Ch.18 Review

1. Ch.18 Review

2. 18.1 What is the nature of the atmosphere

3. The of gases that surround the earth is called the atmosphere • There are several layers that make up the atmosphere • Layers: troposphere, ozone layer, stratosphere, mesosphere, and the thermosphere • The density is the number of gas molecules • The density various throughout the different layers • The lower levels have more density because gravity pulls the molecules to the surface • The force or mass of a column of air per unit is the atmospheric pressure • Because of the lower amount of gas molecule in the air the the atmospheric pressure decreases with altitude

4. 75-80% of the air mass that is n earth is found in the troposphere • The troposphere is the atmospheric layer that is closest to the earth • The troposphere is about 11 miles above the sea level • When you take a deep breathe at least 99% of the air you just breathed is nitrogen and oxygen • The rest is water vapor as well as dust and soot particles, ozone, methane, and argon • The CO2 as well as greenhouse gases in the air is what causes the earths short-term weather and long-term climate • The climate is the average weather in an area that is measured by the temperature and the precipitation

5. Researchers think that soot and other particles in brown clouds are absorbing sunlight and heat from above glaciers • The black soot that falls above the glaciers is decreasing their ability to reflect sunlight • This causes the glaciers to absorb solar energy which increases their melting process • The slow melting of glaciers is signaling the warming atmosphere and the climate change, but researchers point out that the south Asian brown clouds are covering up the problem and are also contributing to it. • The stratosphere is the second layer of the atmosphere • It contains less matter but is composed similar to the troposphere • The atmospheres small amount of ozone is located in the stratosphere

6. 18.2 what are the major outdoor are pollution problems

7. The presence of chemicals in the air that can harm organisms is air pollution • Almost any chemical in the air can become a pollutant is • Pollutants can come from human or natural resources, for example: dust, volcanic eruptions, burning fossil fuels • Outdoor pollutants are classified in two ways: Primary and Secondary pollutants • Primary pollutants are chemicals emitted directly into the air from natural resources • Secondary pollutants are pollutants that form when primary pollutants react to each other • The major pollutants are Carbon oxides, Nitrogen oxides and nitric acid, sulfur dioxide and sulfuric acid, particulates, ozone, volatile organic compounds (VOCs) • Industrialsmog- unhealthy mix of carbon dioxide, suspended droplets of sulfuric acid, and a variety of solid particles

8. Photochemical reaction: any chemical reaction activated by light • Photochemical smog: mixture of primary and secondary pollutants formed under the influence of UV radiation from the sun. • Five natural factors that reduce outdoor air pollution: particles heavier than air settle out as a result of gravitational attraction to the earth, rain and snow, salty sea spray from the oceans, winds, chemical reactions

9. Six natural factors that can increase outdoor air pollution: urban buildings, hills and mountains, high temperatures, VOCs, grasshopper effect, temperature inversions

10. 18.3 what is acid deposition and why is it a problem?

11. Acid deposition- acid rain • Acid deposition is mostly a regional problem • Many acid-producing chemicals generated in one country are exported to other countries by prevailing winds. • The worst acid deposition occurs in Asia • Acid deposition can damage statues, buildings, contributes to human respiratory diseases, and can leach toxic metals from soil and rocks. It can also harm aquatic ecosystems. • Acid deposition can also leach nutrients from forests and damage crops • Mountain top forests are the terrestrial areas hit the hardest by acid deposition • Most of the worlds lakes and forests are not being destroyed, this problem is mostly harming lakes and forests that lie downwind from coal-burning faculties

12. 18.4 what are the indoor major air pollutants

13. Indoor air pollution is the worlds most serious air pollution problem • Since 1990 the EPA has placed indoor air pollution at the top of the list of sources of cancer risks • Living organisms and their excrements can also contribute to indoor air pollution • Another living source of indoor air pollution is fungal growth and mold • The chemical that causes more developed countries difficulty is formaldehyde • Radon-222 is a colorless, odorless, radioactive gas that is produced by the natural radioactive decay of uranium

14. When the gas is released outdoors it disperses quickly and becomes harmless • When it builds up in buildings it can become deadly • This gas quickly decays into solid particles • Your chances of getting cancer from radon depends on how much is in your home

15. 18.5 what are the health effects of air pollution

16. Our respiratory system has a number of ways to protect itself • Hairs in our noses filter out large particles • Sticky mucus in the lining of our upper respiratory tract captures smaller particles • Thousands of hair like structures called cilia line our respiratory tract and expels pollutants • According to WHO 2.4 million people worldwide die prematurely each year because of air pollution • The EPA estimates that the annual number of deaths related to indoor and outdoor air pollutants are 150,000 to 350,000

17. According to the EPA each year more than 125,000 Americans get cancer from breathing fumes. • According to the EPA diesel trucks emit as much particle matter as 150 cars

18. 18.6 how should we deal with air pollution

19. The united states provides and excellent example of how a regulatory system approach can reduce air pollution • Congress directed the EPA to establish air quality standards • A limit to help protect health is the secondary standard, it is intended to prevent environmental and property damage • The EPA also established national emission standards for more than 188 hazardous air pollutants

20. One approach to reducing pollutant emissions has been to allow producers to buy and sell government air pollution allotments • With the goal of reducing SO2 emissions, the Clean Air act of 1990 authorized an emissions trading program • Between 1990 and 2006 the emissions trading system helped to reduce SO2 emissions from power plants by 53%

21. Ways to prevent air pollution is to walk, bike, or use mass transit • Little effort has been put into reducing indoor air pollution even though it poses a greater threat than outdoor air pollution • In less-developed countries indoor air pollution could be reduced • In more-developed countries household plants could bring some relief to the pollution

22. Since 1970, most of the worlds more-developed countries have enacted laws and regulations that have significantly reduced outdoor air pollution • Most of these laws emphasize controlling outdoor air pollution by using output approaches • Environmental and health scientists argue that the next step is to shift our emphasis to preventing air pollution