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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