Transcript Environmental Health

Environmental Health
What is the relationship
between the health of the
planet and our own health?
Types of Environmental Health
Hazards
• Environmental health hazards can be
biological, social, chemical, physical. Can
you think of any environmental health
hazards that exist here in Latrobe, PA?
• Biological: Viruses, bacteria, and other
organisms that cause disease
• Social: Lifestyle choices that endanger
health
• Chemical: Harmful artificial and natural
chemicals in the environment
• Physical: Natural disasters and ongoing
natural phenomena, such as UV radiation,
that can cause health problems
Identifying hazards in the environment is just one part of
environmental health. Scientists also want to understand
how these hazards affect people.
• The study of disease in
human populations—how
and where they occur and
how they can be controlled
• Often involves studying large
groups over long periods
• Can determine statistical
associations between health
hazards and effects, but
can’t prove the hazards
actually caused the effects
• The study of how poisonous
substances affect an
organism’s health
• Toxicity is a measure of how
harmful a substance is.
• Toxicologists look at toxicity
by determining doseresponse relationships.
Individual Responses
• People respond differently to
environmental hazards making it difficult
to predict with certainty how hazards
may affect specific people.
• Sensitivity to hazards varies with age, sex,
weight, and immune system health.
– People with health issues like asthma,
compromised immune systems are more
sensitive.
• Many diseases have genetic as well as
environmental factors.
– Much research has proven that breast cancer can be caused
by either emvironmental or genetic factors…and if caught
early can be curable.
Did You Know?
Thalidomide, a drug
that currently shows
promise for treatment
of Alzheimer's, AIDS,
and some cancers,
caused thousands of
severe birth defects
when it was used as an
anti-nauseal in the
1950s and 60s.
Risk Assessment
Scientists try to determine how likely it is that a given hazard
will cause harm. With chemical hazards, scientists determine
toxicity, human exposure, frequency of exposure, concentration
of exposure, etc.
• Risk: The probability that a
hazard will cause harm
• Risk assessment: The
process of measuring risk
• Takes into account:
• The type of hazard
• How frequently humans
will be exposed to it
• How sensitive people
are to it
Three quarters of infectious disease deaths
are caused by five types of diseases:
respiratory infections, AIDS, diarrheal
diseases, tuberculosis, and malaria.
Tuberculosis-causing
bacteria
Infectious Diseases
• Caused by pathogens
• Spread by human and animal
contact and through contaminated
food and water
• Cause of almost half of all deaths in
developing nations
• Covering your mouth when you
cough, washing your hands often,
and staying home from school if
you’re sick help prevent the
Did You Know? In 2002, AIDS killed
spread of infectious disease.
about 2 million people worldwide—
almost equal to the entire population of
Arkansas.
Emerging Diseases
• Diseases appearing in the human population for the
first time or suddenly beginning to spread rapidly
• Humans have little or no resistance, and no vaccines
have been developed.
• Facilitated by
increasing human
mobility, growing
antibiotic
resistance, and
environmental
changes
Responding to Emerging Diseases
• World Health Organization (WHO):
Monitors health events worldwide and
coordinates international responses to
emerging diseases
• Centers for Disease Control and
Prevention (CDC): Responds to
emerging diseases in the United States;
the CDC developed pandemic plans to
deal with the spread of the H1N1 flu
virus.
H1N1 Virus
Click HERE: History of Pandemics
Social Hazards
•Some social hazards are easier to avoid than others.
•Examples of social hazards include smoking, being
exposed to secondhand smoke, living near an old toxic
waste site, working with harmful chemicals, and eating
fatty foods.
Chemicals are all around us, and all of
them can be harmful to our health in
large enough amounts. In other
words, “The dose makes the poison.”
Chemical Hazards
• Any chemical can be harmful in
large enough amounts.
• A pollutant is something released
into the environment that has
some harmful impact on people
and other organisms.
• Chemical hazards are not
necessarily pollutants, and
pollutants are not necessarily
chemical hazards.
Types of Chemical Hazards
• Carcinogens: Cancer-causing chemicals
• Chemical mutagens: Chemicals that
cause genetic mutations
• Teratogens: Chemicals that harm
embryos and fetuses
• Neurotoxins: Chemicals that affect the
nervous system
• Endocrine disruptors: Chemicals that
interfere with the endocrine system
• Allergens: Chemicals that over-activate
the immune system
Dust mite protein is a common
allergen.
Indoor Chemical Hazards
Radon Mitigation Systems
Sources of Outdoor Chemical
Hazards
• In the air: Natural
sources, such as volcanic
eruptions, or human
sources, such as
pesticides
• In the ground: Pesticide
use, improper disposal of
electronics, etc.
• In the water: Chemical
runoff from land or direct
drainage of toxic
substances into water
Although we cannot prevent most natural
disasters, there are steps that scientists,
engineers, governments, and citizens can take
to resist damage and deal with the aftermath.
A landslide caused by the Great
Sichuan Earthquake in Sichuan
Province, China
Physical Hazards
• Physical hazards in the environment
can pose health risks to humans.
• Earth Quakes, Volcanos, Storms, and
Avalanches are just some examples
of natural disasters that can create
environmental hazards.
• We see biological hazards, chemical
hazards, and social hazards result
from natural disasters when they
strike.
• Although we cannot prevent these
disasters, we can decrease our
vulnerability to them.
Bioaccumulation and
Biomagnification
• Bioaccumulation: The buildup of
toxic substances in the bodies of
organisms
• Biomagnification: The increased
concentration of toxic substances
with each step in a food chain
• Persistent organic pollutants are
biomagnified and stay in the
environment for long periods of
time and over long distances.
CLICK HERE: Mercury in fish
One third of death and disease in the
least developed nations is a direct
result of environmental causes.
Review Questions: Please answer ALL
1. What are the 4 types of
environmental hazards?
2. What is the difference
between epidemiology and
toxicology?
3. Does everyone respond to
environmental hazards in
the same way? Why or why
not?
4. How does the health of the
environment influence
biological hazards such as
infectious disease?
5. How are social hazards
linked to environmental
impacts?
6. Make a chart listing each
of the chemical hazard
categories. Locate a
specific example for each.
ie: carcinogen example =
xxxx
7. Find an example of
something that is a
bioaccumulator in humans
and in the environment.
8. Explain the relationship
between the health of the
environment and the
health of humans on the
planet. Are they linked?