Why Individual Alcohol Absorption and Elimination Rates Make Intoxilyzer Breath Testing Unacceptably Inaccurate
(Article Written by: Kevin Trombole)
PLAIN ENGLISH PROLOGUE, by David E. Rosenbloom, Esq. :
Dubowski is the undisputed father of modern American breath testing for alcohol; in fact, EVERY single police officer that works as a part of ANY state or federal breath testing program, has attended his mandatory three day breath testing education course at Indiana University. (Interestingly, defense attorneys are no longer permitted to attend the course). Dubowski is known as the State’s scientist, and interestingly he has stated unequivocally that single sample breath testing is inherently inaccurate due to mouth alcohol contamination concerns and variable individual “partition ratio” levels.
Utah DUI arrests are largely administered by inaccurate equipment by poorly trained police officers.
In plain English, Dubowski is saying that because the machine uses a fixed partition ratio (2100:1) when actual individual partition ratios vary from 1500:1 – 3300:1 in humans; and uses a fixed temperature (34.1 C) when actual human breath temperature ranges from 32.7 – 35.4 C – that the Intoxilyzer simply cannot render an acceptably accurate individual breath test because the variables – vary too much! In other words, while a test result of .16 may be acceptable, when other indicia of impairment are present, a breath test result of .125 or below has fundamental shortcomings that render the test inaccurate because the machine is using three (3) fixed rather than variable inputs, and in humans, breath temperature and partition ratio fluctuate with every individual.
Dubowski, Absorption, Distribution and Elimination of Alcohol: Highway Safety Aspects, 10 Journal of Studies on Alcohol Supp. 98 (1985)
Key aspects of the pharmacokinetics of alcohol are highly relevant to highway safety. Of particular pertinence are the partition of alcohol between various body tissues and fluids and the resulting alcohol concentration ratios for blood: breath and other body fluids, as well as the irregularity and short-term fluctuations of the blood and breath alcohol curves. Most alcohol pharmacokinetics parameters are subject to wide intersubject variability, as exemplified by peak blood alcohol concentrations reached on ingestion of identical weight-adjusted doses, time to peak after end of drinking and the rate of alcohol elimination from the blood. This great biological intersubject variability, when combined with sex-, age- and time-related differences, makes the blood alcohol information in widely distributed alcohol consumption nomograms and tables based on mean data inappropriate as a guide for the drinking behavior of individuals. Although there is good statistical correlation between the alcohol concentration of different body tissues and fluids in the fully postabsorptive state, wide individual variations from the population mean alcohol partition values exist. It is often impossible to determine whether the postabsorptive state has been reached at any given time. Those factors make it impossible or infeasible to convert the alcohol concentration of breath or urine to the simultaneous blood alcohol concentration with forensically acceptable certainty, especially under per se or absolute alcohol concentration laws. Inclusion of breath alcohol concentrations in drinking-driving statutes, as definitions or per se offense elements, makes unnecessary the conversion of breath alcohol analysis results into equivalent blood alcohol concentrations. Urine alcohol concentrations are inadequately correlated with blood alcohol concentrations or with driver impairment, and analysis of bladder urine is, therefore, inappropriate in traffic law enforcement. Significantly large sex-related differences in pharmacokinetic parameters have been demonstrated (e.g., in peak blood alcohol concentrations for weight-adjusted doses). The effects of age and time of day have been less extensively studies and are less clear. Breath and blood alcohol time curves are subject to short-term fluctuations from the trend line and other irregularities, and often do not follow the typical Widmark pattern. From the existing information on pharmacokinetics of alcohol and the characteristics and variability of blood and breath alcohol versus time curves, the following conclusions can be reached.
1) It is impossible for breath testing to accurately reflect blood alcohol levels unless it is known whether the test subject is in a pre-absorptive or post-absorptive state.
2) It is impossible for breath testing to accurately reflect actual blood alcohol levels unless the individual’s partition ration is known and accounted for, and breath temperature measured and adjusted for in the calculation.
Abstract courtesy of www.pubmed.org – A service of the National Library of Medicine and the National Institutes of Health