Forensic Toxicology

Toxicology

•(from the Greek word toxicos meaning "poisonous" •-logos (-ology) = the study of•Toxicology is the study of the adverse effects of chemicals on living organisms.•It is the study of symptoms, mechanisms, treatments and detection of poisoning, especially the poisoning of people.

Forensic Toxicology

• Forensic toxicology-includes measurement of alcohol, drugs and other toxic substances in biological specimens and interpretation of results in a medicolegal context.

• Drug article…goto DEA

• http://www.justice.gov/dea/pubs/states/newsrel/2010/mia012910.html

Who is the Father of Toxicology?

Mathieu OrfilaMathieu Joseph Bonaventure Orfila

The modern father of toxicology, having given the subject its first formal treatment in 1813 in his Traité des poisons, also called Toxicologie générale

16th century physician Paracelsus

“All substances are poisons; there is none which is not a poison. The right dose differentiates a poison from a remedy.”

Forensic Toxicology

• Accidental Poisoning• Drug Abuse/Overdose• Suicidal/Homicidal Poisoning• Rate of Reaction in body• Recovery rates

Metabolism• Metabolism-transformation of one chemical into

another by the body-producing metabolites

• An individual’s metabolism is unique from any other person.

• How fast/slow you metabolize food, drugs, alcohol or anything else put in your system is unique to you.

• People with particular diseases (like Diabetes, respiratory disease, thyroid, cancer many others) metabolize substances differently.

Respiratory Disease

Alzheimer’s Disease

Who needs a toxicology report?

• If the techies on CSI: Miami can whip up toxicological statements in no time, why does it take so darn long in the real world?

• BACKLOG (to many cases going to one lab at a time NOTE: not all agencies have a toxicology unit)

• STAFF SHORTAGE• If you need expert testimony in a trial, an

expert has to handle/TEST the substances

HOW MANY LABS ARE THERE?

• It depends on the state!!• FLORIDA= 2• FLORIDA

1. Fort Myers 2. Miami Toxicology Testing Service, Inc.Diagnostic Services, Inc. 305-593-2260941-561-8200 / 800-735-5416

Labs in the US and Canada for confirmatory drug testing after screen testing are limited.

What do they usually test?• Labs typically like to collect at least

– 25 mL of heart blood– 10 mL of peripheral blood (RBC, WBC, Platelets)– 50-gram tissue samples of brain, liver, and kidney– SEM of RBC, WBC and Platelets

Scanning electron microscope 10x to 250x (10 to 500,000 times the size)By order of magnitude (10x 100x 1000x…etc)

Blood from the heart

Medical Examiner

• ME collects fluids and tissues from the body for toxicological analysis

• Example: Heroin is made form morphine and when injected into bloodstream-converted back to morphine

Collecting Samples

• Blood-most useful in toxicology-concentrations of medicines and drugs in blood relate with levels of intoxication

• Urine-workplace drug testing-cannot determine if drug exerted any effect on individual at time of collection

• Stomach Contents-Poison or drug ingestion cases

Collecting Samples

• Liver-involved in drug metabolism-many drugs (opiates) concentrate in the liver and bile even when blood shows no traces

• Vitreous humor-liquid in the eyeball-resistant to putrefaction (decay)-drug levels lag behind those found in blood by two hours-testing it shows concentration of toxin in blood two hours earlier

Collecting Samples

• Hair-absorbs heavy metal (arsenic, lead) toxins-provides intoxication timeline for many of these substances

• Insects-Test insects that feed on corpses for drugs

What do they look for?• An analyst then carries out an alcohol screening and a

generalized immunoassay (concentration of drug) test, which can detect broad-based drug groups like opiates or tranquillizers.

• In the event of a positive drug test, the analyst must complete a confirmation procedure, designed to ferret out the exact nature of the offending substance.

• Next, a supervisor reviews the analyst's report and either approves the conclusions or requests more tests.

• This whole process, barring glitches or lengthy tests for hard-to-detect drugs like neuromuscular blockers (Fentanyl/Flaxedil), could take just a couple of days if analysts were able to devote themselves exclusively to a well-preserved specimen.

Who get priority?

• THE LIVING get priority.• Deceased people get lower priority

because their life does not depend on it.• Many times a toxicology report will be

screened for unknown substances so that a cure can be given to a victim

• Data needed for court date may have higher priority

Natural Death• Ex. Coronary artery disease (CAD) takes cocaine-

heart rate increases-heart attack-

• Cause of Death-heart attack

• Contributory factor-cocaine

• ME-extent of heart disease, amount of drugs present,whether heart attack occurred

• If amount of drug is low-severely distressed arteries-natural death

• If amount of drug is high-CAD is mild-accidental

Accidental Death

• Accidental poisonings-common in children

• Dose miscalculations or mixtures of drugs-mixing prescription sedatives and alcohol

Suicidal Deaths

• Suicide-most common manner of death in poisonings-carbon monoxide-most common

• Prescription drugs

• CULT SUICIDES– 11-18-78 (918) People’s Temple- Jonestown,

Guyana “Don’t drink the KoolAid”

– 3-26-97 (39) Heaven’s Gate- San Diego, CA ingested Arsenic in pudding…

Homicide Deaths

• Homicidal poisonings are uncommon

• Determining poisoning to be cause of death-difficult task

POISON

A substance taken in sufficient quantity to cause ill health or death

Specimens for Analysis

• Adipose Tissue Insecticides, Thiopental• Bile Codeine, Morphine• Blood Alcohols, CO• Brain Volatile Poisons• Kidney Heavy metal• Liver Most Toxicants• Lung Methadone, Gases, Inhalants• Stomach/Intestine Contents All toxicants taken orally• Urine Most Toxicants• Vitreous Humor Digoxin, electrolytes, glucose

ELISA TemplateEnzyme-Linked Immunosorbant Assay

• Uses antibodies and enzymes to bind to drug of interest

• Qualitative, not quantitative• Specific

Well Plates• Come pre-coated with specific drug antigens• Add sample• Add conjugate, incubate

– Antibody-enzyme complex that binds primary antibody– For drug testing, drugs will occupy that spot so the

conjugate cannot bind• Wash plate, add substrate (produces color change if

bound to conjugate)• Add stop, stops reaction from continuing, read plate with UV-Vis

Results:

• A clear well indicates the presence of the drug (The drug bound to the plate, prevented conjugate from binding so substrate couldn’t bind and produce a color change)

• A yellow well indicates the absence of the drug (conjugate bound to plate, substrate bound and produced color change)

• Negative Calibrators, +/- Controls, and Cutoff Calibrator

Interpreting Drug Tests

• Need to know if drug caused or contributed to victim’s death

• Route of entry of toxin-concentration of drug is greatest at site where it’s administered

Interpreting Drug Tests

• Ingested Toxins-in stomach, intestines, liver

• Inhaled gases-lungs

• IM Injected Toxins-Drugs most concentrated around injection site

• IV Drugs-enter bloodstream directly-high concentrations in blood, but none in stomach or liver

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

Alcohol

• Ethanol-drinking alcohol-most commonly abused drug

• Blood-alcohol levels-relate to degree of intoxication-grams percent-number of grams of alcohol in every 100 ml of blood

• 0.08-is the illegal limit for intoxication

• 0.40-lethal level

CIRRHOSIS-irreversible damage to a vital organ or tissue

• Alcohol causes cirrhosis of the liver

Cirrhosis is A condition in which the liver slowly deteriorates and

malfunctions due to chronic injury. Scar tissue replaces healthy liver tissue, partially blocking the flow of blood through the liver. Scarring also impairs the liver’s ability to

1. control infections 2. remove bacteria and toxins from the blood 3. process nutrients, hormones, and drugs 4. make proteins that regulate blood clotting 5. produce bile to help absorb fats—including cholesterol—and fat-

soluble vitamins

• ALCOHOL'S TRIP THROUGH THE BODY

• 1 MOUTH: Alcohol is consumed. • 2 STOMACH: Alcohol gets right into the stomach. A

little of it goes through the wall of the stomach and into the bloodstream but most of the alcohol goes down into the small intestine.

• 3 SMALL INTESTINE: Most of the alcohol then goes through the walls of the intestine and into the bloodstream.

• 4 BLOODSTREAM: The bloodstream then carries the alcohol to all parts of the body, such as the brain, heart and liver.

• 5 LIVER: As the bloodstream carries the alcohol around the body, it carries it through the liver. The liver changes the alcohol into water, carbon dioxide, and energy-oxidation. The liver can oxidize (change) only about one-half ounce of alcohol an hour, or .015%. This means that until the liver has time to oxidize all of the alcohol, the alcohol keeps on passing through all parts of the body, including the brain.

• 6 BRAIN: Alcohol goes to the brain almost as soon as it is drunk. The bloodstream carries it there. It keeps passing through the brain until the liver has had time to oxidize all the alcohol.

Tests for Alcohol

• Field Sobriety test-stand on one foot, stand with eyes closed, walk 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

• GC –to determine blood-alcohol level

Breathalyzer Test

• Breath is exposed to water, silver nitrate in sulfuric acid, and potassium dichromate

• Alcohol in the air oxidizes into acetic acid-destroying potassium dichromate in proportion to the amount of alcohol

• Spectrophotometer-measures absorption of light wavelength by remaining potassium dichromate

• As potassium dichromate is destroyed-amount of light it absorbs decreases

• Spectrophotometer measures this change and the degree of change relates to the amount of alcohol in the breath

Schematic diagram of a Breathalyzer Courtesy Draeger Safety, Inc., Breathalyzer Division,

Durango, Colo.

Figure 6-9  To use this diagram, lay a straightedge across your weight and the number of ounces of liquor you’ve consumed on an empty or full stomach. The point where the edge hits the right-hand column is your maximum blood-alcohol level. The rate of elimination of alcohol from the bloodstream is approximately 0.015 percent per hour. Therefore, to calculate your actual blood-alcohol level, subtract 0.015 from the number in the right-hand column for each hour from the start of drinking.

Figure 6-12  The combination of the gas chromatograph and the mass spectrometer enables forensic toxicologists to separate the components of a drug mixture and provides specific identification of a drug substance.

• Blood-Alcohol levels increase post-mortem due to bacteria

• ME tests level in vitreous humor-1-2 hour lag behind blood-alcohol level

Heroin Addiction

• Toxicologist does not test directly for heroin-breaks down into acetylmorphine and then morphine

• ME -pulmonary edema-water in lungs

• Evidence of talc crystals and cotton fibers –used to cut and filter heroin

• February 1, 2006: DEA arrested 22 Heroin Traffickers based out of Colombia used puppies to smuggle drugs. Drug traffickers surgically implanted packets of liquid heroin in dogs

9,291 kilograms of seized cocaine set ablaze by DEA ensuring the drug never reached the street.

Crack Cocaine

• Powder cocaine is dissolved in a solution of sodium bicarbonate and water.

• Solution is boiled and a solid substance separates from the boiling mixture

• Solid substance-crack- is removed and allowed to dry. • The crack cocaine is then broken or cut into "rocks," each

weighing from one-tenth to one-half of a gram. • Crack rocks-75% and 90% pure cocaine. • Crack is smoked-high in less than 10 seconds-immediate and

euphoric effect -crack became popular in the mid 1980s. • Crack is inexpensive both to produce and to buy.

Crack Smoking Equipment

Crack Cocaine

• Powder cocaine is dissolved in a solution of sodium bicarbonate and water.

• Solution is boiled and a solid substance separates from the boiling mixture

• Solid substance-crack- is removed and allowed to dry. • The crack cocaine is then broken or cut into "rocks," each

weighing from one-tenth to one-half of a gram. • Crack rocks-75% and 90% pure cocaine. • Crack is smoked-high in less than 10 seconds-immediate and

euphoric effect -crack became popular in the mid 1980s. • Crack is inexpensive both to produce and to buy.

• Crack demo - step 1 - heating water and dissolving cocaine HCl

• Crack demo -step 2 -addition of bicarbonate

• Crack demo - step 2 (continued) - addition of bicarbonate

• Crack demo - step 3 - conversion of cocaine to base

• Crack demo - cooling converted cocaine

• Crack demo –cocaine base filtrate

Crack demo -filtering cocaine base

Crack Cocaine

Hazards of Cocaine Use

• Disturbances in hearth rhythm and heart attacks

• Chest pain and respiratory failure

• Strokes, seizures and headaches

• Gastrointestinal complications such as abdominal pain and nausea.

Cyanide Poisoning

• Cyanide-gas or hydrogen cyanide (HCN)-used for executions

• Victim’s blood is bright red

• In exhaust of vehicles, in tobacco smoke, and in smoke of burning nitrogen-containing plastics

• Produced in large quantities by chemical industry-used in tempering steel, dying, explosives, engraving, the production of acylic plastics and other chemical products

Ethylene glycol

• Antifreeze-favorite beverage of alcoholics if can’t get ethanol

• Breaks down into oxalic acid which causes oxalate crystals to develop in brain and kidneys

Heavy Metal PoisoningArsenic

• Found in pesticides, laundry aids, tobacco smoke, smog, kelp, table salt, beer, seafood and drinking water.

• High risk-pesticide production, agricultural insecticide spraying, copper smelting, mining, and metallurgical industries

• Cause gastrointestinal injury

• Liver, kidney, brain, and neural damage

Heavy MetalsMercury Poisoning

• From broken mercury thermometers, broken fluorescent light bulbs, dental amalgam fillings, mercury containing latex paints, extraction of gold from ore using mercury

• Cause gastrointestinal injury

• Liver, kidney, brain, and neural damage

Lead Poisoning

• Most common sources of lead poisoning in U.S. children-deteriorated lead-based paint in older homes and high levels of lead-contaminated house dust

• Lead paint is present in about 24 million U.S. homes.

• Cause gastrointestinal injury

• Liver, kidney, brain, and neural damage

Drugs and Poisons Stats

• Less than ½ of 1% of all homicides results from poisoning.

• Accidental drug overdoses are more common.

• More than 50% of the federal prison population and about 20% of the population in state prisons consist of drug offenders.

Controlled Substances—Narcotics

Narcotics reduce pain and can be very addictive

Controlled Substances—Pesticides and Heavy Metals

Pesticides mostly are used to protect plants or food crops. Metal compounds are very poisonous.

Controlled Substances—Pesticides and Heavy Metals

Metal compounds can damage many organs in the body.