Module 2 Potential Exposure Routes and Hazards

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Module 2Potential Exposure Routes and Hazards
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How Nerve Agents Work

• Nervous system controls normal functions through
  use of chemicals
• Chemicals act as instructions to nerves, muscles,
  and glands
• Two forms of instructions
• stimulate (move or work)
• relax (stop or rest)
• Nerve agent interferes with normal transmission
  of instructions

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Leads to Destruction of System Control

• Over-stimulates nerve endings and central nervous
  system
• Causes muscles and certain glands to malfunction

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Normal Nervous System Function
Nerve impulse transmitted along nerve
cells
Target cell is stimulated
Acetylcholine (a neurotransmitter) is
released
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Normal Nervous System Function
Once target cell is stimulated, acetycholine
is deactivated by acetylcholinesterase
Target cell relaxes
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Nerve Agent Interference
Nerve agents inactivate acetylcholinesterase
Excess acytelcholine accumulates Muscle
action becomes uncontrolled and
twitchy Muscle can tire and collapse Gland
continues to secrete sweat, tears, or mucus
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Routes of Exposure
Inhalation Ingestion Direct contact
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Inhalation

• Respiratory failure is the chief cause of death
  after severe exposure

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Direct Contact

• Absorption through skin
• All agents can be absorbed
• VX persists longer
• GB evaporates quickly, but still a threat
• Scrape or cut in skin allows immediate entry
• Entry also through eyes

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Direct Contact

• Absorption through skin
• All agents can be absorbed
• VX persists longer
• GB evaporates quickly, but still a threat
• Scrape or cut in skin allows immediate entry
• Entry also through eyes

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Ingestion

• Access to bloodstream via digestive system
• Effects similar to inhalation, but at greater
  doses

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Inhalation Exposure From Atmospheric Transport

• The critical route of exposure that you should be
  most concerned with is inhalation of agent vapors
  or aerosols

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How Vesicant Agents Work

• Chemical burns to skin especially warm, moist
  surfaces
• Chemical burns to soft membranes
• eyes
• eye ball
• lung tissue
• mouth
• throat

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Sulfur Mustard (HD) Agent Exposure

• Delayed reaction and little or no pain
• Blisters develop in 2 to 36 hours

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Routes of Exposure
Inhalation Ingestion Direct contact
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Inhalation

• Can destroy mucous membrane lining of
• nasal passages
• throat
• bronchial tubes

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Direct contact With Liquid or Vapor

• Highly damaging to skin - especially warm, moist
  areas
• Mucous membranes are very susceptible to effects
  of blister agents including
• lining around eyelids
• inside mouth and nose
• Sweat and moisture increase effect

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Ingestion

• If deposited on or in food items, drink, etc
• Injures warm, moist tissues of mouth, throat and
  esophagus

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Inhalation Exposure From Atmospheric Transport

• The critical route of exposure that you should be
  most concerned with is inhalation of agent vapors
  or aerosols