Environmental Hazards and Human Health

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Environmental Hazards and Human Health

• Chapter 17

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Core Case Study The Global HIV/AIDS Epidemic

• What is the difference between HIV and AIDS?
• Explain why people die with AIDS when the virus
  is not deadly?
• How is the virus transmitted?
• Where are most of the people infected with HIV?
• What are the ramifications of the long incubation
  period of AIDS?

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What Major Health hazards do we face?

• 17-1

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AIDS

• Worldwide, AIDS is the leading cause of death for
  people ages 15-49.
• This is the age structure graph for Botswana with
  24 of ages 15-49 with AIDS.
• How do the premature deaths of so many people
  affect the population age chart and economics?

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Risks Are Usually Expressed as Probabilities
(Terms to Define)

• Risk
• Probability and possibility
• Risk Assessment
• Risk Management

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Types of Hazards

• Five major types of hazards
• Biological pathogens
• Chemical
• Physical
• Cultural
• Lifestyle choices

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What types of biological hazards do we face?

• 17-2

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Some Diseases Can Spread from One Person to
Another

• Nontransmissible disease
• Infectious disease
• Transmissible disease (contagious or communicable
  disease)

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Some Diseases Can Spread from One Person to
Another

• Since 1950, death from infectious diseases have
  declined due to
• Better health care
• Antibiotics
• Vaccines
• Disability-adjusted life years (DALYs)
• Measure of total disease burden in a population
• Assessment of amount of ill health, premature
  death and disability due to specific diseases and
  injuries.

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Infectious Diseases Are Still Major Health
Threats

• Infectious diseases spread through
• Air, Water, Food, Body fluids, Insects, Animals
• From Mother to Baby
• A greater problem in developing countries

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Worlds 7 Deadliest Diseases

• Compare an epidemic to a pandemic.

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Case Study The Growing Global Threat from
Tuberculosis.

1. What causes tuberculosis?
2. Why does tuberculosis spread to so many people?
3. Where is TB most prevalent?
4. What is involved in slowing the spread of TB?
5. What is multidrug-resistant TB?
6. Why are cases of TB on the rise?

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Science Focus Genetic Resistance to Antibiotics
Is Increasing

• How is bacteria becoming genetically resistant to
  antibiotics?
• Reproductive rate
• Travel and trade
• Pesticides
• Antibiotics
• Antibacterial handsoaps
• What is MRSA?
• Cause
• Symptoms
• Results
• Treatment

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Some Viral Diseases Kill Large Numbers of People

• Viruses evolve quickly, are not affected by
  antibiotics, can kill large numbers of people.
• Three most widespread viruses
• Influenza or flu virus - 1
• HIV - 2
• Hepatitis B (HBV) 3
• Damages the liver
• Transmission
• Unsafe sex
• Sharing of needles
• Infected mothers to babies
• Exposure to infected blood

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Some Viral Diseases Kill Large Numbers of People

• WHO global strategy to slow down the spread of
  HIV
• Reduce the number of new infections
• Concentrate on those most likely to spread HIV
• Free testing
• Education for prevention
• Provide free or low-cost drugs
• Research

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Some Viral Diseases Kill Large Numbers of People

• Viruses that move form animals to humans
• West Nile virus
• Infected bird to mosquito to humans
• Severe acute respiratory syndrome (SARS)
• First appeared in China
• Results in life-threatening pneumonia
• Reduce chances of infection
• Wash your hands thoroughly and often
• Avoid touching your face
• Stay away from people who have viral diseases

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Case Study MalariaDeath by Parasite-Carrying
Mosquitoes

• Where is malaria most common?

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Malaria

1. What is the cause?
2. What are the symptoms?
3. What was the attempt to prevent spread of malaria
   in the 1950s and 1960s?
4. Why is this disease re-emerging now?

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• What are the researchers working on now to
  prevent spread of malaria?

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Science Focus Ecological Medicine

1. What is ecological medicine?
2. What are human practices that encourage spread of
   diseases from animals to humans?
3. How is Lyme disease transmitted?
4. What is the best defense against Lyme disease?

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• How has expanding suburbs increased incidence of
  Lyme disease?
• What diseases are carried by bush meat?
• How does factory meat production increase the
  spread of food borne infectious disease to
  humans?

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What types of chemical hazards do we face?

• 17-3

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Some Chemicals Can Cause Cancers, Mutations, and
Birth Defects

• Toxic chemicals
• What are the 5 most toxic substances in terms of
  threats to human and environmental health?
• List three types of potentially toxic agents.

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Toxic Agents

• Carcinogens
• Mutagens
• Teratogens

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Case Study PCBs Are EverywhereA Legacy from the
Past

• What are PCBs?
• Now PCBs are banned but how were they used in the
  past?
• Why are PCBs still found now even through they
  were banned in 1977?
• Banned, but found everywhere

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Some Chemicals May Affect Our Immune, Nervous,
and Endocrine Systems

• Some natural and synthetic chemicals in the
  environment can weaken and harm
• Immune system
• Definition
• Arsenic, methylmercury, dioxins
• Results of exposure
• Nervous system
• Definition
• Neurotoxins
• Examples
• Results of exposure

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Some Chemicals May Affect Our Immune, Nervous,
and Endocrine Systems

• Endocrine Systems
• Definition
• What is the function of a hormone?
• Hormonally active agents (HAAs)
• Description
• Examples
• Hormone mimic
• Hormone blocker
• Gender bender

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Science Focus Mercurys Toxic Effects

• What kind of toxin is mercury?
• What are the natural and human sources of
  mercury?
• What does it mean to say that mercury is
  persistent?
• What are the two ways humans are exposed to
  mercury?

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Science Focus Bisphenol A

• What is Bisphenol A (BPA)?
• Where is BPA found?
• What is the concern about the products containing
  BPA?
• What are the human effects of BPA exposure?
• What is the controversy about BPA?