Ordering of Perceived Risk

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Ordering of Perceived Risk
Activity League of Women Voters College Students Experts
Nuclear Power 1 1 20
Motor Vehicles 2 5 1
Handguns 3 2 4
Smoking 4 3 2
Motorcycles 5 6 6
Alcoholic Bev. 6 7 3
General Aviation 7 15 12
Police Work 8 8 17
Pesticides 9 4 8
Surgery 10 11 5
Firefighting 11 10 18
X-rays 22 17 7
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Risk, Toxicology, and Human Health
G. Tyler Millers Living in the
Environment Chapter 19
3
Human Health

• Health is a state of complete physical, mental,
  social and spiritual well-being and not merely
  the absence of disease or infirmity
• or
• The ability to lead a socially and economically
  productive life

4
Holistic Concept of Health

• This concept recognizes the strength of social,
  economic, political and environmental influences
  on health
• Determinants
• Heredity
• Health and family welfare services
• Environment
• Life-style
• Socio-economic conditions

5
Risk and Probability

• Risk
• possibility of suffering harm from a hazard that
  can cause injury, disease, economic loss, or
  environmental damage.

• Probability
• mathematical statement about how likely it is
  that some event or effect will occur.
• Risk pExposure x pHarm

6
Risk Assessment and Management
7
Risk Analysis

• Identifying hazards
• Risk assessment
• Ranking risks
• Comparative risk analysis
• Determining options
• Risk management
• Informing decision makers
• Risk communicaiton

8
How well do we perceive risks?

• Most of us do poorly at assessing the relative
  risks from the hazards that surround us.

9
What do you think are the highest risk hazards in
the U.S.?
10
Hazards

• Cultural hazards

• Physical hazards

• Chemical hazards

• Biological hazards

Fig. 19-1 p. 409
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Hazard
Shortens average life span in the United States by
7-10 years
Poverty
Born male
7.5 years
Smoking
6 years
Overweight (35)
6 years
Unmarried
5 years
2 years
Overweight (15)
Spouse smoking
1 year
Driving
7 months
Air pollution
5 months
Alcohol
5 months
Drug abuse
4 months
3 months
AIDS
Drowning
1 month
Pesticides
1 month
Fire
1 month
Natural radiation
8 days
Medical X rays
5 days
Oral contraceptives
5 days
Toxic waste
4 days
Flying
1 day
Hurricanes, tornadoes
1 day
Fig. 16.15, p. 414
Living lifetime near nuclear plant
10 hours
12
Yet some of these people are terrified of dying
from

• Commercial plane crash
• 1 in 4.6 million
• Train crash
• 1 in 20 million
• Snakebite
• 1 in 36 million
• Shark attack
• 1 in 300 million

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Toxicology

• Toxicity measures how harmful a substance is.
  Toxicity depends on . .
• Dose
• the amount of a potentially harmful substance a
  person has ingested, inhaled, or absorbed.
• Response
• the type or amount of damage

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Toxicity

• Dose - the amount of a potentially harmful
  substance a person has ingested, inhaled, or
  absorbed.
• Solubility
• Persistence
• Bioaccumulation
• Biomagnification
• Chemical interactions
• Antagonistic reduces
• Synergistic multiplies

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Bioaccumulation and Biomagnification
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Toxicity
Toxicity LD50 Lethal Dose Examples Super lt
0.01 less than 1 drop dioxin,
botulism mushrooms Extreme lt5 less than 7
drops heroin, nicotine Very 5-50 7 drops to 1
tsp. morphine, codeine Toxic 50-500 1 tsp.
DDT, H2SO4, Caffeine Moderate 500-5K 1
oz.-1 pt. aspirin, wood alcohol Slightly 5K
-15K 1 pt. ethyl alcohol,
soaps Non-Toxic gt15K gt1qt. water, table
sugar (LD50 measured in mg/kg of body weight)
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Toxicity

• Response - the type or amount of damage
• Acute effect immediate or rapid
• Chronic effect permanent or long lasting

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Genetic Variation in Individual Responses to
Toxins
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The dose makes the poison. Paracelsus, 1540

• Anything can be harmful if ingested in a large
  enough quantity.

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Poisons

• a chemical that has an LD50 of 50 mg or less per
  kg of body weight
• LD50
• The median lethal dose
• The amount that kills exactly 50 of the animals
  in a test population, within a 14 day period
• Determined by controlled experiments

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Laboratory Investigations

• Animal Studies
• Populations of lab animals usually rodents
• Measured doses under controlled conditions
• Takes two to five years
• Costs 200,000 to 2,000,000 per substance
• Newer methods

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Laboratory Investigations

• Newer methods
• Bacteria
• Cell and tissue culture
• Appropriate tissue
• Stem cells
• Chicken egg membrane

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Laboratory Investigations

• Validity Challenged
• Human physiology is different
• Different species react different to same toxins
• Mice die with aspirin
• Species can be selected depending on
  physiological area
• Pigs circulatory very similar to humans

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Major Types of Hazards

• Chemical hazards

• Biological hazards

• Physical hazards

• Cultural hazards

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Chemical Hazards

• Toxic chemicals
• substances that are fatal
• Hazardous chemicals
• cause harm
• Flammable or explosive
• Irritating or damaging to skin or lungs
• Interfering or preventing oxygen uptake
• Inducing allergic reactions

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Chemical Hazards

• Mutagens
• Cause random changes in DNA
• Passed on to future generations
• Teratogens
• cause birth defects
• alcohol, PCBs, thalidomide, steroid hormones,
  heavy metals

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Chemical Hazards

• Carcinogens
• promote uncontrollable cell growth (malignant or
  cancerous tumors)
• metastasis
• cells break off from tumors and travel in body
  fluids
• Immune, Nervous, and Endocrine System disruptors
• Viruses (HIV), Ionizing radiation, Diet,
  Neurotoxins, Hormonally Active Agents

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Biological Hazards Diseases

• Non-transmissible disease
• not caused by a living organism
• is not spread from one person to another
• Transmissible disease
• caused by living organisms
• Bacteria, virus, protozoa
• is spread from one person to another

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Biological Hazards Diseases

• Pathogens infectious agents
• Vectors organisms that spread pathogens
• Insects
• Worlds Seven Deadliest Diseases
• acute respiratory infection
• acquired immune deficiency syndrome (AIDS)
• diarrheal diseases
• tuberculosis
• malaria
• hepatitis B
• measles

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Biological Hazards Diseases

• Common Viral Diseases
• influenza or flu
• Ebola
• West Nile Virus
• rabies
• AIDS
• Treatment
• Immunization with vaccines

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Malaria - A Protozoal Disease
Anopheles mosquito (vector) in aquatic breeding
area
eggs
adult
larva
pupa
1. Female mosquito bites infected
human, ingesting blood that contains Plasmodium ga
metocytes
4. Parasite invades blood cells, causing malaria
and making infected person a new reservoir
2. Plasmodium develops in mosquito
3. Mosquito injects Plasmodium sporozoites into
human host
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Waterborne Bacteria

• Disease symptoms usually are explosive emissions
  from either end of the digestive tract

Escherichia coli
Vibrio sp.
Barbara E. Moore, Ph.D., Department of Biology,
University of Texas at San Antonio
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Waterborne Protozoans

• Disease symptoms are usually explosive emissions
  from either end of the digestive tract

P. Darben
Giardia sp.
Barbara E. Moore, Ph.D., Department of Biology,
University of Texas at San Antonio
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Waterborne Human Viruses
Hepatitis A virus
Hepatitis E virus
Norwalk virus
Rotavirus
F. Williams
Barbara E. Moore, Ph.D., Department of Biology,
University of Texas at San Antonio
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Case Study on Eradicating Dracunculiasis
Water and Sanitation Critical Elements in
Development - Mike Lee CSU _at_ Hayward
36
Guinea Worm Disease

• People have suffered from Guinea Worms for
  centuries the fiery serpent was mentioned in
  the bible
• People are infected by drinking water that
  contain the larvae in a tiny freshwater
  crustacean called Cyclops
• A year later, larvae mature into 3 feet worms
  that emerge through skin blisters
• This is such a painful process that men and women
  cant work, children cant attend school

Water and Sanitation Critical Elements in
Development - Mike Lee CSU _at_ Hayward
37
The Guinea Worm grows down the leg and its sex
organs appear at the ankle or on the foot
usually, bursting when it senses water, releasing
ova.
http//www.pmeh.uiowa.edu/fuortes/63111/GUINEA/
Water and Sanitation Critical Elements in
Development - Mike Lee CSU _at_ Hayward
38

• No vaccine for Guinea worm is available.
• People do not seem to build up any resistance and
  the disease can be reinfected over and over.
• No research is being conducted for any vaccine or
  cure.
• Worms are removed slowly each day by winding
  around a stick.

http//www.pmeh.uiowa.edu/fuortes/63111/GUINEA/
Water and Sanitation Critical Elements in
Development - Mike Lee CSU _at_ Hayward
39
Spread of Diseases

• Increases international travel
• Migration to urban areas
• Migration to uninhabited areas and deforestation
• Hunger and malnutrition
• Increased rice cultivation
• Global warming
• Hurricanes and high winds
• Accidental introduction of insect vectors
• Flooding

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Reducing Spread of Diseases

• Increase research on tropical diseases and
  vaccines
• Reduce poverty and malnutrition
• Improve drinking water
• Reduce unnecessary use of antibiotics
• Educate people on taking antibiotics
• Reduce antibiotic use in livestock
• Careful hand washing by medical staff
• Slow global warming
• Increase preventative health care

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Epidemiology

• Study of the distribution and causes of disease
  in populations
• how many people or animals have a disease
• the outcome of the disease (recovery, death,
  disability, etc.)
• the factors that influence the distribution and
  outcome of the disease

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Physical Hazards

• Ionizing radiation, airborne particles, equipment
  design, fire, earthquake, volcanic eruptions,
  flood, hurricane, tornado
• Example Radon
• Source
• Arises naturally from decomposition of uranium in
  the Earth
• Occurs at dangerous levels in some buildings and
  homes sick buildings
• Can cause lung cancer

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Cultural Hazards

• Sociological
• Results from living in a society where one
  experiences noise, lack of privacy, and
  overcrowding
• Population growth
• Beyond carrying capacity when environmental
  resources can support no further growth

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Cultural Hazards

• Psychological
• Environmental factors that produce psychological
  changes expressed in stress, depression and
  hysteria