Transcript Chapter 17 Human Health and Environmental Risks

Chapter 17
Human Health and Environmental Risks
Objectives
• Identify the three major categories of human
health risks
• List the major historical and emerging
infectious diseases
• Name the five major types of toxic chemical s
• Distinguish between does-response studies,
retrospective studies, and prospective studies
• Describe th efactors that help determine the
chemical concentrations that organisms
experience
• Explain the factors that go into a risk analysis
and distinguish between the two major
philosophies of chemical regulation
•
•
•
Human Health and
Environmental Risks: Citizen
Scientist
List 3 reasons why the city population of Old Diamond in Norco, Louisiana,
is comprised mostly of lower-income African Americans.
Describe the accidents that occurred in 1973 and 1988 List effects of each
accident.
Describe the actions Margie Richards took to help the people of Old
Diamond
•
•
•
•
•
EPA:
Bucket Brigade:
2002:
2007:
Are there any Shell Oil chemical plants or oil refineries near Los Angeles?
Where? Should action be taken as Margie Richards did for the people of Old
Diamond?
Three categories of human health
risks

physical

biological

chemical
Biological Risks

Infectious diseases- those caused b y infectious
agents, known as pathogens.

Examples: pneumonia and venereal diseases
Biological Risks

Chronic disease- slowly impairs the functioning of a
person’s body.

Acute diseases- rapidly impair the functioning of a
person’s body.
Risk
Historical
Diseases
Plague
Plague
Malaria
Tuberculosis
Malaria
TB
Cause
Effect
Treatment
Emergent
Diseases
HIV/AIDS
Risk
HIV/AIDS
Ebola
Mad
Cow
Disease
Bird Flu
West Nile
Virus
Ebola
Mad Cow
Disease
Bird Flu
West Nile Virus
Cause
Effect
Treatment
Chemical Risks

Neurotoxins- chemicals that disrupt the nervous system

Carcinogens- chemicals that cause cancer

Teratogens- chemicals that interfere with the normal
development of embryos or fetuses

Allergens- chemicals that cause allergic reactions

Endocrine disruptors- chemicals that interfere with the
normal functioning of hormones in an animal’s body
Type
Chemical Risks
Neurotoxins-
chemicals
that disrupt the nervous
system
Carcinogens- chemicals
that cause cancer
Teratogens- chemicals
that interfere with the
normal development of
embryos or fetuses
Allergens- chemicals
that cause allergic
reactions
Endocrine disruptorschemicals that interfere
with the normal
functioning of hormones
in an animal’s body
Neurotoxins
Carcinogens
Teratogens
Allergens
Endocrine
Disruptors
Example of
Chemicals
(Use Table 171)
Sources of
Chemicals
(Use Table 171)
Effects of
Chemicals
(Use Table 171)
Dose-Response Studies

LD50- lethal dose that kills 50% of the individuals

ED50- effective dose that causes 50% of the animals
to display the harmful but nonlethal effect

Synergistic interactions- when two risks come
together and cause more harm that one
would. For example, the health impact of a
carcinogen such as asbestos can be much
higher if an individual also smokes tobacco.
Routes of Exposure
Bioaccumulation

bioaccumulation- an increased concentration
of a chemical within an organism over time
Biomagnification

Biomagnification- the
increase in a chemical
concentration in
animal tissues as the
chemical moves up
the food chain.
Persistence

Persistence- how long a chemical remains in the
environment
Risk Analysis
Personalizing Risk
1 in a 1,000,000 chance
Airplane, swimming
1 in a 100,000 chance
Skydiving
1 in a 10,000 chance
White water kayaking
1 in a 1,000 chance
Motorcycle Racing
1 in a 100 chance
Annual Racing the
Grand Prix Circuit
1 in a 10 chance
Climbing the Himalayas
As it turns out, most people are
willing to take risks up to and
including one in a thousand. The
participation rate drops off
rapidly for risks greater than one
in a thousand. Surprisingly, you
will find people who are willing to
participate in high-risk activities
where the odds are one in a
hundred and even one in ten of
dying. (No wonder it is so difficult
to control deadly STD’s)
Qualitative Risk Assessment

Making a judgment of the relative risks of various
decisions

Probability- the statistical likelihood of an event
occurring and the probability of that event causing
harm
Quantitative Risk Assessment

The approach to conducting a quantitative risk
assessment is:

Risk= probability of being exposed to a hazard X
probability of being harmed if exposed
Stockholm Convention

In 2001, a group of 127 nations gathered in Stockholm,
Sweden, to reach an agreement on restricting the
global use of some chemicals

12 chemicals were to be banned, phased out, or
reduced

These include DDT, PCBs, and certain chemicals that
are by-products of manufacturing processes.
Measuring Your
Impact
How Does Risk Affect Your Life
Expectancy? An interesting way of
examining risky behaviors is to determine
how different behaviors reduce your life
expectancy. Using U.S. government
statistics, we know that the life expectancy
for men is 75.6 years and the life
expectancy for women is 80.8 years.
a. If you choose to smoke, the loss of life expectancy will be
6.6 years for the average man and 3.9 years for the
average woman. What is the life expectancy for men and
women who smoke?
b. Alcoholism leads to a 12-year decline in life expectancy in
both sexes. What would your life expectancy be if you
were an alcoholic man who also smoked?
c. Being overweight causes a loss of 36 days of life
expectancy for every pound that you are overweight. If you
become 20 pounds overweight, by how many years will
your life expectancy be reduced?
d. Based on the above numbers, what is the life expectancy
of an alcoholic woman who smokes and is 20 pounds
overweight?
c.