Toxicology

ToxicologyThe study of poisons and the

identification of drugs that may have been used for medicinal, recreational, or illegal purposes.

PoisonA 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.

ExposureIngestionInhalationInjectionAbsorption

ExposureCan be:

◦Intentional◦Accidental◦Deliberate

ToxicityThe 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

MurderLess 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 ChronicAcute 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 toxinsPoisonous substances produces

by living organisms.◦Bee Sting◦Snake bite

Bacterial ToxinsBotulism

◦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 ToxinsTetanus

◦Severe muscle spasms◦Often called lockjaw◦1 million deaths per year◦About 5 per year in US---Why?

Heavy Metals and PesticidesPesticides

◦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 PesticidesMercury

◦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 MetalsArsenic

◦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

PesticidesStrychnine

◦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

BioterrorismAnthrax

◦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 FACTS40% of all traffic deaths are

alcohol-relatedIt is the most widely used drugIt’s also the most commonly

abused drug40 billion dollars a year are spent

on alcohol

Alcohol ToxicologyBeer 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 IntoxicationThe Breathalyzer

◦Concerns: mouth alcoholField Sobriety Testing

◦Concerns: SubjectiveBlood Alcohol Level

◦Concerns: convenience; nonalcoholic disinfectant; storage

Legal StatusLegal limit is .08 for private drivers and .04

for commercial driversFifth Amendment rights vs. implied

consentSupreme 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 daysKostov 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 cyanideClaimed seven lives in the

Chicago areaThree additional bottles were

found on the shelvesNever solvedhttp://

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=r2xVAKuhrIU