Toxicology • The science dealing with the nature and effects of poisons (antidotes , detection, etc .) • A toxicologist is one who studies the nature and effects of poisons and their treatment.
Toxicology
• The science dealing with the nature and
effects of poisons (antidotes, detection, etc.)
• 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– 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– Hair – Hair has the unique ability of
providing an intoxication timeline for many
toxic substances including lead, arsenic, and
other heavy metals.
Insects– 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 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
CYANIDE
Inhalation
• House fires can cause furniture coverings, carpets and some clothing to 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 breathe normally.
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 Chancellery in
the city center, 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
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.