1. Toxicology: Poisons and Alcohol
Chapter 8
Toxicology: Poisons and Alcohol
Kendall/Hunt

2. Kendall/Hunt Publishing Company
Chapter 8
Objectives
You will understand:
The danger of using alcohol.
A quantitative approach to toxicology.
Kendall/Hunt Publishing Company
Kendall/Hunt

3. Kendall/Hunt Publishing Company
Chapter 8
Objectives, continued
You will be able to:
Discuss the connection of blood alcohol levels to the law, incapacity, and test results.
Understand the vocabulary of poisons.
Design and conduct scientific investigations.
Use technology and mathematics to improve investigations and communications.
Identify questions and concepts that guide scientific investigations.
Communicate and defend a scientific argument.
Kendall/Hunt Publishing Company
Kendall/Hunt

4. Kendall/Hunt Publishing Company
Chapter 8
Toxicology
Toxicology—the study of the adverse effects of chemicals or physical agents on living organisms
Types:
Environmental—air, water, soil
Consumer—foods, cosmetics, drugs
Medical, clinical, forensic
Kendall/Hunt Publishing Company
Kendall/Hunt

5. Kendall/Hunt Publishing Company
Chapter 8
Forensic Toxicology
Postmortem—medical examiner
or coroner
Criminal—motor vehicle
accidents (MVA)
Workplace—drug testing
Sports—human and animal
Environment—industrial,
catastrophic, terrorism
Kendall/Hunt Publishing Company
Kendall/Hunt

6. Kendall/Hunt Publishing Company
Chapter 8
Toxicology
Toxic substances may:
Be a cause of death
Contribute to death
Cause impairment
Explain behavior
Kendall/Hunt Publishing Company
Kendall/Hunt

7. Historical Perspective of Poisoners
Chapter 8
Historical Perspective of Poisoners
Olympias—a famous Greek poisoner
Locusta—personal poisoner of Emperor Nero
Lucretia Borgia—father was Pope Alexander VI
Madame Giulia Toffana—committed over 600 successful poisonings, including two popes
Hieronyma Spara—formed a society to teach women how to murder their husbands
Madame de Brinvilliers and Catherine Deshayes—French poisoners
AND many others through modern times.
Kendall/Hunt Publishing Company
Kendall/Hunt

8. The Severity of the Problem
Chapter 8
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
Kendall/Hunt Publishing Company
Kendall/Hunt

9. People of Historical Significance
Chapter 8
People of Historical Significance
Mathieu Orfila—known as the father of forensic toxicology, published in 1814 Traité des poisons which described the first systematic approach to the study of the chemistry and physiological nature of poisons
Kendall/Hunt Publishing Company
Kendall/Hunt

10. Kendall/Hunt Publishing Company
Chapter 8
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
Kendall/Hunt Publishing Company
Kendall/Hunt

11. Kendall/Hunt Publishing Company
Chapter 8
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
Kendall/Hunt Publishing Company
Kendall/Hunt

12. Toxicity Classification
Chapter 8
Toxicity Classification
LD50 (rat,oral)
Correlation to Ingestion by 150-lb Adult Human
Toxicity
<1 mg/kg
a taste to a drop
Relatively harmless
1–50 mg/kg
to a teaspoon
Practically nontoxic
50–500 mg/kg
to an ounce
Slight
500–5,000 mg/kg
to a pint
Moderate
5–15 g/kg
to a quart
High
Over 15 g/kg
more than 1 quart
Extreme
Kendall/Hunt Publishing Company
Kendall/Hunt

13. Federal Regulatory Agencies
Chapter 8
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)
Kendall/Hunt Publishing Company
Kendall/Hunt

14. Symptoms of Various Types of Poisoning
Chapter 8
Symptoms of Various Types of Poisoning
Type of Poison
Caustic poison (lye)
Carbon monoxide
Sulfuric acid
Hydrochloric acid
Nitric acid
Phosphorus
Cyanide
Arsenic, mercury
Methyl (wood) or isopropyl
(rubbing) alcohol
Symptom/Evidence
Characteristic burns around the lips and
mouth of victim
Red or pink patches on the chest and
thigh, unusually bright red lividity
Black vomit
Greenish-brown vomit
Yellow vomit
Coffee-brown vomit, onion or garlic odor
Burnt almond odor
Extreme diarrhea
Nausea and vomiting, unconsciousness
possibly blindness
Kendall/Hunt Publishing Company
Kendall/Hunt

15. Kendall/Hunt Publishing Company
Chapter 8
Critical Information
Form
Common color
Characteristic odor
Solubility
Taste
Common sources
Lethal dose
Mechanism
Possible methods of administration
Time interval of onset of symptoms
Symptoms resulting from an acute exposure
Symptoms resulting from chronic exposure
Disease states mimicked by poisoning
Notes relating to the victim
Specimens from victim
Analytical detection methods
Known toxic levels
Notes pertinent to analysis of poison
List of cases in which poison was used
—John Trestrail from Criminal Poisoning
Kendall/Hunt Publishing Company
Kendall/Hunt

16. Kendall/Hunt Publishing Company
Chapter 8
To Prove a Case
Prove a crime was committed
Motive
Intent
Access to poison
Access to victim
Death was homicidal
Death was caused by poison
Kendall/Hunt Publishing Company
Kendall/Hunt

17. Kendall/Hunt Publishing Company
Chapter 8
Forensic Autopsy
Look for:
Irritated tissues
Characteristic odors
Mees lines—single transverse white bands on nails
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.
Kendall/Hunt Publishing Company
Kendall/Hunt

18. Human Specimens for Analysis
Chapter 8
Human Specimens for Analysis
Blood
Urine
Vitreous humor of eyes
Bile
Gastric contents
Liver tissue
Brain tissue
Kidney tissue
Hair/nails
Kendall/Hunt Publishing Company
Kendall/Hunt

19. Alcohol—Ethyl Alcohol (C2H5OH)
Chapter 8
Alcohol—Ethyl Alcohol (C2H5OH)
Most abused drug in America
About 40 percent of all traffic deaths are alcohol-related
Toxic—affecting the central nervous system, especially the brain
Colorless liquid, generally diluted in water
Acts as a depressant
Alcohol appears in blood within minutes of consumption; 30–90 minutes for full absorption
Detoxification—about 90 percent in the liver
About 5 percent is excreted unchanged in breath, perspiration, and urine
Kendall/Hunt Publishing Company
Kendall/Hunt

20. Kendall/Hunt Publishing Company
Chapter 8
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
Kendall/Hunt Publishing Company
Kendall/Hunt

21. BAC: Blood Alcohol Content
Chapter 8
BAC: Blood Alcohol Content
Expressed as percent weight per volume of blood
Legal limit in all states is 0.08 percent
Parameters influencing BAC:
Body weight
Alcohol content
Number of beverages consumed
Time since consumption
Kendall/Hunt Publishing Company
Kendall/Hunt

22. Kendall/Hunt Publishing Company
Chapter 8
BAC Calculation
Burn-off rate of percent per hour, but can vary:
Male
BAC =
Female
0.071  (oz)  (% alcohol)
body weight
0.085  (oz)  (% alcohol)
body weight
Kendall/Hunt Publishing Company
Kendall/Hunt

23. Kendall/Hunt Publishing Company
Chapter 8
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.
This ratio of alcohol in the blood to alcohol in the alveolar air is approximately 2,100 to 1. In other words, 1 ml of blood will contain nearly the same amount of alcohol as 2,100 ml of breath.
Kendall/Hunt Publishing Company
Kendall/Hunt

24. Kendall/Hunt Publishing Company
Chapter 8
Field Tests
Preliminary tests—used to determine the degree of suspect’s physical impairment and whether or not another test is justified
Psychophysical tests—three basic 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.
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
Kendall/Hunt Publishing Company
Kendall/Hunt

25. Kendall/Hunt Publishing Company
Chapter 8
The Breathalyzer
More practical in the field
Collects and measures alcohol content
of alveolar breath
Breath sample mixes with 3 ml of percent K2Cr2O7 in sulfuric acid and water:
2K2Cr2O7 +3C2H5OH + 8H2SO4  2Cr2(SO4)3 + 2K2SO4 + 3CH3COOH + 11H2O
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.
Kendall/Hunt Publishing Company
Kendall/Hunt

26. Kendall/Hunt Publishing Company
Chapter 8
Generalizations
During absorption, the concentration of alcohol in arterial blood is higher than in venous blood.
Breath tests reflect alcohol concentration in the pulmonary artery.
The breathalyzer also can react with acetone (as found in diabetics), acetaldehyde, methanol, isopropyl alcohol, and paraldehyde, but these are toxic and their presence means the person is in serious medical condition.
Breathalyzers now use an infrared light-absorption device with a digital readout. Prints out a card for a permanent record.
Kendall/Hunt Publishing Company
Kendall/Hunt

27. Kendall/Hunt Publishing Company
Chapter 8
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 personnel, forensic scientists, and lawyers.
Kendall/Hunt Publishing Company
Kendall/Hunt

28. Kendall/Hunt Publishing Company
Chapter 8
More Information
Read more about forensic toxicology at truTV’s Crime Library:
Kendall/Hunt Publishing Company
Kendall/Hunt