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