Forensic Toxicology Wednesday, 5/20

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Forensic ToxicologyWednesday, 5/20

• Agenda
• Lecture on poisons/intro to forensic toxicology
• Discuss final project and begin sign-up
• Tomorrow
• Continue lecture alcohol intoxication and
  learning about sobriety tests

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Forensic Toxicology

• What is it?
• The science of detecting and identifying the
  presence of drugs and poisons in body fluids,
  tissues, and organs.

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Aspects of Forensic Toxicology

• Postmortemmedical examiner or coroner
• Criminalmotor vehicle accidents (MVA)
• Workplacedrug testing
• Sportshuman and animal
• Environmentindustrial, catastrophic, terrorism

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Toxicology

• Toxic substances may
• Be a cause of death
• Contribute to death
• Cause impairment
• Explain behavior

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Historical Perspective of Poisoners

• Locustapersonal poisoner of Emperor Nero
• Lucretia Borgiafather was Pope Alexander VI,
  known for using arsenic to poison
• Madame Giulia Toffanacommitted over 600
  successful poisonings, including two Popes.
• Hieronyma Sparaformed a society to teach women
  how to murder their husbands
• AND many others through modern times.

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People of Historical Significance

• Mathieu Orfilaknown as the father of forensic
  toxicology, published in 1814 Traite des
  Poisons which described the first systematic
  approach to the study of the chemistry and
  physiological nature of poisons.

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Aspects of Toxicity

• Dosage
• The chemical or physical form of the substance
• The mode of entry into the body
• Body weight and physiological conditions of the
  victim, including age and sex
• The time period of exposure
• The presence of other chemicals in the body or in
  the dose

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Lethal Dose

• LD50 the dose of a substance that kills half the
  test population, usually within four hours
• Expressed in milligrams of substance per kilogram
  of body weight

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Death by WaterHold your wee for a wii

• In 2007, a mother tried to win a wii game for her
  son at a radio show contest
• Contestants had to drink a water bottle every 5
  minutes without using the bathroom
• The mother died of water poisining
• 1.5 to 2.0 gallons of water can be toxic to your
  body

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Toxicity Classes
LD50 (rat,oral) Correlation to Ingestion by 150 lb Adult Human Toxicity
lt1mg/kg a taste to a drop extremely
1-50 mg/kg to a teaspoon highly
50-500 mg/kg to an ounce moderately
500-5000 mg/kg to a pint slightly
5-15 g/kg to a quart practically non-toxic
Over 15g/kg more than 1 quart relatively harmless
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Federal Regulatory Agencies

• Food and Drug Administration (FDA)
• Environmental Protection Agency (EPA)
• Consumer Product Safety Commission
• Department of Transportation (DOT)
• Occupational Safety and Health Administration
  (OSHA)

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Symptoms of Various Typesof Poisoning

• Type of Poison Symptom/Evidence
• Caustic Poison (lye) -Characteristic burns
  around the lips and mouth of the victim
• Carbon Monoxide -Red or pink patches on the
  chest and thighs, unusually
  bright red lividity
• Sulfuric acid -Black vomit
• Hydrochloric acid -Greenish-brown vomit
• Nitric acid -Yellow vomit
• Phosphorous Coffee brown vomit. Onion or garlic
  odor
• Cyanide -Burnt almond odor
• Arsenic, Mercury -Pronounced diarrhea
• Methyl (wood) or -Nausea and vomiting,
  unconsciousness,
• Isopropyl (rubbing) alcohol possibly blindness

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Toxicology of Alcohol

• Alcohol is absorbed through the stomach and
  intestine
• Once absorbed, alcohol is
• Oxidized in liver by alcohol dehydrogenase
• turned into acidic acid
• Excreted by breath, perspiration, and kidneys
  (urine)
• turned into carbon dioxide and water

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Factors that Affect Alcohol Absorption

1. Time of consumption
2. Type of alcoholic beverage
3. Presence of food in stomach

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Toxicology of Alcohol

• Alcohol intoxication depends on
• Amount of alcohol consumed
• Time of consumption
• Body weight
• Rate of alcohol absorption

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Fate of Alcohol

• Alcohol is absorbed into the bloodstream
• Distributed throughout the bodys water
• And finally eliminated by oxidation and excretion

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Alcohol in the Circulatory System

• Measuring the quantity of alcohol in the blood
  system determines the degree to which someone is
  drunk
• Two methods of making this measurement
• Measurement of alcohol content in blood
• Measurement of alcohol in breath

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Circulation Definitions

• Artery a blood vessel that carries blood away
  from the heart
• Vein a blood vessel that transports blood toward
  the heart
• Capillary a tiny blood vesselwalls exchange
  materials between blood and tissues
• Alveoli small sacs in lungsexchange vapors
  between breath and blood

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Circulation Cont

• If alcohol is present, it will be passed from the
  blood into the alveoli where it will be passed on
  to the mouth and nose during the act of
  breathing.
• Evidence has shown that the ratio of alcohol to
  alveoli air is approx. 2100 to 1
• This is a basis for relating breath to
  blood-alcohol concentration.

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Analysis of blood alcohol content (BAC)

• Breath Tests
• Field Sobriety Tests
• Blood Tests

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Breath Tests

• A breath test reflects the alcohol concentration
  in the pulmonary artery.
• One instrument used for breath tests is called
  The Breathalyzer.
• The Breathalyzer is a device for collecting and
  measuring the alcohol content of alveolar breath.

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The Breathalyzer Cont

• The Breathalyzer traps 1/40 of 2100 ml of
  alveolar breath.
• The amount of alcohol in 2100 ml of breath
  approximates the amount of alcohol in 1 ml of
  blood
• Measures the alcohol concentration present in
  1/40 of a ml of blood.

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Breathalyzer Cont

• Once the alveolar breath is trapped it is allowed
  to undergo a chemical reaction

• 2K2Cr2O7 3C2H5OH 8H2SO4 ? 2Cr2(SO4)3 2K2SO4
  3CH3COOH 11H2O
• The Breathalyzer indirectly determines the
  quantity of alcohol consumed by measuring the
  absorption of light by potassium chromate before
  and after its reaction with alcohol, using the
  principle of spectrophotometry

Potassium dichromate
Ethyl alcohol
Sulfuric acid
Chromium sulfate
Potassium sulfate
Acetic acid
Dihydrogen oxide
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Infrared Breath Test
Fuel Cell Breath Test

• Infrared light is absorbed when shined on alcohol
• Infrared light passes through a chamber where it
  will interact with the alcohol and cause the
  light density to decrease.
• The decrease in light intensity is proportional
  to the concentration of alcohol present in the
  captured breath

• A fuel cell converts a fuel and an oxidant into
  an electrical current.
• The breath alcohol is the fuel and atmospheric
  oxygen acts as the oxidant.
• Alcohol is converted, generating an electric
  current that is proportional to the quantity of
  alcohol present in the breath.

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These instruments are used more recently because
they dont depend upon chemical reagents and are
entirely automated.

• Infrared Breath Test uses infrared wavelengths to
  test for alcohol or other interferences in the
  breath
• Fuel Cell Test converts fuel (alcohol) and oxygen
  into a measurable electric current

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Field Sobriety Testing

• Two reasons for the field sobriety test
• Used as a preliminary test to ascertain the
  degree of the suspects physical impairment
• To see whether or not an evidential test is
  justified.

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Field Sobriety Testing Methods

• Field sobriety testing consists of a series of
  psychophysical tests and a preliminary breath
  test (typically done with a handheld fuel cell
  tester)
• These tests are preliminary and non-evidential in
  nature. They only serve to establish probable
  cause requiring a more thorough breath or blood
  test.

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Standardized Field Sobriety Testing

• The three tests of the SFST are
• 1. Horizontal Gaze Nystagmus (HGN),
• 2. Walk-and-Turn (WAT),
• 3. One-Leg Stand (OLS).
• These tests are administered systematically and
  are evaluated according to measured responses of
  the suspect.

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Test 1 Horizontal Gaze Nystagmus (HGN)

• Horizontal Gaze Nystagmus is an involuntary
  jerking of the eye that occurs naturally as the
  eyes gaze to the side.
• Normal circumstances ? nystagmus occurs when the
  eyes are rotated at high peripheral angles.
• Impaired by alcohol ? nystagmus is exaggerated
  and may occur at lesser angles.
• An alcohol-impaired person will also often have
  difficulty smoothly tracking a moving object. The
  examiner looks for three indicators of impairment
  in each eye
• if the eye cannot follow a moving object smoothly
• if jerking is distinct when the eye is at maximum
  deviation,
• if the angle of onset of jerking is within 45
  degrees of center.

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Test 1 Horizontal Gaze Nystagmus (HGN) contd

• If, between the two eyes, four or more clues
  appear, the suspect likely has a BAC of 0.08 or
  greater.
• NHTSA research found that this test allows proper
  classification of approximately 88 of suspects
• https//www.youtube.com/watch?vvjPR5WvYCx0

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Test 2 Walk and Turn (WAT) (divided attention
tasks)

• The Walk-and-Turn test and One-Leg Stand test are
  "divided attention" tests that are easily
  performed by most unimpaired people.
• They require a suspect to listen and follow
  instructions while performing simple physical
  movements.
• Impaired persons have difficulty with tasks
  requiring their attention to be divided between
  simple mental and physical exercises.

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Test 2 Walk and Turn (WAT) (divided attention
tasks)

• In the Walk-and-Turn test, the subject is
  directed to take nine steps, heel-to-toe, along a
  straight line. After taking the steps, the
  suspect must turn on one foot and return in the
  same manner in the opposite direction.
• The examiner looks for 8 indicators of
  impairment
• If the suspect cannot keep balance while
  listening to the instructions
• Begins before the instructions are finished
• stops while walking to regain balance
• Does not touch heel-to-toe
• Steps off the line
• Uses arms to balance
• Makes an improper turn
• Takes an incorrect number of steps.
• https//www.youtube.com/watch?v5BG48Bt2_u8listP
  L379B06AAD3E755E3

NHTSA research indicates that 79 of individuals
who exhibit two or more indicators in the
performance of the test will have a BAC of 0.08
or greater
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Test 3 One-Leg Stand (OLS)

• In the One-Leg Stand test, the suspect is
  instructed to stand with one foot approximately
  six inches off the ground and count aloud by
  thousands (One thousand-one, one thousand-two,
  etc.) until told to put the foot down. The
  officer times the subject for 30 seconds.
• The officer looks for 4 indicators of impairment,
  including
• Swaying while balancing,
• Using arms to balance,
• Hopping to maintain balance,
• And putting the foot down.
• NHTSA research indicates that 83 of individuals
  who exhibit two or more such indicators in the
  performance of the test will have a BAC of 0.08
  of greater
• https//www.youtube.com/watch?v7g7vA_qlckolistP
  L379B06AAD3E755E3

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And now for the best of those soon to be saying
goodbye to their license

• https//www.youtube.com/watch?vjydBvk7R5wU
• https//www.youtube.com/watch?vtTePQi272Nc
• https//www.youtube.com/watch?vp9jpwe6TDas
• https//www.youtube.com/watch?vu78p_-Jc1aU
• https//www.youtube.com/watch?vj6c_mWPSdPolistR
  DCGgOedVC3RY
• https//www.youtube.com/watch?veGCiXBJTonY

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Parts of the brain affected by Alcohol

• Alcohol 1st affects the forebrain and moves
  backward
• Last affected is medulla oblongata

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Alcohol and the Law
At least we dont live in France, Germany,
Ireland, or Japan (0.05) or especially Sweden
(0.02)!

• 1939-1964 intoxicated 0.15 BAC
• 1965 intoxicated 0.10 BAC
• 2003 intoxicated 0.08 BAC

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Alcohol and the Law

• Try the drink wheel http//www.intox.com/wheel/dr
  inkwheel.asp