Chapter 8

Aspects of Toxicity

• Dosage
• the chemical or physical form of the substance
• the mode of the entry into the body
• body weight and physiological conditions of the victim
• the time period of exposure

toxicology

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

Lethal dose

• LD50 refers to the lethal dose needed to kill 50% of the population
• Expressed in milligrams of substance per kilogram of body weight

To prove a case

• prove a crime was committed
• motive
• intent
• access to poison and victim
• death was homicidal or caused by poison

Human Specimens for analysis

• Blood and Urine
• Bile and Gastric content
• Liver, Brain, and kidney Tissue
• hair and nails

Alcohol

• Is the most abused drug in America
• 40% of traffic deaths are caused by drinking and driving
• Affects the central nervous system and the brain
• Is a depressant

Rate of Absorption

• Depends of the amount consumed
• The alcohol content of the beverage
• Time taken to consume the beverage
• Food eaten before or after
• physiology of the consumer

BAC- Blood Alcohol Content

• expressed as percent weight per volume of blood
• legal limit in all states is .08
• body weight, alcohol content, number of beverages and time taken influence BAC

Field Sobriety Test

• Is a preliminary test used to determine the degree of physical impairment
• Tests for:
• Balance- Nine step walk
• Equilibrium- One leg Stand
• Nystagmus- eye bouncing test

Breathalyzer

• more practical in the field
• Takes and measures alcohol content in alveolar breath