1. Forensic Toxicology Wednesday, 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

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

3. Aspects of Forensic Toxicology
Postmortem—medical examiner or coroner
Criminal—motor vehicle accidents (MVA)
Workplace—drug testing
Sports—human and animal
Environment—industrial, catastrophic, terrorism

4. Toxicology Toxic substances may: Be a cause of death
Contribute to death
Cause impairment
Explain behavior

5. Historical Perspective of Poisoners
Locusta—personal poisoner of Emperor Nero
Lucretia Borgia—father was Pope Alexander VI, known for using arsenic to poison
Madame Giulia Toffana—committed over 600 successful poisonings, including two Popes.
Hieronyma Spara—formed a society to teach women how to murder their husbands
AND many others through modern times.

6. People of Historical Significance
Mathieu Orfila—known 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.

7. 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

8. 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

9. Death by Water Hold 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

10. Toxicity Classes LD50 (rat,oral) Toxicity
Correlation to Ingestion by 150 lb Adult Human
Toxicity
<1mg/kg
a taste to a drop
extremely
1-50 mg/kg
to a teaspoon
highly
mg/kg
to an ounce
moderately
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

11. 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)

12. Symptoms of Various Types of 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

13. 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

14. Factors that Affect Alcohol Absorption
Time of consumption
Type of alcoholic beverage
Presence of food in stomach

15. Toxicology of Alcohol Alcohol intoxication depends on
Amount of alcohol consumed
Time of consumption
Body weight
Rate of alcohol absorption

16. Fate of Alcohol Alcohol is absorbed into the bloodstream
Distributed throughout the body’s water
And finally eliminated by oxidation and excretion

17. 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

18. 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 vessel—walls exchange materials between blood and tissues
Alveoli: small sacs in lungs—exchange vapors between breath and blood

19. Circulation Con’t
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 to 1
This is a basis for relating breath to blood-alcohol concentration.

20. Analysis of blood alcohol content (BAC)
Breath Tests
Field Sobriety Tests
Blood Tests

21. 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.

22. The Breathalyzer Con’t
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.

23. Breathalyzer Con’t
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

24. 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.

25. These instruments are used more recently because they don’t 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

26. Field Sobriety Testing
Two reasons for the field sobriety test:
Used as a preliminary test to ascertain the degree of the suspect’s physical impairment
To see whether or not an evidential test is justified.

27. 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.

28. 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.

29. 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.

30. Test 1: Horizontal Gaze Nystagmus (HGN) cont’d
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

31. 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.

32. 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.
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

33. 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

34. And now for the ‘best’ of those soon to be saying goodbye to their license…

35. Parts of the brain affected by Alcohol
Alcohol 1st affects the forebrain and moves backward
Last affected is medulla oblongata

36. Alcohol and the Law 1939-1964: intoxicated = 0.15% BAC
At least we don’t live in France, Germany, Ireland, or Japan (0.05%) or especially Sweden (0.02%)!
Alcohol and the Law
: intoxicated = 0.15% BAC
1965: intoxicated = 0.10% BAC
2003: intoxicated = 0.08% BAC

37. Alcohol and the Law
Try the drink wheel: