Toxicology: Poisons and Alcohol
This presentation is the property of its rightful owner.
Sponsored Links
1 / 28

Toxicology: Poisons and Alcohol PowerPoint PPT Presentation


  • 93 Views
  • Uploaded on
  • Presentation posted in: General

Toxicology: Poisons and Alcohol. Objectives. You will understand: The danger of using alcohol. A quantitative approach to toxicology. Objectives, continued. You will be able to: Discuss the connection of blood alcohol levels to the law, incapacity, and test results.

Download Presentation

Toxicology: Poisons and Alcohol

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Toxicology poisons and alcohol

Toxicology: Poisons and Alcohol


Objectives

Objectives

You will understand:

The danger of using alcohol.

A quantitative approach to toxicology.

Kendall/Hunt Publishing Company


Objectives continued

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.

Kendall/Hunt Publishing Company


Toxicology

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

Kendall/Hunt Publishing Company


Forensic toxicology

Forensic Toxicology

Postmortem—medical examiner

or coroner

Criminal—motor vehicle

accidents (MVA)

Workplace—drug testing

Sports—human and animal

Environment—industrial,

catastrophic, terrorism

Kendall/Hunt Publishing Company


Toxicology1

Toxicology

Toxic substances may:

Be a cause of death

Contribute to death

Cause impairment

Explain behavior

Kendall/Hunt Publishing Company


Historical perspective of poisoners

Historical Perspective of Poisoners

Olympias—a famous Greek poisoner

Locusta—personal poisoner of Emperor Nero

Lucretia Borgia—father was Pope Alexander VI

Madame GiuliaToffana—committed over 600 successful poisonings, including two popes

HieronymaSpara—formed a society to teach women how to murder their husbands

Madame de Brinvilliers and CatherineDeshayes—French poisoners

AND many others through modern times.

Kendall/Hunt Publishing Company


The severity of the problem

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

Kendall/Hunt Publishing Company


People of historical significance

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

Kendall/Hunt Publishing Company


Aspects of toxicity

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

Kendall/Hunt Publishing Company


Lethal dose

Lethal Dose

LD50refers 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

Kendall/Hunt Publishing Company


Toxicity classification

Toxicity Classification

Kendall/Hunt Publishing Company


Federal regulatory agencies

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)

Kendall/Hunt Publishing Company


Symptoms of various types of poisoning

Symptoms of Various Types of Poisoning

Type of Poison

Caustic poison (lye)

Carbon monoxide

Sulfuric acid

Hydrochloric acid

Nitric acid

Phosphorus

Cyanide

Arsenic, mercury

Methyl (wood) or isopropyl

(rubbing) alcohol

Symptom/Evidence

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

Kendall/Hunt Publishing Company


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

Critical Information

—John Trestrail from Criminal Poisoning

Kendall/Hunt Publishing Company


To prove a case

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

Kendall/Hunt Publishing Company


Forensic autopsy

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.

Kendall/Hunt Publishing Company


Human specimens for analysis

Blood

Urine

Vitreous humor of eyes

Bile

Gastric contents

Liver tissue

Brain tissue

Kidney tissue

Hair/nails

Human Specimens for Analysis

Kendall/Hunt Publishing Company


Alcohol ethyl alcohol c 2 h 5 oh

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

Kendall/Hunt Publishing Company


Rate of absorption

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

Kendall/Hunt Publishing Company


Bac blood alcohol content

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

Kendall/Hunt Publishing Company


Bac calculation

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

Kendall/Hunt Publishing Company


Henry s law

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.

Kendall/Hunt Publishing Company


Field tests

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

Kendall/Hunt Publishing Company


The breathalyzer

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.

Kendall/Hunt Publishing Company


Generalizations

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.

Kendall/Hunt Publishing Company


People in the news

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.

Kendall/Hunt Publishing Company


More information

More Information

Read more about forensic toxicology at truTV’s Crime Library:

http://www.crimelibrary.com/criminal_mind/forensics/toxicology/2.html

Kendall/Hunt Publishing Company


  • Login