Environmental Health Exam 3

Front 1

describe the different types of demand on freshwater and how much water is used by each type of demand

Back 1

Irrigation and other agricultural uses 700 galls per day per person

electrical power production 600 gallons per day per person

industrial use 370 gallons per day per person

residential use 100 gallons per day per person

Front 2

What is the number one use of water world wide?

Back 2

agriculture

Front 3

name the two consequences of overdrawing surface waters

Back 3

results in shortages

ecological effects

Front 4

14. What is the maximum percentage of the average flow of a river that can be taken without facing future shortages and other problems?

Back 4

30%

Front 5

What are Estuaries?

Back 5

o Bays in which fresh water from a river mixes with sea water
o Most productive ecosystem on earth

Front 6

16. What are the 4 environmental effects of overdrawing ground water?

Back 6

oFalling water tables & depletion
–Overuse for crop production
–About 50% of drinking water is pumped from aquifers
oDiminishing surface waters
oLand subsidence
oSalt water intrusion

Front 7

17. Approximately what percent of water comes from groundwater sources?

Back 7

50%

Front 8

18. Describe the 4 steps in water purification

Back 8

•alum coagulation
•settling
•filtration
•disinfection (usually with chlorine gas)

Front 9

19. What is the primary consideration in determining the amount of water purification?

Back 9

The amount of treatment is dependent on the quality of the water source

Front 10

20. What are 3 problems in water treatment

Back 10

oFailure to kill microbes
–fecal coliform test to monitor for contamination
oChemical overdoses
–high fluoride or high chlorine
oChemical residuals
–disinfection by-products

Front 11

21. What test is used to determine if sewage contamination is present in drinking water

Back 11

•Fecal coliform test

Front 12

22. What are some of the concerns regarding drinking water in the 3rd World? -

Back 12

access to safe drinking water supplies is limited
•Less than 50% have safe supplies
•This can lead to diseases such as cholera

Front 13

23. Discuss the needs & prospects for obtaining more water

Back 13

•Growing populations create an ever-increasing demand for additional water for irrigation & industrial/municipal use
•Prospects for increasing the supply are poor, so conservation is the only answer

Front 14

24. List 3 ways of reducing water demands

Back 14

oDrip irrigation systems
oThrough improvements in municipal systems
–Retrofitting plumbing devices
–Xeroscaping: landscape with desert plants & rocks
–Use gray water on plants
–Treat sewer water
o Desalting waterGetting industry to include the cost of water treatment in the price of consumer goods

Front 15

25. What is water pollution, and what are 2 types of water pollution? (Be sure you understand the difference between the 2 types.)

Back 15

• Any chemical, biological, or physical change in water quality that has a harmful effect on living organisms or makes water unsuitablePoint source vs non-point source

point sources - specific locations of highly concentrated pollution discharge, such as factories, power plants, sewage treatment plants, underground coal mines, and oil wells

nonpoint sources - scattered, widely spread sources of pollutants, such as runoff from farm fields, golf courses, and construction sites.

Front 16

26. Describe the different zones when pollution is added to a river:

Back 16

• The river changes from a clean zone to a decomposition zone, a septic zone, and a recovery zone.
• The amount of oxygen present in the water will drop due to the presence of pollution
• If no additional pollution sources are present, the river will revert to a clean zone.

Front 17

27. Describe the effects of pollution on lakes

Back 17

• Lakes cannot dilute pollutants as quickly as a flowing stream or river.
• As a result, lakes change from Oligotrophic (low in nutrients) to Eutrophic (high in nutrients

Front 18

28. What is the “cell from hell?”

Back 18

• Pfiesteria is a micro-organism capable of changing into 24 forms
o free living algae eater or
o as a dinoflaellate, it releases neurotoxins that can stun fish or make humans ill
• “Blooms” of Pfiesteria have been linked to run-off from hog & chicken feedlots.

Front 19

29. What is the Clean Water Act (CWA) of 1972?

Back 19

• Clean Water Act (CWA) of 1972 controlling the discharge of pollutants

Front 20

31. What is the most important purpose of municipal sewage treatment?

Back 20

o Needed to alleviate health & aesthetic problems related to sewage disposal
o Effective in dealing with problems created by dumping raw sewage into waterways

Front 21

32. What are the 4 steps/ levels of sewage treatment?

Back 21

o Preliminary treatment – removal of grit & debris
o Primary treatment – coagulate & settle
o Secondary treatment - Biological nutrient removal & disinfect ion (usually with chlorine)
o Tertiary treatment Cleansing of specific chemicals

Front 22

33. What are the 4 categories of pollutants in raw sewage?

Back 22

• Debris and grit, particulate organic materials, colloidal and dissolved organic chemicals, dissolved inorganic chemicals

Front 23

34. What are the different levels of sewage treatment

Back 23

 Preliminry, Primary, Secondary, and Tertiary

Front 24

35. What is the level that most municipal systems reach?

Back 24

• Preliminary, primary, and secondary treatment but no more

Front 25

36. What are 4 sludge treatment options?

Back 25

o Anaerobic digestion
o Composting
o Pasteurization & drying
o Lime stabilization

Front 26

37. What are examples of 5 alternative treatment systems?

Back 26

o Using effluents for irrigation
o Reconstructed wetlands systems
o Artificial wetland systems
o Greenhouse wetland systems
o Overland flow systems

Front 27

38. Describe a typical septic treatment system?

Back 27

o Onsite wastewater treatment systems
o System set-up: Septic tank & Soil absorption field or sand filter (no-chlorine)

Front 28

39. What kinds of toxic materials get into wastewater treatment system that can not be removed using secondary treatment?

Back 28

o Synthetic organic compounds
o Toxic pollutants
o Household chemicals

Front 29

40. What is storm water and why is it a problem?

Back 29

• It is the water that washes off of roofs, streets and other hard surfaces
• It is a problem because it becomes contaminated with oil, fertilizer, or anything dumped on the street

Front 30

41. When is industrial pretreatment required

Back 30

• It is necessary to remove toxic chemicals that will not be removed by conventional (secondary treatment

Front 31

42. What was the purpose of the Safe Drinking Water Act?

Back 31

• EPA sets maximum contaminant levels for specified pollutants found in drinking water
• Prescribed schedule for monitoring & testing treated water
• Report water quality results to appropriate state agencies

Front 32

43. Describe the process of total product life cycle

Back 32

o Raw materials are minded, transported, refined, transported, manufactured into a product, transported, used & disposed of
o The environment may be contaminated by a hazardous material or waste at many points in its life cycle

Front 33

44. What are bioaccumulation and biomagnification?

Back 33

• Bioaccumulation accumulation of higher & higher concentrations of potentially toxic chemicals in organisms (the selective absorption and storage of a great variety of molecules. this allows them to accumulate nutrients and essential minerals)
• Biomagnification through several levels of the food chain. increase in concentration of certain stable chemicals in succesively higher trophic leels of a food chain or web

Front 34

45. What was the Safe Drinking Water Act of 1974?

Back 34

• Set standards for allowable pollutants in drinking water

Front 35

46. What is groundwater remediation and what is the problem with it?

Back 35

• – very expense way of cleaning contaminated groundwater

Front 36

47. What was the Superfund and what is one of the problems with it?

Back 36

o It set priorities for clean up of hazardous waste sites based on current & potential threat to groundwater supplies, threat to human health, immediate & severe threats-NPL sites
o Problem with costs applied to legal fees

Front 37

48. What is the National Priority List (NPL)?

Back 37

• It is those sites that require cleanup to prevent further environmental and health damage

Front 38

49. What was the Resource Conservation and Recovery Act (RCRA) of 1976?

Back 38

o Cornerstone legislation designed to prevent unsafe or illegal disposal of wastes on land

Front 39

50. What was the Underground Storage Tank (UST) standard

Back 39

o Requires strict monitoring of fuel supplies, tanks, & piping so that leaks may be detected early

Front 40

51. What are the Worker Right to Know and the Community Right to Know standards?

Back 40

o Law & especially one rule the Hazard Communication Standard requires business & industries to make information regarding hazardous materials & suitable protective equipment available to all employees
o SARA Title III the Community Right to Know law – similar to the OSHA standard for workers

Front 41

52. What are 3 approaches to hazardous waste prevention?

Back 41

• Pollution avoidance – accomplished by:
o Responsible care
o Green products

Front 42

53. What is Municipal Solid Waste (MSW)?

Back 42

o Total of all materials thrown away from homes & commercial establishments

Front 43

54. How do we dispose of MSW

Back 43

o Landfills
o Incineration, including Waste to Energy (WTE)
o Only about 25-30% is recycled in the US

Front 44

55. The amount of waste has grown steadily due to what?

Back 44

• population growth, use of disposables, lifestyle & packaging

Front 45

56. What are the most common types of MSW?

Back 45

mostly paper & yard waste – things that should be recycled

Front 46

57. What are 4 problems with landfills?

Back 46

 Leachate generation & groundwater contamination
 Methane production
 Incomplete decomposition
 Settling

Front 47

58. What are the advantages & disadvantages of incineration

Back 47

 Reducing the volume of waste, easier handling, make electricity
 But the materials should go into recycling & reuse

Front 48

59. What is the best method of dealing with refuse?

Back 48

 Reduce the generation of it in the 1st place

Front 49

60. What percentage of waste could be recycled?

Back 49

– 75%

Front 50

61. What are the two kinds of recycling?

Back 50

 Pre-consumer waste and post consumer waste

Front 51

62. How do we encourage recycling?

Back 51

 Simplified system of collection
 Pay as you throw

Front 52

63. What is composting

Back 52

 Natural biological decomposition of organic matter in the presence of air
 Economic & environmental benefits

Front 53

64. What is "Integrated Waste Management"

Back 53

 Waste reduction
 Recycling
 Some disposal

Front 54

65. Explain the difference between a hazard & a risk

Back 54

 Hazard is the potential of something to do harm it may be: chemical, biological, physical, or cultural
 Risk is the probability of some harmful event occurring

Front 55

66. Hazards fall into which 4 categories? (Be able to distinguish between them)

Back 55

 Cultural
 Physical
 Chemical
 Biological

Front 56

67. Can all hazards be avoided?

Back 56

 No, e.g., certain natural hazards like earthquakes can not be avoided

Front 57

68. What is the difference between a toxic and a hazardous substance

Back 57

 A substance is rated for toxicity based on the amount of material necessary to kill 50% of test animals
 Toxins are just one type of hazardous chemical. Hazardous chemicals may cause harm by being flammable, damaging to tissues, interfering with oxygen uptake, cause allergic reactions, or many other problems

Front 58

69. What is an LD 50?

Back 58

lethal dose The amount of a substance that will kill half of the population.