Toxicology Flashcards
Toxicology
the study of the adverse effects of chemicals or physical agents on living organisms
environmental toxins are found in
air, water, soil
consumer toxins are found in
food, cosmetics, drugs
POisons
chemicals that can injure or impair body functions
Venoms
substances injected by one species into another
Toxins
mostly described as drugs produced by microorganisms
venoms and toxins are mostly ______ or _____
proteins or polypeptides
what are alkaloids?
drugs of plant origin
many venoms and toxins are _____ (origin)
alkaloids
How long has poison been used
6500+ years
Where was poison the favorite method of assassination
Roman empire
Is intentional poisoning more or less common in the modern era
less common
Where is poison more oftentimes seen (assassination weapon, modern times)
Russia
Acute
single exposure or multiple exposures in a short period of time
chronic
long-term exposure, patient becomes gradually ill
Factors affecting poison
dose, concentration, rate of administration, tolerance, age, route of absorption, state, health, idiosyncrasy, cumulative effect
Toxic substances may be:
COD, contribute to death, impair, explain behavior
What are the classes of poison
gas, inorganic poison, heavy metals, corrosives, alkaloidial poison, non alkaloidial poisons
What is carbon monoxide poisoning
occurs when you inhale too much CO
Why is CO difficult to detect
colorless, odorless, tasteless
How long does it take for someone to die at 1% CO concentration
3 minutes
Why is lead dangerous
interferes nervous system development
what can lead poisoning in children lead to
learning and behavioral disorders
Symptoms of mercury poisoning
sensory impairment, disturbed sensation, lack of coordination
cause of mercury poisoning
fish ingestion
What is arsenic poisoning caused by
ingestion of groundwater with arsenic in it
symptoms of arsenic poisoning
fingernail pigmentation changes and convulsions
Thallium and polonium are both _______ elements
radioactive
How can cyanide enter the body
inhalation, ingestion, or direct skin contact
Where is cyanide most commonly used
executions
What does cyanide damage
internal workings of the cell
How would an ME be able to tell if the COD was cyanide?
blood is a bright cherry red
WHat is strynchnine
plant based rat poison
Why is strychnine hard to disguise
extremely bitter taste
Why is strychnine not typical in suicides
extremely painful
What does strychnine cause
convulsions
How does someone die when they ingestion strychnine
asphyxia
in the context of strychnine, rigor mortis is ____
quick
Where is Ricin found
seeds of castor oil plant
How much Ricin does it take to kill an adult human
just a few grains
How does pesticide poisoning occur
when pesticide interferes with organisms not targeted
examples of common household poisons
bleach, dish soap, antifreeze, laundry detergent, drain openers, oven cleaners, pain relievers
Examples of fatal poisonous plants
nightshades, hemlock, oleander, yew, curare, mistletoe, mushrooms
What do you need in order to prove an intentional poisoning case?
crime was committed, motive, intent, access to poison, access to victim, homicidal death, death caused by poison
What does the degree of toxicity of any substance depend on?
Depends on how much enters your body and over what period (Dosage)
What are the 3 questions that a forensic toxicologist will ask when investigating a case?
“Were they under influence”, “Has this person been making drugs”, “Was it a toxin that killed a person”
Intoxicant
Requires that you ingest a large amount to be lethal
What are some examples of intoxicants
alcohol, CO
Is CO an intoxicant or a poison
Intoxicant
Poison
Requires only a very small amount to kill
Who is involved in the report of how someone died?
Medical examiner finds out how, but a toxicology report is required as well
Where are poisons found (in the body) in a medical examination
fluids and tissue samples
Where are ingested toxins found (decedent)?
Stomach, intestines, or liver
Where are inhaled gases found (decedent)?
Concentrated in lungs
Where are toxins injected into muscle (intramuscularly) found (in a decedent)?
concentrations around the injection site
Where are drugs that are given intravenously found (in a decedent)?
throughout the body, low in stomach + liver and high in the bloodstream
intravenous
Absorbed directly into the blood bypassing the stomach and liver
What are the best tissues to sample for poisons?
Blood, urine, stomach contents
What is the most useful place to look for toxins?
Blood shows chemicals + its metabolites, blood levels show what was going on at TOD
Why is urine useful to look for toxins
easy to obtain, high concentrations will be found if taken due to kidneys filtering toxins
Why are stomach contents useful to look for toxins
digestion stops at the moment of death
Biotransformation
Instantaneously breaking something down into metabolites
metabolites
building blocks of something that was ingested into the body
Best tissues to sample for proteins
liver, vitreous humor, hair, insects
Why is liver good to look for toxins
it’s a toxin sponge and can reflect levels of toxins that blood might not reveal
Why is the vitreous humor good to look for toxins
(eyeball fluid) very slow to decay, retains toxins longer than other organs
Why is hair good to look for toxins
chemicals take about 5 days to show up in the core of a hair shaft (timeline)
Why are insects good for looking for toxins
bioaccumulation occurs when they feed off of decomposed bodies
