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

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