1 Forensic Aspects of Alcohol and DrivingOntario Mutual Insurance Association October 29th 2013 Cambridge, ON James G. Wigmore Forensic Alcohol Toxicologist LinkedIn

2 Alcohol Ethanol, ethyl alcohol, grain alcohol (CH3CH2OH)Small, simple molecule Mixes with water in all proportions Enters the blood by diffusion (from area of high concentration to a lower concentration)

3 Absorption, Distribution EliminationAbsorption: alcohol is absorbed into the blood by simple diffusion from stomach and small intestine Distribution: Once alcohol is in the blood it is distributed to all parts of the body that contain water Elimination: Once blood passed into the liver there is elimination of alcohol (95-98%)

4 Absorption Alcohol rapidly absorbed through the stomach and small intestine after oral ingestion as it requires no digestion (WOA ) Concentration of alcohol in the stomach decreases so rapidly that it is seldom effective for gastric lavage (stomach pump) for alcohol-poisoned persons (WOA10105) Food slows absorption and promotes a “plateau” but does not increase time to peak BAC (WOA10106) Carbonation increases alcohol absorption but not warm beverages or salty foods (WOA )

5 Distribution Tissues with a high water content will hold more alcohol than tissues with low water content. High Brain, blood, liver, kidney Low Bone, fat The amount of water in the body depends on the person’s body weight and gender.

6 Distribution The greater the total body water of the individual the lower the BAC, as the consumed alcohol is diluted. 1 fld oz of vodka distributed in a 190 lb man (70% water) is equal to 15 mg/100mL 1 fld oz of vodka distributed in a 90 lb woman (60% water) is equal to 37 mg/100mL

7 Elimination Alcohol is eliminated from the body by two processes; oxidation of alcohol by the liver (95-98%)and passive diffusion via breath sweat and urine (2-5%) Oxidation of alcohol occurs in liver by enzymes, alcohol is converted at a fixed rate into acetaldehyde and eventually to carbon dioxide and water Social drinkers (mean 15) mg/100mL/h (WOA10313) Chronic heavy drinkers (mean 25) mg/100mL/h (WOA10301)

8 Fate of Alcohol in the Body After DrinkingRe-do as pure PowerPoint slide - Past in Pics of Beer, Wine etc...

9 Blood Alcohol Hospital will routinely analyse for alcohol (EtOH) in cases of trauma Typically will analyse serum/plasma by an enzymatic method and report results in mmol/L (ETOH, ETHANOL) Multiply result by 4 to determine BAC, so 50 mmol/L = 200 mg/100mL 30 mmol/L = 120 mg/100mL

10 Blood Alcohol Forensic labs usually analyse whole blood from kits by headspace gas chromatography

11 Headspace

12 Gas Chromatograph

13 Principles of Breath TestingAlcohol is a volatile compound and evaporates readily into the air, it is water soluble and is a drug that is ,000X greater concentration in the blood than other drugs Henry’s Law (1803) There is a fixed ratio of a volatile between a liquid and air at equilibrium at constant temperature

14 Henry’s Law (1803) “When the water solution of a volatile compound is brought into equilibrium with air, there is a fixed ratio between the concentration of the compound in air and its concentration in water. This ratio is constant at a given temperature.”

15 Henry’s Law

16 Respiratory Tract 250 million alveoli large surface area entire blood supply each min

17 Breath Alcohol Concentration and Forced Vital Capacity (FVC)

18 Advantages of Breath TestingNoninvasive, no needles required no possibility of injury or infection Results are known immediately not 2-3 weeks No medical staff or phlebotomists No continuity, transportation or storage problems No problem with real or alleged blood/needle phobia (WOA pg 104)

19 Breath Testing Program in OntarioStopped Driver Approved Instrument (e.g., Intoxilyzer 5000C) ASD Alcotest 7410 GLC DIGITAL 0 to g/210L Graduated Licensing WARN 0.050 to g/210L 12-Hour Suspension Suspicion RPG FAIL 0.100 g/210L and above

20 Alcotest 6810 Screener (Fuel Cell) Digital (0-49) Warn (50-99) Fail (100+)

21 Functional Diagram of ASD

22 Electromagnetic Spectrum

23 IR Spectrum for Alcohol

24 Intoxilyzer and 9.4 um IR

25 Optical System of IR Instrument

26 Characteristics of Drinking DriversArrested drinking drivers 87% male 38% < 26 years of age Beer consumed by 70% of male drivers and 30% of female drivers (wine consumed by 0.1% of male drinking drivers) 51% drinking at bar or restaurant before arrest Mean BAC to g/100mL the more serious the MVC the more likely alcohol is involved

27 Characteristics of Drinking DriversHigh Incidence of Alcoholism/Alcohol Dependency Incidence of alcoholism in general population is 5 to 7% In drinking drivers the incidence is approximately 50% 69% of first offenders and 87% of repeat offenders were alcoholics

28 Drinking Patterns of Drinking Drivers (n=435) (WOA10401)Location Drinking time (hrs) Per cent drink beer Time waited Pub 2.0 73% 24 minutes Hotel bar 86% 29 minutes Own home 1.8 39% 38 minutes

29 Alcohol and Driving Laboratory studies- RT, visual searchLaboratory driving simulators Closed course driving of actual motor vehicles Highway driving or observations Field (epidemiological studies of MVC, FMVCs

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31 Closed course study 23 sober and 25 drinking drivers, drove a Mercedes around 2.5 km track Mean BAC 70 mg/100mL Surprise grey foam barrier appeared, no sober drivers but 5 drinking drivers hit it One drinking driver caused damage to front spoiler after it got stuck on icy patch

32 Epidemiological Study- Borkenstein Grand Rapids 1974Relative probability of causing a collision

33 Effects of Alcohol on Driving“Alcohol impairs driving skills by its effects on the central nervous system, acting like a general anesthetic. It renders slower and less efficient both information acquisition and information processing, making divided attention tasks such as steering and braking more difficult to carry out without error. The influences of alcohol on emotions and attitudes may be a crash risk factor related to driving style in addition to driving skill “ (AMA, 1986)

34 Driving Skills and Increasing BACDivided attention 20 mg/100mL Visual tracking, complex RT 50 mg/100mL Psychomotor skills, information processing 70 mg/100mL Concentrated attention 80 mg/100mL Simple RT > 80 mg/100mL

35 Impaired Driving and AgeTends to be a fixation on the 80 mg/100mL, BACs above 80 indicates impairment and below no impairment of driving ability Young drivers (typically with low tolerance to alcohol and new, not-established driving experience) are at a greater risk of MVCs at “low” BACs (WOA )

36 Impaired Driving and AgeRelative risk of MVC is greater at lower BACs for drivers< 21 years of age (WOA50504) Basis of GLC and zero tolerance laws for novice drivers (WOA ) BAC RR 0.000 1.00X 10 1.13X 20 1.34X 40 2.09X 60 3.72X 100 16.0X 150 135.0X

37 Relative risk of FMVC and Age (Mayhew et al 1986)

38 BAC Limit Various organizations/studies have recommended the criminal BAC limit be lowered from 80 to 50 mg/100mL CMA AMA NHTSB -2013 Recent scientific reviews (Martin et al. 2013) EU countries (except UK)

39 Wigmore on Alcohol Wigmore on Alcohol Courtroom Alcohol Toxicology for the Medicolegal Professional 711 studies divided into 8 chapters, 66 sections, 87 tables, 5 indices e.g. Chapter 2 Blood Alcohol, (methods of analysis, serum/plasma/red blood cells, storage /preservation, swabs/blood collection, endogenous BACs Published by Irwin Law Inc. Toronto in 2011 Blog

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