Download presentation
Presentation is loading. Please wait.
Published byAlan Lloyd Modified over 9 years ago
1
6-1 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein FORENSIC TOXICOLOGY Chapter 6
2
6-2 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Introduction Toxicologists: detect and identify drugs and poisons in body fluids, tissues, and organs identify a drug overdose or monitor the intake of drugs work in crime laboratories, medical examiners’ offices, hospital laboratories and health facilities measure the amount of alcohol or other abused drugs in the body for violations of criminal law
3
6-3 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Role of Toxicologist The toxicologist uses general screening procedures with the hope of narrowing thousands of possibilities to one, if the victim does not present any symptoms. A drug analyst may have gram or milligram quantities to work with, but the toxicologist must work with nanogram or microgram amounts ➡ Due to drugs being distributed throughout the body
4
6-4 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Role of Toxicologist Must be prepared to assess the toxicity of the drug or poison. Toxicity - The degree to which a substance (a toxin or poison) can harm humans or animals.
5
6-5 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Collection and Preservation of Toxicological Evidence In the deceased, the following may be collected: blood organ tissue vitreous humor (liquid in the eye) gastric contents
6
6-6 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Collection of Toxicological Evidence In living victims blood and urine are collected.
7
6-7 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Techniques Used in Toxicology Toxicologists must detect, isolate and identify a toxic substance. Drug extraction is based on the acidity and basicity of drugs.
8
6-8 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Acids and Bases An acid a compound that donates H + ion to another compound - Example: acetic acid CH 3 COO-H A base is a compound capable of accepting a hydrogen ion - Example: NH 3 Techniques Used in Toxicology
9
6-9 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein
10
6-10 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Techniques Used in Toxicology Water is neutral with a pH of 7 A drug can be recovered by changing the pH of water Acidic drugs are extracted from an acidified water solution (pH < 7) Basic drugs are extracted from a basic water solution (pH > 7)
11
6-11 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Over-the-Counter Drugs Can cause accidental poisoning or even death OTC drugs include: - alcohol - aspirin - antacids - other pain relievers - nicotine
12
6-12 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein OTC Drugs Drugs can be detected in overdosed victims by acidified and basic solutions. A color change may be observed Carbon dioxide gas may also be produced
13
6-13 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Alcohol Statistics Ethyl alcohol is the most heavily abused drug in Western countries. 40% of all traffic deaths in the US, are alcohol related.
14
6-14 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Toxicology of Alcohol Alcohol effects the central nervous system, particularly the functions of the brain. The analysis of alcohol demonstrates: A second objective of forensic toxicology—to determine influence of drugs on human behavior.
15
6-15 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Metabolism of Alcohol Metabolism – the transformation of a chemical to other chemicals to aid in its elimination from the body Metabolism consists of three steps: Absorption Distribution Elimination
16
6-16 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Metabolism of Alcohol Alcohol appears in the blood within minutes after it has been taken by mouth Slowly increases in concentration while it is being absorbed from the stomach and the small intestine into the bloodstream. Absorption – passage of alcohol across the wall of the stomach and small intestine into the bloodstream
17
6-17 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Question Name four factors that determine the rate at which alcohol is absorbed into the bloodstream.
18
6-18 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein
19
6-19 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Metabolism of Alcohol Factors such as time taken to consume the drink, the alcohol content, the amount consumed, and food present in the stomach determine the rate at which alcohol is absorbed. As the alcohol is circulated by the bloodstream, the body begins to eliminate it. Alcohol is eliminated by two mechanisms -oxidation - excretion
20
6-20 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Metabolism of Alcohol Oxidation – the combination of oxygen with other substances to produce new products Excretion – elimination of alcohol from the body in an unchanged state; alcohol is normally excreted in breath, urine and perspiration.
21
6-21 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Alcohol Levels Is measured as the quantity of alcohol present in the blood (BAC) or the alcohol content in the breath The amount of alcohol exhaled in the breath is directly proportional to the alcohol concentration in the blood https://www.youtube.com/watch?v=zXjANz9r5F0
22
6-22 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein 22 BAC: Blood Alcohol Content Expressed as percent weight per volume of blood Legal limit in all states is 0.08 percent The average elimination or “burn-off” rate of alcohol is about 0.015 percent w/v per hour Parameters influencing BAC: Body weight Alcohol content Number of beverages consumed Time since consumption
23
6-23 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein 23 BAC Calculation BAC = N oz x % alcohol x 0.075 - ( 0.015 x hr drinking) body weight Video Example
24
6-24 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein
25
6-25 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Metabolism of Alcohol
26
6-26 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein
27
6-27 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Alcohol & Circulatory System Humans have a closed circulatory system consisting of a heart, arteries, veins, and capillaries.
28
6-28 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Alcohol & Circulatory System Alcohol is absorbed from the stomach and small intestines into the blood stream. Alcohol is carried to the liver where the process of its destruction starts.
29
6-29 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Alcohol & Circulatory System Blood, carrying alcohol, moves to the heart and is pumped to the lungs.
30
6-30 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Alcohol & Circulatory System In the lungs, CO 2 and alcohol leave the blood and O 2 enters the blood in the air sacs known as alveoli. Then CO 2 and alcohol are exhaled during breathing.
31
6-31 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Testing for Intoxication
32
6-32 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein 1. Breath Testers – Light Absorption Device Breath testers are designed to analyze alveolar breath. The captured breath is exposed to infrared light. The infrared light source allows the instrument to measure the (BAC) in the captured breath. Other breath testing devices use fuel cells. https://www.youtube.com/watch?v= rvVzlg26bCM
33
6-33 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein 2. Field Testing Police officers use field sobriety tests to: estimate a motorist’s degree of physical impairment by alcohol
34
6-34 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Field Testing Three major field tests: 1.Horizontal gaze nystagmus test – (involuntary jerking of the eye) 2.Walk and turn 3.One-leg stand All considered reliable and effective psychophysical tests. Video1Video Video 2 Video 3
35
6-35 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein
36
6-36 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Field Testing A portable, handheld, roadside breath tester can be used to determine a preliminary BAC.
37
6-37 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein 3. Collection of Blood A confirmation blood test is always performed Blood must always be drawn under controlled conditions by qualified personnel. A nonalcoholic disinfectant must be applied before the suspect is stuck with a sterile needle. The blood is collected in a glass tube that contains anticoagulant/preservative and is refrigerated.
38
6-38 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Collection and Preservation of Blood Anticoagulant - a substance that prevents clotting of blood Preservative – stops the growth of microorganisms in blood Blood clot
39
6-39 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein 3. The Analysis of Blood for Alcohol A confirmation blood test is always performed 3. Gas chromatography is used to determine blood alcohol levels. The resultant alcohol peak is compared to ones obtained with known blood-alcohol standards The alcohol level can be calculated.
40
6-40 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein
41
6-41 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Techniques Used in Toxicology Once a drug has been extracted, a toxicologist will take a 2-step approach: 1.Screening Test - A large number of drug samples can be analyzed in a short time 2. Confirmation Test - Results from screening test are verified with confirmation tests
42
6-42 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Techniques used in Toxicology 1.Screening Tests (3 widely used) Thin-layer chromatography Gas chromatography Immunoassay Based on specific drug antibody reactions
43
6-43 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein 2.Confirmation Tests Gas chromatography/mass spectrometry (test of choice) Infrared Spectrophotometry
44
6-44 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein
45
6-45 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein
46
6-46 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Amy Winehouse
47
6-47 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Question Using iPad, search for symptoms of alcohol poisoning, and what causes death?
48
6-48 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Collecting Samples for Drug Tests 1.Blood Tests 2.Urine Tests 3.Hair Testing Drugs become permanently entrapped in hair’s hardening protein structure As hair grows, the drug’s location on hair shaft becomes a time marker for drug intake Drug use can be dated back to a period of weeks, months, or even years, depending on hair’s length
49
6-49 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Detecting Nondrug Poisons
50
6-50 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Arsenic has been called “The King of Poisons”, for its discreetness and potency – it was virtually undetectable, so it was very often used either as a murder weapon or as a mystery story element. But that’s until the Marsh test came and signaled the presence of this poison in water, food and the like. However, this king of poisons has taken many famous lives: Napoleon Bonaparte and Simon Bolivar to name a few. On another note, arsenic, like belladonna, was used by the Victorians for cosmetic reasons. A couple of drops of the stuff made a woman’s complexion white and pale.
51
6-51 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Cyanide seems to be extremely popular (spies use cyanide pills to kill themselves when caught) and there are plenty of reasons for this. Firstly, it is found in a great variety of substances like almonds, apple seeds, apricot kernel, tobacco smoke, insecticides, and pesticides. Murder in this case can be blamed on a household accident, such as ingestion of pesticide – a fatal dose of cyanide for humans is 1.5 mg per kilogram of body weight. Secondly, it’s a rapid killer: depending on the dose, death occurs within 1 to 15 minutes. Hydrogen cyanide gas was used by Nazi Germany for mass murders in gas chambers during the Holocaust.
52
6-52 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein The deadliest snake is a Belcher's Sea-snake. It takes only 0.02 milligrams of venom to kill a person. They usually injects around 35 milligrams and that can kill around 15,000 people with one bite. Death can happen within 2 minutes.
53
6-53 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein An estimated 12,000 people die annually from Cobra bites in India. It is possible that under the right conditions a person could die from a cobra bite in 30 minutes
54
6-54 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein http://modernsurvivalblog.com/survival- skills/the-4-deadly-poisonous-snakes-in- america/http://modernsurvivalblog.com/survival- skills/the-4-deadly-poisonous-snakes-in- america/
55
6-55 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Carbon Monoxide Carbon monoxide poisoning can happen when fires, stoves, heaters or ovens are used in rooms, huts which do not have proper ventilation to let the gas out.
56
6-56 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Incidence CO is leading cause of poisoning deaths in industrialized countries. CO may be responsible for half of all poisonings worldwide. ~5,000–6,000 people die annually in the United States as a result of CO poisoning. ~40,000–50,000 emergency department visits annually result from CO poisoning. Source: Hampson NB. Trends in the incidence of carbon monoxide poisoning in the United States. Am J Emerg Med. 2005;23:838-841
57
6-57 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein What Is Carbon Monoxide? CO is a compound of Carbon and Oxygen One atom carbon to one atom oxygen Colorless Odorless Tasteless POISONOUS Gas
58
6-58 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Where Does It Come From? CO is Produced by the Incomplete Combustion of Various Fuels, Including: Coal Wood Oil Natural Gas Charcoal Kerosene Propane Note production of CO from the fire on right
59
6-59 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Common Causes of Incomplete Combustion Smoldering Fires Burning Wet Wood Burning Green Wood Lack of O 2 During Combustion Malfunctioning Appliances Malfunctioning Exhaust Systems
60
6-60 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Common Sources of Carbon Monoxide Pollution WATER HEATERS & FURNACES FIREPLACES
61
6-61 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Sources (Cont.) VEHICLE EXHAUSTSMOKING INDOORS
62
6-62 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein The Hidden Dangers of CO Carbon Monoxide Poisoning is the Most Common Exposure Poisoning in the United States Carbon Monoxide is Not Easily Recognized Because the Signs and Symptoms Are Similar to Those of Other Illness Causes Sudden Illness and Death
63
6-63 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Carbon Monoxide in the Body Normally oxygen binds to hemoglobin in red blood cells. When CO enters the body: -it binds to hemoglobin If too much CO is binding to hemoglobin, then oxygen cannot bind, and cannot be carried to tissues. Death by asphyxiation occurs. Hemoglobin
64
6-64 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Prevent Accidental CO Poisoning List of DO’s DETECTORS UNITS WITH DIGITAL READOUT BETTER THAN UNITS WITHOUT DO- Install a Battery- operated CO Detector In Your Home – check or replace the battery when you change the time on your clocks each spring and fall If the Detector Sounds Leave Your Home Immediately and Call 911.
65
6-65 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Detecting Nondrug Poisons Heavy metals Once commonly encountered in criminal cases of murder They include: - Arsenic - Bismuth - Antimony - Mercury Video1 Video2
66
6-66 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Detecting Heavy Metals To detect heavy metals: 1.Reinsch test The suspected body fluid containing sample will be dissolved in hydrochloric acid and a copper strip is inserted Appearance of silver or dark coating on copper indicates presence of heavy metal
67
6-67 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Significance of Toxicological Findings For many drugs, blood concentration levels are readily determined and can be used to estimate the pharmacological effects on the individual. Urine is a poor indicator of how extensively an individual’s behavior is influenced by the drug. Drugs can be found in the urine one to three days after being taken Urine is still valuable
68
6-68 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Alcohol and Law To prevent a person’s refusal to take a test for alcohol consumption, the National Highway Traffic Safety Administration recommended an “implied consent” law. Adopted by all states by 1973, this law states that the operation of a motor vehicle on a public highway automatically carries with it the stipulation that a driver will submit for a test for alcohol intoxication if requested or be subject to loss of the license.
69
6-69 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein Schmerber v. California Issue of unreasonable search and seizure by police Police seized blood sample from Schmerber without a search warrant The Court said the blood was taken in a justly, medical manner Process of collecting evidence is judged only on case-by-case basis.
70
6-70 PRENTICE HALL ©2008 Pearson Education, Inc. Upper Saddle River, NJ 07458 FORENSIC SCIENCE An Introduction By Richard Saferstein End of Chapter 6
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.