Poisons

“The poison is in the dosing”

Socrates: killed with hemlock: 1st recorded homicide by poison 339 BC

Strongest poison: botulismNow used to diminish wrinkles

Toxicology: study of adverse effects of chemicals on the body

Level of toxicity affected by:DosageChemical or physical form of the drugHow enters bodyBody wt. and physical conditionTime period of exposureOther chemicals in body

Chelating agent: binds with a chemical and changes it’s effects.

Synergism: substances that work together

Antagonism: substances with opposing results

Chronic exposure: exposure over a long period of time

Acute: over short period of time

LD 50: lethal dose for half the test population (animals): usually within 4 hours

3 most lethal compounds are natural products:RicinDioxinbotulin

Government regulatory agencies:FDA: pharmaceuticals and food additives and

medical devicesEPA: agricultural and industrial chem.s into

environment.Dept. of transport: shipments of toxic materialsOSHA: occupational safety and health admin.

LeadLead paint ban in 1978

Lead gasoline ban in 1995Lead leaches into the soilLead leads to nervous system problems and

learning disabilities in children

AlcoholAlcohol (ethanol, ethyl alcohol)

Most abused drug in the US

Most widely used drug on college campuses

20% of all alcohol produced is consumed by teenagers

Drink and drive40% of all traffic deaths involve alcohol

Highest risk group: males 16-24 years old

Males 2x as likely to be in MVA

Males consume 2x as much as women

Dept of TransportationSignificant impairment at BAC of .02 to .05

Change reaction time

Change time between stimulus and response

Change stop ability by 15 to 21 feet at moderate speed (40mph)

.04 is legal limit for commercial vehicle operation

.08 is legal limit for personal vehicle operation

.15 to .20 is blood alcohol for most arrests in US

.30 comatose

.40 is LD 50 (lethal dose for half of people)

.50 most references say certain death

Myth: being intoxicated reduces your risk of injury in an mva.

False. Half of people that suffer traumatic brain injury in US are intoxicated

Can have alcohol induced cerebral edema

Alcohol produces acidosis which can change breathing patterns

Alcohol Ethanol is toxic

Affects central nervous system, liver, digestive, skin

Rate of absorption into bloodAmount consumedAlcohol content of beverageHow quickly consumedAmount food in stomachOther drugs in system

90% of alcohol is processed in the liver

Alcohol - acetylaldehyde - acetic acid – CO2 + water

Liver processes .5ounce per hour (NOTHING will increase this rate)

Alcohol kills liver cells, fatty deposits, cirrhosis

10% removed through sweat, breathe, urine

Alcohol is a diuretic

Absorption of alcohol start in mucus membrane of mouth.

90 seconds to circulate throughout body.

Food or juice in stomach will slow absorption.

Digestive tract:

Alcohol irritates the lining of stomach: ulcers

Alcohol linked to cancer of mouth, esophagus, stomach, intestines

Alcohol has calories and no nutritional value

So alcoholics are malnourished and dehydratedHair is dryLips crackedAcneSkin puffyBroken veins

Brain: Initially, frontal lobe: euphoric and decreased

inhibitionsThen, reach cerebellum: coordination and

perceptionMid brain: reflexes, confusion, stuporMedulla: heart rate and breathing

BAC: blood alcohol content in percent weight per volume

Legal limit: .08%

.08 grams alcohol/100ml of blood

Increase tolerance with chronic abuse:

1 drink: 12oz beer, 5oz wine, 1oz whiskey

Overtime develope physical and psychological dependence: alcoholism

BAC: Blood alcohol contentMust consider

Body weight # of drinks% alcohol in each drinkOver what time period (-.15 per hour)Male/female (males more alcohol dehydrogenase)

BAC: male

.071 x (ounces consumed) (% alcohol)Divided by body weight

BAC: female

.085 x (ounces consumed) (%alcohol)Divided by body weight

Metabolism (detoxify) begins almost immediately.

Average rate of removal: .015% /hour

Alcohol content in a liquid can be stated in “proof”

Actual % alcohol is HALF the “proof”

Henry’s Law:Alcohol concentration in breath is proportional to

alcohol concentration in the blood.Breathalyzer invented in 1954

Color change with chemical reactionNew breathalyzer: more sensitive

Infrared spectrophotometry