Radiation, Water Quality, and Air Pollution: Chapters 9–10

1. Ionizing radiation

Radiation with enough energy to remove electrons and break chemical bonds.

2. Non

ionizing radiation - Radiation that cannot ionize atoms but can cause heating and photochemical effects.

3. Electromagnetic spectrum

Radio → Microwave → Infrared → Visible → Ultraviolet → X-ray → Gamma.

4. Alpha radiation

A large particle with low penetration; dangerous if inhaled or swallowed.

5. Beta radiation

An emitted electron with skin-deep penetration.

6. Gamma/X

ray radiation - High-penetration electromagnetic radiation; shielded by lead or concrete.

7. Neutron radiation

High-penetration radiation associated with nuclear reactor settings.

8. Gray (Gy)

Measures absorbed radiation energy per kilogram. 1 Gy = 100 rad.

9. Sievert (Sv)

Measures effective dose adjusted for biological effectiveness and tissue sensitivity. 1 Sv = 100 rem.

10. Becquerel (Bq)

Measures radioactive activity; one decay per second.

11. Gray vs. Sievert

Gray measures absorbed energy; Sievert adjusts for biological effects.

12. Stochastic effects

Effects where probability increases with dose, with no assumed threshold. Example: cancer.

13. Deterministic effects

Effects that occur above a threshold dose; severity increases with dose.

14. Linear No

Threshold (LNT) model - Assumes cancer risk rises linearly with radiation dose, with no safe threshold.

15. Acute Radiation Syndrome (ARS)

A condition that can follow a high whole-body radiation dose, generally above 1 Sv.

16. ALARA

As Low As Reasonably Achievable; minimize unnecessary radiation exposure.

17. Radiation protection methods

Reduce time, increase distance, and use shielding.

18. Radon

A radioactive gas produced by uranium-226 decay.

19. Radon action level

4 pCi/L; test every two years, according to the review.

20. UVA, UVB, and UVC

UVA: aging; UVB: sunburn and skin cancer; UVC: mostly filtered by the atmosphere.

Chapter 9: Water Quality

21. Microbial contaminants

Bacteria, viruses, and protozoa, often from fecal contamination.

22. Chemical contaminants

Substances such as nitrates, arsenic, lead, PFAS, and disinfection byproducts.

23. Physical contaminants

Physical characteristics such as turbidity and temperature.

24. Turbidity

Cloudiness caused by suspended particles in water.

25. Cryptosporidium

A protozoan parasite that can contaminate water and resist routine chlorination.

26. Water treatment steps

Coagulation → Sedimentation → Filtration → Disinfection → Finishing.

27. Coagulation

Alum makes small particles clump into larger groups called flocs.

28. Sedimentation

Flocs settle to the bottom through gravity.

29. Filtration

Water passes through materials such as sand and activated carbon.

30. Disinfection

Chlorine, UV, or ozone kills or inactivates microorganisms.

31. Finishing

Final adjustments, including pH adjustment, fluoridation, and preparation for distribution.

32. Giardia and Cryptosporidium

Protozoan parasites that can resist chlorine.

33. Safe Drinking Water Act (SDWA)

Federal law enacted in 1974 to protect public drinking water systems.

34. Maximum Contaminant Level (MCL)

An enforceable limit for contaminants in public drinking water.

35. Nitrate MCL

10 mg/L as NO₃-N.

36. Blue baby syndrome

A condition associated with high nitrate exposure in infants under six months.

37. Action level

A contaminant level that triggers corrective action or additional steps.

38. MCL vs. Action level

MCL is an enforceable drinking water limit; an action level triggers corrective action.

39. Lead exposure

The safe threshold for children is zero.

40. PFAS

Per- and polyfluoroalkyl substances, a group of chemical contaminants.

41. Disinfection byproducts (DBPs)

Chemicals that can form when disinfectants react with organic matter.

Chapter 10: Air Quality

42. Air pollution

The presence of harmful substances in the air that can affect health and the environment.

43. Six criteria air pollutants

Particulate matter, ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, and lead.

44. PM2.5

Particulate matter 2.5 micrometers or smaller; can reach the bloodstream.

45. PM10

Particulate matter 10 micrometers or smaller.

46. Ground

level ozone - Forms when nitrogen oxides (NOx) and VOCs react in sunlight.

47. Carbon monoxide (CO)

Blocks hemoglobin's ability to transport oxygen.

48. Nitrogen dioxide (NO₂)

Contributes to ozone and acid rain formation and can indicate traffic pollution.

49. Sulfur dioxide (SO₂)

Causes airway irritation and contributes to acid rain.

50. National Ambient Air Quality Standards (NAAQS)

EPA standards for outdoor air quality.

51. State Implementation Plan (SIP)

A state plan for meeting federal air quality standards.

52. Clean Air Act

Federal law authorizing regulation of air pollution and outdoor air quality.

53. Clean Air Act amendments

Strengthened in 1970 and 1990; originally enacted in 1963.

54. Air Quality Index (AQI)

Communicates how polluted the air is and what health effects may be expected.

55. AQI 101

Unhealthy for sensitive groups; sensitive groups should limit exertion.

56. Hazardous AQI

Begins at 301.

57. Ambient air

Outdoor air regulated by the EPA through NAAQS.

58. Indoor air

Air inside buildings, largely outside EPA authority according to the review.

59. Ambient vs. Indoor air

Ambient is regulated outdoor air; indoor air is largely outside EPA authority.

60. Sick building syndrome

Health symptoms associated with time spent in a particular building.

61. Indoor air pollutants

Radon, secondhand smoke, carbon monoxide, nitrogen dioxide, VOCs, and mold.

62. Time spent indoors

Approximately 90% of Americans' time.

63. Indoor air pollution

Indoor air can be approximately 2-5 times more polluted than outdoor air.

64. Atherosclerosis

Buildup of plaque in arteries.

65. PM2.5 cardiovascular pathway

Inhalation → Bloodstream → Systemic inflammation → Atherosclerosis → Heart attack or stroke.

Chapter 11: Food Safety

66. Foodborne illness

An illness caused by consuming contaminated food or beverages.

67. Foodborne infection

Illness from consuming a live pathogen that multiplies in the gut.

68. Foodborne intoxication

Illness from consuming a preformed toxin; a live organism is not needed.

69. Infection vs. Intoxication

Infection involves a live pathogen; intoxication involves a preformed toxin.

70. Salmonella incubation period

Approximately 6-48 hours.

71. Staphylococcal toxin onset

Approximately 1-6 hours.

72. Norovirus

Associated with ill food handlers and shellfish; causes approximately 19-21 million U.S. illnesses yearly.

73. Norovirus infectious dose

As few as 18 viral particles can cause infection.

74. Salmonella sources

Poultry, eggs, and produce.

75. Salmonella

A leading cause of foodborne hospitalization.

76. Campylobacter

Associated with poultry; a leading bacterial cause of foodborne illness.

77. E. coli O157:H7 sources

Ground beef and leafy greens.

78. E. coli O157:H7

Has a low infectious dose and can cause HUS in children.

79. Hemolytic uremic syndrome (HUS)

A serious complication that can damage the kidneys.

80. Listeria sources

Deli meats and soft cheeses.

81. Listeria during pregnancy

Can cause miscarriage and stillbirth.

82. C. botulinum sources

Home-canned low-acid foods.

83. HACCP

Hazard Analysis and Critical Control Point; a preventive food safety system.

84. HACCP purpose

Identifies and controls critical points where food safety hazards can occur.

85. HACCP origins

NASA and Pillsbury.

86. Poultry cooking temperature

165°F.

87. Food Safety Modernization Act (FSMA)

2011 law that shifted food safety toward prevention instead of reaction.

88. FDA responsibility

Approximately 80% of the food supply, including produce, seafood, dairy, and packaged foods.

89. USDA/FSIS responsibility

Approximately 20% of the food supply, including meat, poultry, and processed egg products.

90. CDC responsibility

Investigates outbreaks and conducts disease surveillance; does not regulate a share of the food supply.

91. Big Four food safety practices

Clean, Separate, Cook, and Chill.

92. Clean

Wash hands and food-contact surfaces.

93. Separate

Keep raw foods away from ready-to-eat foods.

94. Cook

Cook foods to their proper internal temperatures.

95. Chill

Refrigerate food within two hours.

96. Antimicrobial resistance (AMR)

When microorganisms develop the ability to resist medicines used to treat infections.

97. AMR projected deaths by 2050

10 million deaths per year.