Chapter 6 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 Toxicology and Alcohol Students will learn:  A quantitative approach to toxicology.  The danger of using alcohol. Chapter 6 1 Toxicology and Alcohol Students will be able to:       Chapter 6 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. 2 Toxicology Definition—the study of the adverse effects of chemicals or physical agents on living organisms. Types:  Environmental—air, water, soil  Consumer—foods, cosmetics, drugs  Medical  Forensic Chapter 6 3 Forensic Toxicology  Postmortem—medical examiner or coroner  Criminal—motor vehicle accidents (MVA)  Workplace—drug testing  Sports—human and animal  Environment—industrial, catastrophic, terrorism Chapter 6 4 Toxicology Toxic substances may:  Be a cause of death  Contribute to death  Cause impairment  Explain behavior Chapter 6 5 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 6 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 6 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 6 8 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 6 9 Lethal Dose  LD50—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 6 10 Death by Water Hold your wee for a wii  In 2007, a mother tried to win a wii game for her son at a radio show contest  Contestants had to drink a water bottle every 5 minutes without using the bathroom  The mother died of water poisining Chapter 6 11 How much water is too much water?  1.5 to 2.0 gallons can be toxic to your body Chapter 6 12 Toxicity Classes LD50 (rat,oral) Correlation to Ingestion by 150 lb Adult Human Toxicity <1mg/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 15g/kg more than 1 quart relatively harmless Chapter 6 13 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 6 14 Symptoms of Various Types of Poisoning Type of Poison Symptom/Evidence  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  Carbon Monoxide        Sulfuric acid Hydrochloric acid Nitric acid Phosphorous Cyanide Arsenic, Mercury Methyl (wood) or Isopropyl (rubbing) alcohol Chapter 6 15 Critical Information on Poisons           Form Common color Characteristic odor Solubility Taste Common sources Lethal dose Mechanism Possible methods of administration Time interval of onset of symptoms. Chapter 6  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 “Criminal Poisoning” 16 To Prove a Case        Prove a crime was committed Motive Intent Access to poison Access to victim Death was caused by poison Death was homicidal Chapter 6 17 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 6 18 Human Specimens for Analysis  Blood  Urine  Vitreous Humor of Eyes  Bile  Gastric contents Chapter 6  Liver tissue  Brain tissue  Kidney tissue  Hair/nails 19 Alcohol—Ethyl Alcohol (C2H5OH)  Most abused drug in America  About 40% 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% in the liver About 5% is excreted unchanged in breath, perspiration and urine Chapter 6 20 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 6 21 BAC Blood Alcohol Content  Expressed as percent weight per volume of blood  Legal limits in all states is 0.08%  Parameters influencing BAC:     Chapter 6 Body weight Alcoholic content Number of beverages consumed Time between consumption 22 BAC  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 6 23 Chapter 6 24 Field Tests  Preliminary tests—used to determine the degree of suspect’s physical impairment and whether or not another test is justified.  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 6 25 Implied Consent Law Driver must consent to tests or lose license Implemented to prevent refusal to take breath test on grounds of self incrimination Chapter 6 Mouth Alcohol  Alcohol present in a breath test subject’s mouth  Presence of mouth alcohol causes the concentration detected in exhaled breath to be higher then the actual blood concentration  Sources include  Regurgitation  Belching  Recent intake of an alcoholic beverage  Recent gargling of alcohol containing mouthwash Chapter 6 Forensics 4/1/13  Welcome back! Any good spring break stories?  Don’t forget to turn in extra credit assignment  Midterm Friday: includes CH 6 quiz (toxicology) CH. 8 blood, CH. 5 Drugs  CH 6 supp questions are due this Fri 4/5/12 (Bring your textbook Wednesday) Chapter 6 28 Case Study Read the Case Study: Death by Tylenol  Answer the following questions as a group: 1. Where did this event take place? 2. What is Product Tampering ? 3. How do you think the investigators determined the capsules contained a quantity of poison “ten thousand times what was needed to kill an average person” ? Chapter 6 29 The Metabolism of alcohol  Metabolism: The transformation of a chemical in the body to other chemicals to facilitate its elimination from the body Happens in three steps: absorption, distribution and elimination Chapter 6 30 Absorption  Alcohol enters the blood stream by passing across the wall of the stomach and small intestine Chapter 6 31 Distribution  The alcohol becomes evenly distributed throughout the watery parts of the body (including the blood and the brain) Chapter 6 32 Elimination  Alcohol is eliminated in two ways: 1.oxidation: the combination of alcohol with oxygen to produce carbon dioxide and water (oxidation occurs in the liver) 2. excretion: elimination of alcohol from the body in an unchanged state (breath and urine) 95% of consumed alcohol eliminated through oxidation Chapter 6 33 Alveoli  Small sacks in the lungs that exchange oxygen, carbon dioxide and other gases with the blood  Carbon dioxide and other volatile chemicals (alcohol) are then expelled through the nose and mouth Chapter 6 34 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 2100 to 1. In other words 1 ml of blood will contain nearly the same amount of alcohol as 2100 ml of breath. Chapter 6 35 The Breathalyzer  More practical in the field  Collects and measures alcohol content of alveolar breath  Breath sample mixes with 3 ml of 0.025 % K2Cr2O7 in sulfuric acid and water 2K2Cr2O7 + 3C 2H5OH + 8H 2SO4  2Cr2(SO4)3 + 2K2SO4 + 3CH3COOH + 11 H2O  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 6 36 The Breathalyzer  More modern breathalyzers don’t use chemicals 1. Infrared Light Absorption: Alcohol present in a subject’s breath reacts with a particular wavelength of inrared light 2. The Fuel Cell: a chemical reaction involving alcohol produces electricity (electrons) Chapter 6 37 Generalizations  During absorption, the concentration of alcohol in arterial blood will be higher than in venous blood.  Breath tests reflect alcohol concentration in the pulmonary artery.  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.  Breathalyzers now use an infrared light absorption device with a digital read-out. Prints out a card for a permanent record. Chapter 6 38 Forensics 4/2/13  Don’t forget to bring your textbook Wednesday/Thursday so that you can work on your CH 6 questions and prepare for your midterm Friday!  Midterm Friday: Primarily on CH 6 with questions from CH 5 (drugs) and CH 8 (blood) Chapter 6 39 A man of 185 lbs drinks three shots (1.5 oz/shot) of Jack Daniels 80 proof (40%) in an hour. 1. What is his BAC? 2. Is it ok for him to drive home? Explain 3. What is the BAC if the above person is a woman? 4. Why the difference from male to female for BAC? Chapter 6 Rank from most to least intoxicated and explain your reasoning. John 200lb had eight 8oz drinks on a full stomach. Frank 170 lb had four 8oz drinks on an empty stomach Gary 240 lb had six 8oz drinks on an empty stomach Stephan 180 lb had six 8oz drinks on a full stomach Chapter 6 Blood Samples  Clean injection site with non-alcohol astringent  Need preservative and refrigeration  Over time alcohol breaks down Chapter 6 Blood Samples  Forensic Laboratories use gas chromatography to determine blood-alcohol content Compare alcohol peaks with KNOWN bloodalcohol standards Chapter 6 43 Hair samples  The only viable option if it is necessary to ascertain whether a subject has been abusing a drug over a longer period of time ( drugs remain in blood stream for 24 hours and in urine for up to 72 hours) Chapter 6 44 Hair Samples  Hair is nourished by blood flowing close to the hair root  Drugs present in blood become permanently trapped in hair’s protein structure  Can date the presence of drugs dating back over a period of weeks, months and sometimes years Chapter 6 45 Case Study  Read the case study: Joann Curly: Caught by hair  Answer the following questions as a group: 1. If Bobby’s urine showed high levels of thallium in his body, does this indicate recent or distant exposure? 2. How did investigators determine that Bobby wasn’t exposed to the poison at work? Chapter 6 46 Match the organization to the concerns Organizations 1) FDA 2) EPA 3) Consumer Product Safety Commission 4) DOT 5) OSHA Concerns a. Toxins in consumer products b. Exposure to chemicals in the work place c. Agricultural and industrial chemicals d. Pharmaceuticals, food additives and medical devices e. Shipment of toxic chemicals Chapter 6 More Information on alcohol  http://www.intox.com/t-AboutAlcohol.aspx  http://www.intox.com/t-Physiology.aspx Chapter 6 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, forensic scientists and lawyers. Chapter 6 49 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 6 50