forensic toxicology. toxicologist an individual charged with the responsibility of detecting and...
TRANSCRIPT
Forensic ToxicologyForensic Toxicology
ToxicologistToxicologist
An individual charged with the An individual charged with the responsibility of detecting and identifying responsibility of detecting and identifying the presence of drugs and poisons in the presence of drugs and poisons in body fluids, tissues, and organsbody fluids, tissues, and organs
Not only for death Not only for death investigationsinvestigations
Hospitals labs for drug overdosesHospitals labs for drug overdoses Blood tests on children for exposure to Blood tests on children for exposure to
lead lead Examine urine of addictsExamine urine of addicts
ToxinsToxins
Any material exerting life threatening Any material exerting life threatening effects upon a living organismeffects upon a living organism
A toxin is a poisonous substance A toxin is a poisonous substance produced by a living organism produced by a living organism
Poisons are a subcategory of toxinsPoisons are a subcategory of toxins
Toxins vs PoisonsToxins vs Poisons
May enter the body May enter the body in different ways.in different ways.
Work in low Work in low quantities or low quantities or low levelslevels
Easy to detectEasy to detect If treatment is early, If treatment is early,
the person can be the person can be saved.saved.
Normally enter in a Normally enter in a single massive dosesingle massive dose
Normally are found in Normally are found in huge doses.huge doses.
Hard to detect Hard to detect People often die People often die
because the reason because the reason for illness is not for illness is not detected soon detected soon enough.enough.
Dose-Response Dose-Response RelationshipRelationship
Relationship between the amount of a Relationship between the amount of a substance that a human would be substance that a human would be exposed to and the relationship to their exposed to and the relationship to their body after exposure. body after exposure.
Lethal DoseLethal Dose
Lethal dose is the dose taken that would Lethal dose is the dose taken that would cause death to the organismcause death to the organism
To determine the Lethal Dose scientists To determine the Lethal Dose scientists test two different animals and two test two different animals and two different methods of exposure (one being different methods of exposure (one being the way humans would take the the way humans would take the substance)substance)
Lethal DoseLethal Dose
In a lethal dose study, scientists will In a lethal dose study, scientists will study how much will have to be given to study how much will have to be given to the two different animals in order to the two different animals in order to cause death.cause death.
Animals in these studies normally die Animals in these studies normally die within 14 days and scientists can take within 14 days and scientists can take their results from these tests and relate their results from these tests and relate them to human beings.them to human beings.
Most heavily abused Most heavily abused substance is legal!!substance is legal!!
Ethyl AlcoholEthyl Alcohol 40% traffic deaths40% traffic deaths 17,500 fatalities a year17,500 fatalities a year 2 million injuries a year2 million injuries a year
Toxicology of AlcoholToxicology of Alcohol
Metabolism- the transformation of a Metabolism- the transformation of a chemical in the body to other chemicals chemical in the body to other chemicals for facilitating its elimination from the for facilitating its elimination from the bodybody
3 steps3 steps AbsorptionAbsorption DistributionDistribution EliminationElimination
AbsorptionAbsorption
Alcohol appears in the blood minutes Alcohol appears in the blood minutes after consumption and increases in after consumption and increases in concentration while it is being absorbed concentration while it is being absorbed from the stomach and small intestine into from the stomach and small intestine into the bloodstream.the bloodstream.
Absorption= the passage of a substance Absorption= the passage of a substance across the wall of the stomach and small across the wall of the stomach and small intestine into the blood streamintestine into the blood stream
What affects rate of What affects rate of absorptionabsorption
How long it takes to consume a beverageHow long it takes to consume a beverage Alcohol content of beverage (proof)Alcohol content of beverage (proof) The amount consumedThe amount consumed Food present in stomachFood present in stomach
Distribution of AlcoholDistribution of Alcohol
BloodstreamBloodstream
BAC tests performed BAC tests performed
EliminationElimination
Oxidation- 95-98% of the alcohol Oxidation- 95-98% of the alcohol undergoes this chemical process which undergoes this chemical process which converts alcohol to carbon dioxide and converts alcohol to carbon dioxide and water. Occurs in liver.water. Occurs in liver.
Elimination- 2-5% is excreted by Elimination- 2-5% is excreted by perspiration, urination, and breathingperspiration, urination, and breathing
Breathalyzer TestBreathalyzer Test
The amount of alcohol exhaled in the The amount of alcohol exhaled in the breath is in direct proportion to the breath is in direct proportion to the concentration of alcohol in the blood.concentration of alcohol in the blood.
Elimination varies with Elimination varies with individualindividual
WeightWeight Muscle tone or physical conditionMuscle tone or physical condition History with drug (tolerance)History with drug (tolerance) MetabolismMetabolism AgeAge
Blood Alcohol Blood Alcohol concentrationconcentration
Blood Alcohol ContentBlood Alcohol Content
Most accurate testMost accurate test Requires bloodRequires blood
AbsorptionAbsorption
20% absorbed by the stomach20% absorbed by the stomach 80% by small intestines80% by small intestines All alcohol is broken down by liverAll alcohol is broken down by liver
Arteries will have a higher BAC than Arteries will have a higher BAC than veins during absorptionveins during absorption
Blood tests retrieve blood from veinsBlood tests retrieve blood from veins
Testing for intoxicationTesting for intoxication
BAC not convenient for traffic officersBAC not convenient for traffic officers Breath testing performedBreath testing performed BreathalyzerBreathalyzer
Developed 1954 by R.F. BorkensteinDeveloped 1954 by R.F. Borkenstein Uses chemicals to detect BACUses chemicals to detect BAC
Fuel Cell detectorFuel Cell detector
A chemical reaction involving alcohol A chemical reaction involving alcohol produces electricityproduces electricity
Will give officer a digital readout of BACWill give officer a digital readout of BAC
Errors in detectionErrors in detection
Police are supposed to ensure no foreign Police are supposed to ensure no foreign material is in mouth for 15 minutes before material is in mouth for 15 minutes before testtest
Regurgitation (throwing up) Regurgitation (throwing up) BelchingBelching Recent DrinkingRecent Drinking Gargling with an alcohol based Gargling with an alcohol based
mouthwashmouthwash
Field sobriety testsField sobriety tests
Deal with physical impairmentsDeal with physical impairments Stand on one legStand on one leg Walk straight lineWalk straight line Horizontal gaze nystagmusHorizontal gaze nystagmus Walk heel to toeWalk heel to toe
Alcohol and the lawAlcohol and the law
1992 US Department of Transportation 1992 US Department of Transportation (DOT) required states adopt 0.08% BAC(DOT) required states adopt 0.08% BAC
Made federal law in 2000Made federal law in 2000 If an individual exceeds .08% they are If an individual exceeds .08% they are
deemed “intoxicated”deemed “intoxicated” In 2003 states that did not abide with this In 2003 states that did not abide with this
law lost federal funding for highway law lost federal funding for highway constructionconstruction
Alcohol and the lawAlcohol and the law Commercial drivers such as bus or 18 Commercial drivers such as bus or 18
wheelers must not exceed .04 % BACwheelers must not exceed .04 % BAC
Is it constitutional??Is it constitutional??
55thth amendment states that you have the amendment states that you have the right to not incriminate yourselfright to not incriminate yourself
Driving is a privilege not a “right” so they Driving is a privilege not a “right” so they may take away your license for refusing may take away your license for refusing to test (6 months-12 months)to test (6 months-12 months)
Role of the ToxicologistRole of the Toxicologist
Generally there are few signs that Generally there are few signs that indicate what type of poison in systemindicate what type of poison in system Clues arise fromClues arise from
Medicine bottlesMedicine bottles Household chemicalsHousehold chemicals Postmortem pathological examinationPostmortem pathological examination
Toxicologist mustToxicologist must
Work with nanograms and micrograms of Work with nanograms and micrograms of specimen due to absorption of bodyspecimen due to absorption of body
Pure samples are easier to analyzePure samples are easier to analyze The body metabolizes each substance The body metabolizes each substance
differentlydifferently Example- heroin is almost immediately Example- heroin is almost immediately
broken down to morphine in the bodybroken down to morphine in the body Toxicity levels vary by individualToxicity levels vary by individual
Toxicologist handlesToxicologist handles
Blood (a minimum of 10 ml required)Blood (a minimum of 10 ml required) UrineUrine
90% of the drugs 90% of the drugs encountered in a toxicology encountered in a toxicology lab are:lab are:
CocaineCocaine AlcoholAlcohol MarijuanaMarijuana
Acid/Base TestsAcid/Base Tests
Toxicologist can extract acidic drugs from Toxicologist can extract acidic drugs from acidified water using chloroformacidified water using chloroform
Basic drugs can be extracted using basic Basic drugs can be extracted using basic water solutions and organic solventswater solutions and organic solvents
DrugsDrugs
AcidicAcidic BarbituatesBarbituates AspirinAspirin
BasicBasic PhencyclidinePhencyclidine MethadoneMethadone AmphetaminesAmphetamines CocaineCocaine
Famous casesFamous cases
1982 Tylenol was tampered with in 1982 Tylenol was tampered with in Chicago. Someone opened up the gels Chicago. Someone opened up the gels capsules and replaced drug with capsules and replaced drug with potassium cyannidepotassium cyannide
7 deaths7 deaths $100,000 reward from tylenol for $100,000 reward from tylenol for
information information
Toxicology of hairToxicology of hair
Most drugs leave bloodstream within 24 Most drugs leave bloodstream within 24 hours. Urine tests are accurate up to 72 hours. Urine tests are accurate up to 72 hours on averagehours on average
Drugs present in blood diffuse through Drugs present in blood diffuse through capillary walls into the base of hair and capillary walls into the base of hair and become permanently entrapped in the become permanently entrapped in the protein structure protein structure
Toxicology of hairToxicology of hair
As the hair grows, the drugs location on As the hair grows, the drugs location on the hair shaft becomes a historical the hair shaft becomes a historical marker for drug intakemarker for drug intake
Human hair grows an average of 1 cm a Human hair grows an average of 1 cm a monthmonth
Nondrug poisonsNondrug poisons
Heavy metals- Substance is placed in HCl with Heavy metals- Substance is placed in HCl with a copper strip. Silver or dark coating means a copper strip. Silver or dark coating means presence of heavy metal. Confirmation tests presence of heavy metal. Confirmation tests necessary.necessary. ArsenicArsenic BismuthBismuth LeadLead AntimonyAntimony MercuryMercury ThalliumThallium
Nondrug poisonsNondrug poisons
Carbon Monoxide (CO)Carbon Monoxide (CO) Suicide by car- usually a vacuum hose or Suicide by car- usually a vacuum hose or
garden hose in tailpipe to stream gas into garden hose in tailpipe to stream gas into car. 5-10 minutes in single car garage with car. 5-10 minutes in single car garage with car running is sufficient for deathcar running is sufficient for death
Also seen in fires.Also seen in fires.
Drug Recognition ExpertsDrug Recognition Experts
3-5 month Training3-5 month Training Can suggest if victim/offender exhibited Can suggest if victim/offender exhibited
behaviors associated with:behaviors associated with: CNS depressantsCNS depressants CNS stimulantsCNS stimulants HallucinogensHallucinogens Dissociative Anesthetics (phencyclidine)Dissociative Anesthetics (phencyclidine) InhalantsInhalants Narcotic AnalgesicsNarcotic Analgesics CannabisCannabis