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

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

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

People of Historical Significance Mathieu Orfila—known as the father of forensic toxicology, published in 1814 “Traite des Poisons” which described the first systematic approach to the study of the chemistry and physiological nature of poisons.

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

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.

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.

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

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 50-500 mg/kg to an ounce moderately 500-5000 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

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

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

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

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

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

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

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

Lead Poisoning Leaded pipes in homes  banned 1986 Seeped into drinking water Leaded gasoline  banned in 1995 http://www.youtube.com/watch?v=juuuhR_fz3U (Taste of Poison – Forensic Case Study 52 mins) http://www.veoh.com/watch/e1077915X5GNatn?h1=Princess+Bride+-+Battle+of+Wits (5 mins)

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

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

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

BAC Blood Alcohol Content

BAC Burn off rate of 0.015% per hour but can vary: Male Female BACmale = 0.071 x (oz) x (% alcohol) body weight Female BACfemale = 0.085 x (oz) x (% alcohol)

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 = 0.071 x (oz) x (% alcohol) body weight BACmale = 0.071 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)

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)

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

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

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

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 https://www.youtube.com/watch?v=T6-qEaJssdM) (Pt. 2 https://www.youtube.com/watch?v=9mmJMIwsaDQ)