Risks and Hazards

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Risks and Hazards

• Stephanie Antonucci, David Drag, Jim Cunningham,
  and Ashley Petronaci

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What is Risk??

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

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Major Types of Risk

• Chemical hazards from harmful chemicals in the
  air, water, soil, and food
• Physical hazards such as ionizing radiation,
  fires, earthquakes, volcanic eruptions, floods,
  tornadoes, and hurricanes
• Biological hazards from pathogens, pollen, and
  other allergens

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Toxicity
Major Factors that determine toxicity
1. Solubility 2. Substance
Persistence 3. Bioaccumulation
4. Biomagnification
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Solubility

• Water soluble toxins move through environment get
  into water supplies (inorganic compounds)
• Oil and fat soluble toxins can accumulate in body
  tissues and cells(organic compounds)

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Substance Persistence

• How long a substance can last before breaking
  down?
• Chemicals such as CFCs, chlorinated hydrocarbons,
  and plastics resist breakdown
• They can have long lasting effects on the
  environment

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Bioaccumulation

• Molecules are absorbed and stored in organs or
  tissues at higher then normal levels

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Biomagnification

• Levels of toxins are magnified as they pass
  through food chains and webs
• Examples pesticide DDT, PCBs, radioactive
  isotopes
• Stored in body fat, chemicals can be passed along
  to offspring through
• gestation or egg laying and as mothers nurse
  their young

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Estimating Toxicity

• Case Reports-People suffering from adverse health
  effects after exposure to chemicals
• Epidemiological Studies-Experimental group is
  compared to control group
• Laboratory Experiments

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Laboratory Experiments

• Is animal testing ethical?
• Humane Methods?
• Bacteria use
• Cell and tissue cultures
• Chicken egg membranes

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Toxic and Hazardous Chemicals

• TOXIC
• Fatal to more than 50 of test animals at
  given concentrations

• HAZARDOUS
• Flammable or explosive, irritate or damage skin
  or lungs, induce allergic reactions

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Bodys Systems

• Immune System-
• specialized cells and tissues that protect the
  body against disease and harmful substances by
  forming antibodies that destroy invading agents

• Nervous System-brain spinal cord
• Many toxins are neurotoxins that attack nerve
  cells

• Endocrine System-
• network of glands that release hormones into the
  bloodstream of all vertebrates

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Toxicologists know a great deal about a few
chemicals, a little about many, and next to
nothing about most
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What should we do?

• Put greater influence on pollution prevention
• Those proposing to introduce a new chemical or
  technology would bear the burden of establishing
  its safety
• New chemicals and technologies should be assumed
  guilty before proven innocent

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Potential Effects of Volcanic Gases

• Volcanic gases that pose the greatest potential
  hazard to people, animals, agriculture, and
  property
• are.
• Sulfur Dioxide
• Carbon Dioxide
• Hydrogen Fluoride

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Lava flows

• The speed at which lava moves across the ground
  depends on several factors.
• type of lava erupted and its viscosity
• steepness of the ground over which it travels
• whether the lava flows as a broad sheet, through
  a confined channel, or down a lava tube and
• rate of lava production at the vent
• Flows move only a few kilometers per hour and
  rarely extend more than 8 km from their vents

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Tephra

• Volcanic ash consists of
• of tiny jagged particles of rock and natural
  glass blasted into the air by a volcano
• What ash affects
• The Health of People and Live Stock
• Hazard to flying jet aircraft, damage
  electronics and machinery, interrupt power
  generation and telecommunications
• Wind
• Ash can be carried Thousands of Miles affecting
  far more people than any other volcanic hazard.

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Earthquakes

• An earthquake is a sudden movement of the Earth,
  caused by the abrupt release of strain that has
  accumulated over a long time
• The forces of plate tectonics have shaped the
  Earth as the huge plates that form the Earth's
  surface slowly move over, under, and past each
  other these boundaries are
• Divergent Plate Boundaries
• Convergent Plate Boundaries
• Transform Boundaries

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Sliding Plates
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What Are Earthquake Hazards?

• Ground shaking
• Sliding Plates
• Flooding
• Tsunami
• Seiches

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Ground Shaking and Ground Displacement

• Hazards
• Buildings can be damaged
• Ground beneath structures can settle to a
  different levels than before the earthquake
  occurred.
• Ground Displacement
• If a structure is built along a fault, the ground
  displacement during an earthquake could seriously
  damage or rip apart that structure.

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Flooding, Tsunami, and Seiches

• Flooding
• Break dams or levees along a river.
• Damaging buildings
• Maybe sweeping away or drowning people
• Tsunami
• Earthquake under the ocean.
• Can do enormous damage to the coastline
• Seiche
• Small Tsunamis few feet high
• They occur on lakes that are shaken by the
  earthquake

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Three Types of Pathogens
Bacterium
Protozoa
Virus
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Bacterium A uni-cellular microorganism that can
clone itself by simple cell division.
Virus a microscopic, non-cellular infectious
agent.
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How A Virus Works
The virus attaches to the host cell. The entire
virus may enter or it may inject its genetic
material.
Virus
Genetic material
Host cell
Surface proteins
Cell membrane
The viral genetic material uses the host cell's
DNA to replicate again and again.
Each new copy of the virus directs the cell to
make it a protein shell.
The new viruses emerge from the host cell capable
of infecting other cells. This process
often destroys the first cell.
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Infectious diseases cause approximately one out
of every four deaths in developing countries.
This may be due to

• MUTANT GENES through natural selection.
• GENETIC RESISTANCE to antibiotics.

Every major disease-causing bacterium has
strains that resist at least one of the
approximately 160 antibiotics used today.
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The three greatest threats to human health from
viruses are

• AIDS
• HEPATITIS B
• VIRAL PNEUMONIA

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More examples of Viruses

• Influenza (the flu)
• Ebola
• West Nile Virus
• SARS

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How are they treated?
NO ANTIBIOTICSthey are useless and increase
genetic resistance in disease-causing bacteria.
The best weapons are
VACCINES!
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VACCINES
They stimulate the bodys immune system and
produce antibodies to ward off viral infections.
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How Does This Tie into Environmental Science?

• Human Travel
• Unnecessary Prescriptions
• Overuse of Pesticides
• Antibiotics in Animals

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How do we prevent or reduce the incidence of
infectious diseases from pathogens?

• Increase research on disease vaccinations
• Reduce poverty
• Make sure to take all of a prescription
• Cut down on pesticide use.

• Reduce unnecessary use of antibiotics.
• Frequent hand washing
• Immunizations for children
• Global campaign to reduce HIV/AIDS

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Risk Analysis Involves

• Identifying hazards
• Evaluating their risks
• Ranking Risks
• Determining options
• Making decisions about reducing or eliminating
  risks
• Informing decision makers and the public about
  risks

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Greatest risks people face

• Rarely dramatic enough to make the daily news
• Poverty

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Estimating risks for Technological Systems

• The more complex
• The more people needed to design and run it
• The more difficult it is to estimate the risks
• System Reliability () Technology Reliability x
  Human Reliability

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Advantages of Risk Analysis

• It is a useful way to
• Organize and analyze available scientific
  information
• Identify significant hazards
• Focus on areas that need much more research

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Risk Management involves answering the following
questions

• How reliable is the risk analysis for each risk?
• Which risks should be given the highest priority?
• How much risk is acceptable?

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• How much will it cost to reduce each risk to an
  acceptable level?
• How should limited funds be spent to provide the
  greatest benefit?
• How will risk management plan be monitored,
  enforced, and communicated to the public?

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The public tends to see a product as being
riskier than experts do if its

• New or complex rather than familiar
• Perceived as mostly involuntary
• Viewed as unnecessary rather than as beneficial
  or necessary
• Large, well-publicized death toll from a single
  catastrophic accident
• Unfair distribution of risks