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.