Forensic Toxicology Toxicology- the study of the chemical and physical properties of toxic substances and their physiological effect on living organisms Forensic Toxicology: includes the measurement of alcohol, drugs and other toxic substances in biological specimens and interpretation of such results in a medicolegal context. Swiss physician Paracelsus ( ) credited with being “the father of modern toxicology.” “All substances are poisons: there is none which is not a poison. The right dose differentiates a poison from a remedy.”

The Dose Makes the Poison An apparently nontoxic chemical can be toxic at high doses. (Too much of a good thing can be bad). Highly toxic chemicals can be life saving when given in appropriate doses. (Poisons are not harmful at a sufficiently low dose). What may be a poison to one Species may be food to another. Ex: some mushrooms are deadly to humans yet birds eat them.

Lethal Doses Source: Marczewski, A.E., and Kamrin, M. Toxicology for the citizen, Retrieved August 17, 2000 from the World Wide Web: Approximate Lethal Doses of Common Chemicals (Calculated for a 160 lb. human from data on rats) ChemicalLethal Dose Sugar (sucrose)3 quarts Alcohol(ethyl alcohol)3 quarts Salt (sodium chloride)1 quart Herbicide (2, 4-D)one half cup Arsenic (arsenic acid)1-2 teaspoons Nicotineone half teaspoon Food poison (botulism)microscopic

Toxicologists: Know the chemical makeup, physiological actions, and byproducts of drugs Understand how drugs are metabolized in the body and the potentially toxic properties of those metabolites Know how these chemicals affect healthy people and people with addictions or illness Recognize the symptoms from the drugs Deaths Investigated by Toxicologists 1.Accidental Poisonings 2.Drug Abuse Cases 3.Suicidal Poisonings 4.Homicidal Poisonings

< 1/2 of 1% of homicides are from poisoning. Acute Poisoning vs Chronic Poisoning Acute: High dose over short period of time Ex: cyanide: fatal 6-8 minutes after ingestion arsenic: fatal within 30 minuts of ingestion Chronic: Low doses over long periods of time producing Gradual symptoms Ex: Mercury Poisoning: “Mad Hatter’s Disease” Lead Poisoning

The Chicago Tylenol murders occurred when seven people died after taking pain-relief capsules that had been poisoned. The poisonings, code-named TYMURS by the FBI, took place in the autumn of 1982 in the Chicago area of the United States. These poisonings involved Extra-Strength Tylenol medicine capsules which had been laced with potassium cyanide.[1] The incident led to reforms in the packaging of over-the-counter substances and to federal anti-tampering laws. The case remains unsolved and no suspects have been charged. A $100,000 reward, offered by Johnson & Johnson for the capture and conviction of the "Tylenol Killer," has never been claimed.

Ethylene glycol is the ingredient that makes antifreeze tasty. Though colorless and odorless, the syrupy alcohol derivative—which is excellent at lowering the freezing points of vital engine fluids—has a sweet taste that jibes well with soda, juice, and other sugary beverages. As many concerned pet owners and parents are well aware, dogs, cats, and kids are prone to lap up puddles of antifreeze left on garage floors. Every year, 90,000 animals and 4,000 children ingest the toxic liquid; if not treated immediately, the consequences of the poisoning can include renal or cardiovascular failure, brain damage, and death. The Black Widow: Antifreeze murder

Jonestown was the informal name for the Peoples Temple Agricultural Project, an intentional community in northwestern Guyana formed by the Peoples Temple, a cult led by Jim Jones. It became internationally notorious when, on November 18, 1978, 918 people died in the settlement as well as in a nearby airstrip and in Georgetown, Guyana's capital. The name of the settlement became synonymous with the incidents at those locations. A total of 909 Temple members died in Jonestown, all but two from apparent cyanide poisoning, in an event termed "revolutionary suicide" by Jones and some members on an audio tape of the event and in prior discussions. The poisonings in Jonestown followed the murder of five others by Temple members at a nearby Port Kaituma airstrip. The victims included Congressman Leo Ryan, the first member of Congress assassinated in the line of duty in the history of the United States. Four other Temple members died in Georgetown at Jones's command. To the extent the actions in Jonestown were viewed as a mass suicide, it is the largest such event in modern history and resulted in the largest single loss of American civilian life in a non-natural disaster until the events of September 11, 2001.[1]

Illegal Drugs vs Controlled Substances Illegal Drug: no currently accepted medical use in the United States Controlled Substance: a legal drug that has restrictions on its sale, possession, and use due to the high potential for abuse. 5 Classes of Controlled Substances: 1. Hallucinogens 2. Narcotics 3. Stimulants 4. Anabolic Steroids 5. Depressants

Hallucinogens: Marijuana, MDMA (ecstasy), LSD, PCP Produce changes in perceptions, thought processes, and mood by interfering with neural pathways and sensory perception Narcotics: Opium, Heroin, Codeine, Morphine, Methadone, Oxycodone -induce sleep and relieve pain by suppressing the central nervous system’s ability to send pain messages to the brain Stimulants: Amphetamines(speed), Cocaine/crack cocaine, Methamphetamines - increase alertness, provide a sense of well-being and Confidence by speeding up functions of the CNS Anabolic Steroids: synthetic testosterone - Promote cell division and tissue growth, leading to muscle growth, but have severe side effects such as depression, anger, destructive behavior. Depressants: Alcohol, barbituates, tranquilizers (valium, xanax) produce mild euphoria followed by drowsiness or reduce anxiety by slowing down the CNS, including brain activity

Toxicological Analysis of Tissue a.Collect sample of all body fluids b.Collect samples from organs and tissues c.A forensic toxicologist cannot simply look for the presence of a toxin or drug in a body, he/she must also understand how the body processes these molecules (which organs, rate of metabolism, etc.) d.Toxicological analysis must start as soon as possible after a person’s deathL 1.Is a drug or poison present? What substance? 2.How much of the substance is present? Is it’s concentration in the body sufficient to cause death? 3.How was the drug/poison administered?

Methods of Detection 1.Color tests with Indicators 2. Chromatography: based on solubility 3.Spectroscopy: study of the absorption and emission of light by matter. Every substance’s reaction to wavelengths of light is unique and can be used to identify the subsance. 4.Ex: some substances “glow” when exposed to UV light Ex: each substance has a unique absorption pattern when exposed to certain wavelenghts of light (see next slide)

Example UV-vis Spectrum Example IR Spectrum

Drugs and Their Dependence…. Psychological dependance--the conditioned use of a drug caused by underlying emotional needs. Physical dependance--need for a drug that has been brought about by its regular use--withdrawl sickness when stopped

Alcohol Ethanol (drinking alcohol)-most commonly abused drug Blood alcohol levels-relate to degree of intoxication--number of grams of alcohol in every 100 ml of blood.08-legal limit for intoxication.4-lethal level

Tests for Alcohol Field Sobriety test- stand on one foot, stand with eyes closed, walk a straight line,…… Breathalyzer test-alcohol passes unchanged through lungs--going to bloodstream into air sacs of lungs Breath test related directly to blood-alcohol level (1/2100 of amt. in blood)