Chapter%206%20Toxicology:%20Poisons%20and%20Alcohol

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Chapter 6 ToxicologyPoisons 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

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Toxicology and Alcohol
Students will learn

• A quantitative approach to toxicology.
• The danger of using alcohol.

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Toxicology and Alcohol
Students 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.

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Toxicology

• Definitionthe study of the adverse effects of
  chemicals or physical agents on living organisms.
• Types
• Environmentalair, water, soil
• Consumerfoods, cosmetics, drugs
• Medical
• Forensic

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Forensic Toxicology

• Postmortemmedical examiner or coroner
• Criminalmotor vehicle accidents (MVA)
• Workplacedrug testing
• Sportshuman and animal
• Environmentindustrial, catastrophic, terrorism

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Toxicology

• Toxic substances may
• Be a cause of death
• Contribute to death
• Cause impairment
• Explain behavior

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Historical Perspective of Poisoners

• Olympiasa famous Greek poisoner
• Locustapersonal poisoner of Emperor Nero
• Lucretia Borgiafather was Pope Alexander VI
• Madame Giulia Toffanacommitted over 600
  successful poisonings, including two Popes.
• Hieronyma Sparaformed a society to teach women
  how to murder their husbands
• Madame de Brinvilliers and Catherine
  DeshayesFrench poisoners.
• AND many others through modern times.

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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

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People of Historical Significance

• Mathieu Orfilaknown 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.

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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

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Lethal Dose

• LD50refers 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

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Death by WaterHold 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

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How much water is too much water?

• 1.5 to 2.0 gallons can be toxic to your body

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Toxicity Classes
LD50 (rat,oral) Correlation to Ingestion by 150 lb Adult Human Toxicity
lt1mg/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
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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)

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Symptoms of Various Typesof Poisoning

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

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Critical Informationon Poisons

• Form
• Common color
• Characteristic odor
• Solubility
• Taste
• Common sources
• Lethal dose
• Mechanism
• Possible methods of administration
• Time interval of onset of symptoms.

• 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
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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

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Forensic Autopsy

• Look for
• Irritated tissues
• Characteristic odors
• Mees linessingle 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

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Human Specimens for Analysis

• Blood
• Urine
• Vitreous Humor of Eyes
• Bile
• Gastric contents

• Liver tissue
• Brain tissue
• Kidney tissue
• Hair/nails

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AlcoholEthyl Alcohol (C2H5OH)

• Most abused drug in America
• About 40 of all traffic deaths are
  alcohol-related
• Toxicaffecting 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
• Detoxificationabout 90 in the liver
• About 5 is excreted unchanged in breath,
  perspiration and urine

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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

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BACBlood Alcohol Content

• Expressed as percent weight per volume of blood
• Legal limits in all states is 0.08
• Parameters influencing BAC
• Body weight
• Alcoholic content
• Number of beverages consumed
• Time between consumption

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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

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Field Tests

• Preliminary testsused to determine the degree of
  suspects physical impairment and whether or not
  another test is justified.
• Psychophysical tests3 Basic Tests
• Horizontal gaze nystagmus (HGN) follow a pen or
  small flashlight, tracking left to right with
  ones 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.

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Implied Consent Law

• Driver must consent to tests or lose license
• Implemented to prevent refusal to take breath
  test on grounds of self incrimination

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Mouth Alcohol

• Alcohol present in a breath test subjects 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

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Forensics 4/1/13

• Welcome back! Any good spring break stories?
• Dont 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)

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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 ?

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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

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Absorption

• Alcohol enters the blood stream by passing across
  the wall of the stomach and small intestine

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Distribution

• The alcohol becomes evenly distributed throughout
  the watery parts of the body (including the blood
  and the brain)

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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

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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

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Henrys 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.

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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

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The Breathalyzer

• More modern breathalyzers dont use chemicals
• 1. Infrared Light Absorption Alcohol present
  in a subjects breath reacts with a particular
  wavelength of inrared light
• 2. The Fuel Cell a chemical reaction involving
  alcohol produces electricity (electrons)

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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.

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Forensics 4/2/13

• Dont 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)

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A man of 185 lbs drinks three shots (1.5 oz/shot)
of Jack Daniels 80 proof (40) in an hour.

• What is his BAC?
• Is it ok for him to drive home? Explain
• What is the BAC if the above person is a woman?
• Why the difference from male to female for BAC?

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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

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Blood Samples

• Clean injection site with non-alcohol astringent
• Need preservative and refrigeration
• Over time alcohol breaks down

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Blood Samples

• Forensic Laboratories use gas chromatography to
  determine blood-alcohol content
• Compare alcohol peaks with KNOWN blood-
  alcohol standards

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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)

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Hair Samples

• Hair is nourished by blood flowing close to the
  hair root
• Drugs present in blood become permanently trapped
  in hairs protein structure
• Can date the presence of drugs dating back over a
  period of weeks, months and sometimes years

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Case Study

• Read the case study Joann Curly Caught by hair
• Answer the following questions as a group
• 1. If Bobbys urine showed high levels of
  thallium in his body, does this indicate recent
  or distant exposure?
• 2. How did investigators determine that Bobby
  wasnt exposed to the poison at work?

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Match the organization to the concerns

• Organizations
• FDA 2) EPA 3) Consumer Product Safety Commission
  4) DOT 5) OSHA
• Concerns
• Toxins in consumer products
• Exposure to chemicals in the work place
• Agricultural and industrial chemicals
• Pharmaceuticals, food additives and medical
  devices
• Shipment of toxic chemicals

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More Information on alcohol

• http//www.intox.com/t-AboutAlcohol.aspx
• http//www.intox.com/t-Physiology.aspx

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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 Childrens Hospital
  Regional Poison Center. In addition, he wrote the
  book, Criminal Poisoning, used as a reference by
  law enforcement, forensic scientists and lawyers.

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More Information

• Read more about Forensic Toxicology from Court
  TVs Crime Library at
• http//www.crimelibrary.com/criminal_mind/forensi
  cs/toxicology/2.html