Jan 18, 2016
Forensic Toxicology
The study and practice of the application of toxicology to the purposes of the law
Began in 19th Century
Types:
Environmental—air, water, soil
Consumer—foods, cosmetics, drugs
Medical, clinical, forensic
Poison.. What is it?Any substance that causes
injury, illness, or death especially by chemical means.
“All Things are poison and nothing (is) without poison; only the dose makes that a thing is no poison.”
Paracelsus 1493-1541
Earliest Record of Poison
339 BC Socrates execution- extract of hemlock (plant related to the carrot. Contains an alkaloid similar to nicotine effects the nervous system.
Using poisons became an art; like to use ones with no trace, because it looked as if people died from natural causes
Where Toxicology occurs
Postmortem—medical examiner or coroner
Criminal—motor vehicle accidents (MVA)
Workplace—drug testing
Sports—human and animal
Environment—industrial, catastrophic, terrorism
Post-Mortem Forensic ToxDetermines the absence or presence of
drugs & their metabolites.Chemicals such as ethanol and other
volatile substances, CO and other gases, metals & other toxic chemicals in human fluids & tissues & evaluates their role as a determinant or contributory factor in the cause & manner of death.
Historical Perspective of Poisoners
Locusta—personal poisoner of Emperor Nero
Lucretia Borgia—father was Pope Alexander VI
She used a ring with poison. She “killed” her lovers and her fathers political “enemies”.
Madame Giulia Toffana—responsible for over 600 successful poisonings, including two popes She sold the “Toffana Water” to women who wanted to kill their husbands (lead, arsenic, belladona) [1600’s]
Hieronyma Spara—
formed a society to teach women how to murder their husbands (arsenic)
To aid women to inherit money (1600’s)
Father of Toxicology
Mathieu Orfila—
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
Aspects of ToxicityDosageThe chemical or physical form of the
substanceThe mode of entry into the bodyBody weight and physiological
conditions of the victim, including age and sex
The time period of exposureThe presence of other chemicals in the
body or in the dose
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
Toxicity ClassificationLD50 (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
Symptoms of PoisoningType of Poison
Carbon monoxide
Sulfuric acid
Hydrochloric acid
Nitric acid
Phosphorus
Cyanide
Arsenic,
mercury
Symptom/Evidence
Red or pink patches on the chest &
thigh, unusually bright red lividity
Black vomit
Greenish-brown vomit
Yellow vomit
Coffee-brown vomit, onion or garlic odor
Burnt almond odor & slow breathing
Extreme diarrhea & Nausea and vomiting, unconsciousness, possibly blindness
Impaired speech, lose of vision, pins and needles feelings
Lead Poisoning
Lead- not highly poisonous, chronic exposure can cause health risks (more in children than adults)
More than 400,000 children under 6 have higher than normal blood levels of lead which can lead to brain damage, memory loss and decrease critical thinking skills
Where is Lead found?
Most common: Lead based PaintsLead is sweet, children would teethed on
windowsills1992 passed a law houses had to disclose if
they used lead based paintLead-gasoline – still remains in soilLead pipes- if water is acidic lead can be
leached from metalLead crystal should not be used to store
acidic foods or drinks
What can it do to your body?
Lead poisoning can causeBrain damageAffecting memory & thought processes