Transcript Chapter 17 Human Health and Environmental Risks

CHAPTER 17
HUMAN HEALTH AND ENVIRONMENTAL RISKS
CASE STUDY – CITIZEN SCIENTISTS – PG 463
FIGHT AGAINST MALARIA – PG 484
CHAPTER 17 PART 1
CASE STUDY – CITIZENS SCIENTISTS
1. Describe the location of this case
study?
2. What were the diseases that led
residents to be suspicious?
3. What was the primary goal of the
Concerned Citizens of Norco?
4. What data did this group need to
present their case and how did
they do it?
CITIZEN SCIENTISTS
5. What did the group find out
about their data?
6. How long did it take the
group to win fight against
Shell Oil Company?
7. What did the community
win?
THREE CATEGORIES OF HUMAN
HEALTH RISKS
•
Physical
•
Environmental factors
Natural disasters - examples
Natural phenomenon - examples
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Biological
•
Disease
•
•
Define
Chemical
•
•
Natural – example
Synthetic – example
LEADING CAUSES OF DEATH WORLDWIDE
• Which cause leads to the most deaths?
INFECTIOUS DISEASES
•
Infectious diseases
•
•
•
Define
Causes – pathogens
Top three
•
Non-infectious diseases
•
Two categories of all diseases (define)
• Chronic
• Acute
LEADING HEALTH RISKS WORLDWIDE
• WHO – World Health Organization
Developing – risk factors associated with:
Developed – risk factors associated with:
TRANSITION OF RISKS
How is the economic development of a country related to disease?
TERMINOLOGY
• Compare and Contrast
• Similarities
• Differences
• Epidemic
• Pandemic
PATHWAYS OF TRANSMITTING
PATHOGENS
Cholera
Tuberculosis
AIDs
Gastrointestinal
diseases
Mad Cow
disease
Plague
HISTORICAL IMPORTANT INFECTIOUS
DISEASES
Name
Plague
Bubonic plague
Black death
Cause
Bacterium
Transmission
Vector
Fleas to rodents
Fleas to humans
Rodents to
humans
Symptoms
Treatment
Swollen glands Antibiotics
Black spots on
skin
Extreme pain
Killed ¼ of European population
in 1300s
MALARIA
Predominately tropical areas
Most affected is Africa
Cause
Protists –
Plasmodium
Transmission Vector
Symptoms
Treatment
Mosquito to human Flu-like symptoms • Mosquito
eradication
program
• DDT
• Antimalarial drugs
• Mosquito tents
CASE STUDY GLOBAL FIGHT AGAINST
MALARIA PG. 484
1. What is the modern history of malaria in terms of
infection and death?
2. Where are most malaria cases?
3. Who is most likely to die from malaria?
4. How was malaria eradicated in the U.S.?
5. What were the unintended consequences of this
eradication?
6. What is the problem with spraying to eliminate
mosquitoes?
7. What are the multiple strategies now being used
to eradicate the mosquitoes?
8. What did Bill Gates do differently to help in the
eradication?
9. What are the challenges that remain?
10.What is new on the horizon?
TUBERCULOSIS
TB
Cause
Bacterium
Transmission Vector
Symptoms
Treatment
Person to person
Weakness
Taking antibiotics for
through air
Night sweats
a year
(coughing)
Coughing up blood Often people stop
taking the drug
before all bacteria are
killed. Leads to drug
resistant strains of
bacteria.
DECLINE OF TUBERCULOSIS IN THE U.S.
Due to:
EMERGENT DISEASES
• Emergent disease
• Define:
• Since 1970 in the world at least one emergent disease every year.
• Since 1970 most of the emergent diseases are from pathogens
that normally infect animal hosts but unexpectedly jumped to
human hosts.
•
•
•
•
•
HIV/AIDS
Ebola
Mad Cow Disease
Bird Flu
West Nile Virus
THE EMERGENCE OF NEW DISEASES
ACQUIRED IMMUNE DEFICIENCY SYNDROME
AIDS
Cause
Symptoms
Human
Originally from
Immunodeficiency chimpanzees
virus
• butchering
• eating the
chimps.
Transmission
Symptoms
Treatment
Person to
person
 Sexual
contact
 Sharing
needles
 Infected
blood
• Weight loss
Antiviral
• Recurring fever
drugs
• Profuse night
sweats
• Extreme tiredness
• Swelling of the
lymph glands in the
armpits, groin, or
neck
• Sores of the mouth,
anus, or genitals
• Pneumonia
• Red, brown, pink, or
purplish blotches on
or under the skin
• Depression,
neurologic
disorders.
EBOLA HEMORRHAGIC
FEVER
Cause
Ebola virus
Source
Unknown
Transmission
Symptoms
Treatment
• Contact with
• Fever, vomiting None
virus
• Internal and
• Republic of
external
Congo
bleeding
• Near Ebola River • Death in 2 weeks
MAD COW DISEASE
Cause
Source
Transmission
Prions – proteins in Cows  Eating meat of
cattle brains that
infected cattle
mutate into deadly
 Cow to cow –
proteins that act like
CAFOs (eating
pathogens
infected cows)
 Cow to person
Symptoms
 Loss of
coordination
 Death
Treatment
 None
 Banning of
export of cows
from infected
herds
 New rules
prevent feeding
animal remains
to cows
BIRD FLU
Transmission primarily to people
who handle birds.
Cause
H1N1 Virus
Source
Wild Birds
Transmission
Symptoms
• Wild birds to
• Fever, cough, sore
domesticated
throat, and muscle
birds.
aches.
• Ducks,
• Some people also
chickens,
have nausea,
turkeys
vomiting, diarrhea,
• Birds to people
eye infections.
Treatment
Vaccine
WEST NILE VIRUS
First human case in West Nile region of
Uganda – 1937
First case in U. S. New York - 1999
West Nile Virus in U.S.
Cause
Virus
Source
Birds
Transmission
Bird to bird by
mosquito
Mosquitoes to
horses and
humans
Symptoms
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Abdominal pain
Diarrhea
Fever
Headache
Muscle aches
Nausea
Rash
Sore throat
Swollen lymph nodes
Vomiting
Treatment
Destroy the
mosquitoes.
Protect against
mosquito bites
TOXICOLOGY CHART
RISK ASSESSMENT
CHAPTER 17 PART 2
TOXICOLOGY
• Study of chemical risks
• 5 Types
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Neurotoxins
Carcinogens
Teratogens
Allergens
Endocrine disrupters
Type
Effects
Examples
DECLINE IN LEAD IN CHILDREN
What caused the decline?
When was lead removed
from gasoline and paint?
CARCINOGENS
Effects
Examples
CARCINOGENS IN TOBACCO
Chemical
Acetaldehyde
Acrylonitrile
4-Aminobiphenyl
o-Anisidine hydrochloride
Arsenic
Benzene
Beryllium
1,3-Butadiene
Cadmium
1,1-Dimethylhydrazine
Ethylene oxide
Formaldehyde
Furan
Heterocyclic amines
Hydrazine
Isoprene
Lead
2-Naphthylamine
N-Nitrosodi-n-butylamine
N-Nitrosodiethanolamine
N-Nitrosodiethylamine
N-Nitrosodimethylamine
N-Nitrosodi-npropylamine
4-(NNitrosomethylamino)-1(3-pyridyl)-1-butanone
N-Nitrosonornicotine
N-Nitrosopiperidine
N-Nitrosopyrrolidine
N-Nitrososarcosine
Polonium-210
Polycyclic aromatic
hydrocarbons
o-Toluidine
Vinyl chloride
Teratogens
Effects
Examples
Thalidomide
– Prescribed to pregnant women to combat morning
sickness between 1950 and 1960.
– Taken off the market in 1961.
– On the market now to treat leprosy, AIDS and some
cancers.
FETAL ALCOHOL SYNDROME
• Small head
• Facial abnormalities
• Poor coordination
• Poor socialization skills
• Difficulty building and maintaining friendships
• Lack of imagination or curiosity
• Learning difficulties, including poor memory, inability to understand
concepts such as time and money, poor language comprehension,
poor problem-solving skills.
• Behavioral problems, including hyperactivity, inability to concentrate,
social withdrawal, stubbornness, impulsiveness, and anxiety.
ALLERGENS
Effects
Examples
http://www.youtube.com/watch?v=BQKBh5tB1Xs
ENDOCRINE
DISRUPTERS
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Male animals normally make
estrogen then convert it to
testosterone.
With the site blocked the male
has higher concentration of
estrogen.
Testes make sperm and eggs
or only eggs
Found in male reptiles,
amphibians and fish.
Effects
Examples
Dose-Response Studies
•
Exposure of animals or plants
to different amounts of a
chemical and then observe a
variety of possible responses
including mortality or changes
in behavior or reproduction
•
Measured
– Concentration
– Dose
– Dose studies
•
Acute studies
– Threshold
Dose Studies
•
Mortality response
– S-shaped curve
• Low dose
• Threshold dose
• Highest dose
• LD50
• Measurement for comparing effects of different chemicals.
• Whether a new chemical is more or less lethal in
comparison to other chemicals.
• ED50
– Sub-lethal effects
• Dose that causes 50% of the population to display harmful
but non-lethal effects.
DOSE-RESPONSE STUDIES
SAFE CONCENTRATIONS
• For animals
• LD50 divided by 10
• For humans
• LD50 and ED50 from rats
and mice
• Divided by 1,000
• Tested on plants and
animals.
• LD50 5.5
• For animals
• For humans
.55
.0055
TESTING STANDARDS
• Regulation – EPA
• Toxic Substances Control Act of 1976
• Give the EPA the authority to regulate many chemicals.
• Excludes food, cosmetics and pesticides.
• Testing
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Cannot test every chemical on every organism.
Test a few species – mammal, bird, fish, invertebrate.
Don’t test amphibians. Why?
Organism selected from each group is the one thought to
be the most sensitive to a particular chemical.
CHRONIC STUDIES
• Studies conducted for longer periods of time
• Determining the long-term effects of chemicals.
Effects on behaviors and
on reproduction.
RETROSPECTIVE VERSUS PROSPECTIVE
STUDIES
 Epidemiology
 Alternative studies to lethal dose studies for humans.
• Retrospective studies
• Study of people who have been exposed to a chemical at some
time in the past compared to a second group who have not been
exposed.
• Prospective studies
• Monitor people who might become exposed to harmful chemicals in
the future.
• Participants keep track of the food they eat, tobacco they use and
the alcohol they drink for the next 40 years.
• For researchers to determine if their habits of the participants have
any association with future health problems.
• Concern - Synergistic interactions
FACTORS THAT DETERMINE
CONCENTRATIONS OF CHEMICALS
• Routes of Exposure
• Knowing the exposure:
• Determine the chemical
solubility.
• Potential for bioaccumulation.
• Potential for biomagnification.
• Bisphenol A
• Chemical used in the
manufacture of hard plastic
toys, food containers and
baby bottles.
SOLUBILITY
• How well a chemical can dissolve in a liquid.
• Determines how a chemical moves through the
environment.
• Water-soluble chemicals
• Chemical could be found in ground and surface water
• Fat and Oil soluble chemicals
• Chemical could be found in soil
Bioaccumulation
• Oil soluble chemicals are stored in
the fat tissues of animals.
• Continued exposure causes
more of the chemical to be
stored.
• Bioaccumulation.
• Depends on:
Biomagnification
• The increase in a chemical
concentration in animal
tissues as the chemical
moves up the food chain.
• Each tropic level is exposed
to higher concentrations.
PERSISTENCE
• How long a chemical remains in the environment.
• Depends on:
RISK ANALYSIS
• Risk Analysis
• Risk Assessment
• Risk Acceptance
• Risk Management
• Environmental hazard
TYPES OF RISK ASSESSMENT
Qualitative
Quantitative
• Categorize risks as being low,
• Risk =
medium or high.
probability of being exposed to a hazard
X
• Make judgments based on our
probability of being harmed if exposed
perceptions but not based on
actual probability
Risk of dying in a plane crash.
• Statistical likelihood of an
• Probability of plane crash = Very low
event causing harm.
• Personal risk assessment often • Probability of dying if the plane crashes =
100%
does not match the actual risk.
• Choose to slow down on a wet
highway because it is safer.
• Choose a more expensive car
because it is safer.
Risk of dying of cancer from eating peanut
butter which does have tiny amounts of
carcinogens
• Probability of eating peanut butter = 100%
• Probability of getting cancer from peanut
butter = very low
Perceived Risk vs. Actual Risk
Fundamental Rule of
Risk Assessment:
The risk of a rare event
that has a high
likelihood of causing
harm can be equal to the
risk of a common event
that has a low likelihood
of causing harm..
Risk Acceptance
Risk Management
• Level of risk that can be tolerated.
• Balance the possible harm against other
• According to EPA
considerations.
• 1 in a million risk is acceptable for
• Economic considerations
most environmental hazards.
• Cultural or social or ethical
considerations.
• Example:
• 1 in a million chance of death
• Example: Regulation of arsenic in drinking
from radiation leaks is small price
water.
to pay for electricity generated by
• 50 mcl/L of arsenic causes cancer
nuclear power.
• EPA announced lowering to 10 mcl
• Economic burden on mining
companies/areas with high natural
arsenic.
• EPA caved to 50 mcl.
• National Academy of Sciences said 5
mcl
• Compromise to 10 mcl of arsenic/L
WORLDWIDE STANDARDS OF RISK
• 80,000 registered chemicals worldwide.
• Not regulated the same way everywhere.
• Types of regulation is used:
STOCKHOLM CONVENTION
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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
• Dirty dozen POPs – Persistant Organic Pollutants
These include DDT, PCBs, and certain chemicals that are
by-products of manufacturing processes; all known to be
endocrine disrupters.
These countries continue to meet; in 2009 - 9 more
chemicals have been added.
LAWS
• Occupational Safety and Health Act OSHA
• Created to protect worker and health
• Its main aim was to ensure that employers provide their workers
with an environment free from dangers to their safety and health,
such as exposure to toxic chemicals, excessive noise levels,
mechanical dangers, heat or cold stress or unsanitary conditions
• Consumer Product Safety Act
• Purpose is to protect the public against unreasonable risks of
injury associated with consumer products.