Transcript CHAPTER 2 SCIENCE LITERACY AND THE PROCESS OF

CHAPTER 6 ENVIRONMENTAL HEALTH
ERADICATING A
PARASITIC
NIGHTMARE
Human health is intricately
linked to the environment
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ERADICATING A PARASITIC
NIGHTMARE
Human health is intricately linked to the environment
Water contamination and
other environmental changes
can contribute to infectious
disease transmission. Better
sanitation and access to public
health programs, as well as
clean air and water, can
improve human health.
Main
Concept
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ERADICATING A PARASITIC
NIGHTMARE
Human health is intricately linked to the environment
At the end of this chapter
you will know:
• What environmental
hazards impact human
health and facilitate the
transmission of diseases
• How public health
programs can reduce
health problems in both
more developed and
less developed nations
Learning Outcomes
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Environmental hazards impact human health
TERMS TO KNOW:
Waterborne disease
Vector-borne disease
Infectious diseases
Pathogen
Tiny water fleas, seen as black flecks in the
water supply, are responsible for worm
infections that sweep through villages every
year or so.
While not fatal, the worms temporarily incapacitate workers, often during the
harvest season. The female worms will burrow through the tissues and cause painful
blisters on the skin.
The simple process of filtering the water can stop the cycle of infection since the
worm’s life cycle cannot be completed without a human host ingesting the larvae.
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Environmental hazards impact human health
TERMS TO KNOW:
Public health
Epidemiologist
The role of public health is to improve
the health of the human population,
both in more developed nations and in
less developed nations.
Educating people in how to improve
sanitation and other behaviors is a
part of the preventative treatment
provided by health care workers
around the world.
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Environmental hazards impact human health
TERMS TO KNOW:
Public health
Epidemiologist
Understanding different social and
cultural systems is an important part
of public health.
Public health professionals identify
specific risks, analyze relevant
information, and develop methods
(cultural, social, and medical) to
eliminate or mediate those risks.
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Environmental hazards impact human health
TERMS TO KNOW:
Noncommunicable
diseases
Zoonotic disease
Noncommunicable diseases have
a more significant impact but
cannot be transferred from one
individual to another.
Cardiovascular disease is usually
the result of behavior or genetics.
Infectious diseases are those that can move from one victim to the next by a vector
or another organism. Many rely on other organisms as intermediate hosts.
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Environmental hazards impact human health
TERMS TO KNOW:
Noncommunicable
diseases
Zoonotic disease
Noncommunicable diseases have
a more significant impact but
cannot be transferred from one
individual to another.
Cardiovascular disease is usually
the result of behavior or genetics.
Infectious diseases are those that can move from one victim to the next by a vector
or another organism. Many rely on other organisms as intermediate hosts.
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Environmental hazards impact human health
TERM TO KNOW:
Emerging infectious
diseases
Many emerging infectious diseases are related
to environmental changes such as climate
change and habitat loss. Other causes are
related to contaminated water supplies.
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Environmental hazards impact human health
Viruses must be
ingested or injected
by the new host.
Fleas biting humans
transmitted plague
and the Hantavirus
particles are inhaled
by the victim.
Bacteria can be
found in
contaminated food
or water. Examples
include cholera,
cellulitis, and E coli.
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Examples of infectious
diseases caused by
protozoans include
giardiasis and malaria.
The use of antibiotics
can eliminate good
bacteria which control
fungal growth in the
body.
Worms are an indicator
of undercooked food
and contaminated
water.
Environmental hazards impact human health
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Environmental hazards impact human health
Different parts of the world have
different public health concerns.
In the U.S., loss of biodiversity
has lead to increases in mice
capable of carrying Lyme disease
and human encroachment brings
people in contact with these mice
more often.
Deforestation in tropical areas
increases mosquito habitat, thus allowing for an increase in malaria cases.
Agricultural runoff adds nutrients and floodwaters add fecal contaminants to local
water supplies, triggering outbreaks of cholera and other waterborne diseases.
Dam building and urbanization increase the amount of standing and stagnant
water, allowing increasing cases of guinea worm, river blindness, and others.
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Biological hazards contribute to the global burden of disease
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Biological hazards contribute to the global burden of disease
The small copepods
carry a larval form
of the guinea worm.
Drinking water
containing the
copepods allows the
larvae into the body.
The acidic
environment of the
stomach will kill the
copepods and
release the larvae
which quickly move
into the host’s body.
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Biological hazards contribute to the global burden of disease
After maturing and
mating, the males
die while the
females migrate to
the surface of the
body and burrow
out.
When the victim
eases the pain by
soaking their foot or
leg, the female
releases the next
generation of
worms.
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Biological hazards contribute to the global burden of disease
The larvae grow and
develop inside
copepods in the
water.
The cycle is
completed when
another person
drinks water
containing the
copepods.
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Biological hazards contribute to the global burden of disease
The cycle can be
stopped several
different ways:
Drinking water that
has been filtered or
purified
Treating the water
with a mild
pesticide
Not putting infected
limbs in water
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The factors that affect human health differ significantly
between developed and developing nations
Differences in
access to medical
care, sanitation,
water treatment,
food safety, social
and economic
stability, and
technology can
reduce the risks of
environmental
diseases.
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The factors that affect human health differ significantly
between developed and developing nations
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The factors that affect human health differ significantly
between developed and developing nations
While the leading
causes of death in
developing nations
are infectious and
communicable, the
leading causes of
death in high
income nations are
primarily
noncommunicable.
Leading causes of
death in middle
income countries is
a mixture of both
communicable and
noncommunicable
diseases.
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Environmentally mediated diseases can be mitigated
with funding, support, and education
Guinea worm cases have been significantly reduced over the last 25 years. In the
villages, men guard the water supply to insure nobody with blisters goes into the
water. Water and food are brought to infected people until the worms emerge.
Hunters carry small portable filters to prevent infection while hunting. Women
teach girls the importance of filtering water before giving it to their families.
These and other policies have reduced reported cases by more than 99%.
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Environmentally mediated diseases can be mitigated
with funding, support, and education
New wells and ways to filter groundwater supplies are ways to provide clean
water, but cost money and materials that often must be brought into the country.
Proper waste disposal and preventing runoff from contaminating water supplies
can be done locally, but require trained people to educate local populations.
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Environmentally mediated diseases can be mitigated
with funding, support, and education
Education programs can be used to teach people how to identify and eliminate
vector habitat, such as standing stagnant water for mosquitoes.
Solar cookers can be used in areas where fuel supplies are limited or where
people use animal dung for cooking fuel, reducing the pollutants in the air.
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Environmentally mediated diseases can be mitigated
with funding, support, and education
Education is a key part of the solution. Eliminating pathogens, changing behaviors,
and other ways to reduce risks all require educating the people.
Public and government support allows for the efficient and coordinated activities
across and between different localities.
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PERSONAL CHOICES THAT HELP
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UNDERSTANDING THE ISSUE
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ANALYZING THE SCIENCE
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EVALUATING NEW INFORMATION
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MAKING CONNECTIONS