Toxicology Poisons and Alcohol Toxicology Poisons and Alcohol

Toxicology: Poisons and Alcohol

Toxicology: Poisons and Alcohol Objectives You will understand: The danger of using alcohol. A quantitative approach to toxicology. Chapter 8 Kendall/Hunt Publishing Company 2 2

Toxicology: Poisons and Alcohol 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. Chapter 8 Kendall/Hunt Publishing Company 3 3

Toxicology: Poisons and Alcohol 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 Chapter 8 Kendall/Hunt Publishing Company 4 4

Toxicology: Poisons and Alcohol Forensic Toxicology Postmortem—medical examiner or coroner Criminal—motor vehicle accidents (MVA) Workplace—drug testing Sports—human and animal Environment—industrial, catastrophic, terrorism Chapter 8 Kendall/Hunt Publishing Company 5 5

Toxicology: Poisons and Alcohol Toxicology Toxic substances may: Be a cause of death Contribute to death Cause impairment Explain behavior Chapter 8 Kendall/Hunt Publishing Company 6 6

Toxicology: Poisons and Alcohol Historical Perspective of Poisoners Olympias—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. Chapter 8 Kendall/Hunt Publishing Company 7 7

Toxicology: Poisons and Alcohol 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 Chapter 8 Kendall/Hunt Publishing Company 8 8

Toxicology: Poisons and Alcohol 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 Chapter 8 Kendall/Hunt Publishing Company 9 9

Toxicology: Poisons and Alcohol 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 Chapter 8 Kendall/Hunt Publishing Company 10 10

Toxicology: Poisons and Alcohol Lethal Dose LD 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 Chapter 8 Kendall/Hunt Publishing Company 11 11

Toxicology: Poisons and Alcohol Toxicity Classification LD 50 (rat, oral) Correlation to Ingestion by Toxicity 150 -lb Adult Human <1 mg/kg a taste to a drop Relatively harmless 1– 50 mg/kg to a teaspoon Practically nontoxic 50– 500 mg/kg to an ounce Slight 500– 5, 000 mg/kg to a pint Moderate 5– 15 g/kg to a quart High Over 15 g/kg more than 1 quart Extreme Chapter 8 Kendall/Hunt Publishing Company 12 12

Toxicology: Poisons and Alcohol 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) Chapter 8 Kendall/Hunt Publishing Company 13 13

Toxicology: Poisons and Alcohol Symptoms of Various Types of Poisoning Type of Poison Symptom/Evidence Caustic poison (lye) 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 Carbon monoxide Sulfuric acid Hydrochloric acid Nitric acid Phosphorus Cyanide Arsenic, mercury Methyl (wood) or isopropyl (rubbing) alcohol Chapter 8 Kendall/Hunt Publishing Company 14 14

Toxicology: Poisons and Alcohol Critical Information Form Common color Characteristic odor Solubility Taste Common sources Lethal dose Mechanism Possible methods of administration Time interval of onset of symptoms Chapter 8 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 —John Trestrail from Kendall/Hunt Publishing Company Criminal Poisoning 15 15

Toxicology: Poisons and Alcohol 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 Chapter 8 Kendall/Hunt Publishing Company 16 16

Toxicology: Poisons and Alcohol 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. Chapter 8 Kendall/Hunt Publishing Company 17 17

Toxicology: Poisons and Alcohol Human Specimens for Analysis Blood Liver tissue Urine Brain tissue Vitreous humor of eyes Kidney tissue Bile Hair/nails Gastric contents Chapter 8 Kendall/Hunt Publishing Company 18 18

Toxicology: Poisons and Alcohol—Ethyl Alcohol (C 2 H 5 OH) 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 Chapter 8 Kendall/Hunt Publishing Company 19 19

Toxicology: Poisons and Alcohol 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 Chapter 8 Kendall/Hunt Publishing Company 20 20

Toxicology: Poisons and Alcohol 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 Chapter 8 Kendall/Hunt Publishing Company 21 21

Toxicology: Poisons and Alcohol BAC Calculation Burn-off rate of 0. 015 percent per hour, but can vary: Male BAC = 0. 071 (oz) (% alcohol) body weight Female BAC = 0. 085 (oz) (% alcohol) body weight Chapter 8 Kendall/Hunt Publishing Company 22 22

Toxicology: Poisons and Alcohol 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. Chapter 8 Kendall/Hunt Publishing Company 23 23

Toxicology: Poisons and Alcohol 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 Chapter 8 Kendall/Hunt Publishing Company 24 24

Toxicology: Poisons and Alcohol 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 K 2 Cr 2 O 7 in sulfuric acid and water: 2 K 2 Cr 2 O 7 +3 C 2 H 5 OH + 8 H 2 SO 4 2 Cr 2(SO 4)3 + 2 K 2 SO 4 + 3 CH 3 COOH + 11 H 2 O 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. Chapter 8 Kendall/Hunt Publishing Company 25 25

Toxicology: Poisons and Alcohol 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. Chapter 8 Kendall/Hunt Publishing Company 26 26

Toxicology: Poisons and Alcohol 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 De. Vos 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. Chapter 8 Kendall/Hunt Publishing Company 27 27

Toxicology: Poisons and Alcohol More Information Read more about forensic toxicology at tru. TV’s Crime Library: http: //www. crimelibrary. com/criminal_mind/forensics/toxicol ogy/2. html Chapter 8 Kendall/Hunt Publishing Company 28 28