1. 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 ( ).
Swiss physician and chemist

2. The Study of Poisons Arsenic is poisonous…
Yet it is in our water, food, and is used to
treat certain types of cancer
Botulin is the most deadly poison known
1 gram would kill more than 1 million people
Yet it is used to erase wrinkles
Botulin is produced by bacterium Clostridium botulinum

3. Toxicology
The study of the adverse effects of chemicals or physical agents on living organisms

4. People of Historical Significance
Mathieu Orfila—known as the father of forensic toxicology, published in “Traite des Poisons” which described the first systematic approach to the study of the chemistry and physiological nature of poisons.

5. Elements of Toxicity Dosage
The chemical or physical form of the substance
How it enters the body
Body weight, age, & sex of victim
The time period of exposure
Other chemicals in the body or in the dose

6. Elements of Toxicity
Toxin – substance that causes injury to the health of a living thing on contact or absorption
Chronic exposure – continuing exposure to toxins over a long period of time
Acute toxicity – occurring almost immediately (hours or days) after an exposure to a large dose
Toxins usually interact with enzymes/receptors. Typically reserved for naturally produced substances that kill rapidly in small quantities.

7. Elements of Toxicity
Synergism – combined effect of substances that exceeds the sum of their individual effects
Anatagonism – combined effect of substances that decrease their individual effects
Toxins usually interact with enzymes/receptors. Typically reserved for naturally produced substances that kill rapidly in small quantities.

8. Lethal Dose
LD50 (Lethal Dose) – refers to the dose of a substance that kills half the test population, usually within four hours
Expressed in milligrams of substance per kilogram of body weight

9. Correlation to Ingestion by 150 lb Adult Human
Toxicity Classes
LD50 (rat, oral)
Correlation to Ingestion by 150 lb Adult Human
Toxicity
<1mg/kg
a taste to a drop
extremely
1-50 mg/kg
to a teaspoon
highly
mg/kg
to an ounce
moderately
mg/kg
to a pint
slightly
5-15 g/kg
to a quart
practically non-toxic
Over 15g/kg
more than 1 quart
relatively harmless

10. Federal Regulatory Agencies
Food and Drug Administration (FDA) –
pharmaceuticals, food additives, medical devices
Environmental Protection Agency (EPA) –
agricultural + industrial chemicals
Consumer Product Safety Commission –
toxins in consumer products

11. Federal Regulatory Agencies
Department of Transportation (DOT) –
shipment of toxic chemicals
Occupational Safety & Health Admin. (OSHA) –
exposure to chemicals in the workplace
Communication program:
Material Safety Data Sheets (MSDS)
Includes facts on the physical and chemical properties of the material

12. Forensic Autopsy Look for: Order toxicological screens
Irritated tissues
Characteristic odors
Mees’ lines—single transverse white bands on nails
Order toxicological screens
Post-mortem samples should be taken at the scene
if poisoning is suspected

13. Human Specimens for Analysis
Blood
10 ml usually sufficient for tox screening
Urine
Many drugs have higher concentrations and remain longer than in blood
Vitreous Humor
Protects sample from trauma or degradation
Vitreous humor – clear gel between the lens and retina of eyeball

14. Human Specimens for Analysis
Hair/nails
Chemicals in bloodstream transferred to hair follicle (≈ 90 days)
Also transferred to keratin in nails
2-4 weeks in fingernails
Up to 1 year in toenails
Saliva
Gaining importance for showing recent drug use
Gastric contents
Undigested pills or liquids

15. Human Specimens for Analysis
Drugs & poisons also can be concentrated in:
Liver tissue
Brain tissue
Kidney tissue

16. Lead Poisoning Not highly poisonous, unless chronic exposure occurs
Can lead to brain damage, affects memory and thought
processes
Common method of exposure = lead paint
(banned in 1978)
Tastes sweet, so children would eat paint chips

17. Lead Poisoning Leaded pipes in homes  banned 1986
Seeped into drinking water
Leaded gasoline  banned in 1995
(Taste of Poison – Forensic Case Study 52 mins)
(5 mins)

18. Alcohol—Ethyl Alcohol (C2H5OH)
Most abused drug in America
About 40% of all traffic deaths are alcohol-related
Toxic—affecting the central nervous system, especially
the brain
Alcohol appears in blood within minutes of consumption;
30-90 minutes for full absorption
90% of alcohol is processed in the liver
Finally broken down to carbon dioxide and water
Also known as ethanol

19. Rate of Absorption Depends on: Amount of alcohol consumed
Alcohol content of the beverage
Time taken to consume it
Quantity & type of food present in stomach
Physiology of the consumer

20. BAC Blood Alcohol Content
Expressed as % weight per volume of blood
Legal limits in all states is 0.08%
Or 0.08g of alcohol for every 100 ml of blood
Parameters influencing BAC:
Body weight
Alcoholic content
Number of beverages consumed
Time between consumption

21. BAC Blood Alcohol Content

22. BAC Burn off rate of 0.015% per hour but can vary: Male Female
BACmale = x (oz) x (% alcohol)
body weight
Female
BACfemale = x (oz) x (% alcohol)

23. BAC
For example, a 185-lb. man drinks 3 shots (1.5 oz each) of Jack Daniels (80 proof = 40% alcohol) in one hour. Can he drive home?
BACmale = x (oz) x (% alcohol)
body weight
BACmale = x (4.5) x (40) = 0.07
185
A: No. He is not legally drunk, but reactions and perceptions are distorted, ect. (see BAC chart)

24. Alcohol Terminology DUI – Driving Under the Influence
DWI – Driving While Intoxicated
OUI – Operating Under the Influence
OWI – Operating While Intoxicated
MIP – Minor in Possession
DUI could also mean being under the influence of a drug (wouldn’t be a DWI since you aren’t intoxicated)
OUI and OWI are just different terms used by different states (mean basically the same thing as DUI and DWI)

25. Henry’s Law The concentration of alcohol in breath is proportional to
that in the blood
1 ml of blood will contain nearly the same amount of
alcohol as 2,100 ml of breath
Breath tests (breathalyzer) can be done
in place of a blood tests for BAC

26. Field Tests
Preliminary tests—used to determine the degree of suspect’s physical impairment and whether or not another test is justified
Psychophysical tests—3 Basic Tests
Horizontal gaze nystagmus (HGN): follow a pen or small flashlight, tracking left to right with one’s eyes
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 instructions at one time

27. Connecticut Laws Connecticut's legal limit is 0.08
In CT, drivers under age 21 with a 0.02 BAC are
subject to DUI penalties
While it is illegal for a driver to consume alcohol, passengers in the car may drink and have open containers

28. Connecticut Laws
You must be 21 to drink in Connecticut, but only 18 to serve alcohol in a restaurant or work as a bartender or in a package store
With the first DUI offense (if under 21), the DMV imposes a mandatory license suspension for 1 year
Second offense = 3 year suspension
Third offense = Driver’s license is revoked
3rd offense = felony (punishable by more than 1 year in prison)
Sobering up Mythbusters: (Pt. 1 (Pt. 2