Transcript Toxicology - PlazaDeals.net

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 Orfila
Mathieu 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
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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
Diagnostic Services, Inc.
941-561-8200 / 800-735-5416
2. Miami Toxicology Testing Service, Inc.
305-593-2260
 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 toxicologyconcentrations 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 cocaineheart 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 arteriesnatural death
• If amount of drug is high-CAD is mild-accidental
Accidental Death
• Accidental poisonings-common in children
• Dose miscalculations or mixtures of drugsmixing 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 deathdifficult task
POISON
A substance taken in sufficient
quantity to cause ill health or death
Specimens for Analysis
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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 Template
Enzyme-Linked Immunosorbant Assay
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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
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control infections
remove bacteria and toxins from the blood
process nutrients, hormones, and drugs
make proteins that regulate blood clotting
produce bile to help absorb fats—including cholesterol—and
fat-soluble vitamins
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ALCOHOL'S TRIP THROUGH THE BODY
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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.
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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 heroinbreaks 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 industryused 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 Poisoning
Arsenic
• 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 Metals
Mercury 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
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Less than ½ of 1% of all homicides results
from poisoning.
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Accidental drug overdoses are more
common.
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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.