1. ENVIRONMENTAL SCIENCE
CHAPTER 14: Environmental Hazards and Human Health

2. Core Case Study: BPA Controversy (1)
Hormones
Hormone mimics
Estrogen mimics
Bisphenol A, an estrogen mimic

3. Core Case Study: BPA Controversy (2)
Found in hardened plastics
Baby bottles
Sipping cups
Reusable water bottles
Sports drink and juice bottles
Microwave dishes
Food storage containers
Nearly all canned food liners

4. Core Case Study: BPA Controversy (3)
93% of Americans have BPA in their bodies
Controversy over health risk
Human health
Fetuses
Infants

5. Fig. 14-1, p. 344

6. Fig. 14-2, p. 344

7. 14-1 What Major Health Hazards Do We Face?
Concept People face health hazards from biological, chemical, physical, and cultural factors, and from the lifestyle choices they make.

8. Risk and Hazards
Risk
Probability
Risk assessment
Risk management

9. Fig. 14-3, p. 345

10. Major Types of Hazards
Biological
Chemical
Physical
Cultural
Lifestyle

11. 14-2 What Types of Biological Hazards Do We Face?
Concept The most serious infectious diseases are flu, AIDS, tuberculosis, diarrheal diseases, and malaria.

12. Biological Hazards Nontransmissible diseases
Transmissible (infectious) disease
Pathogens
Epidemic
Pandemic

13. Fig. 14-4, p. 348

14. Pets Livestock Wild animals Insects Food Water Air Fetus and babies
Figure 14.4: Science: pathways for infectious disease in humans.
Question: Can you think of other pathways not shown here?
Fetus and babies
Other humans
Humans
Fig. 14-4, p. 348

15. Figure 14.4: Science: pathways for infectious disease in humans.
Pets
Livestock
Wild animals
Insects
Food
Water
Air
Fetus and babies
Other humans
Humans
Figure 14.4: Science: pathways for infectious disease in humans.
Question: Can you think of other pathways not shown here?
Stepped Art
Fig. 14-4, p. 348

16. Fig. 14-5, p. 348

17. (bacteria and viruses) 3.2 million
Disease
(type of agent)
Deaths per year
Pneumonia and flu
(bacteria and viruses)
3.2 million
HIV/AIDS
(virus)
3.0 million
Diarrheal diseases
(bacteria and viruses)
2.1 million
Malaria
(protozoa)
2.0 million
Tuberculosis
(bacteria)
Figure 14.5: Global outlook: The World Health Organization estimates that each year, the world’s seven deadliest infectious diseases
kill 11.1 million people—most of them poor people in developing countries. This is an average of about 30,400 mostly preventable
deaths every day. It would be roughly equal to wiping out everyone in the U.S. states of Massachusetts and Alabama or all the people
in Delhi, India, each year. Question: How many people, on average, die prematurely from these diseases every hour? (Data from the
World Health Organization, 2009)
1.6 million
Hepatitis B
(virus)
1 million
Measles
(virus)
800,000
Fig. 14-5, p. 348

18. Case Study: the Tuberculosis Threat (1)
TB spreading rapidly
1 in 3 infected; 5-10% will eventually develop it
2008: 9.3 million active cases
Poor countries in Asia and Africa
~ 1.6 million will die

19. Case Study: the Tuberculosis Threat (2)
Inadequate screening
Increased resistance to antibiotics
Increased person-to-person contacts
Inadequate treatment
Multidrug resistant TB

20. Science Focus: Growing Resistance to Antibiotics
High bacterial reproductive rate
Genetic resistance
Global travel
Use of pesticides
Overuse of antibiotics

21. Most Deadly Viral Diseases
Influenza/flu
HIV – AIDS
Hepatitis B
Other viruses
West Nile
SARS

22. Case Study: HIV/AIDS Epidemic (1)
Acquired immune deficiency syndrome
Human immunodeficiency virus
Spread by
Unsafe sex
Sharing needles
Infected mother to child
Exposure to infected blood

23. Case Study: HIV/AIDS Epidemic (2)
Living with AIDS 2008
33 million worldwide
2/3 in sub-Saharan Africa
1 million in the U.S.
2.7 million new cases
27 million deaths,

24. Case Study: Malaria 1 in 5 at risk Parasite spread by mosquitoes
Kills 2700 people per day, mostly in Africa
Mosquito nets for beds
Spray homes with DDT

25. Fig. 14-6, p. 350

26. Fig. 14-7, p. 351

27. infected human, ingesting blood that contains Plasmodium gametocytes
Female mosquito bites
infected human, ingesting
blood that contains
Plasmodium gametocytes
Merozoites enter
bloodstream
and develop into
gametocytes
causing malaria
and making
infected person
a new reservoir
Plasmodium
develop in
mosquito
Figure 14.7: Science: the life cycle of malaria. Plasmodium parasites
circulate from mosquito to human and back to mosquito.
Sporozoites
penetrate liver
and develop
into merozoites
Female mosquito injects
Plasmodium sporozoites
into human host.
Fig. 14-7, p. 351

28. Figure 14.7: Science: the life cycle of malaria. Plasmodium parasites
Female mosquito bites infected human,
ingesting blood that contains Plasmodium
gametocytes
Merozoites enter blood-stream and develop into gametocytes causing malaria and making
infected person a new reservoir
Plasmodium
develops in
mosquito
Figure 14.7: Science: the life cycle of malaria. Plasmodium parasites
circulate from mosquito to human and back to mosquito.
Sporozoites penetrate liver
and develop into merozoites
Female mosquito injects Plasmodium sporozoites into human host
Stepped Art
Fig. 14-7, p. 351

29. Fig. 14-8, p. 351

30. Fig. 14-9, p. 352

31. Solutions Infectious Diseases
Increase research on tropical
diseases and vaccines
Reduce poverty
Decrease malnutrition
Improve drinking water quality
Reduce unnecessary use of
antibiotics
Educate people to take all of an
antibiotic prescription
Reduce antibiotic use to promote
livestock growth
Figure 14.9: Ways to prevent or reduce the incidence of infectious
diseases, especially in developing countries. Question: Which three
of these approaches do you think are the most important?
Require careful hand washing by all medical personnel
Immunize children against major
viral diseases
Provide oral rehydration for
diarrhea victims
Conduct global campaign to reduce
HIV/AIDS
Fig. 14-9, p. 352

32. 14-3 What Types of Chemical Hazards Do We Face?
Concept There is growing concern about chemicals that can cause cancer and birth defects and disrupt the human immune, nervous, and endocrine systems.

33. Chemical Hazards (1)
Toxic chemicals
Carcinogens
Mutagens
Teratogens

34. Chemical Hazards (2) Immune system disruptors Neurotoxins
Hormonally active agents (HAA)
DDT, PCBs, atrazine, aluminum, mercury, BPA, PCBs
Males of many species becoming more feminine
BPA of special concern

35. Fig , p. 353

36. Figure 14.10: Potential pathways on which toxic chemicals can move
Atmosphere
Vegetation
Crops
Surface water
Humans
Animals
Surface water
Fish
Groundwater
Water table
Vegetation
Figure 14.10: Potential pathways on which toxic chemicals can move
through the living and nonliving environment.
Soil
Groundwater
Water table
Rock
Rock
Fig , p. 353

37. Science Focus: Mercury (1)
Nerve and organ damage
Birth defects
Natural sources
Human activities
Coal burning

38. Science Focus: Mercury (2)
Humans exposed through
Inhaling vaporized mercury and mercury compounds
Contaminated fish
High fructose corn syrup
30,000 to 60,000 U.S. newborns likely have reduced IQ
Need to end coal burning and waste incineration

39. Fig. 14-A, p. 354

40. Solutions Mercury Pollution
Prevention
Control
Phase out waste incineration
Sharply reduce mercury emissions from coal-burning plants and incinerators
Remove mercury from coal before it
is burned
Heavily tax each unit of mercury
emitted by coal-burning plants and
incinerators
Switch from coal to natural gas and
renewable energy resources such as
wind, solar cells, and hydrogen
Figure 14.A: Ways to prevent or control inputs of mercury into the environment from human sources—
mostly coal-burning power plants and incinerators. Question: Which four of these solutions do you think
are the most important?
Require labels on all products
containing mercury
Convert coal to liquid or gaseous fuel
Phase out use of mercury in
batteries, TVs, compact fluorescent
lightbulbs, and all other products
unless they are recycled
Collect and recycle mercury-containing electric switches, relays, compact fluorescent lightbulbs, and dry-cell batteries
Fig. 14-A, p. 354

41. 14-4 How Can We Evaluate Chemical Hazards?
Concept 14-4A Scientists use live laboratory animals, case reports of poisonings, and epidemiological studies to estimate the toxicity of chemicals, but these methods have limitations.
Concept 14-4B We can reduce the major risks we face by becoming informed, thinking critically about risks, and making careful choices.

42. Determining Chemical Safety
Toxicology
Toxicity
Dose
Water and fat soluble toxins
Persistence
Biological magnification

43. Type and Severity of Health Damage
Response – dose dependent
Acute effect
Chronic effect

44. Case Study: Protecting Children from Toxic Chemicals
Toxic chemicals in newborns’ blood
Infants and children more susceptible
Increased intake of air, water, food for their body weights
Put contaminated objects in their mouths
Less-developed immune systems

45. Estimating Toxicity Test on live animals Dose-response curve
Lethal dose
Median lethal dose (LD50)
Extrapolation from data

46. Table 14-1, p. 357

48. Fig , p. 360

49. Shampoo
Perfluorochemicals
to add shine
Teddy bear
Some stuffed animals
made oversees contain
flame retardants and/or
pesticides
Clothing
Can contain
perfluorochemicals
Baby bottle
Can contain
bisphenol-A
Nail polish
Perfluorochemicals
and phthalates
Mattress
Flame retardants in stuffing
Perfume
Phthalates
Hairspray
Phthalates
Carpet
Padding and carpet fibers
contain flame retardants,
perfluorochemicals, and
pesticides
Food
Some food contains
bisphenol-A TV
Wiring and plastic casing
contain flame retardants
Milk
Fat contains dioxins
and flame retardants
Figure 14.12: Some potentially harmful chemicals found in most homes. Most people have traces of these chemicals
in their blood and body tissues. We do not know the long-term effects of exposure to low levels of such chemicals.
(Data from U.S. Environmental Protection Agency, Centers for Disease Control and Prevention, and New York
State Department of Health) Questions: Does the fact that we do not know much about long-term harmful effects
of these chemicals make you more likely or less likely to minimize your exposure to them? Why?
Sofa
Foam padding contains
flame retardants and
perfluorochemicals
Frying pan
Nonstick coating contains
perfluorochemicals
Tile floor
Nonstick coating contains
perfluorochemicals,
phthalates, and pesticides
Fruit
Imported fruit may
contain pesticides
banned in the U.S.
Water bottle
Can contain
bisphenol-A
Computer
Flame retardant
coatings of plastic
casing and wiring
Toys
Vinyl toys
contain
phthalates
Tennis shoes
Can contain
phthalates
Fig , p. 360

50. Protection against Harmful Chemicals
Pollution prevention
Precautionary principle
Persistent organic pollutants (POPs)
The dirty dozen

51. Individuals Matter: Ray Turner
CFCs harm the ozone layer
Ray Turner worked at Hughes Aircraft
Developed citrus-based compounds to clean electronics instead of CFC-based compounds

52. 14-5 How Do We Perceive Risks and How Can We Avoid the Worst of Them?
Concept We can reduce the major risks we face by becoming informed, thinking critically about risks, and making careful choices.

53. Evaluating Risks (1) Risk analysis (risk assessment)
Comparative risk analysis
Risk management
Risk communication
Poverty – the greatest risk

54. Evaluating Risks (2) Risks from lifestyles Don’t smoke
Lose excess weight
Eat healthy foods
Exercise regularly
Little or no alcohol
Avoid excess sunlight
Practice safe sex

55. Fig , p. 361

56. Cause of death
Annual deaths
Poverty/
malnutrition/
disease cycle
11 million (150)
Tobacco
5.4 million (74)
Pneumonia and flu
3.2 million (44)
Air pollution
2.4 million (33)
HIV/AIDS
2 million (27)
Diarrhea
1.6 million (22)
Tuberculosis
1.5 million (21)
Automobile accidents
1.2 million (16)
Work-related
injury and disease
Figure 14.13: Global outlook: number of deaths per year in the world from various causes. Numbers in parentheses give these deaths in terms of the number of fully
loaded 200-passenger jet airplanes crashing every day of the year with no survivors. Because of the lack of media coverage of the largest annual causes of death and
sensational coverage of other causes of death, most people are misinformed and guided by irrational fears about the comparative levels of risk. Question: Which
three of these items are most likely to shorten your life span? (Data from World Health Organization, 2007)
1.1 million (15)
1 million (14)
Malaria
Hepatitis B
1 million (14)
Measles
800,000 (11)
Fig , p. 361

57. Fig , p. 364

58. Fig , p. 364

59. Fig , p. 364

60. Cause of Death Deaths Tobacco use 442,000 Accidents
101,500 (43,450 auto)
Alcohol use
85,000
Infectious
diseases
75,000 (16,000 from AIDS)
Pollutants/toxins
55,000
Figure 14.16: Annual deaths in the United States from tobacco use and other causes in 2004 (the latest data available). Smoking is by
far the nation’s leading cause of preventable death, causing more premature deaths each year than all the other categories in this figure
combined. (Data from U.S. National Center for Health Statistics and Centers for Disease Control and Prevention and U.S. Surgeon
General, 2007)
Suicides
30,600
Homicides
20,622
Illegal drug use
17,000
Fig , p. 364

61. Estimating Risks from Technologies
System reliability (%) = Technological reliability x Human reliability
Difficulties in estimating reliability
Perceived risk vs. actual risk

62. Improving Risk Evaluation
Compare risks
Determine how much risk you are willing to accept
Determine the actual risk involved
Concentrate on evaluating and carefully making important lifestyle choices

63. Three Big Ideas from This Chapter - #1
We face significant hazards from infectious diseases such as flu, AIDS, tuberculosis, diarrheal diseases, and malaria, and from exposure to chemicals that can cause cancers and birth defects and disrupt the human immune, nervous, and endocrine systems.

64. Three Big Ideas from This Chapter - #2
Because of the difficulty in evaluating the harm caused by exposure to chemicals, many health scientists call for much greater emphasis on pollution prevention.

65. Three Big Ideas from This Chapter - #3
Becoming informed, thinking critically about risks, and making careful choices can reduce the major risks we face.

66. Animation: HIV Replication
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67. Animation: Life Cycle of Plasmodium
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68. Animation: Formation of Photochemical Smog
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69. Animation: Thermal Invasion and Smog
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70. Animation: Positron-Emission Tomography
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71. Video: To See Again
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72. Video: New Nerves
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73. Video: Fat Man Walking
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74. Video: Second-Chance Heart
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75. Video: Regenerative Human Organs
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76. Video: The Problem with Pork
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77. Video: Polio Scare
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78. Video: AIDS Conference in Brazil
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79. Video: Bird Flu
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80. Video: Beach Pollution
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81. Video: Food Allergy Increase
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82. Video: World AIDS Day
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83. Video: Clean Air Act
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84. Video: MTBE Pollution
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85. Video: U.S. Earth Summit
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86. Video: Frogs Galore
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