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Midterm

Exam 4 Study Guide.doc


Department
Health Sciences
Course Code
HSC 156
Professor
All
Study Guide
Midterm

Page:
of 8
HSC 156 – Study Guide for Exam #4
1. What is acid deposition?
- Acidic form of precipitation
- Sulfur dioxide and nitrogen oxides react with sunlight, OH, & water vapor that comes back
down as either dry acid or mixes with water to form acid rain
- Primary sources are coal burning power plants and motor vehicles
2. Explain the effects of acid rain
- Leach nutrients in the ground
- Kill nitrogen-fixing microorganisms that nourish plants
- Kill fish
- Release toxic metals
3. What are acid rain controls?
- fuel switching (wind, solar, etc)
- coal washing (economically & environmentally costly)
-Scrubbers (spray smoke to remove 95% pollutants/ turns into ash or slurry)
-Fluidized bed combustion (burn coal with sand and lime)
-Reduced consumption of energy (conservation best solution)
4. Describe the "Greenhouse Effect"
- Normally, the suns rays are absorbed and some are converted to infrared radiation that is
transmitted back into space
- Some of the infrared is absorbed by green house gasses insulating the Earth
- More accumulations of greenhouse gases traps more heat, causing global warming
5. What are the greenhouse gases?
- carbon dioxide
- water vapor
- methane
- nitrous oxide
- CFC’s
6. What is the role of CO2 in the Greenhouse Effect?
- Moderates the Earth’s temperature
- Without CO2, temperature would be 90 degrees cooler
- Increase will have impact on global climate conditions
7. Describe the major impacts of global warming
- Diminishing crop yields
- Human illness/ death
- Rising sea levels
- Loss of biodiversity
8. What was the Kyoto Protocol?
- In 1997, 161 nations met to discuss global warming
- Required developed countries to cut greenhouse gas emissions >5%
- Exempted developing countries
9. Are there feasible alternatives to address global warming concerns? What are they?
- Yes, energy efficiency, alternative energy solutions (wind/ solar power)
10. What is the ozone layer? Where is it? Is this good ozone or bad ozone?
- Ozone is generated in the stratosphere from UV on O2
- Most UV is absorbed by the ozone layer
- Unabsorbed UV can cause skin damage, cataracts, an harm to plants and aquatic organisms
11. Explain the effects of destruction of ozone
- As CFC’s are released into the sky, chlorine and bromine atoms convert ozone to oxygen,
reducing amount of ozone in the atmosphere
- This allows more UV to penetrate the Earth
- This causes health effects, damage crops, and causes more smog
12. What are UV health effects?
- Skin cancer
- Premature skin aging
- Eye damage
- Mutations
13. Discuss the problem with the “hole in the sky”
- Evidence proves a direct link between ozone layer destruction & CFC emissions
- Ozone depletion is worst at N and S poles
- Ozone loss continues, but situation has stabilized because of Montreal Protocol
14. What was the Policy Response-Montreal Protocol?
- Aimed at controlling the chemicals most responsible for ozone layer depletion
- Mostly dealt with CFC reduction, halting CFC’s entirely by 1999
15. What are air pollutants?
- Substances in the atmosphere that have harmful effects on the environment & on animals,
plants, and microbes
16. What is the difference between primary and secondary pollutants?
-Primary: produced by natural, stationary and nonstationary sources
-Secondary: once they get into the air, they may change (combine or break down)
17. Which source of air pollution is easiest to control?
Stationary
18. What is an inversion? (be able to describe it)
-Layer of warm air trapped between 2 layers of cold air
-Pollutants get trapped in the warm air close to Earth, causing problems
19. Describe the Clean Air Act of 1970 and the Amendments in 1990
1970
- administered by EPA, foundation of air pollution control efforts in the US
- indentifying the most widespread pollutants by settling ambient air standards
1990
- tighten emission standards even more
- encourage development and use of cleaner burning fossil fuels
- encourage people to drive less
- identified 189 toxic pollutants
- EPA acknowledged the need to pay more attention to problem of accidental releases of such
chemicals
20. What are Ambient Air Standards?
- Set levels of air contaminants that is ok
-Guidelines can be changed base on needs
21. What are two kinds of smog?
- Industrial Smog:
-Photochemical Smog:
22. List some of the major air pollutants
-Sulfur Oxides
-Particulates (PM2.5, PM10)
-VOC’s (volatile organic compounds)
-Nitrogen Oxides
-Ozone and other photochemical oxidants
-Lead, mercury, other heavy metals
-Air toxics and radon
23. What are the major sources of pollution emissions in the US?
-Sulfur dioxide: burning fuel, especially coal for electricity
-Particulate matter: burning fuels, dust from agriculture & construction, factory emissions
-Volatile organic compounds: factory emissions and transportation
- Nitrogen oxides: fuel burning and transportation
- Carbon monoxide: transportation
24. Describe the effects of air pollution on humans
-
25. Describe effects of air pollution on the environment
-Plants are very sensitive to gaseous air pollutants; mostly effected by exposure to ozone and
other photochemical oxidants
-Damage can occur directly when pollutants destroy leaves or tree bark or indirectly when toxic
substances enter the soil, destroying roots and soil microorganisms
26. Describe the progress in limiting pollutants from motor vehicles
-90% reduction of vehicle exhausts emissions by 1975
-New cars today emit 75% less pollutants than pre-1970
-The catalytic converter is the major reason for this success