Toxicology: Poisons and Alcohol - PowerPoint Presentation

Slide1

Toxicology: Poisons and Alcohol

ToxicologyToxicology—

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

Forensic ToxicologyPostmortem

—

medical examiner

or coroner

Criminal

—

motor vehicle

accidents (MVA)

Workplace

—

drug testing

Sports

—

human and animal

Environment

—

industrial,

catastrophic, terrorism

Toxic substances may:Be a cause of death

Contribute to death

Cause impairment

Explain behavior

Historical PoisonersOlympias—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.

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

Aspects of Toxicity1. Dosage

2. The chemical or physical form of the substance

3. The mode of entry into the body

4. Body weight and physiological conditions of the victim, including age and sex

5. The time period of exposure

6. The presence of other chemicals in the body or in the dose

Lethal DoseLD

50

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 Classification

Federal Regulatory AgenciesFood and Drug Administration (FDA)Environmental Protection Agency (EPA)

Consumer Product Safety Commission

Department of Transportation (DOT)

Occupational Safety and Health Administration (OSHA)

Symptoms of Various Types of Poisoning

Type of Poison

Symptom/Evidence

Caustic poison (lye)

Characteristic burns around the lips and

mouth of victim

Carbon monoxide

Red or pink patches on the chest and

thigh, unusually bright red

lividity

Sulfuric acid

Black vomit

Hydrochloric acid

Greenish-brown vomit

Nitric acid

Yellow vomit

Phosphorus

Coffee-brown vomit, onion or garlic odor

Cyanide

Burnt almond odor

Arsenic, mercury

Extreme diarrhea

Methyl (wood) or isopropyl

(rubbing) alcohol

Nausea and vomiting, unconsciousness

possibly blindness

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

Human Specimens for AnalysisBloodUrine Vitreous humor of eyes

Bile

Gastric contents

Liver tissue

Brain tissue

Kidney tissue

Hair/nails

Alcohol—Ethyl Alcohol (C2H5OH)Most abused drug in AmericaAbout 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

Rate of Absorption of AlcoholDepends 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

BAC: Blood Alcohol ContentExpressed 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

BAC Calculation

Burn-off rate of 0.015 percent per hour, but can vary:

Male

BAC =

Female

BAC =

0.071



(

oz

)



(% alcohol)

body weight

0.085



(

oz

)



(% alcohol)

body weight

Field TestsPreliminary 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