Chapter 17 Human Health and Environmental Risks

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Chapter 17 Human Health and Environmental Risks
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Case study Citizen Scientists pg 463fight
against malaria pg 484

• Chapter 17 Part 1

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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?

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Citizen Scientists

• What did the group find out about their data?
• How long did it take the group to win fight
  against Shell Oil Company?
• What did the community win?

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Three categories of human health risks

• Physical
• Environmental factors
• Natural disasters - examples
• Natural phenomenon - examples
• Biological
• Disease
• Define
• Chemical
• Natural example
• Synthetic example

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Leading causes of death worldwide

• Which cause leads to the most deaths?

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Infectious Diseases

• Infectious diseases
• Define
• Causes pathogens
• Top three
• Non-infectious diseases
• Two categories of all diseases (define)
• Chronic
• Acute

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Leading Health risks worldwide

• WHO World Health Organization

Developing risk factors associated
with Developed risk factors associated with
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Transition of risks
How is the economic development of a country
related to disease?
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Terminology

• Compare and Contrast
• Similarities
• Differences
• Epidemic
• Pandemic

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Pathways of Transmitting Pathogens
Cholera
Tuberculosis
AIDs
Gastrointestinal diseases
Mad Cow disease
Plague
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Historical important infectious Diseases
Name Cause Transmission Vector Symptoms Treatment
Plague Bubonic plague Black death Bacterium Fleas to rodents Fleas to humans Rodents to humans Swollen glands Black spots on skin Extreme pain Antibiotics
Killed ¼ of European population in 1300s
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Malaria
Predominately tropical areas Most affected is
Africa
Cause Transmission Vector Symptoms Treatment
Protists Plasmodium Mosquito to human Flu-like symptoms Mosquito eradication program DDT Antimalarial drugs Mosquito tents
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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?

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1. What is the problem with spraying to eliminate
   mosquitoes?
2. What are the multiple strategies now being used
   to eradicate the mosquitoes?
3. What did Bill Gates do differently to help in the
   eradication?
4. What are the challenges that remain?
5. What is new on the horizon?

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TuberculosisTB
Cause Transmission Vector Symptoms Treatment
Bacterium Person to person through air (coughing) Weakness Night sweats Coughing up blood Taking antibiotics for a year Often people stop taking the drug before all bacteria are killed. Leads to drug resistant strains of bacteria.
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Decline of Tuberculosis in the U.S.
Due to
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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

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The Emergence of New diseases
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Acquired Immune Deficiency SyndromeAIDS
Cause Symptoms Transmission Symptoms Treatment
Human Immunodeficiency virus Originally from chimpanzees butchering eating the chimps.   Person to person Sexual contact Sharing needles Infected blood Weight loss Recurring fever 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. Antiviral drugs
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Ebola Hemorrhagic Fever
Cause Source Transmission Symptoms Treatment
Ebola virus Unknown Contact with virus Republic of Congo Near Ebola River Fever, vomiting Internal and external bleeding Death in 2 weeks None
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Mad cow disease
Cause Source Transmission Symptoms Treatment
Prions proteins in cattle brains that mutate into deadly proteins that act like pathogens Cows Eating meat of infected cattle Cow to cow CAFOs (eating infected cows) Cow to person Loss of coordination Death None Banning of export of cows from infected herds New rules prevent feeding animal remains to cows
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Bird Flu
Transmission primarily to people who handle birds.
Cause Source Transmission Symptoms Treatment
H1N1 Virus Wild Birds   Wild birds to domesticated birds. Ducks, chickens, turkeys Birds to people Fever, cough, sore throat, and muscle aches. Some people also have nausea, vomiting, diarrhea, eye infections. Vaccine
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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 Source Transmission Symptoms Treatment
Virus Birds Bird to bird by mosquito Mosquitoes to horses and humans Abdominal pain Diarrhea Fever Headache Muscle aches Nausea Rash Sore throat Swollen lymph nodes Vomiting   Destroy the mosquitoes. Protect against mosquito bites
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Toxicology ChartRisk assessment

• Chapter 17 Part 2

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Toxicology

• Study of chemical risks
• 5 Types
• Neurotoxins
• Carcinogens
• Teratogens
• Allergens
• Endocrine disrupters

Type Effects Examples

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Decline in lead in children
What caused the decline? When was lead removed
from gasoline and paint?
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Carcinogens
Effects Examples

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Carcinogens in tobacco
N-Nitrosodi-n-butylamine
N-Nitrosodiethanolamine
N-Nitrosodiethylamine
N-Nitrosodimethylamine
N-Nitrosodi-n-propylamine
4-(N-Nitrosomethylamino)-1-(3-pyridyl)-1-butanone
N-Nitrosonornicotine
N-Nitrosopiperidine
N-Nitrosopyrrolidine
N-Nitrososarcosine
Polonium-210
Polycyclic aromatic hydrocarbons
o-Toluidine
Vinyl chloride
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
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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.

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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.

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Allergens
Effects Examples

http//www.youtube.com/watch?vBQKBh5tB1Xs
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Endocrine Disrupters

• 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

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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

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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.

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Dose-Response Studies
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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 .55
• For humans .0055

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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
• Cannot test every chemical on every organism.
• Test a few species mammal, bird, fish,
  invertebrate.
• Dont test amphibians. Why?
• Organism selected from each group is the one
  thought to be the most sensitive to a particular
  chemical.

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Chronic Studies

• Studies conducted for longer periods of time
• Determining the long-term effects of chemicals.

Effects on behaviors and on reproduction.
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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

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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.

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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

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• Bioaccumulation

• Biomagnification

• Oil soluble chemicals are stored in the fat
  tissues of animals.
• Continued exposure causes more of the chemical to
  be stored.
• Bioaccumulation.
• Depends on

• 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.

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Persistence

• How long a chemical remains in the environment.
• Depends on

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Risk Analysis

• Risk Analysis
• Risk Assessment
• Risk Acceptance
• Risk Management
• Environmental hazard

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Types of Risk assessment

• Quantitative

• Qualitative

• Categorize risks as being low, medium or high.
• Make judgments based on our perceptions but not
  based on actual probability
• Statistical likelihood of an event causing harm.
• Personal risk assessment often 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
• probability of being exposed to a hazard
• X
• probability of being harmed if exposed
• Risk of dying in a plane crash.
• Probability of plane crash Very low
• Probability of dying if the plane crashes 100
• 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

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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..
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• Risk Acceptance

• Risk Management

• Level of risk that can be tolerated.
• According to EPA
• 1 in a million risk is acceptable for most
  environmental hazards.
• Example
• 1 in a million chance of death from radiation
  leaks is small price to pay for electricity
  generated by nuclear power.

• Balance the possible harm against other
  considerations.
• Economic considerations
• Cultural or social or ethical considerations.
• Example Regulation of arsenic in drinking
  water.
• 50 mcl/L of arsenic causes cancer
• 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

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Worldwide Standards of risk

• 80,000 registered chemicals worldwide.
• Not regulated the same way everywhere.
• Types of regulation is used

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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
• 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.

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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.