Forensic Toxicology

Forensic Science Unit 13

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Am I Legally Intoxicated? o Answer the question at the top of

the Handout and show your teacher.

o  For Homework- use the link on the handout to go to the Blood Alcohol Calculator. Enter your information, fill out the sheet and answer the questions.

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What is toxicology? o Toxicology is the study of drugs

and poisons, and their interactions with or effects on the body

o Forensic Toxicology is the application of toxicology to the law, including n Workplace or Forensic Drug

Testing n Postmortem Toxicology n Human Performance Testing 3

History of Toxicology o Socrates was one of the earliest

reported victims of poisoning, by hemlock, in 399 BC.

o By the 17th century, it was not uncommon for rich European families to use poisoning as a means of settling disputes. n Arsenic became known as

“inheritance powder.” 4

History of Toxicology, con’t o Mathieu Orfila (1787-1853) is

considered one of the fathers of toxicology as he helped to develop a method of chemical analysis to identify arsenic and other toxins in human tissue

o Today, less than 0.5% of all

homicides result from poisoning 5

Role of the Toxicologist o Studies body fluid, tissue, and organs

for drugs and/or poisons o Must detect, identify, quantify, and

assess toxicity n May have extremely minute

quantities to test o May conduct postmortem pathological

examinations, and examination of personal effects and empty containers, etc.

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Collecting Toxicological Evidence

o When possible, collect both blood and urine n Collect two voids (samples) of urine in

separate specimen containers n Collect a sample of blood if a

physician or registered nurse (RN) is available

n If Medical Examiner case, the organs will also be collected for analysis.

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Toxicology of Alcohol o Approximately 40% of traffic deaths

in the U.S. are alcohol-related (2008)

o Toxicologists have had to develop specific procedures for measuring the degree of alcohol intoxication

o Methods for diagnosis must be defendable within the framework of the legal system

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Toxicology of Alcohol

o Alcoholic beverages contain ethanol, also called ethyl alcohol, which is obtained by the fermentation of sugars from grains, fruits, and vegetables.

o Alcohol is a depressant, a chemical that slows the heart rate and brain activity, and causes drowsiness

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Alcohol Levels

Experimental evidence has verified that the amount of alcohol exhaled in the breath is in direct proportion to the blood concentration.

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Alcohol & Circulatory System Humans have a closed circulatory system consisting of a heart, arteries, veins, and capillaries. Capillaries are tiny vessels

that connect the arteries with the veins. The exchange of materials (like Alcohol) between the blood & other tissues takes place across the thin walls of the capillaries. 11

Alcohol Metabolism o 20% of the Alcohol is absorbed through

the walls of the stomach o 80% is absorbed by the small intestine o Which is then distributed by blood

throughout the body. o If the blood contains Alcohol or other

volatiles, the alcohol will also pass through the alveoli in the lungs with the carbon dioxide and be expelled through the nose and mouth.

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Factors affecting Alcohol Absorption: 1. Time to consume the drink

2. Alcohol content of the drink 3. The amount consumed 4.  Quantity & type of food present in

stomach at time of drinking

Normally, it takes 30-90 minutes from time of final drink until absorption is completed

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Elimination of Alcohol

o Elimination of alcohol throughout the body is accomplished through oxidation and excretion.

o Oxidation (substance + oxygen = new

products) takes place almost entirely in the liver

o Alcohol is excreted unchanged in the breath, urine, and perspiration.

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o In the liver, the enzyme alcohol dehydrogenase (ADH) breaks down ethanol into acetylaldehyde (causes hangovers) and then into acetic acid that undergoes oxidation, then eventually into carbon dioxide and water.

o The liver can normally metabolize 1-2 drinks (15-30 mL or up to 1 ounce) an hour. When a person drinks more than the liver can metabolize, the excess is distributed to the tissues of the body which can damage them.

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Alcohol Concentration

o The extent to which an individual may be under the influence of alcohol is usually determined by either measuring the quantity of alcohol present in the blood system or by measuring the alcohol content in the breath.

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Alcohol in the Blood o Blood Alcohol Content (BAC) is usually

written as a decimal n Example: 0.08 n This means there are 8 g of alcohol

per 10,000 mL of blood; your blood is 0.08% alcohol.

0.03 – 0.12 0.25 – 0.40 0.35 – 0.50 0.40 and up euphoria vomiting, loss of

bladder control circulatory and

respiratory system

impairment

coma and death

Effects of Alcohol at Different BACs

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BAC and the Law o A BAC greater than 0.08 is considered to be

“drunk driving”

o Implied Consent Law- says drivers who receive a driver's license are automatically consenting to be tested for blood alcohol content if a police officer has probable cause n While a driver can refuse to take this test,

implied consent laws often automatically revoke licenses on the spot if they refuse.

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Constitutional Issues o Schmerber v. California o Read the case on Pg. 229 of your book. Discuss

and answer the following questions: o What does the 5th Amendment guarantee? o What was the Supreme Court Ruling in this case? o What evidence did they say was not protected under

the 5th Amendment and why? o Were Mr. Schmerber’s 4th Amendment Rights

violated? o Why did they say blood removal was not covered

under the 4th Amendment? 19

BAC and the Law

o Between 1939 and 1964 a person having a blood-alcohol level in excess of 0.15 percent w/v was to be considered under the influence, which was lowered to 0.10 percent by 1965.

o In 1972 the impairment level was recommended to be lowered again to 0.08 percent w/v.

o Starting in 2003, states adopted the 0.08 percent w/v level.

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BAC and the Law

o DUI- Driving Under the Influence o DWI- Dring While Intoxicated o Most states use one or other to mean Driving

while under the Influence of alcohol but some use both where DUI is for driving under the influence of other drugs and DWI is for driving under the influence of Alcohol

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o Minors (under the age of 21 for alcohol laws) who purchase, attempt to purchase, possess, or consume alcoholic beverages, as well as minors who are intoxicated in public or misrepresent their age to obtain alcoholic beverages

MIP- Minor In Possession

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o Class C misdemeanor, punishable by a fine up to $500

o Alcohol awareness class o 8 to 40 hours community service o 30 to 180 days loss or denial of

driver's license

Consequences of Minor in Possession (not driving)

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o If a minor is seventeen years of age or older and the violation is the third offense, the offense is punishable by a fine of $250 to $2,000, confinement in jail for up to 180 days or both, as well as automatic driver's license suspension.

Consequences of Minor in Possession (not driving)

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Consequences of Minor in Possession (not driving)

o A minor with previous alcohol-related convictions will have his or her driver's license suspended for one year if the minor does not attend alcohol awareness training that has been required by the judge.

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Zero Tolerance Law

o In Texas it is illegal for a person under 21 to operate a motor vehicle in a public place while having ANY detectable amount of alcohol in their system. On September 1, 2009, this law was expanded to include watercraft in addition to motor vehicles.

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First Offense: n Class C misdemeanor, a fine up to $500 n Attendance at an alcohol awareness class n 20 to 40 hours of mandatory community

service n 60 days driver's license suspension. The

minor would not be eligible for an occupational license for the first 30 days.

Consequences of Minor Driving While Intoxicated

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Consequences of Minor Driving While Intoxicated

Second Offense: n Class C misdemeanor, a fine up to $500 n Attendance at an alcohol awareness class at

the judge's discretion n 40 to 60 hours of mandatory community

service n 120 days driver's license suspension. The

minor would not be eligible for an occupational license for the first 90 days. 28

Third Offense: o Is not eligible for deferred adjudication. The

minor's driver's license is suspended for 180 days and an occupational license may not be obtained for the entire suspension period.

o If the minor is 17 years of age or older, the fine increases to $500 to $2,000, confinement in jail for up to 180 days, or both.

Consequences of Minor Driving While Intoxicated

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Pass out the color brochures concerning underage drinking to each group. Have each group create their own brochure to encourage and inform other students not to participate in underage drinking. file:///C:/Users/Dad/Downloads/Smart_Choices_-_If_You_Are_Under_21_Brochure.pdf

Create Your Own Brochure: Materials Needed- Colored pencils, markers, and white paper

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Field Sobriety Tests o  If a police officer smells alcohol on a driver, he/she

may perform field sobriety tests, including: n  Horizontal gaze nystagmus (HGN) test

p Nystagmus is involuntary jerking movements of the eyes; more pronounced when intoxicated

n  Walk and turn p Heel to toe in a straight line, following

directions n  One leg stand

p Count aloud by 1000’s for 30 seconds or recite alphabet backwards 31

o https://www.youtube.com/watch?v=vjPR5WvYCx0

o http://www.ask.com/youtube?qsrc=1&o=2801&l=dir&q=Police+walk+and+turn+videos

o https://www.youtube.com/watch?v=7g7vA_qlcko

o Try it out with a partner now

Watch Nystagmus, walk and turn video

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Alcohol Breath Test

o 90% of alcohol is processed by the liver. The remaining 10% is excreted through breath, perspiration, and urine

o A breath test, such as a Breathalyzer measures the amount of alcohol in exhaled air.

o The amount of alcohol in breath is 1/2100 the amount in blood. n 2100 mL of air has the same amount of

alcohol as 1 mL of blood. 33

o It’s the degree of the interaction of the light with alcohol in the captured breath sample that allows the instrument to measure a blood alcohol concentration in breath.

o Some breath testing devices also use fuel cells.

How the Breath Tester Works?

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Breath Testers

Breath testers that operate on the principle of infrared light absorption are becoming increasingly popular within the law enforcement community. 0.167

Step 3

Step 4

Step 2

Step 1

0.000

0.000

0.000

0.000

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n All alcohols are toxic to the body.

o Consumption of alcohol can lead to liver damage, possibly cirrhosis. Chronic alcohol abuse can lead to Korsakoff’s Syndrome.

o Driving while intoxicated can have deadly results.

o Alcohol may change the effect of medications. n Never consume alcohol while taking drugs

with a sedative effect.

Negative Effects of Alcohol

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Fatal Vision Activity

Visit each of the 5 Stations and perform the Activity first without the goggles, and then with the goggles and record your observations on the handout.

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Alcohol: Depressants

o Depressants are used to relieve anxiety and produce sleep.

o Depressants reduce body functions such as heart rate.

o Overdose can cause coma and death. o Mixing depressants with other drugs or

alcohol can increase their effects and health risks.

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Poisons!

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Toxins and Poisons

o A poison is any substance that causes disturbance to an organism

o More specifically, a toxin is poison produced naturally by an organism n Examples: snake venom, poison ivy

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Intake of Poisons

o Poisons enter and affect the body in different ways: n Ingestion (poisons are eaten)

p 90% of all poisonings involve children swallowing household products or medicine

n Inhaled (i.e. carbon monoxide, sarin nerve gas)

n Injected (i.e. Heroine) n Absorbed (through skin, eyes, or mucous

membranes, i.e. poison ivy or sumac plant) 41

Poisons: Pesticides

o Pesticides are by definition poisons as they are used to kill organisms that threaten plants such as food crops n Example: DDT (for mosquitoes)

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Poisons: Heavy Metals o Metal compounds can enter the body by

ingestion, inhalation, or absorption through the skin or mucous membranes

o Metals are stored in soft body tissues and damage organs

o Examples: n Lead, Mercury, Arsenic n Cyanide n Strychnine

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Poisons: Heavy Metals o Arsenic Poisoning

n Within 30 minutes: abdominal pain, severe nausea, vomiting and diarrhea, muscle cramps, convulsions, kidney failure, delirium, and death.

o Cyanide Poisoning n Can be fatal in 6-8 minutes. n Signs of poisoning include weakness,

confusion, coma, pink skin, and an almond-like odor. 44

Poisons: Bioterrorism Agents o A bioterrorism attack is the deliberate release

of viruses, bacteria, toxins or other harmful agents used to cause illness or death in people, animals, or plants. Examples include: n Ricin & Anthrax, n Mustard Gas:

p used in World War I p A man-made gas p Forms large blisters on exposed skin and

the lungs 45

Testing for Drugs

o To test for drugs we must remove the drug from the biological specimen and separate them.

o Acids- Hydrogen ion donator o Bases- Hydrogen ion acceptor o Chemists use pH Scale to separate between

the two pH 0-6-> acid 7-> neutral 8-14-> base

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Testing for Drugs, con’t q By controlling the pH of the water into

which the sample is dissolved in, we can control what drugs are extracted in to the water.

q Acidic drugs (i.e. Barbituates, Aspirin) are extracted from water with pH below 7

q Basic drugs (i.e. PCP, Methadone, Cocaine) are extracted from water with pH above 7

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Testing For Alcohol, Toxins, & Poisons

o There are several types of tests to screen for the presence of alcohols, toxins, & poisons n Screening test: preliminary test that

reduces number of possibilities such as: n Thin Layer Chromatography (TLC) n Gas Chromatography (GC) n Immunoassay (IA)

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Testing For Alcohol, Toxins, & Poisons con’t

p Thin Layer Chromatography- separates a chemical into its components (often different colors) so they can be identified

p Gas Chromatography-separates mixtures based on distribution between a stationary phase & moving gas phase of the sample

p  Immunoassay- uses drug specific antibodies to detect low concentrations of drugs

n Confirmatory test: a single test that identifies a specific substance

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Example: Determination of Alcohol level in blood

o For Ethanol level in blood- we use “Headspace” Gas Chromatography (GC) - heat up the sample so the Ethanol volatilizes from the sample, then take a sample of the headspace gas and inject it through the GC.

o Mass Spectrometer (MS) is used for the Confirmation Test 50

Example: Determination of Alcohol Level in Blood con’t

Gas Chromatography coupled with Mass Spectrometry offers the toxicologist the most widely used approach for determining alcohol levels in blood.

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Virtual Lab: Analysis of Blood Alcohol by Gas Chromatography

o http://www.pearsonhighered.com/mediaproducts/mycrimekit/index.html

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