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

Chapter 8 T HE S TUDY OF P OISONS 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

Chapter 8 T OXICOLOGY The study of the adverse effects of chemicals or physical agents on living organisms

Chapter 8 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.

Chapter 8 E LEMENTS OF T OXICITY  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

Chapter 8 E LEMENTS OF T OXICITY 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

Chapter 8 E LEMENTS OF T OXICITY Synergism – combined effect of substances that exceeds the sum of their individual effects Anatagonism – combined effect of substances that decrease their individual effects

Chapter 8 L ETHAL D OSE  LD 50 (Lethal Dose) – refers to the dose of a substance that kills half the test population, usually within four hours

Chapter 8 T OXICITY C LASSES LD 50 (rat, oral) Correlation to Ingestion by 150 lb Adult Human Toxicity <1mg/kga taste to a dropextremely 1-50 mg/kgto a teaspoonhighly mg/kgto an ouncemoderately mg/kgto a pintslightly 5-15 g/kgto a quartpractically non-toxic Over 15g/kgmore than 1 quartrelatively harmless

Chapter 8 F EDERAL R EGULATORY A GENCIES  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

Chapter 8 F EDERAL R EGULATORY A GENCIES  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)

Chapter 8 F ORENSIC A UTOPSY Look for :  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

Chapter 8 H UMAN S PECIMENS FOR A NALYSIS  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

Chapter 8 H UMAN S PECIMENS FOR A NALYSIS  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

Chapter 8 H UMAN S PECIMENS FOR A NALYSIS Drugs & poisons also can be concentrated in:  Liver tissue  Brain tissue  Kidney tissue

Chapter 8 L EAD P OISONING  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

Chapter 8 L EAD P OISONING  Leaded pipes in homes  banned 1986  Seeped into drinking water  Leaded gasoline  banned in 1995

Chapter 8 A LCOHOL — E THYL A LCOHOL (C 2 H 5 OH)  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; minutes for full absorption  90% of alcohol is processed in the liver  Finally broken down to carbon dioxide and water

Chapter 8 R ATE OF A BSORPTION 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

Chapter 8 BAC B LOOD A LCOHOL C ONTENT  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

Chapter 8 BAC B LOOD A LCOHOL C ONTENT

Chapter 8 BAC  Burn off rate of 0.015% per hour but can vary:  Male BAC male = x (oz) x (% alcohol) body weight  Female BAC female = x (oz) x (% alcohol) body weight

Chapter 8 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? BAC male = x (oz) x (% alcohol) body weight BAC male = x (4.5) x (40) =

Chapter 8 A LCOHOL T ERMINOLOGY DUI – Driving Under the Influence DWI – Driving While Intoxicated OUI – Operating Under the Influence OWI – Operating While Intoxicated MIP – Minor in Possession

Chapter 8 H ENRY ’ S L AW  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

Chapter 8 F IELD T ESTS  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

Chapter 8 C ONNECTICUT L AWS  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

Chapter 8 C ONNECTICUT L AWS  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 the DMV imposes mandatory license suspension for 1 year  Second offense = 3 year suspension  Third offense = driver’s license is revoked