Chapter 8
Toxicology:
Poisons and Alcohol
“All substances are poisons. There is none which is not. The right dose differentiates a poison
and remedy.”---Paracelsus (1495-1541). Swiss physician and chemist.
Was Paracelsus Right?
*_________________—refers to the concept promoted by Paracelsus: that substances
that kill at high doses are actually beneficial at low doses--________________________
-This appears to be true for many substances: ____________________________
Historical Perspective of Poisoners
*____________________--a famous Greek poisoner
*____________________--personal poisoner of Emperor Nero
*_________________________--father was Pope Alexander VI
*____________________________--committed over 600 successful poisonings,
including two Popes.
*_________________________--formed a society to teach women how to murder their
husbands
*_________________________________________________--French poisoners
AND many others through modern times.
People of Historical Significance
*_____________________--known as the father of __________________________,
published in 1814, “___________________________” which described the first
systematic approach to the study of the chemistry and physiological nature of poisons.
Toxicology
*___________________--the study of the adverse effects of chemicals or physical
agents on living organisms.
*Types:
1. ___________________________--air, water, soil
2. ___________________________--foods, cosmetics, drugs
3. __________________________________--prescription medication
4. ____________________________--use of toxicology to aid in the investigation
of death, poisoning and drug use.
Forensic Toxicology
*____________________--medical examiner or coroner
*___________________--motor vehicle accidents (MVA)
*___________________--drug testing
*___________________--human and animal
*___________________--industrial, catastrophic, terrorism
Toxins
*Toxin—a substance that causes ____________________________________ on
contact or absorption, typically by interacting with enzymes and receptors. (Usually a
naturally produced substance that kills rapidly in small quantities)
Toxic Substances
*Toxic substances may:
1. ________________________________
2. ________________________________
3. ________________________________
4. ________________________________
Elements of Toxicity
1. _________________: many substances are only lethal in high doses
2. The _________________________________ of the substance
Ex: Arsenic is not very poisonous in its natural form (metal); but arsenic trioxide
or arsenic gas is very poisonous
3. The ______________________ into the body: some substances are most poisonous
if _____________________; others must be ________________________________
4. _______________________ and physiological conditions of the victim, including
age and sex
Ex: Blood alcohol content is directly _______________________________
Infants and elderly are more __________________________________
5. The ________________________________
-Sometimes ________________________________________ create a tolerance
for the toxin
-_______________________ (larger amounts over time) can create serious
medical problems
-_______________________--very large dose causing immediate problems,
including death
6. The presence of _____________________________________ or in the dose.
-_______________________: combination of two chemicals increases the effects
of both in the system Ex: antihistamine and alcohol
-_______________________: combination of two chemicals decreases the
effects of both in the system Ex: Chelating agent and arsenic
Lethal Dose
*_______--refers to the dose of a substance that _______________________________,
usually within _______________ (Note: test population is usually mice or rats)
*Expressed in ____________________________________________________________.
A correlation is then made to humans based on the body weight data.
*However, estimating lethal doses for humans is often complicated by the fact that
resistance to certain chemicals __________________________ between species.
Toxicity Classes
LD50 (rat, oral)
<1mg/kg
1-50 mg/kg
50-100 mg/kg
500-5000 mg/kg
5-15 g/kg
Over 15 g/kg
Correlation to Ingestion by 150lb Adult Human
a taste to drop
to a teaspoon
to an ounce
to a pint
to a quart
more than 1 quart
Toxicity
LD50 Update
*Because a single test may kill as many as ___________________, the U.S. and other
members of the Organization for Economic Cooperation and Development agreed in
December 2000 to phase out the LD50 test in favor of alternatives that ____________
_____________________________________________________________________
Federal Regulatory Agencies
*To ensure public safety, the federal government has created several regulatory
agencies related to toxic substances:
1. __________________________________--deals with pharmaceuticals, food
additives, and medical devices
2. __________________________________--works with agricultural and
industrial chemicals released to the environment
3. _________________________________--concerned with toxins in consumer
products
4. ________________________________ --watches shipment of toxic chemicals
5. ____________________________________________--concerned with
exposure to chemicals in the workplace
Symptoms of Various Types of Poisoning
Type of Poison
Symptom/Evidence
Characteristic burns around the lips and mouth of the victim
Red or pink patches on the chest and thighs, unusually bright red lividity
Black vomit
Greenish-brown vomit
Yellow vomit
Coffee brown vomit. Onion or garlic odor
Burnt almond odor
Pronounced diarrhea
Nausea and vomiting, unconsciousness
Possibly blindness
Critical Information on Poisons
Form
Common color
Characteristic odor
Solubility
Taste
Common sources
Lethal dose
Mechanism
Possible methods of administration
Time interval of onset of symptoms
Symptoms resulting from an acute exposure
Symptoms resulting from chronic exposure
Disease states mimicked by poisoning
Notes relating to the victim
Specimens from victim
Analytical detection methods
Known toxic levels
Notes pertinent to analysis of poison
List of cases in which poison was used
To Prove a Case
*Prove a _______________________________
*__________________
*__________________
*Access to __________________
*Access to __________________
*Death was _____________________________
*Death was ______________________
Forensic Autopsy
*Look for:
1. _________________________
2. Characteristic _____________
3. ______________________--single transverse white bands on nails
*Order toxicological screens
1. ____________________________ should be done at the scene for comparison
2. No realistic calculation of dose can be made from a _______________________
Human Specimens for Analysis
*___________________________
*___________________________
*___________________________
*___________________________
*___________________________
*_________________________
*_________________________
*_________________________
*_________________________
Alcohol—Ethyl Alcohol (C2H5OH)
*_____________________________ in America
*About ______________________________ are alcohol related
*__________--affecting the ____________________________, especially the ________
*Colorless liquid, generally diluted in water
*Acts as a _____________________
*Alcohol ___________________________________ of consumption: 30-90 minutes for
full absorption
*__________________--about 90% is done in the liver at a rate of about 0.015% per hr.
*About _____________________ unchanged in breath, perspiration and urine
Rate of Absorption
*Depends on:
1. _______________ of alcohol consumed
2. the _______________________ of the beverage
3. __________________________________
4. __________________________________ present in the stomach
5. _____________________ of the consumer
BAC Blood Alcohol Content
*Expressed as ___________________________________________________
*Legal limits in all states is ___________ (0.08 grams of pure alcohol for every 100 ml of
blood)
*Parameters influencing BAC:
1. ___________________________
2. ___________________________
3. _____________________________________
4. _____________________________________
BAC
*Burn off rate of 0.015% per hour but can vary:
*Male: BAC male =
*Female: BAC female =
Sample Problem: What would be the approximate BAC of a 185 pound man who has
consumed three shots (1.5 oz. each) of Jack Daniels (80 proof = 40% alcohol) in an hour?
Henry’s Law
*Henry’s Law provides ______________________ for the breath test check for sobriety.
*When a volatile chemical is dissolved in a liquid and is brought to equilibrium with air,
there is a fixed ratio between the concentration of the volatile compound in the air
and its concentration in the liquid; this ratio is constant for a given temperature.
*THEREFORE, ____________________________________________________________
*This ratios of alcohol in the blood to alcohol in the alveolar air is approximately
2100 to 1. In other words, 1 ml of blood will contain nearly the same amount of
alcohol as 2100ml of breath.
Field Tests
*_________________________--used to determine the degree of suspect’s physical
impairment and whether or not another test is justified.
*_______________________________--3 Basic Tests
1. _____________________________________: follow a pen or small flashlight,
tracking left to right with one’s eyes. In general, wavering at 45 degrees
indicates 0.10 BAC
2. _____________________________________: comprehend and execute two or
more simple instructions at one time
3. _____________________________________: maintain balance, comprehend
and execute two or more simple instructions at one time.
The Breathalyzer
*Invented in _____________
*More ____________________________
*Collects and __________________________________________________________
*Breath sample mixes with _______________________________________________
*Potassium dichromate is yellow, as concentration decreases its light absorption
diminishes so the breathalyzer indirectly measures alcohol concentration by
____________________________________________________________________
____________________________________________________________________
Generalizations
*During absorption, the concentration of alcohol in _______________________ will be
higher than in ________________________
*Breath tests reflect alcohol ________________________________________________
*The breathalyzer also can react with acetone (as found with diabetics), acetaldehyde,
methanol, isopropyl alcohol, and paraldehyde, but these are toxic and their presence
means the person is in serious medical condition.
*Breathalyzers _______________________________ absorption device with a
_____________________. Prints out a card for a permanent record.