Chapter 9 Physiology of Alcohol and Poisons © 2012 Cengage Learning. All Rights Reserved

Introduction—Objectives Describe the role of a forensic toxicologist. Discuss the legal importance of blood alcohol levels. Explain the effects of alcohol and specific drugs and poisons on the body. Discuss chemical agents that may be used for bioterrorism. Describe analytical techniques for detection and identification of alcohol, poisons, and toxins in bodily fluids. Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Introduction—Vocabulary depressant—a chemical that slows the heart rate and brain activity and causes drowsiness Immunoassay—a test that relies on the antigen-antibody response Nystagmus—involuntary jerking movement of the eyes Poison—a chemical that can harm the body if ingested, absorbed, or breathed in sufficiently high concentrations Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Introduction—Vocabulary Tolerance—in response to prolonged, heavy intake of alcohol or other drugs, the body’s need for progressively larger amounts of a chemical to cause the same levels of intoxication Toxin—a type of poison produced naturally by living things Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Michael Jackson June 25, 2009, an accidental homicide Homicide—a person died at the hands of another person An overdose of medicines prescribed by Jackson’s doctor, Conrad Murray Coroner’s determination—the interaction of anesthetics and sedatives caused Jackson to stop breathing. 5 Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

History (Obj 9.1) Early 1700’s—first use of chemistry to detect poisons Early 19th century—toxicology became a new scientific discipline France in 1840—Charles Lafarge trial involved testing for arsenic Forensic toxicologists—study the legal and medical aspects of alcohol, drugs, poisons, and toxins in bodily fluids. Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Alcohol (Obj 9.2, 9.3) In everyday speech, alcohol usually refers to the ethanol used in alcoholic beverages. In chemistry, alcohols are a group of substances with a hydroxyl group. Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Alcohol All alcohols are toxic in sufficient quantities As little as 30 mL of methanol can kill Ethanol, ethyl alcohol, is a colorless liquid obtained from fermented grains or fruits Initial reaction to alcohol is euphoria Alcohol is actually a depressant Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Alcohol in the Body Alcohol diffuses through the stomach and small intestines As alcohol concentration increases: ability to respond to stimuli decreases temporary euphoria results from depressing inhibitions lose coordination and become confused memory diminishes Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Alcohol in the Body The liver metabolizes alcohol with an enzyme called alcohol dehydrogenase (ADH) Resulting product is acetaldehyde More enzymes break this into CO2 and H2O The body can metabolize 15 to 30 mL of alcohol per hour Excess alcohol is distributed to body tissues Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Stages of Intoxication A blood alcohol concentration of 0.08 means 8 g of alcohol per 10,000 mL of blood Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Stages of Intoxication Alcohol affects different people differently Concentration Behavior 0.01 to 0.05 Normal behavior 0.03 to 0.12 Euphoria begins 0.09 to 0.25 Vision blurs, loss of balance, sleepiness 0.18 to 0.30 Speech slurs, dizzy, disoriented, emotional Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Stages of Intoxication (cont.) Alcohol affects different people differently Concentration Behavior 0.25 to 0.40 Standing and walking is difficult 0.35 to 0.50 Impaired respiratory and circulatory systems Over 0.45 Potentially fatal Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Stages of Intoxication Factors affecting alcohol absorption Body weight How much alcohol is consumed Over what time period Amount of food in the stomach Frequency of drinking alcohol Body fat percentage Medications and popular energy drinks Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Stages of Intoxication Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Tolerance Metabolic tolerance—the body produces larger amounts of alcohol dehydrogenase Functional tolerance—a person displays fewer visible symptoms of intoxication without affecting blood alcohol concentration Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Field Sobriety Tests Horizontal gaze nystagmus (HGN) test Nystagmus is the involuntary jerking of human eyes, which increases with intoxication Divided-attention tests Breath tests Direct correlation between alcohol in the breath and alcohol in the blood stream Ratio is 1:2100 Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Blood and Urine Tests Toxicology labs use gas chromatography/ mass spectrometry (GC/MS) Gas chromatography separates the sample into individual components Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Poisons (Obj 9.3, 9.4) Eaten (ingested) Inhaled Injected Absorbed 90% - at home, involving children household cleaners Inhaled carbon monoxide sarin, a nerve gas Injected heroin Absorbed Poison sumac, mustard gas, ricin, anthrax Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Drugs Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Toxicological Testing (Obj 9.5) Detect trace amounts of drugs in the blood, urine, and body tissues with thin layer chromatography, gas chromatography, and immunoassay techniques Confirmation is achieved using GC/MS. Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Toxicological Testing Reinsch test—for heavy metal poisoning Certain metals dipped in hydrochloric acid produce a silver-colored coating on copper Emission spectroscopy or atomic absorption spectrophotometry—identifies the specific metal Blood gas screenings—detects level of CO in the blood stream Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Toxicological Testing Immunoassay—measures the level of antibodies produced in response to antigens (poisons) entering the bloodstream EMIT—enzyme-multiplied immunoassay technique Rapidly detects several drugs and their metabolites Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Chapter Summary Poisons are chemicals that harm the body if ingested, inhaled, or absorbed through the skin. Forensic toxicologists investigate the legal and medical aspects of alcohol, drugs, poisons, and toxins in the body; also testifying as expert witnesses, collaborating with the medical examiner, and analyzing evidence. Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Chapter Summary The role of forensic toxicologist also includes: testing employees for drug use, screening athletes for drug use, and testing sexual assault victims for the presence of date rape drugs. In everyday speech, alcohol usually refers to the ethanol used in alcoholic beverages. In chemistry, alcohols are a group of substances with a hydroxyl group. Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Chapter Summary Alcohol is a depressant. Initially, it causes feelings of euphoria. When more is consumed, motor skills become impaired, brain function is depressed, and the person may even lapse into a coma and die. The liver can metabolize about 15 to 30 mL of alcohol per hour. A person becomes intoxicated when consumption exceeds that. Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Chapter Summary When a driver is suspected of intoxication, several field sobriety tests are given Presumptive tests horizontal gaze nystagmus and divided-attention tests Conclusive test breath tests can determine blood alcohol levels. Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved

Chapter Summary How the poison enters the body determines its effect on the body inhaled poisons can cause asphyxia ingested poisons often target specific organs Testing procedures Chromatography techniques, mass spectrometry, and immunoassay are used to detect various poisons and drugs in urine and blood Reinsch test detects heavy-metal poisoning Forensic Science II: Physiology of Alcohol and Poisons, Chapter 9 © 2012 Cengage Learning. All Rights Reserved