Human Health
Risk Factors
3 Categories of Human
Health Risks
1. Physical
 2. Biological
 3. Chemical

Leading Causes of Death in the
World
Leading Causes of Death in the
World
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1.
2.
3.
4.
5.
6.
7.
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Infectious Diseases
1.
2;
3.
4.
5.
6.
7.
Biological Risks
Infectious
diseases- those
caused by infectious agents,
known as pathogens.
 Examples:
4 Types of Pathogens
Viral
 Bacterial
 Fungal
 Parasites (protists)

Biological Risks
Chronic Disease- slowly impairs the
functioning of the person’s body
Acute Disease-rapidly impairs the
functioning of the person’s body
Leading World Health Risks for
Chronic diseases:
Comparison of Low-income countries
to high-income countries
Low-income
1.
 2.
 3.
 4.
 5.
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High-income
Changes in Risks over Time
Describe the changes in Risks over
time.
Historical Disease:
Common diseases that have been around
a long time
 Examples:

 Malaria
 Tuberculosis
 Plague
Emergent Diseases
Relatively new infectious diseases
 Examples

 AID/HIV
 Ebola
Hemorrhagic Fever
 Mad Cow disease
 Bird Flu
 West Nile Virus
Locations of Emergent Diseases
Ebola hemorrhagic fever-highly
lethal; no known treatment.
Pathways of Transmitting
Pathogens
Pathways of Transmitting
Pathogens
1.
 2.
 3.
 4.
 5.
 6.
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Infectious Diseases have Killed
large numbers of people
Epidemic: When a pathogen causes a
rapid increase in disease
 Pandemic: When an epidemic occurs
over a large geographic area.
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The Future of Human Health

To combat diseases in Low-income
countries
 Improve
nutrition
 Wider availability of clean water
 Better sanitation
 More access to vaccinations
The Future of Human Health

In high-income countries health efforts
should focus on
Healthier
lifestyle choices
More physical activity
Balanced diet-eat less-more
fruits and vegetables
Decrease tobacco use
Types of Harmful Chemicals
Neurtotoxins
 Carcinogens
 Teratogens
 Allergens
 Endocrine Disruptors
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Neurotoxins
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Chemicals that disrupt the nervous system
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Examples: insecticides, lead, mercury

In 1970’s government started requiring
reductions of lead in gasoline and paint.
Decline of lead in children over
time.
Describe the changes in lead levels
in children since 1976.
Carcinogens
Chemicals that cause cancer
 They cause cell damage and lead to
uncontrolled cell growth.
 Can cause mutations in DNA of genes that
regulate cell growth. These types are
called mutatgens

Common Carcinogens
Asbestos
 Radon
 Formaldehyde
 Chemicals in tobacco

Teratogens
Interfere with normal
development of embryos
or fetuses.
 Most famous one
was thalidomide
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Allergens

Chemicals that cause allergic reactions
Stimulate an immune response
Can cause breathing difficulties and death
Examples: peanuts, chemicals in milk, drugs
like penicillin and codeine.
Endocrine disruptors
Chemicals that interfere with the normal
functioning of hormones.
 Can enter wastewater from farm animals,
Can enter wastewater from birth control
pills in residential sewage, and
can be pesticides that mimic animal
hormones.

List 4 chemicals of major concern.
List one from each type

Tell what type it is and what its effect is.
Physical Risk Factors
Natural disasters that cause injury and death
 Excessive exposure to UV radiation from the
sun, or exposure to radioactive substances like
radon or spills from Nuclear power plants.
 Natural disasters and exposures can be linked.
Example Japan earthquake in 2011 and the
Fukushima Nuclear Power plant leakage of
radioactive coolant
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 Both
UV and radioactivity can cause cancer.
Classification of causes of Diseases
Infectious- caused by a biological agent.
 Congenital- a condition existing at or before
birth or develops within the first month
 Inherited- caused by a defective gene that
is inherited.
 Trauma-physical injury or deeply distressing
or disturbing incident.
 Acquired, but not infectious-disease
originating after birth but not infectious
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What are the 10 major categories
of diseases?
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1. Heart lung and other organ diseases.
2. Blood and immune system diseases
3. Cancer
4. Injury
5. Brain and Nervous System
10 major diseases
continued
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6. Endocrine System Diseases
7. Infectious and parasitic diseases
8. Pregnancy and Childbirth related
9. Inherited diseases
10. Environmentally-acquired diseases