FORENSIC SCIENCE
TOXICOLOGY AND ALCOHOL
The study of Poisons and how they affect
the human body.
Toxicology
Toxicology—the study of the adverse
effects of chemicals or physical
agents on living organisms…
Poisons
Types:
Environmental—air, water, soil
Consumer—foods, cosmetics, drugs
Medical, clinical, forensic
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MATHIEU ORFILA
(1787-1853)
“Father of Toxicology”
He gave the subject its first formal
treatment in 1813 in his book Traité
des poisons, also called Toxicologie
générale. (General Toxicology)
Wrote about the detection of poisons
& their effects on animals.
Forensic Toxicology
Postmortem—medical examiner
or coroner
Criminal—motor vehicle
accidents (MVA)
Workplace—drug testing
Sports—human and animal
Environment—industrial,
catastrophic, terrorism
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Toxicology
Toxic substances may:
Be a cause of death
Contribute to death
Cause impairment
Explain behavior
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Aspects of Toxicity
Dosage – Has 5 factors:
The chemical or physical form of the
substance
The mode of entry into the body
Body weight and physiological conditions
of the victim, including age and sex
The time period of exposure
The presence of other chemicals in the
body or in the dose
6
Lethal Dose
LD50 refers to the dose of a
substance that kills 50% of the test
population, usually within four
hours
Expressed in milligrams of
substance per kilogram of
body weight
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Toxicity Classification
LD50 (rat,oral)
Correlation to
Ingestion by 150-lb
Adult Human
Toxicity
<1 mg/kg
a taste to a drop
extreme
1–50 mg/kg
to a teaspoon
high
50–500 mg/kg
to an ounce
moderate
500–5,000 mg/kg
to a pint
slight
5–15 g/kg
to a quart
practically nontoxic
Over 15 g/kg
more than 1 quart
relatively harmless
Link to LD 50 table
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In 1984 at the Union Carbide India pesticide plant in
Bhopal,. Over 500,000 people were exposed to methyl
isocyanate gas and other chemicals. The toxic substance
made its way in and around the shanty towns located
near the plant. The government of India confirmed a
total of 3,787 deaths related to the gas release.[3] Others
estimate 8,000 died within two weeks and another
8,000 or more have since died from gas-related
diseases
Video
The deadliest snake is a Belcher's Sea-snake. It
takes only 0.02 milligrams of venom to kill a person.
They usually injects around 35 milligrams and that
can kill around 15,000 people with one bite. Death
can happen within 2 minutes.
An estimated 12,000 people die annually from
Cobra bites in India. It is possible that under the
right conditions a person could die from a cobra
bite in 30 minutes
Symptoms of Various Types of Poisoning
Type of Poison
Caustic poison (lye)
Carbon monoxide
Sulfuric acid
Hydrochloric acid
Nitric acid
Phosphorus
Cyanide
Arsenic, mercury
Methyl (wood) or
isopropyl
(rubbing) alcohol
Symptom/Evidence
Characteristic burns around the lips and
mouth of victim
Red or pink patches on the chest and
thigh, unusually bright red lividity
Black vomit
Greenish-brown vomit
Yellow vomit
Coffee-brown vomit, onion or garlic odor
Burnt almond odor
Extreme diarrhea
Nausea and vomiting, unconsciousness
possibly blindness
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Hemlock or Conium is a highly toxic flowering
plant indigenous to Europe and South Africa. It was a
popular one with the ancient Greeks, who used it to kill
off their prisoners. For an adult, the ingestion of 100mg
of conium or about 8 leaves of the plant is fatal – death
comes in the form of paralysis, your mind is wide
awake, but your body doesn’t respond and eventually
the respiratory system shuts down. Probably the most
famous hemlock poisoning is that of Greek
philosopher, Socrates. Condemned to death for impiety
in 399 BC, he was given a very concentrated infusion of
hemlock.
Arsenic has been called “The King of Poisons”,
for its discreetness and potency – it was virtually
undetectable, so it was very often used either as
a murder weapon or as a mystery story element.
But that’s until the Marsh test came and
signaled the presence of this poison in water,
food and the like. However, this king of poisons
has taken many famous lives: Napoleon
Bonaparte and Simon Bolivar to name a few. On
another note, arsenic, like belladonna, was used
by the Victorians for cosmetic reasons. A couple
of drops of the stuff made a woman’s
complexion white and pale.
If you’re watching Sherlock Holmes, then you’ll know
about this one. The Botulinum toxin causes Botulism, a
fatal condition if not treated immediately. It involves
muscle paralysis, eventually leading to the paralysis of
the respiratory system and, consequently, death. The
bacteria enter the body through open wounds or by
ingesting contaminated food. By the way, botulinum toxin
is the same stuff used for Botox injections!
Cyanide seems to be extremely popular (spies use
cyanide pills to kill themselves when caught) and
there are plenty of reasons for this. Firstly, it is
found in a great variety of substances like almonds,
apple seeds, apricot kernel, tobacco smoke,
insecticides, and pesticides. Murder in this case
can be blamed on a household accident, such as
ingestion of pesticide – a fatal dose of cyanide for
humans is 1.5 mg per kilogram of body weight.
Secondly, it’s a rapid killer: depending on the dose,
death occurs within 1 to 15 minutes. Hydrogen
cyanide gas was used by Nazi Germany for mass
murders in gas chambers during the Holocaust.
There are three forms of mercury which are extremely
dangerous. Elemental mercury is the one you can find in
glass thermometers, it’s not harmful if touched, but lethal
if inhaled. Inorganic mercury is used to make batteries,
and is deadly only when ingested. And finally, organic
mercury is found in fish, such as tuna and swordfish
(consumption should be limited to 170g per week), but
can be potentially deadly over long periods of time. A
famous death caused by mercury is that of Amadeus
Mozart, who was given mercury pills to treat his syphilis.
The name of this plant is derived from Italian and
means beautiful woman. That’s because it was used
in the middle-ages for cosmetic purposes – diluted
eye-drops dilated the pupils, making the women
more seductive (or so they thought). Also, if gently
rubbed on their checks, it would create a reddish
color, what today would be known as blush! This
plant seems innocent enough, right? Well, actually, if
ingested, a single leaf is lethal and that’s why it was
used to make poison-tipped arrows. The berries of
this plant are the most dangerous – consumption of
ten of the attractive-looking berries is fatal.
To Prove a Case of Poisoning
Prove a crime was committed:
1. Motive ?
2. Intent?
3. Access to poison?
4 Access to victim?
5. Death was homicidal?
6. Death was caused by poison?
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Pattern of poisoning
Chemical products, most often swallowed
by children include household cleaners
(bleach, detergents) fuel (kerosene,
paraffin), cosmetics, medicines, paints and
products for household repairs and
household pesticides.
 Bites and stings of animals and insects,
and ingestion of poisonous plants and
seeds also considerably account for
outdoor poisoning in children.

POISONING IN CHILDREN
Poison is a substance that causes harm if it
gets into the body.
 The poisoning in children could occur due to
diverse causes and could be classified as

◦ accidental,
◦ homicidal or
◦ suicidal.

Erroneous administration of over dosage of
drugs by the parents or by the medical staff
is also frequent.
Accidental Poisoning
Accidental poisoning in children is a global
problem. The relative importance of
poisoning as a cause of childhood morbidity
and mortality increases when malnutrition
and infections are brought under control.
 Accidental poisoning is the twelfth leading
cause of admissions in pediatric wards in
India and accounts for about one percent
of the hospitalized patients. Most cases of
accidental poisoning are preventable.
Continuing morbidity and mortality due to
accidental poisoning is serious challenge to
the pediatricians and public health officials.

Acute or Chronic Exposure
Acute exposure is a single contact that lasts
for seconds, minutes or hours, or several
exposures over about a day or less. Chronic
exposure is contact that lasts for many days,
months or years.
 A poison may get into the body through
ingestion, inhalation (gas, vapors, dust, fumes,
smoke, spray), skin contact (pesticides), or
injection (bites and stings, drug injection

Carbon Monoxide

Carbon monoxide poisoning can
happen when fires, stoves, heaters or
ovens are used in rooms, huts which
do not have proper ventilation to let
the gas out.
TOXICOLOGY OF ALCOHOL
Alcohol—Ethyl Alcohol
(C2H5OH)
Most abused drug in America
About 40 percent of all traffic deaths are alcoholrelated
Toxic—affecting the central nervous system,
Acts as a depressant, especially the brain.
Colorless liquid, generally diluted in water
Alcohol appears in blood within minutes of
consumption; 30–90 minutes for full absorption
Detoxification—about 90 percent in the liver
About 5 percent is excreted unchanged in breath,
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perspiration, and urine
Alcohol & Circulatory System
• Alcohol is absorbed from the stomach and small
intestines into the blood stream.
• Alcohol is carried to the liver where the process of
its oxidation starts.
•
It also goes through the circulatory
system into the lungs where it is
exhaled as a gas.
Alcohol Effects
upon the body
As can be seen,
the effects of
alcohol upon the
body are not
good. With
repeated
exposure,
general health
declines.
Alcohol Breaks down to Acetaldehyde
In humans, acetaldehyde is a carcinogen and is the reason for
hang overs. It causes drowsiness, delirium, hallucinations and
loss of intelligence. Exposure may also cause severe damage to
the mouth, throat and stomach; accumulation of fluid in the
lungs, chronic respiratory disease, kidney and liver damage,
throat irritation, dizziness, reddening and swelling of the skin
ALCOHOL-INDUCED FATTY LIVER
Alcohol & Circulatory System
• In the lungs, carbon dioxide and alcohol
leave the blood and oxygen enters the
blood in the air sacs known as alveoli.
• Then the carbon dioxide and alcohol are
exhaled during breathing.
• Estimated costs of alcohol related
crashes in 2000 were over $114 b ($51
billion in monetary costs, $63 b in quality
of life losses)
MEASURING THE ALCOHOL IN
THE HUMAN BODY
• A major branch of
forensic toxicology
deals with the
measurement of
alcohol in the body
for matters that
pertain to violations
of criminal law.
Rate of Absorption
Depends on:
Amount of alcohol
consumed
The alcohol content of
the beverage
Time taken to consume it
Quantity and type of food
present in the stomach
Physiology of the consumer
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BAC: Blood Alcohol Content
Expressed as percent
weight per volume of
blood
Legal limit in all states is
0.08 percent
Parameters influencing BAC:
• Body weight
• Alcohol content
• Number of beverages consumed
• Time since consumption
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BAC Calculation
Your liver oxidizes alcohol to filter it out of
the body. This Burn-off rate is 0.0015
percent per hour, (but can vary)
Healthy liver metabolizes about
0.5 oz = 15 ml of alcohol per hour
Male
BAC = 0.071  (oz)  (% alcohol)
body weight
Female
BAC =
0.085  (oz)  (% alcohol)
body weight
What's a "standard" drink?
Many people are surprised to learn what counts as a drink. In the United States, a "standard" drink is any drink that
contains about 0.6 fluid ounces or 14 grams of "pure" alcohol. Although the drinks below are different sizes, each
contains approximately the same amount of alcohol and counts as a single standard drink.
12 fl oz of = 8-9 fl oz of = 5 fl oz of =
regular
malt
table wine
beer
liquor
(shown in
a 12-oz
glass)
3-4 oz of = 2-3 oz of =
fortified
cordial,
wine
liqueur, or
(such as
aperitif
sherry or
(2.5 oz
port; 3.5
shown)
oz shown)
1.5 oz of = 1.5 fl
brandy
oz
(a single
shot
jigger or
of
shot)
80proof
spirits
("hard
liquor"
)
BLOOD ALCOHOL LEGAL LIMITS
Legal maximum BAC in USA is
.08% or 0.8 grams/kilogram
• 1 beer = 0.6 oz alcohol = 14 grams
• 150 lb adult = 68 kg
• 63% body weight from blood = 42.8 kg
• 14/42800 = 0.000327or 0.327
grams/kg or .0327%
• 2.5 beers produces BAC of about
0.083%
BLOOD ALCOHOL CONCENTRATIONS
.020 - light to moderate drinkers begin to feel some effects
* .040 - most people begin to feel relaxed
* .060 - judgment is somewhat impaired, people are less able to make rational
decisions about their capabilities (for example, driving)
* .080 - there is a definite impairment of muscle coordination and driving skills;
this is legal level for intoxication in all states
* .10 - there is a clear deterioration of reaction time and control; this is legally
drunk in most states
* .120 - vomiting usually occurs. Unless this level is reached slowly or a person
has developed a tolerance to alcohol
* .150 - balance and movement are impaired. This blood-alcohol level means
the equivalent of 1/2 pint of whiskey is circulating in the blood stream
* .300 - many people lose consciousness
* .400 - most people lose consciousness; some die
* .450 - breathing stops; this is a fatal dose for most people
BLOOD ALCOHOL CHART
WHAT IS BLOOD ALCOHOL CONCENTRATION:
What is blood alcohol concentration?
• Ratio of amount of alcohol in the
blood to the amount of blood.
• 1 gram of alcohol per kilogram of
blood is a ratio of 1/1000 or 0.001
alcohol/blood.
• 0.001 alcohol/blood concentration is
0.10%
BLOOD ALCOHOL CALCULATOR
://health.discovery.com/tools/calculat
ors/alcohol/alcohol.html
HOW MANY DRINKS IN DIFFERENT EXAMPLES?
In the United States, a "standard" drink is any drink that contains about 0.6 fluid
ounces or 14 grams of "pure" alcohol. Below is the approximate number of
standard drinks in different sized containers of
Regular Beer (5%)
Malt Liquor (7%)
Table Wine (12%) 80 proof liquor
12 fl oz = 1 oz
12 fl oz = 1/5 oz
750 ml bottle =
A shot (50ml or 1.5 oz = 1
16 fl oz = 1.3
16 = 2
5 drinks
200 ml (half pint) =4.5
22 fl oz = 2
22 fl oz = 2.5
375 ml (pint) = 8.5 drinks
40 fl oz = 3.5
40 fl oz = 4.5
750 ml (a fifth) = 17
NOW YOUR TURN
Find the BAC for a 255-lb man who, in
2 hours, has drunk 13 beers. (Assume
that each beer is 12 oz with a 4.5%
alcohol content.) Round your answer to
the nearest thousandth.
SOLUTION
BAC =
0.071  (oz)  (% alcohol)
body weight
BAC = 0.071 x 12 oz x 13 beers x 4.5%= 0.19%
255 lbs
Alcohol Levels
• Experimental
evidence has verified
that the amount of
alcohol exhaled in the
breath is in direct
proportion to the
blood concentration.
Field Testing
• Law enforcement officers typically use field
sobriety tests to estimate a motorist’s degree of
physical impairment by alcohol and whether or
not an evidential test for alcohol is justified.
• The horizontal gaze nystagmus test, walk and
turn, and the one-leg stand are all considered
reliable and effective psychophysical tests.
Field Tests
Preliminary tests—used to determine the degree of
suspect’s physical impairment and whether or not
another test is justified
Psychophysical tests—three basic tests:
• Horizontal gaze nystagmus (HGN): follow a pen or
small flashlight, tracking left to right with one’s
eyes. In general, wavering at 45 degrees indicates
0.10 BAC.
• Nine-step walk and turn (WAT): comprehend and
execute two or more simple instructions at one
time
• One-leg stand (OLS): maintain balance;
comprehend and execute two or more simple
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instructions at one time
Breath Testers
• 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.
• Some breath testing devices also use
fuel cells.
Modern Breath Testers
• Breath testers that operate on the principle of
infrared light absorption are becoming increasingly
popular within the law enforcement community.
Breathalyzer
One of the first breathalyzers used chemical
reactions to measure alcohol in field.
Collects and measures alcohol content
of alveolar breath
Breath sample mixes with 3 ml of 0.025 percent K2Cr2O7
in sulfuric acid and water:
2K2Cr2O7 +3C2H5OH + 8H2SO4  2Cr2(SO4)3 + 2K2SO4
+ 3CH3COOH + 11H2O
Potassium dichromate is yellow; as concentration
decreases, its light absorption diminishes, so the
breathalyzer indirectly measures alcohol concentration
by measuring light absorption of potassium
dichromate before and after the reaction with alcohol.
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Generalizations
During absorption, the concentration of alcohol in arterial
blood is higher than in venous blood.
Breath tests reflect alcohol concentration in the
pulmonary artery.
The breathalyzer also can react with acetone (as found in
diabetics), acetaldehyde, methanol, isopropyl alcohol,
and paraldehyde, but these are toxic and their
presence means the person is in serious medical
condition.
Breathalyzers now use an infrared light-absorption
device with a digital readout. Prints out a card for a
permanent record.
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Breath Testers
• Many types of breath testers are designed to
analyze a set volume of breath.
• The captured breath is exposed to infrared light.
• Can be built into cars.
• Car can’t start if drunk.
Field Testing
• A portable, handheld, roadside breath tester
may be used to determine a preliminary breathalcohol content.
Gas Chromatography Testing
• Gas chromatography offers the toxicologist the
most widely used approach for determining
alcohol levels in blood.
DRUNK DRIVER KILLS CYCLIST
Alcohol and Law
• The American Medical Association and the
National Safety Council have been able to exert
considerable influence in convincing the states
to establish uniform and reasonable bloodalcohol standards.
• 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.
Alcohol and Law
• In 1972 the impairment level was recommended to
be lowered again to 0.08 percent w/v.
• Starting in 2003, states adopted the 0.08 percent
• Commercial drivers are allowed only 0.04%
because of the possible dangers of driving large
and hazardous payloads.
Alcohol and Law
• To prevent a person’s refusal to take a test for
alcohol consumption, the National Highway Traffic
Safety Administration recommended an “implied
consent” law.
• Adopted by all states by 1973, this law states that
the operation of a motor vehicle on a public
highway automatically carries with it the stipulation
that a driver will submit for a test for alcohol
intoxication if requested or be subject to loss of the
license.