion volcanos
Section 2 Review 3. How is photochemical smog formed? What kinds of harm does it cause? • Forms when nitrogen oxides, hydrocarbons, and other pollutants react in the presence of sunlight • Can irritate breathing passages, harm plants, and damage rubber, paint, and some plastics
Section 2 Review 4. What substances combine to form acid rain? • Nitrogen oxides • Sulfur oxides • Water in the air
Section 2 Review 5. Do you think that photochemical smog levels are higher during the winter or during the summer? Explain. • During the Summer • Production of photochemical smog requires sunlight • The sun’s rays are more direct during the summer and there are more daylight hours