Forensic Toxicology

Forensic Toxicology

• Definition:

• The science of detecting and identifying the presence of drugs and poisons in body fluids, tissues, and organs.

Controlled Substances Act

• Federal Law established 5 schedules of classification of controlled substances based on– Drug’s potential for abuse– Potential to physical and

psychological dependence– Medical Value

• Note: Federal law also controls materials that are used in making drugs and those that are manufactured to resemble drugs

Prison sentences in US

• Highest in world

• 750 out of 100,00 people

• 70% are drug abuse cases

Drug Schedules

• Schedule I: • Drugs with high potential for abuse and

addiction, NO medical valueEx: Heroin, LSD, Ecstasy, Marijuana

• Schedule II: • Drugs with high potential for abuse and

addiction, have some medical value with restrictionsEx: Cocaine, Amphetamines

Drug Schedules

• Schedule III: • Drugs with less potential for abuse and

addiction, currently acceptable for medical useEx: Codeine, Steroids

• Schedule IV: • Drugs with low potential for abuse and

addiction, currently acceptable for medical useEx: Tranquilizers like Valium

Drug Schedules

• Schedule V:

• Drugs with low potential abuse, medical use, lowest potential dependency

• Ex: Some Opiates with Non-Narcotic Ingredients

Poisonous chemicals introduced in body• Arsenic

• Cadmium

• Nickel

• lead

How do folks get drugs

• From legal medicine

• From over 18 folks

• From peers (most common)

• From adults at home (prescriptions)

How are drugs taken in

• Under skin

• Pills orally in mouth

• IV – heroin

• Sniffed cocaine

Withdrawal symtoms

• Restless, muscle pain

• Insomnia, diarrhea

• Cold sweat, dilated pupils

• Tremors, panic

• Shallow breathing

• stroke

People who died of overdose• Know which drug:

• Jim Morrison

• Janis Joplin

• John Belushi

Mixing drugs

• Pure cocaine – from coca plant

• Crack cocaine – mixed

• Speed ball – an upper (cocaine) plus a downer (heroin)

How do drugs work

• Some are hallucigens like LSD

• Causes changes in emotions, thinking, memory

• From fungus- LSD is odorless, colorless, tasteless- eaten as a capsule

Norcotics

• Feel No pain

• Like heroin, morphine

• Happy, dizzy, drowsy, not hungry, pupils drawn towards each other, cannot use rest room, heart races

Cocaine

• Appetite suppressant

• Initial euphoria

• Lose weight

• Can stay awake

• Very expense

Crack cocaine

• Cheaper

• Very dangerous

• Causes heart attacks

• Most hospital cases for drug abuse

Marijuana – to legalize or not to legalize• Plant has more than 60 different

chemicals called cannabinoids that can give a high

• Has receptor in brain

• More in the frontal lobes, induces deep sleep

• No receptors in brain stem

Marijuana continued

• Receptors in spleen- reduces stress

• Does not cause overdose

• The receptors the cannabinoids bind to is used by a normal endorphin, Anandamoids

• Used throughout history as pain killers

Anandamoids

• An endorphin (natural pain killer)

• Induced naturally by activity such as in pregnancy- when fetal cells bind to uterus

• Making love

• Eating spicy foods, chocolate

• Endorphins also called runners high

Marijuana continued

• Deaths per year due to marijuana use = 0

• Deaths per year due to alcohol overdose – 331

• Be able to argue 2 reasons why it should be legal and 2 reasons why it should not be legal

Toxicology samples

• blood

• 2 consecutive urine samples– Some drugs take a while to show up in

urine (1-3 days)

• Vitreous humor (fluid behind eye)

• Hair samples

Color Tests

• Marquis Test: – Turns purple in the presence of Heroin,

morphine, opium – Turns orange-brown in presence of

Amphetamines

• Scott Test: Three solutions

– Blue then pink then back to blue in the presence of Cocaine

• Duquenois-Levine: – Test for marijuana –turns purple

More Analytical Tests

• Chromatography: separate drugs/tentative ID

• Mass Spectrometry: chemical “fingerprint” no two drugs fragment the same

Why?

• Think of all the people that you have “heard” do drugs.

• US drug manufacturers produce enough barbiturates and tranquilizers each year to give every person in the US 40 pills

• (that’s about 12 billion pills)• 18,000 out of 44,000 annual traffic deaths

are alcohol related and send over 2 million people to the hospital

Toxicology of Alcohol

• Alcohol intoxication depends on– Amount of alcohol consumed– Time of consumption– Body weight– Rate of alcohol absorption

Fate of Alcohol

• Alcohol is absorbed into the bloodstream

• Distributed through-out the body’s water

• And finally eliminated by oxidation and excretion

Analysis of BAC

• Breath Tests

• Field Sobriety Tests

• Blood Tests

Breath Tests

• A breath test reflects the alcohol concentration in the pulmonary artery.

• One instrument used for breath tests is called The Breathalyzer.

• The Breathalyzer is a device for collecting and measuring the alcohol content of alveolar breath.

The Breathalyzer

Field Sobriety Testing

• Two reasons for the field sobriety test:

1. Used as a preliminary test to ascertain the degree of the suspect’s physical impairment

2. To see whether or not an evidential test is justified.

Field Sobriety Tests

• Horizontal Gaze Nystagmus– Involuntary eye jerk as eye moves horizontally

• Walk and Turn (divided attention tasks)• One-Leg Stand

Parts of the brain affected by Alcohol• Alcohol 1st

affects the forebrain and moves backward

• Last affected is medulla oblongata

Alcohol and the Law• 1939-1964:

intoxicated = 0.15% BAC

• 1965: intoxicated = 0.10% BAC

• 2003: intoxicated = 0.08% BAC

At least we don’t live in France, Germany, Ireland, or Japan (0.05%) or especially Sweden (0.02%)!

Alcohol and the Law

• Try the drink wheel: http://www.intox.com/wheel/drinkwheel.asp

A nerve cell

http://learn.genetics.utah.edu/content/addiction/drugs/• Go to this site

• go to the middle of the page and click on Mouse Party

• Place each mouse in the chair to know

• 1. how the drug works in the brain

• 2. what does the drug do to the person