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Environmental Health

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Title: Environmental Health


1
Environmental Health Toxicology
  • Chapter 15
  • APES
  • 2012

2
WELCOME TO APES DISEASE DAY
  • PLEASE CREATE THE FOLLOWING CHART

DISEASE VECTOR PATHOGEN SYMPTOMS
1.
2.
3.
4.
5.
6.
7.
8.
3
(No Transcript)
4
Some Vocab
  • WHO- World Health Organization
  • Health- state of complete physical, mental, and
    social well being (not just the absence of
    disease)
  • Disease- change in the bodys condition in
    response to an environmental factor
  • Ex nutritional, chemical, biological or
    psychological
  • Morbidity- illness
  • Pathogen- disease-causing organism
  • Vector- organism that spreads disease
  • Emergent- new, not identified or absent for last
    20 years
  • Zoonotic- transmitted from animal host to humans

5
PATHOGENIC VS. NON-PATHOGENIC
  • 43 of all disease-related deaths are from
    pathogens
  • 57 from cardiovascular disease, cancer, lung
    disease, injuries, etc.

6
DISEASE ETC. MILLIONS OF DEATHS PER YEAR
Cardiovascular disease 9.7
Cancers 6.0
Chronic Lung Disease Ex tuberculosis 5.5
Acute Lung Disease Ex pneumonia, flu, pertussis (whooping cough) 4.1
Injuries Mostly in 18-39 age group due to car accidents 4.0
Perinatal conditions Mostly from Infections 3.2
Diarrhea From bacteria pathogens excessive can cause mental/developmental retardation 3.0
HIV/AIDS 2/3 of all cases are in Africa most cannot afford the 10,000 drugs (like people in U.S.) 2.3
Malaria 500 million new cases each year making a comeback 2.0
Vaccine-preventable infections Polio, Measles, Hepatitis B, Tetanus LDC have no access/money for these vaccines 1.7
Other known disease 3.9
Unknown causes 5.9
Total 51.0
7
Morbidity Quality of Life
  • Not everyone dies from disease, but still can
    cause severe suffering and debilitation
  • When sick
  • Crops not planted/harvested
  • Animals not tended
  • Work not done
  • Kids not fed
  • Poorest people are most affected because they
    live in unhealthiest environments dont have
    for health care.
  • Lack of adequate housing, sanitation, safe
    drinking water causes most cases of diarrhea
    which is made worse by malnutrition.

8
Part I Infectious Diseases
  • Onchocerciasis (river blindness)
  • Vector Black fly
  • Many roundworms get into eyes die causing
    blindness
  • Control with insecticide sprays
  • Merck Co. are providing free ivermectin to help
    eradicate.

9
Onchocerciasis (river blindness)update 2012- The
Carter Center
10
Infectious Diseases
  • Elephantiasis
  • Vector Mosquitoes
  • Roundworm gets into lymph system and blocks lymph
    vessels causing fluid build up in the
    extremities.
  • SmithKline Beecham is supplying free albendazole
    to eradicate.

11
Infectious Diseases
  • Drancunculiasis-
  • Guinea worm
  • Vector Drinking Water contaminated with Cyclops
  • 3 meter long worm that lives under skin. Forms
    blister must be wound out of skin to remove

12
Countdown to eradication
  • Drancunculiasis-
  • Guinea worm video

13
Infectious Diseases
  • Hemorrhagic Fever
  • Some Types
  • Ebola Vector- unknown
  • Lassa Vector- Mastomys rat species
  • Hanta Vector- Deer mice
  • All cause tissue deterioration, bleeding,
    pulmonary edema.
  • Ebola has 90 mortality rate symptoms black
    vomit, profuse bleeding, most major outbreaks in
    Africa.

14
Emerging Diseases
15
Infectious Diseases
  • Dengue Fever
  • Vector Mosquitoes
  • 20 million new cases 2.5 billion current cases

16
Infectious Diseases
  • Malaria
  • Vector Mosquitoes(Anopholes)
  • Pathogen Plasmodium
  • 655,000 deaths 2010, 250 million cases each year,
    90 of them in Africa, 1out of 5 childhood deaths
  • In 1950s 60s, sprayed DDT knocked down from
    millions cases each year to thousands, now back
    to 2.5 million new cases
  • Some Aedes aegypti mosquitoes seen along Gulf
    Coast of America- due to climate change?

17
Infectious Diseases
  • Cholera
  • Cause Bacteria in unclean drinking water
  • Severe stomach cramping, severe diarrhea,
    vomiting
  • Thought eradicated but has made comeback due to
    ships dumping bilges in harbors of cities with
    inadequate water treatment

18
Infectious Diseases
  • Tuberculosis
  • Cause bacillus bacteria Mycobacterium
    tuberculosis
  • Eliminated but has returned stronger than ever
  • Some strains drug resistant
  • Spreads rapidly
  • EX Russian prisons

19
What causes disease to spread so rapidly?
20
What causes disease to spread so rapidly?
  • Population density ?, so contact ?
  • Moving into remote areas for agriculture ?
    exposure.
  • Deforestation, pollution causing local global
    climate change (? in temp ? in mosquito pop.)
  • Eliminating predators so ? in rodent, roach,
    mosquito pop.
  • ? in speed frequency of travel (airplanes,
    ships) to other countries
  • ? in resistance (Malaria) Superbugs
  • Taking medication improperly leads to superbugs
  • Antibiotics given to farm animals increases their
    resistance.

21
Part IIDangerous Chemicals
  • Hazardous (dangerous)
  • Some are harmless when diluted
  • Classifications
  • Flammable
  • Explosive
  • Irritant
  • Acids
  • Caustic
  • Toxic (poisonous)
  • Harmful even in small amounts
  • Ricin- protein in castor beans is thought to be
    the most toxic organic compound on Earth.
  • Ricin is 200x more lethal than dioxin.

22
Toxic Chemicals
  • Allergens
  • overactivate immune system
  • Ex formaldehyde
  • Immune System Depressants
  • Suppress immune system
  • Ex PCBs used as flame retardants electrical
    insulators (seals dolphins died due to
    infections brought on by suppressed immune
    system)

23
Toxic Chemicals
  • Mutagens
  • Chemicals or radiation that damages or alters DNA
  • Can cause birth defects or tumors
  • Can be passed through sperm/egg
  • Ex aflatoxin (from mold) caffeine, LSD,
    benzapyrene (in cigarettes) nitrous oxide ozone

24
Toxic Chemicals
  • Teratogens
  • Chemicals that cause abnormalities during
    embryonic development
  • Ex Thalidomide
  • Sold as OTC sleeping pill in Europe
  • Caused Phocomelia (had hands feet but no arms
    or legs)
  • Can have immediate affect
  • Positive can be used to treat leprosy, AIDS,
    cancer, tissue rejection
  • Alcohol is most prevalent teratogen- Fetal
    alcohol syndrome results in low birth weight,
    mental delays

25
Butch Lumpkin
26
Toxic Chemicals
  • Carcinogens
  • Cause cancer
  • Increasing in developed countries
  • 2nd cause of death in US
  • Maybe result of toxic chemicals in life
  • Foods/preservatives
  • Pesticides
  • smoking
  • Breast, Testicular, Skin cancers increasing
  • Stomach, Uterine, Colon cancers decreasing due to
    new technology for treatment.
  • Ex
  • Formaldehyde- particle board
  • Paradichlorobenzene- toilet cleaner
  • Perchloroethylene- dry cleaning
  • Pesticides- 2,4 dichlorophenoxyacetate

Some foods contain carcinogens (broccoli) but the
other benefits outweigh the risk.
27
Toxic Chemicals
  • Neurotoxins
  • Kill nerve cells
  • Disrupt cell membrane of nerve cell
  • Inhibit acetylcholinesterase- enzyme that
    transmits nerve signals
  • suppress nervous system
  • EX
  • Heavy metals like lead mercury (Minamata
    Disease p.300)
  • Anesthetics- ether, chloroform, halothane
  • Chlorinated Hydrocarbons- DDT, Dieldrin, Aldrin
    (POPs)
  • See page 300 table 15.1/Toxin handout
  • Organophosphates- parathion
  • Carbamates- carbaryl (Bhopal, India)

28
Toxic Chemicals
  • Endocrine Disruptors or Hormonally Active Agents
    (HAAs)- toxicants that interfere with the
    endocrine system by mimicing the hormone.
  • Newly discovered
  • Includes chemicals such as herbicides,
    pesticides, PCBs, phthalates (found in
    chlorinated plastics)
  • Problems breast, prostate, ovarian cancer,
    abnormal testicular development, thyroid related
    abnormalities
  • Hermaphroditic frogs, alligators w/ genital
    abnormalities

29
(No Transcript)
30
Bhopal, IndiaWorst Industrial Accident in History
  • December 1984
  • Union Carbide- American company located in Bhopal
    manufactured carbaryl methyl isocyanate (MIC)
    used to make pesticide Sevin (as in Sevindust)
  • Holding tanks at the plant malfunctioned (due to
    human error lack of routine maintenance)
  • Toxic MIC gas cloud released late at night
  • People who were exposed began choking, frothing
    at the mouth, vomiting blood, many died within
    minutes. The streets were littered with dead
    bodies.
  • 15,000-33,000 have died from this accident
  • 100,000 that survived are blind and/or are having
    reproductive, neurological, respiratory
    problems.
  • Soil water are contaminated
  • No one has been held responsible- DOW and Union
    Carbide have washed their hands of the problem.

31
Minamata Bay and Mercury
  • 1950s in Kyushu, Japan
  • Japanese live on island so eat fish and shellfish
    from Minamata Bay.
  • 1st signs seen in animals, especially cats-
    appeared to dance but were really having
    seizures.
  • People began experiencing neurological problems,
    paralysis, uncontrollable shaking, vision
    problems
  • Children born with brain atrophy, malformed
    limbs, etc.
  • Plastic factory was dumping mercury into Minamata
    Bay.
  • Mercury was accumulating through the food chain-
    Biomagnification

32
OTHER ENVIRONMENTAL HEALTH HAZARDS
  • Radiation- power lines, nuclear power plants
  • Noise
  • Trauma- accidents violence
  • Stress- heart attack, stroke, ulcers increase
    chance for infectious disease
  • Diet- too much bad food causes stress on body,
    leads to cardiovascular disease

33
What determines how dangerous a chemical is?
FACTORS RELATED TO TOXIC AGENT
1. Chemical composition reactivity
2. Physical traits- solubility, state of matter
3. Presence of impurities
4. Stability and storage traits
5. Availability of vehicle to carry agent
6. Movement of agent thru environment into cells
FACTORS RELATED TO EXPOSURE
1. Dose- concentration volume of exposure
2. Route, Rate, and site of exposure
3. Duration and frequency of exposure
4. Time of exposure (time of day, season, year)
FACTORS RELATED TO ORGANISM
1. Resistance to uptake, storage, or cell permeability
2. Ability to metabolize or inactivate agent
3. Tendency to change non-toxic to toxic in body
4. Concurrent infections or physical stress
5. Species and genes of organism
6. Nutritional status of subject
7. Age, sex, body weight, immunological status maturity
  • Persistence in environment
  • Route/method of exposure
  • Characteristics of target organism

34
Characteristics in determining how, when, and
where a toxic material will move thru the
environment
  • Solubility
  • Dissolve in Water
  • Move rapidly widely
  • Readily access cells in body
  • Dissolve in Oil
  • Need a carrier into thru body
  • Penetrate tissue readily, stored in fat cells of
    body
  • Take many years to break down
  • Bioaccumulation- accumulation of toxins within an
    individual organism. May be dilute in
    environment but reach dangerous levels in the
    body.

35
  • Biomagnification- accumulation of toxins thru a
    food web.
  • Chemical intensifies at each step
  • DDT, mercury,PCBs are examples

36
Characteristics in determining how, when, and
where a toxic material will move thru the
environment
  • Persistence- how long does it last in
    environment?
  • Some unstable degrade quickly
  • Some resistant to degradation (PVC plastic, DDT,
    CFCs, asbestos)
  • This may be why they are used- asbestos, PVC, DDT
  • May be an unfortunate side-effect
  • DDT was valued because it broke down slowly did
    not have to be reapplied.
  • We did not know the affects it would cause in
    fish, birds of prey, and people
    (biomagnification).

37
Characteristics in determining how, when, and
where a toxic material will move thru the
environment
  • Chemical Interactions
  • Antagonistic interactions- interfere with effects
    or stimulate the breakdown of other chemicals
  • Ex Vitamins A and E interfere with some
    carcinogens
  • Synergistic interactions- one substance makes the
    affects of another worse.
  • Occupation asbestos exposure increase lung cancer
    rate 20 fold
  • Smoking increases lung cancer rate 20 fold
  • A smoker that works with asbestos increases his
    chance for lung cancer 400 fold

38
Mechanisms for minimizing toxic effects
  • Every material can be poisonous/toxic at some
    level.
  • Most chemicals have safe levels or thresholds
    below which their affects are undetectable.
  • EX 100 cups of coffee have enough caffeine to
    kill if consumed all at once- but most people
    dont consume that much.
  • Taken in small doses, chemicals can be broken
    down by the body and released.

39
Measuring Toxicity
  • How a material is delivered plays a vital role in
    determining toxicity.
  • At what rate? (a little over time or all at once)
  • Through which route of entry? (skin, mouth, nose)
  • In what medium? (solid, liquid, gas)
  • Different species respond differently and
    different individuals in a species can react
    differently.

40
Animal Testing
  • Most common widely accepted measure of toxicity
  • Cons
  • Expensive
  • Time consuming
  • Painful/debilitating
  • Takes thousands of animals lots of money
  • Alternates
  • Cell cultures
  • Computer simulation
  • Some animals of a species are more sensitive than
    others so some die off quicker. Some are hardier
    than others so they live longer. This produces a
    bell shaped curve
  • Should we set safety limits to protect all
    including most sensitive or just the average
    person?
  • By protecting all, it might cost more money

41
LD50Lethal Dose 50
  • LD50- dose at which 50 of the test population
    dies.
  • See Table 15.4 on page 309 of textbook for lethal
    doses of some toxic organic chemicals.

42
Acute vs. Chronic Exposure
  • Acute effects- caused by single source and are
    immediately effective causing immediate health
    problems.
  • Chronic- takes place over a long period
  • Continuous or repeated sub-lethal exposure
  • For ex. Exposure to low levels of radiation over
    lifetime may cause mutations and lead to disease.

43
FDA Regulations
  • 1958 Delaney Clause to US FDA Act forbids the
    addition of any amount of known carcinogen to
    food and drugs.
  • 1966 No Reasonable Harm addendum says that
    carcinogens OK if less than one cancer for every
    million people exposed over a lifetime.

44
Assessing Risk
  • What factors influence how we perceive risk?
  • People will downplay risk to suit their own
    agendas
  • Some dont understand probability.
  • Personal experiences can be misleading- (Love
    Canal)
  • We have an exaggerated view of our abilities.
  • Media is mostly biased
  • Fear or distrust of certain technologies (Nuclear
    Power)

45
Accepting Risk
  • How much risk is acceptable?
  • Individualized
  • If you enjoy doing an activity you will accept
    those risks.
  • If an activity benefits someone else, you may not
    take those risks.
  • EX
  • Chance of dying from lung cancer if you smoke 1
    pack/ day is 1 in 1000.
  • EPA limits for trichloroethylene is 2 in 1
    billion. People will demand water with 0 levels
    of trichloroethylene but still smoke cigarettes.

46
What do you think are the highest risk hazards in
the U.S.?
47
Deaths
Cause of Death
Tobacco use
431,000
Alcohol use
150,000
Accidents
95,600 (42,000 auto)
Pneumonia and Influenza
84,400
Suicides
30,500
Homicides
19,000
Hard drug use
15,000
AIDS
14,000
Fig. 16.1, p. 396
48
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
49
Actual Risks vs. Perceived Risks
Natural disasters 1 7
Structure fires 1 6
Drowning 1 5
Driving an automobile 5 7
Drinking tap water 1 1
Tobacco use 8 4
Bicycling 1 2
Indoor air pollution 4 3
Outdoor air pollution 4 5
Alcohol use 4 5
Medical x-rays 1 3
Flying commercial airlines 1 3
Being overweight (10-20 lbs.) 8 4
Being obese (BMI gt 30) 10 5
Pesticide residues on food 2 4
AIDS 3 7
Living with a smoker 6 7
Toxic waste 1 6
Drug abuse 4 8
Living in poverty 10 6
50
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

51
Each year 99.1 of the people on Earth do not die.
  • Average life expectancy continues to increase.

52
Relative Risks to Human Welfare (from EPA)
  • High Risk Health Problems
  • Indoor air pollution
  • Outdoor air pollution
  • Worker exposure to industrial/farm chemicals
  • Pollutants in drinking water
  • Pesticide residues on food
  • Toxic chemicals in consumer products
  • High Risk Ecological Problems
  • Habitat alteration destruction
  • Species extinction loss of diversity
  • Stratospheric ozone depletion
  • Global climate change
  • Medium Risk Ecological Problems
  • Herbicides/pesticides
  • Toxics pollutants in surface water
  • Acid deposition
  • Airborne toxics
  • Low Risk Ecological Problems
  • Oil spills
  • Groundwater pollution
  • Radionuclides (uranium, radon)
  • Thermal pollution
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