THEORY OF SCENT and SCENT TRANSPORT

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Canine Search Specialist Training
Unit 5 Scent Theory
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Unit Objective

• Upon completion of this unit, you will be able to
  explain the theory of scent as it relates to the
  canine search for live victims in a collapsed
  structure

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Enabling Objectives

• Explain the rationale for understanding scent
  movement
• Describe the factors that may affect scent
• Describe how scent is transported away from the
  victim
• Plan the search of a collapsed structure to
  efficiently work canines into scent

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Rationale

• Dogs see the world through their nose
• Scent is 3-dimensional to them
• Our job is to put them where they can best detect
  scent

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The Canine
Olfactory System
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The Nose Knows
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Canine Olfactory System

• Olfactory sensory cell estimates
• Human 5 million
• Canine 220 million

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CONTRIBUTORS TO HUMAN SCENT COMPLEX
Adipose
Bacterial Action
MEOH H2SO4 Volatile Fatty Acids
K, Cl, Urea, Ca Mg, PO4, HOH
Human Scent
Sebaceous
Eccrine
Sebum, Squalene
Volatile Fatty Acids Amines
Respiratory Tract GI Tract
Apocrine
Other factors Genetic, Diet, Environment
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Huh?
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What is scent to a canine?
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The Raft Theory

• Dying/dead, bacteria laden skin cellscalled
  rafts
• Rafts are shed from
• Skin
• Respiratory and digestive tracks

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Skin raft loss

• Approximately
• 40,000 per minute!

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• If one gram of butyric acid was made to
  evaporate evenly in all the rooms of a ten story
  office building, a man would barely be able to
  perceive its existence by standing in one of the
  rooms. However, if the same gram of butyric acid
  was diluted to fill the air above the entire city
  of Hamburg, the dog could still perceive it at an
  altitude of 300 feet.
• William Syrotuck
• Scent and the Scenting Dog, pg. 13

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How is scent dispersed?

• The scent is heaviest at the source and dispersed
  away from the victim in a cone

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Scent Dispersal
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Influences on Scent Dispersal
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Environmental Influences
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Environmental Influences

• Temperature
• Wind strength and direction
• Humidity
• Sun

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Temperature

• Hot
• Cold
• The temperature of victim versus the temperature
  of the environment

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Wind

• Strength
• Direction

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Humidity

• High
• Low
• Rain

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Sun

• Clear
• Overcast
• Night

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Day-time Patterns
Night-time Flows
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Structural Influences
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Structural Influences

• Building architecture
• Elevator shafts
• Closed stairwells
• Windows
• Breached floors/walls

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Structural Influences (continued)

• Scent flows well in
• Broken rubble
• Light framing
• Brick

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Katrina 2005
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Scent Flow and Detection
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Scent Flow and Detection

• The disaster search canine is trained to indicate
  the presence of a live victim by performing a
  focused bark alert at the point in the rubble
  where the strongest live human scent is emitted

Bark! Bark!
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DETECTION versus LOCATION

• Dogs are SCENT detectors NOT victim locators!

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Scent FlowChanneling
BARK
scent cone
scent cone
scent cone

• Solid Slabs
• Large Chunks

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• Solid Slabs
• Large Chunks

BARK
BARK
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Scent Source Detection

• Be able to interpret your dogs alert
• Document
• Debrief
• Handler to STM
• Handler to Handler

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Scent FlowFunneling
Bark! Bark!
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Scent FlowPooling
Bark! Bark!
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Typical Collapse Patterns

• Lean-To
• V
• Pancake
• Cantilever

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Lean-To
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V
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Pancake
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Cantilever
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What is this?
Cold Wall
Hot Wall
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Use your scent knowledge

• Identify scenting conditions
• Surveyors tape, puff bottles/talc mirror scent
  pattern
• Interpret pattern of alerts
• Send canine from position which maximizes
  probability of detection

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Considerations

• Hazardous materials
• Live versus dead
• Number of victims found
• Distractions

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Questions?
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Scent Theory/Air Movement Demonstration
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Unit Summary and Evaluation
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Unit Summary

• Explain the rationale for understanding scent
  movement
• Describe the factors that may affect scent
• Describe how scent is transported away from the
  victim
• Plan the search of a collapsed structure to
  efficiently work canines into scent

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Unit Evaluation

• Please fill out the evaluation on this briefing