Transcript File

Toxicology
• The science dealing with the effects, antidotes,
detection, etc., of poisons
• A toxicologist is one who studies the nature and
effects of poisons and their treatment.
How can we detect toxins?
• Toxins are difficult to find
because they are metabolized
quickly to metabolites (ex.
Heroin  morphine)
– Blood – Concentrations
of medications and drugs
within the blood are
proportional with the
levels of intoxication and
with levels that can
potentially kill a person.
The Liver
– Liver – Forensic investigators
can measure drug
concentrations in the liver
since many drugs, especially
opiates, can be found in the
liver and bile, even when blood
tests yield no presence of
drugs. The liver may show drug
concentration during the hours
prior to death, and the bile may
tell what drugs were present in
the system during the past
three to four days. However,
neither test is accurate.
The stomach
– Stomach contents – Getting stomach contents is
crucial where criminal investigators suspect
poisoning or drug overdose. Concentrations of any
drugs found in the stomach are not necessarily
proportional with their levels in the blood and thus
their effects on an individual.
Hair and Insects
– Hair – Hair has the unique ability of providing an
intoxication timeline for many toxic substances
including lead, arsenic, and other heavy metals.
– Insects – Forensic scientists may test insects that eat
up dead bodies for drugs in the event of severely
decomposed bodies. Since particular drugs tend to
reside in the tissues of these bugs, they may provide
information about whether a drug was present in the
victim.
The eyes
• Vitreous Humor – In
severely decomposed bodies,
this fluid may be what is left
of a body that can be tested.
Concentration levels of
drugs within the vitreous
humor may lag behind the
drug concentration levels
found in blood by about 1 to
2 hours. Therefore, testing
the vitreous humor reveals
the concentration of a toxic
substance in the blood 1 to 2
hours prior.
Urine
• Urine – Since the kidneys serve as a major
depot for the body's drug and toxin elimination
routes, forensic medical examiners/toxicologists
can many times find such toxic substances in
greater concentrations in the urine. However,
the relation between urine concentration of a
drug and its effects in the body lacks proportion.
Common Poisons
CYANIDE
• Symptoms: coma, seizures, cardiac arrest, in low
doses, giddiness, shortness of breath, weakness,
fatigue
• Administration: ingestion, inhalation (house
fires), or absorbed through the skin
• Odor: light almond scent
• Action: denatures the enzyme that produces
ATP in the mitochondria – chemical suffocation
Inhalation
• House fires can cause furniture coverings, carpets and
some clothing can release cyanide when it burns
• Hydrogen cyanide poisoning is hard to distinguish from
carbon monoxide poisoning.
– Hydrogen cyanide inhalation will result in difficulty breathing,
the person gasping for air even when he/she is brought out
to fresh air.
– With carbon monoxide poisoning he/she may simply feel
sleepy but breath normally.
The use of Cyanide in the fishing
industry
• Fisherman often use potassium cyanide and other
poisons to stun and capture valuable reef fish. Divers
squirt a cyanide solution from bottles directly onto fish
resting on corals, killing the corals and stunning the
fish. The fish often escape into crevices and the
fishermen have to break apart the coral to get to their
paralyzed prey. With this technique not only the fish are
poisoned, but also the coral polyps and other creatures
in the area. Places where cyanide was spread will first
form black slime, then they will just become dead coral
rock.
CYANIDE
World War II
• Perhaps the most insidious use of cyanide
occurred during World War II.
– German concentration camp directors ordered
captives to enter air tight chambers where hydrogen
cyanide was introduced into the ventilation system.
• There have also been claims that former Iraqi
president Saddam Hussein used hydrogen
cyanide gas to kill thousands of Kurds during an
uprising in the late 1980s.
After intense street-to-street
combat, when Soviet troops
were spotted within a block or
two of the Reich Chancellory in
the city centre, Hitler committed
suicide in the Führerbunker on
April 30, 1945 by means of a
self-delivered shot to the head
(it is likely he simultaneously bit
into a cyanide ampoule).
Hitler's body and that of Eva
Braun (his long-term mistress
whom he had married the day
before) were put in a bomb
crater, partially burned with
gasoline by Führerbunker aides
and hastily buried
STRYCHNINE
• Administration:inhalation, swallowing or
absorption through eyes or mouth.
• Action: Death from asphyxiation caused by
paralysis of the brain's breathing apparatus
• Symptoms: muscles spasm, with continuous
painful convulsions, rigor mortis sets in
immediately!
• Commonly used as a pesticide
Strychnine tree found in Southeast
Asia
Mushrooms
• The Death Cap
NO MUSHROOM is
worthier of fear than
the terribly poisonous
Death Cap (Amanita
phalloides). This single,
widespread species of
mushroom is solely
responsible for the
majority of fatal and
otherwise serious
mushroom poisoning
cases
"but I thought it was edible…"
• most known victims
to date were natives
of Laos, Cambodia,
Vietnam who
apparently mistake
Death Caps for edible
"Paddy-Straw"
mushrooms.
Mushrooms
• Action: inhibit the production of specific
proteins within liver and kidney cells
• Symptoms: nausea, vomiting, abdominal pain,
and diarrhea, followed by a brief period of
apparent improvement, but without treatment,
severe liver damage and kidney failure > death
Ethylene glycol
• Administration: usually accidental, due its sweet
taste, children and animals will sometimes ingest
large quantities (also homeless alcoholics)
• Symptoms: intoxication, dizziness, leading to
hypertension, kidney failure
• Action: buildup of oxalic acid
Mmmmm…
Tasty!!
Lethal dose =
100ml
Oxalic Acid
• Symptoms:Irritates the lining of the gut and can
lead to bleeding in the mouth & cardiac arrest,
bloody urine, convulsions
• Action:removes calcium from blood, blocks
kidney tubules
• In nature: found in most plants, notably rhubarb,
black pepper
Insulin
• Action: increased insulin level causes
glucose absorption and storage in cells,
too much can lead to acute or
prolonged hypoglycemia > brain
damage / death
• Administration: injection
Why abuse it?
• On July 23, 2004, news reports
claimed that a former spouse
of a prominent international
track athlete said that, among
other drugs, the ex-spouse had
used insulin as a way of
'energizing' the body. The
intended implication would
seem to be that insulin has
effects similar to those alleged
for some steroids.
Anthrax
Anthrax
• In nature: caused by a common soil bacterium
found in sheep and cattle
• Action: attacks lymphatic system, severe internal
bleeding
• Symptoms: flu-like symptoms for several days,
followed by severe respiratory collapse. If not
treated soon after exposure, inhalational anthrax
has near 100% mortality
Arsenic
Arsenic
• highly favored poison, for it is odorless,
easily incorporated into food and drink …
• Until 1836 – Marsh test
• Action: disrupts ATP production
• Death from multi-system organ failure, red
mucus due to severe hemorrhaging
Arsenic
• Arsenic is one of the most
important environmental global
toxicants that cause acute and
chronic adverse health effects,
including cancer. In many countries
exposure to arsenic is a daily
occurrence because of its
environmental pervasiveness and
millions of people around the
world have been, and are, exposed
to arsenic through geologically
contaminated drinking water.