Chapter 8 Toxicology Poisons and Alcohol All substances

Chapter 8 Toxicology: Poisons and Alcohol “All substances are poisons. There is none which is not. The right dose differentiates a poison and remedy. ” —Paracelsus (1495 -1541). Swiss physician and chemist Kendall/Hunt Publishing Company

Toxicology and Alcohol Students will learn: N A quantitative approach to toxicology. N The danger of using alcohol. Chapter 8 Kendall/Hunt Publishing Company 1

Toxicology and Alcohol Students will be able to: § § § Chapter 8 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 2

Toxicology Definition—the study of the adverse effects of chemicals or physical agents on living organisms. Types: NEnvironmental—air, water, soil NConsumer—foods, cosmetics, drugs NMedical, clinical, forensic Chapter 8 Kendall/Hunt Publishing Company 3

Forensic Toxicology N Postmortem—medical examiner or coroner N Criminal—motor vehicle accidents (MVA) N Workplace—drug testing N Sports—human and animal N Environment—industrial, catastrophic, terrorism Chapter 8 Kendall/Hunt Publishing Company 4

Toxicology Toxic substances may: N Be a cause of death N Contribute to death N Cause impairment N Explain behavior Chapter 8 Kendall/Hunt Publishing Company 5

Historical Perspective of Poisoners N N 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. N Hieronyma Spara—formed a society to teach women how to murder their husbands N Madame de Brinvilliers and Catherine Deshayes— French poisoners. AND many others through modern times. Chapter 8 Kendall/Hunt Publishing Company 6

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 7

People of Historical Significance Mathieu Orfila—known as the father of forensic toxicology, published in 1814 “Traite 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 8

Aspects of Toxicity N Dosage N The chemical or physical form of the substance N The mode of entry into the body N Body weight and physiological conditions of the victim, including age and sex N The time period of exposure N The presence of other chemicals in the body or in the dose Chapter 8 Kendall/Hunt Publishing Company 9

Lethal Dose N LD 50—refers to the dose of a substance that kills half the test population, usually within four hours N Expressed in milligrams of substance per kilogram of body weight Chapter 8 Kendall/Hunt Publishing Company 10

Toxicity Classes LD 50 (rat, oral) Correlation to Ingestion by 150 lb Adult Human Toxicity <1 mg/kg a taste to a drop extremely 1 -50 mg/kg to a teaspoon highly 50 -500 mg/kg to an ounce moderately 500 -5000 mg/kg to a pint slightly 5 -15 g/kg to a quart practically non-toxic Over 15 g/kg more than 1 quart relatively harmless Chapter 8 Kendall/Hunt Publishing Company 11

Federal Regulatory Agencies N Food and Drug Administration (FDA) N Environmental Protection Agency (EPA) N Consumer Product Safety Commission N Department of Transportation (DOT) N Occupational Safety and Health Administration (OSHA) Chapter 8 Kendall/Hunt Publishing Company 12

Symptoms of Various Types of Poisoning Type of Poison Symptom/Evidence N Caustic Poison (lye) Characteristic burns around the lips and mouth of the victim Red or pink patches on the chest and thighs, unusually bright red lividity Black vomit Greenish-brown vomit Yellow vomit Coffee brown vomit. Onion or garlic odor Burnt almond odor Pronounced diarrhea Nausea and vomiting, unconsciousness, possibly blindness N Carbon Monoxide N N N N Sulfuric acid Hydrochloric acid Nitric acid Phosphorous Cyanide Arsenic, Mercury Methyl (wood) or Isopropyl (rubbing) alcohol Chapter 8 Kendall/Hunt Publishing Company 13

Critical Information on Poisons N N N N N Form Common color Characteristic odor Solubility Taste Common sources Lethal dose Mechanism Possible methods of administration Time interval of onset of symptoms. Chapter 8 N Symptoms resulting from an acute exposure N Symptoms resulting from chronic exposure N Disease states mimicked by poisoning N Notes relating to the victim N Specimens from victim N Analytical detection methods N Known toxic levels N Notes pertinent to analysis of poison N List of cases in which poison was used —John Trestrail from “Criminal Poisoning” Kendall/Hunt Publishing Company 14

To Prove a Case N N N N Prove a crime was committed Motive Intent Access to poison Access to victim Death was caused by poison Death was homicidal Chapter 8 Kendall/Hunt Publishing Company 15

Forensic Autopsy Look for: N Irritated tissues N Characteristic odors N Mees lines—single transverse white bands on nails. Order toxicological screens N Postmortem concentrations should be done at the scene for comparison N No realistic calculation of dose can be made from a single measurement Chapter 8 Kendall/Hunt Publishing Company 16

Human Specimens for Analysis N Blood N Urine N Vitreous Humor of Eyes N Liver tissue N Brain tissue N Kidney tissue N Hair/nails N Bile N Gastric contents Chapter 8 Kendall/Hunt Publishing Company 17

Alcohol—Ethyl Alcohol (C 2 H 5 OH) N Most abused drug in America N About 40% of all traffic deaths are alcohol-related N Toxic—affecting the central nervous system, especially N N N 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% in the liver About 5% is excreted unchanged in breath, perspiration and urine Chapter 8 Kendall/Hunt Publishing Company 18

Rate of Absorption Depends on: N amount of alcohol consumed N the alcohol content of the beverage N time taken to consume it N quantity and type of food present in the stomach N physiology of the consumer Chapter 8 Kendall/Hunt Publishing Company 19

BAC Blood Alcohol Content N Expressed as percent weight per volume of blood N Legal limits in all states is 0. 08% N Parameters influencing BAC: § § Chapter 8 Body weight Alcoholic content Number of beverages consumed Time between consumption Kendall/Hunt Publishing Company 20

BAC N Burn off rate of 0. 015% per hour but can vary: § Male BAC male = 0. 071 x (oz) x (% alcohol) body weight § Female BAC female = 0. 085 x (oz) x (% alcohol) body weight Chapter 8 Kendall/Hunt Publishing Company 21

Henry’s Law N 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. N This ratio of alcohol in the blood to alcohol in the alveolar air is approximately 2100 to 1. In other words 1 ml of blood will contain nearly the same amount of alcohol as 2100 ml of breath. Chapter 8 Kendall/Hunt Publishing Company 22

Field Tests N Preliminary tests—used to determine the degree of suspect’s physical impairment and whether or not another test is justified. N Psychophysical tests— 3 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 23

The Breathalyzer N More practical in the field N Collects and measures alcohol content of alveolar breath N Breath sample mixes with 3 ml of 0. 025 % 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 N 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 24

Generalizations N During absorption, the concentration of alcohol in arterial blood will be higher than in venous blood. N Breath tests reflect alcohol concentration in the pulmonary artery. N The breathalyzer also can react with acetone (as found with diabetics), acetaldehyde, methanol, isopropyl alcohol, and paraldehyde, but these are toxic and their presence means the person is in serious medical condition. N Breathalyzers now use an infrared light absorption device with a digital read-out. Prints out a card for a permanent record. Chapter 8 Kendall/Hunt Publishing Company 25

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, forensic scientists and lawyers. Chapter 8 Kendall/Hunt Publishing Company 26

More Information Read more about Forensic Toxicology from Court TV’s Crime Library at: http: //www. crimelibrary. com/criminal_mind/forensic s/toxicology/2. html Chapter 8 Kendall/Hunt Publishing Company 27