Toxicology ppt

Download Report

Transcript Toxicology ppt

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 (1495-1541). Swiss
physician and chemist
Toxicology and Alcohol
Students will be able to:






Chapter 8
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
1
Toxicology
Definition—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
2
Uses of 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
3
Toxicology
Toxic substances may:
 Be a cause of death
 Contribute to death
 Cause impairment
 Explain behavior
Chapter 8
Kendall/Hunt Publishing Company
4
Historical Perspective
of Poisoners
 Olympias—a famous Greek poisoner, mother of Alexander the
Great (375 - 316 BC)
 Locusta—personal poisoner of Emperor Nero (54 AD)
 Lucretia Borgia—father was Pope Alexander VI (1480-1519)
 Catherine Medici- Queen of France poisoned political rivals, and
experimented with poisons on the poor (1519-1589 AD)
 Madame Giulia Toffana—committed over 600 successful
poisonings, including two Popes (1659 AD)
 Hieronyma Spara—formed a society to teach women how to murder
their husbands (1659 AD)
 Madame de Brinvilliers and Catherine Deshayes—Convicted
French witches poisoners. (1640 - 1680 AD)
Chapter 8
Kendall/Hunt Publishing Company
5
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.
Chapter 8
Kendall/Hunt Publishing Company
6
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
7
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
8
Toxicity Classes
LD50 (rat,oral)
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
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
Chapter 8
Kendall/Hunt Publishing Company
9
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
10
Symptoms of Various Types
of Poisoning
Type of Poison
Symptom/Evidence
 Caustic Poison (lye)
Characteristic burns around the lips and
mouth of the victim
Red or pink patches on the chest and thighs,
unusually bright red lividity
Black vomit
Greenish-brown vomit
Yellow vomit
Coffee brown vomit. Onion or garlic odor
Burnt almond odor
Pronounced diarrhea
Nausea and vomiting, unconsciousness,
possibly blindness
 Carbon Monoxide







Sulfuric acid
Hydrochloric acid
Nitric acid
Phosphorous
Cyanide
Arsenic, Mercury
Methyl (wood) or
Isopropyl (rubbing) alcohol
Chapter 8
Kendall/Hunt Publishing Company
11
Critical Information
on Poisons










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 “Criminal Poisoning”
Kendall/Hunt Publishing Company
12
To Prove a Case







Prove a crime was committed
Motive
Intent
Access to poison
Access to victim
Death was caused by poison
Death was homicidal
Chapter 8
Kendall/Hunt Publishing Company
13
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
14
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.
Chapter 8
Kendall/Hunt Publishing Company
15
More Information
Read more about Forensic Toxicology from
Court TV’s Crime Library at:
http://www.crimelibrary.com/criminal_mind/forensic
s/toxicology/2.html
Chapter 8
Kendall/Hunt Publishing Company
16