Science Fair Project

Report
Toxicology: Poisons and Alcohol
Toxicology: Poisons and Alcohol
Objectives
You will understand:
The danger of using alcohol.
A quantitative approach to toxicology.
Chapter 8
Kendall/Hunt Publishing Company
2
2
Toxicology: Poisons and Alcohol
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.
Chapter 8
Kendall/Hunt Publishing Company
3
3
Toxicology: Poisons and Alcohol
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
Chapter 8
Kendall/Hunt Publishing Company
4
4
Toxicology: Poisons and Alcohol
Forensic Toxicology
Postmortem—medical examiner
or coroner
Criminal—motor vehicle
accidents (MVA)
Workplace—drug testing
Sports—human and animal
Environment—industrial,
catastrophic, terrorism
Chapter 8
Kendall/Hunt Publishing Company
5
5
Toxicology: Poisons and Alcohol
Toxicology
Toxic substances may:
Be a cause of death
Contribute to death
Cause impairment
Explain behavior
Chapter 8
Kendall/Hunt Publishing Company
6
6
Toxicology: Poisons and Alcohol
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.
Chapter 8
Kendall/Hunt Publishing Company
7
7
Toxicology: Poisons and Alcohol
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
Chapter 8
Kendall/Hunt Publishing Company
8
8
Toxicology: Poisons and Alcohol
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
Chapter 8
Kendall/Hunt Publishing Company
9
9
Toxicology: Poisons and Alcohol
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
Chapter 8
Kendall/Hunt Publishing Company
10
10
Toxicology: Poisons and Alcohol
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
Chapter 8
Kendall/Hunt Publishing Company
11
11
Toxicology: Poisons and Alcohol
Toxicity Classification
LD50 (rat,oral)
Correlation to Ingestion
by 150-lb Adult Human
Toxicity
<1 mg/kg
a taste to a drop
extreme
1–50 mg/kg
to a teaspoon
high
50–500 mg/kg
to an ounce
moderate
500–5,000 mg/kg
to a pint
slight
5–15 g/kg
to a quart
practically nontoxic
Over 15 g/kg
more than 1 quart
relatively harmless
Chapter 8
Kendall/Hunt Publishing Company
12
12
Toxicology: Poisons and Alcohol
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)
Chapter 8
Kendall/Hunt Publishing Company
13
13
Toxicology: Poisons and Alcohol
Symptoms of Various Types of Poisoning
Type of Poison
Symptom/Evidence
Caustic poison (lye)
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
Carbon monoxide
Sulfuric acid
Hydrochloric acid
Nitric acid
Phosphorus
Cyanide
Arsenic, mercury
Methyl (wood) or isopropyl
(rubbing) alcohol
Chapter 8
Kendall/Hunt Publishing Company
14
14
Toxicology: Poisons and Alcohol
Critical Information
Form
Common color
Characteristic odor
Solubility
Taste
Common sources
Lethal dose
Mechanism
Possible methods of
administration
Time interval of onset of
symptoms
Chapter 8
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
Kendall/Hunt
Publishing
Company
Criminal Poisoning
15
15
Toxicology: Poisons and Alcohol
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
Chapter 8
Kendall/Hunt Publishing Company
16
16
Toxicology: Poisons and Alcohol
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.
Chapter 8
Kendall/Hunt Publishing Company
17
17
Toxicology: Poisons and Alcohol
Human Specimens for Analysis
Blood
Liver tissue
Urine
Brain tissue
Vitreous humor of eyes
Kidney tissue
Bile
Hair/nails
Gastric contents
Chapter 8
Kendall/Hunt Publishing Company
18
18
Toxicology: Poisons and Alcohol
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
Chapter 8
Kendall/Hunt Publishing Company
19
19
Toxicology: Poisons and Alcohol
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
Chapter 8
Kendall/Hunt Publishing Company
20
20
Toxicology: Poisons and Alcohol
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
Chapter 8
Kendall/Hunt Publishing Company
21
21
Toxicology: Poisons and Alcohol
BAC Calculation
Burn-off rate of 0.015 percent per hour, but can vary:
Male
BAC = 0.071  (oz)  (% alcohol)
body weight
Female
BAC = 0.085  (oz)  (% alcohol)
body weight
Chapter 8
Kendall/Hunt Publishing Company
22
22
Toxicology: Poisons and Alcohol
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.
Chapter 8
Kendall/Hunt Publishing Company
23
23
Toxicology: Poisons and Alcohol
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
Chapter 8
Kendall/Hunt Publishing Company
24
24
Toxicology: Poisons and Alcohol
The Breathalyzer
More practical in the field
Collects and measures alcohol content
of alveolar breath
Breath sample mixes with 3 ml of 0.025 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.
Chapter 8
Kendall/Hunt Publishing Company
25
25
Toxicology: Poisons and Alcohol
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.
Chapter 8
Kendall/Hunt Publishing Company
26
26
Toxicology: Poisons and Alcohol
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.
Chapter 8
Kendall/Hunt Publishing Company
27
27
Toxicology: Poisons and Alcohol
More Information
Read more about forensic toxicology at truTV’s Crime Library:
http://www.crimelibrary.com/criminal_mind/forensics/toxicol
ogy/2.html
Chapter 8
Kendall/Hunt Publishing Company
28
28

similar documents