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Toxicology
Toxicology
The study of poisons and the
identification of drugs that may have been
used for medicinal, recreational, or illegal
purposes.
Poison
A naturally occurring or manufactured
substance that can cause severe harm or
death
◦ A toxin is a subgroup of poisons that are
naturally produced by bacteria, plants, or
animals.
Exposure
Ingestion
Inhalation
Injection
Absorption
Exposure
Can be:
◦ Intentional
◦ Accidental
◦ Deliberate
Toxicity
The degree to which a substance is
poisonous.
◦ Depends on a variety of factors:
Dose
THE DOSE MAKES THE POISON
Duration
Method of exposure
Individual factors
Murder
Less than one percent of homicides result
from poisoning.
Most common agents are arsenic, cyanide,
strychnine, and fertilizers.
Accidental overdoses are much more
common.
Acute or Chronic
Acute poisoning is caused by a high dose
in a short time which produces
immediate symptoms.
◦ Cyanide
Chronic poisoning is lower doses over a
longer time which produce gradual
symptoms
◦ Mercury or Lead
DID YOU KNOW?
Saliva based drug tests are just as
accurate as urine based tests.
If two people use the exact same amount
of a drug the person with darker hair will
retain more of the drug in their hair.
Organic toxins
Poisonous substances produces by living
organisms.
◦ Bee Sting
◦ Snake bite
Bacterial Toxins
Botulism
◦ Most poisonous biological agent known
◦ Neurotoxin that paralyzes muscles
◦ Toxic in small amounts
◦ If caught early an antitoxin is available
◦ From contaminated food or bacterial spores
◦ Current uses????
Bacterial Toxins
Tetanus
◦ Severe muscle spasms
◦ Often called lockjaw
◦ 1 million deaths per year
◦ About 5 per year in US---Why?
Heavy Metals and Pesticides
Pesticides
◦ Accumulate in fat causing anxiety, seizures,
twitching, weakness, sweating, diarrhea, rapid
heartbeat, coma, and death
Lead
◦ Nausea, stomach pain, headache, weight loss,
anemia, kidney problems, seizure, coma, death
Heavy Metals and Pesticides
Mercury
◦ Acute---flu like symptoms
◦ Chronic: personality changes, irritability, memory and balance problems, damage to gums, teeth, and mouth. Can cause death.
Cyanide
◦ Fatal in 6-8 minutes
◦ Weakness, confusion, coma, and pink skin
◦ Almond odor
◦ Used in manufacturing of precious metals
Heavy Metals
Arsenic
◦ Within 30 minutes produces nausea, stomach
pain, vomiting, diarrhea, difficulty speaking,
kidney failure, convulsions, death
◦ Chronic exposure causes skin lesions, pigment
changes, personality changes, nausea and
vomiting, convulsions, and coma.
◦ Found in metal finishing, some pesticides and
insecticides, and treating wood
Pesticides
Strychnine
◦ Spasms, increased temperature, convulsions,
and rigor mortis within minutes.
◦ Found in pesticides
Bioterrorism
Ricin
◦ Results from production of castor oil.
◦ Tiny amount can be fatal
◦ Can be inhaled, ingested, or injected
◦ Prevents cells from making proteins which
causes cell death
◦ Symptoms appear 6-8 hours later.
Fever, cough, nausea, vomiting, bloody urine, low
blood pressure, hallucinations, convulsions, death
Bioterrorism
Anthrax
◦ Caused by a bacteria
◦ Human to human transmission has not been
reported.
◦ Inhalation—most fatal type. More than 70%
die with treatment
◦ Ingestion—25-60% fatal
◦ Skin---20% of untreated cases result in death.
Causes a painless black sore
Alcohol FACTS
40% of all traffic deaths are alcohol-
related
It is the most widely used drug
It’s also the most commonly abused drug
40 billion dollars a year are spent on
alcohol
Alcohol Toxicology
Beer is absorbed more slowly than other
alcohol because of the carbohydrates.
Alcohol is absorbed faster on an empty
stomach.
Alcohol is broken down by the liver at a
rate of .015% per hour (but this varies
person to person)
Highest Blood Alcohol level is 30-90
minutes after your last drink
Testing for Intoxication
The Breathalyzer
◦ Concerns: mouth alcohol
Field Sobriety Testing
◦ Concerns: Subjective
Blood Alcohol Level
◦ Concerns: convenience; nonalcoholic
disinfectant; storage
Legal Status
Legal limit is .08 for private drivers and .04
for commercial drivers
Fifth Amendment rights vs. implied consent
Supreme court ruled that your 5th
amendment right applies only to testimonial
evidence not physical evidence
SC also ruled that it constitutes “an
emergency circumstance” and that waiting
for a warrant could destroy evidence.
Markov and Kostov (1978)
Markov (political writer) was injected with ricin while walking.
Modified umbrella was used to administer the poison.
Died after three days
Kostov was poisoned ten days earlier but survived because the poison lodged in a muscle which prevented it from circulating.
http://www.pbs.org/wnet/secrets/umbrella-assassin-watch-full-episode/1549/
Tylenol tampering (1982)
Laced with cyanide
Claimed seven lives in the Chicago area
Three additional bottles were found on
the shelves
Never solved
http://www.nbcnews.com/video/nightly-
news/29021271#29021271
Stella Nickell (1986)
Laced Excedrin with cyanide to kill her
husband for his life insurance.
Placed three additional bottles in the
Seattle store to make it look random.
Killed one additional woman, Susan Snow
Sentenced to 99 years in prison.
https://www.youtube.com/watch?v=r2xVA
KuhrIU