Toxicology- Forensics

Almost half of all the individuals in federal prison are there because of \___________ \________________ offenses.

drug-related

Continued use of drug can lead to \___________________ and \____________________________ .

addiction, dependence

Abuse of a drug is defined as...

inappropriate, unwarranted, or over use

Physical dependence

when a drug becomes necessary for a person's body to function normally

Psychological dependence

when a person thinks they need a drug to function normally

Illegal drugs

a drug that is against the law to have, use, or distribute

Illicit drugs

a legal drug used in an inappropriate or illegal way

Schedule I drugs

high potential for abuse and have no current medical use

Examples of Schedule I drugs

heroin, marijuana, LSD, PCP

Schedule II drugs

high potential for abuse and have some medicinal use

Examples of Schedule II drugs

cocaine, opium, some opium derivatives, dronabinol (synthetic marijuana)

Schedule III drugs

less potential for abuse than I & II, current accepted medical use, low to moderate physical dependence, and high psychological dependence

Examples of Schedule III drugs

barbiturate preparations, certain preparations of codeine, ketamine, testosterone

Schedule IV drugs

lower potential for abuse than III, valid medical use, and limited dependence

Examples of Schedule IV drugs

xanax, ativan, valium, ambien

Schedule V drugs

low abuse potential, valid medical use, lower potential for producing dependence than IV

Examples of Schedule V drugs

robitussin, lyrica

Narcotics

induce a state of lethargy or sluggishness (most come from the poppy plant)

Examples of narcotics

morphine, methadone, heroin, codeine, oxycontin

Hallucinogens

cause marked alterations in normal thought process, perceptions, and moods

Examples of hallucinogens

marijuana, LSD, PCP, acid

Depressants

depress (slow down) action in the central nervous system

Examples of depressants

alcohol, barbiturates, inhalants

Stimulants

stimulate (speed up) action in the central nervous system

Examples of stimulants

cocaine, crack, crystal meth, amphetamines

Screening/presumptive tests

only tells if a drug is possibly present

color test, microcrystalline test (reagent is added to produce unique precipitates to certain drugs), and chromatography

Confirmatory tests

will reveal if a drug is positively present

spectrophotometry, ultraviolet (UV), visible, infrared (IR), mass spectrometry

What is the most important factor in toxicology?

the dosage or amount of exposure

Target organ

an organ that a specific chemical and specific dosage may bring more harm to as opposed to other chemicals

Local effects

effects of drug only occur locally to where the drug entered the body

Systemic effects

effects of the drug may target other areas different from the area where the drug entered the body

What are 7 factors that affect toxicity of a substance?

1\.form and innate chemical activity

2\.exposure route \n 3. species \n 4. gender \n 5. metabolism \n 6. distribution within the body \n 7. nutritional status

Acute toxic effects

occur shortly after exposure

Chronic toxic effects

occur due to long term exposure

Selective toxicity

toxic chemicals affect different species of animals differently if the two species are exposed simultaneously

Subchronic toxicity

repeated exposure to a toxin for several weeks or months

Carcinogenicity

a complex multistage process of abnormal cell growth and differentiation that can lead to cancer

Benign tumors

grow at the site of the organ, do not invade adjacent tissue or metastasize, and are generally treatable

Malignant tumors

invade adjacent tissues or migrate to different sites through metastasis, are more difficult to treat because they are cancerous, and can lead to death.

Developmental toxicity

adverse toxic effects the the developing embryo or fetus (occurs through toxicant exposure to either parent before conception or to the mother and her developing embryo or fetus)

Gene toxicity

results from damage to DNA and altered genetic expression which is called mutagenesis

Toxicology

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

Environmental toxicology

air, water, soil

Consumer toxicology

foods, cosmetics, drugs

What are some other types of toxicology?

medical, clinical, forensic

Poisons

chemicals that can injure or impair body functions

Venoms

substances injected by one species into another

Toxins

mostly described as drugs produced by microorganisms

Classes of poisons

1. Gases
2. Inorganic Poisons (heavy metals or corrosives)
3. Alkaloidal Poisons
4. Nonalkaloidal Poisons

Symptoms of carbon monoxide poisoning

dizziness, headache, disorientation, visual disturbances, disease of heart and respiratory, muscle weakness, seizures, nausea

Symptoms of lead poisoning

interferes with central nervous system, particularly toxic to children, causes permanent learning and behavior disorders

Symptoms of mercury poisoning

sensory impairment, disturbed sensation, and lack of coordination

Symptoms of arsenic poisoning

green markings on hands/body, convulsions, changes in fingernail pigmentation

Symptoms of thallium and polonium poisoning

radiation poisoning (vomiting, nausea, hair falling out, burns, seizures dizziness, severe pain)

Symptoms of cyanide poisoning

most commonly leads to death (very lethal), damages inter workings of cells, turns victim's blood a cherry red color

Symptoms of strychnine poisoning (plant-based rat poison)

convulsions, asphyxia, and leads to death

Ricin

a highly toxic naturally occurring protein produced in the seeds of castor oil plants

Pesticides

toxic substances released intentionally into our environment to kill living things (herbicides, insecticides, fungicides, and rodenticides)

Examples of common toxic household items

bleach, antifreeze, drain openers, oven cleaners, pain relievers, dish soap, laundry detergent

Examples of fatal poisonous plants

nightshade, hemlock, curare, mushrooms, oleander, yew, mistletoe

How does someone prove a case with toxicology evidence?

1. Prove a crime was committed
2. Motive
3. Access to poison
4. Access to victim
5. Death was homicidal
6. Death was caused by poison

About \______% of alcohol is processed in the liver

90

It takes \____ - \____ minutes for alcohol to be fully absorbed into the bloodstream

30, 90

Where is alcohol absorbed?

stomach and small intestine into the bloodstream

When blood containing alcohol enters the brain, \_______________________ effects can occur

neurological

Rate of absorption

how long it takes for alcohol to be absorbed into the body

Rate of absorption depends on...

1. Amount of alcohol consumed
2. The alcohol content of the beverage \n 3. Time taken to consume it \n 4. Quantity and type of food present in the stomach \n 5. Physiology of the consumer

An alcohol content of above \________% (\________% for commercial drivers) is considered DUI

0.08, 0.04

Horizontal gaze nystagmus

an involuntary jerking of the eyes that occurs as the eyes move to the side (exaggerated in people under the influence of alcohol)

Walk-and-Turn and One-Leg Stand tests

tests that require a person to listen to and follow instructions while performing simple physical movements (officers observe and record clues that could indicate impairment)

Implied consent law

by accepting a driver's license, a person agrees to be tested for BAC if stopped for suspicion of alcohol or drug use while driving

What is another more accurate test of BAC than breath and urine tests?

blood tests

What is forensic and legal testing for alcohol used for?

if a driver has a BAC over the legal limit, an under-age minor had been drinking, someone on parole has abstained from alcohol, alcohol consumption has contributed to an accident, determine whether alcohol contributed to a person's death (post-mortem ethanol testing)

What is the detection window for a BAC test or ethanol test dependent on?

1. The amount of alcohol ingested
2. The sex of the suspect
3. The metabolism rate of the individual

Synergism

combination of two drugs causes an effect that is greater than the sum of the individual effects of each drug alone

LD50 values

determine how much of a substance will kill at least 50% who are exposed

What is the most commonly used illicit drug in the U.S.?

marijuana

Death rate formula

number of deaths / sample size

Additive effect

combined effect of two drugs that is equal to the sum of the effects of each drug taken alone

Antagonistic effect

one drug reduces the effect of another drug

BAC stands for...

blood alcohol content

Who is the father of toxicology?

Mathieu Orfila

What is the pound to kilogram conversion?

1 pound \= .453592 kilograms

How is a lethal dose calculated?

mass x LD50 / 1000 (to convert to grams)

mass x LD50 (to convert to milligrams)