1. 1 Module 2 Potential Exposure Routes and Hazards

2. 2 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

3. 3 Leads to Destruction of System Control Over-stimulates nerve endings and central nervous system Causes muscles and certain glands to malfunction

4. 4 Normal Nervous System Function Nerve impulse transmitted along nerve cells Acetylcholine (a neurotransmitter) is released Target cell is stimulated

5. 5 Normal Nervous System Function Once target cell is stimulated, acetycholine is deactivated by acetylcholinesterase Target cell relaxes

6. 6 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

7. 7 Routes of Exposure Inhalation Ingestion Direct contact

8. 8 Inhalation Respiratory failure is the chief cause of death after severe exposure

9. 9 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

10. 10 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

11. 11 Ingestion Access to bloodstream via digestive system Effects similar to inhalation, but at greater doses

12. 12 Inhalation Exposure From Atmospheric Transport The critical route of exposure that you should be most concerned with is inhalation of agent vapors or aerosols

13. 13 How Vesicant Agents Work Chemical burns to skin – especially warm, moist surfaces Chemical burns to soft membranes –eyes –eye ball –lung tissue –mouth –throat

14. 14 Sulfur Mustard (HD) Agent Exposure Delayed reaction and little or no pain Blisters develop in 2 to 36 hours

15. 15 Routes of Exposure Inhalation Ingestion Direct contact

16. 16 Inhalation Can destroy mucous membrane lining of: –nasal passages –throat –bronchial tubes

17. 17 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

18. 18 Ingestion If deposited on or in food items, drink, etc Injures warm, moist tissues of mouth, throat and esophagus

19. 19 Inhalation Exposure From Atmospheric Transport The critical route of exposure that you should be most concerned with is inhalation of agent vapors or aerosols