0. Chapter 8 Toxicology: Poisons and Alcohol
“All substances are poisons. There is none which is not. The right dose differentiates a poison and remedy.”
—Paracelsus ( ). Swiss physician and chemist

1. Toxicology
Definition—the study of the adverse effects of chemicals or physical agents on living organisms.

2. Types: Environmental—air, water, soil Consumer—foods, cosmetics, drugs
Toxicology
Types:
Environmental—air, water, soil
Consumer—foods, cosmetics, drugs
Medical, clinical, forensic

3. Postmortem—medical examiner or coroner
Forensic Toxicology
Postmortem—medical examiner or coroner
Criminal—motor vehicle accidents (MVA)
Workplace—drug testing

4. Sports—human and animal
Forensic Toxicology
Sports—human and animal
Environment—industrial, catastrophic, terrorism

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

6. The Severity of the Problem
“If all those buried in our cemeteries who were poisoned could raise their hands, we would probably be shocked by the numbers.”
—John Harris Trestrail, “Criminal Poisoning”

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

8. The time period of exposure
Aspects of Toxicity
The time period of exposure
The presence of other chemicals in the body or in the dose

9. Expressed in milligrams of substance per kilogram of body weight
Lethal Dose
LD50—refers to 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

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

13. Symptoms of Various Types of Poisoning
Type of Poison Symptom/Evidence
Phosphorous Coffee brown vomit. Onion or garlic odor
Cyanide Burnt almond odor
Arsenic, Mercury Pronounced diarrhea
Methyl (wood) or Nausea and vomiting, Isopropyl (rubbing) unconsciousness,
alcohol possibly blindness

14. Critical Information on Poisons
Common color
Characteristic odor
Solubility
Taste
Common sources
—John Trestrail from “Criminal Poisoning”

15. Critical Information on Poisons
Mechanism
Possible methods of administration
Time interval of onset of symptoms.
Symptoms resulting from an acute exposure
Symptoms resulting from chronic exposure
—John Trestrail from “Criminal Poisoning”

16. Critical Information on Poisons
Disease states mimicked by poisoning
Notes relating to the victim
Specimens from victim
Analytical detection methods
—John Trestrail from “Criminal Poisoning”

17. Critical Information on Poisons
Known toxic levels
Notes pertinent to analysis of poison
List of cases in which poison was used
—John Trestrail from “Criminal Poisoning”

18. Prove a crime was committed Motive Intent Access to poison
To Prove a Case
Prove a crime was committed
Motive
Intent
Access to poison

19. Death was caused by poison Death was homicidal
To Prove a Case
Access to victim
Death was caused by poison
Death was homicidal

20. Mees lines—single transverse white bands on nails.
Forensic Autopsy
Look for:
Irritated tissues
Characteristic odors
Mees lines—single transverse white bands on nails.

21. Order toxicological screens
Forensic Autopsy
Order toxicological screens
Postmortem concentrations should be done at the scene for comparison
No realistic calculation of dose can be made from a single measurement

22. Human Specimens for Analysis
Blood
Urine
Vitreous Humor of Eyes
Bile
Gastric contents
Liver tissue
Brain tissue
Kidney tissue
Hair/nails

23. Alcohol—Ethyl Alcohol (C2H5OH)
Most abused drug in America
About 40% of all traffic deaths are alcohol-related
Toxic—affecting the central nervous system, especially the brain

24. Alcohol—Ethyl Alcohol (C2H5OH)
Colorless liquid, generally diluted in water
Acts as a depressant
Alcohol appears in blood within minutes of consumption; minutes for full absorption

25. Alcohol—Ethyl Alcohol (C2H5OH)
Detoxification—about 90% in the liver
About 5% is excreted unchanged in breath, perspiration and urine

26. amount of alcohol consumed the alcohol content of the beverage
Rate of Absorption
Depends on:
amount of alcohol consumed
the alcohol content of the beverage
time taken to consume it
quantity and type of food present in the stomach
physiology of the consumer

27. BAC Blood Alcohol Content
Expressed as percent weight per volume of blood
Legal limits in all states is 0.08%
Parameters influencing BAC:
Body weight
Alcoholic content
Number of beverages consumed
Time between consumption

28. BAC Burn off rate of 0.015% per hour but can vary: Male
BAC male = x (oz) x (% alcohol)
body weight
Female
BAC female = x (oz) x (% alcohol)

29. Henry’s Law
When a volatile chemical is dissolved in a liquid and is brought to equilibrium with air, there is a fixed ratio between the concentration of the volatile compound in the air and its concentration in the liquid; this ratio is constant for a given temperature. THEREFORE, the concentration of alcohol in breath is proportional to that in the blood.

30. Henry’s Law
This ratio of alcohol in the blood to alcohol in the alveolar air is approximately 2100 to 1. In other words 1 ml of blood will contain nearly the same amount of alcohol as 2100 ml of breath.

31. Field Tests
Preliminary tests—used to determine the degree of suspect’s physical impairment and whether or not another test is justified.

32. Psychophysical test— 3Basic Tests
Field Tests
Psychophysical test—
3Basic Tests
Horizontal gaze nystagmus (HGN): follow a pen or small flashlight, tracking left to right with one’s eyes. In general, wavering at 45 degrees indicates 0.10 BAC.

33. Field Tests
Nine Step walk and turn (WAT): comprehend and execute two or more simple instructions at one time.
One-leg stand (OLS): maintain balance, comprehend and execute two or more simple instructions at one time.

34. More practical in the field
The Breathalyzer
More practical in the field
Collects and measures alcohol content of alveolar breath
Breath sample mixes with 3 ml of % K2Cr2O7 in sulfuric acid and water
2K2Cr2O7 + 3C 2H5OH + 8H 2SO4  2Cr2(SO4) K2SO4 + 3CH3COOH + 11 H2O

35. The Breathalyzer
Potassium dichromate is yellow, as concentration decreases its light absorption diminishes so the breathalyzer indirectly measures alcohol concentration by measuring light absorption of potassium dichromate before and after the reaction with alcohol

36. Breath tests reflect alcohol concentration in the pulmonary artery.
Generalizations
During absorption, the concentration of alcohol in arterial blood will be higher than in venous blood.
Breath tests reflect alcohol concentration in the pulmonary artery.

37. Generalizations
The breathalyzer also can react with acetone (as found with diabetics), acetaldehyde, methanol, isopropyl alcohol, and paraldehyde, but these are toxic and their presence means the person is in serious medical condition.

38. Generalizations
Breathalyzers now use an infrared light absorption device with a digital read-out. Prints out a card for a permanent record.

39. People in the News
John Trestrail is a practicing toxicologist who has consulted on many criminal poisoning cases. He is the founder of the Center for the Study of Criminal Poisoning in Grand Rapids, Michigan which has established an international database to receive and analyze reports of homicidal poisonings from around the world. He is also the director of DeVos Children’s Hospital Regional Poison Center. In addition, he wrote the book, Criminal Poisoning, used as a reference by law enforcement, forensic scientists and lawyers.

40. Read more about Forensic Toxicology from Court TV’s Crime Library at:
More Information
Read more about Forensic Toxicology from Court TV’s Crime Library at:

41. Toxicology and Drugs
Chapter 7 Drugs
“Having sniffed the dead man’s lips, I detected a slightly sour smell, and I came to the conclusion that he had poison forced upon him.”
—Sherlock Holmes, in Sir Arthur Conan Doyle’s
A Study in Scarlet

42. Drugs and Crime
A drug is a natural or synthetic substance designed to affect the subject psychologically or physiologically.

43. Drugs and Crime
“Controlled substances” are drugs that are restricted by law
Controlled Substances Act is a law that was enacted in 1970; it lists illegal drugs, their category and their penalty for possession, sale or use.

44. Controlled Substances Act
Schedule I – high potential for abuse; no currently acceptable medical use in the U.S.; a lack of accepted safety for use under medical supervision

45. Controlled Substances Act
Schedule II – high potential for abuse; a currently accepted medical use with severe restrictions; abuse may lead to severe psychological or physical dependence

46. Controlled Substances Act
Schedule III – lower potential for abuse than the drugs in I or II; a currently accepted medical use in treatment in the U.S.; abuse may lead to moderate physical dependence or high psychological dependence

47. Controlled Substances Act
Schedule IV – low potential for abuse relative to drugs in III; a currently accepted medical use in treatment in the U.S.; abuse may lead to limited physical dependence or psychological dependence relative to drugs in III

48. Controlled Substances Act
Schedule V – low potential for abuse relative to drugs in IV; currently accepted medical use in treatment in the U.S.; abuse may lead to limited physical dependence or psychological dependence relative to drugs in IV

49. Examples of Controlled Substances and Their Schedule Placement
Schedule I—heroin (diacetylmorphine), LSD, marijuana, ecstasy (MDMA)
Schedule II—cocaine, morphine, amphetamines (including methamphetamines), PCP, Ritalin

57. Examples of Controlled Substances and Their Schedule Placement
Schedule III—intermediate acting barbiturates, anabolic steroids, ketamine
Schedule IV—other stimulants and depressants including Valium, Xanan, Librium, phenobarbital, Darvon

58. Examples of Controlled Substances and Their Schedule Placement
Schedule V—codeine found in low doses in cough medicines

59. Identification of Drugs
PDR—Physicians’ Desk Reference
Field Tests—presumptive tests
Laboratory Tests—conclusive tests

60. Human Components Used for Drug Analysis
Blood
Urine
Hair
Gastric Contents
Bile
Liver tissue
Brain tissue
Kidney tissue
Spleen tissue
Vitreous Humor of the Eye

61. Physicians’ Desk Reference
PDR—a physicians’ desk reference is used to identify manufactured pills, tablets and capsules. It is updated each year. This can sometimes be a quick and easy identifier of the legally made drugs that may be found at a scene. The reference book gives a picture of the drug, whether it is a prescription, over the counter, or a controlled substance; as well as more detailed information about the drug.

62. PDR Key

63. Microcrystalline test—
Drug Identification
Screening or presumptive tests
Spot or color tests
Microcrystalline test—
a reagent is added that produces a crystalline precipitate which is unique for a certain drug.
Chromatography

64. Confirmatory tests Spectrophotometry Ultraviolet (UV) Visible
Drug Identification
Confirmatory tests
Spectrophotometry
Ultraviolet (UV)
Visible
Infrared (IR)
Mass spectrometry

65. Presumptive Color Tests
Marquis—turns purple in the presence of most opium derivatives and orange-brown with amphetamines

66. Presumptive Color Tests
Dillie-Koppanyi—turns violet-blue in the presence of barbiturates
Duquenois-Levine—turns a purple color in the presence of marijuana

67. Presumptive Color Tests
Van Urk—turns a blue-purple in the presence of LSD
Scott test—color test for cocaine, blue

68. A technique for separating mixtures into their components
Chromatography
A technique for separating mixtures into their components
Includes two phases—a mobile one that flows past a stationary one.
The mixture interacts with the stationary phase and separates.

69. Types of Chromatography
Paper
Thin Layer (TLC)
Gas (GC)
Pyrolysis Gas (PGC)
Liquid (LC)
High Pressure Liquid (HPLC)
Column

70. Stationary phase—paper Mobile phase—a liquid solvent
Paper Chromatography
Stationary phase—paper
Mobile phase—a liquid solvent
Capillary action moves the mobile phase through the stationary phase

71. Thin Layer Chromatography
Stationary phase— a thin layer of coating (usually alumina or silica) on a sheet of plastic or glass
Mobile phase—
a liquid solvent

72. People of Historical Significance
Francis William Aston was a British physicist who won the 1922 Nobel Prize in Chemistry for his work in the invention of the mass spectrograph. He used a method of electromagnetic focusing to separate substances. This enabled him to identify no fewer than 212 of the 287 naturally occurring elemental isotopes.