It is not uncommon to find high rates of alcohol elimination in drinking drivers with high BACs. This blog is a review of a study published by top forensic alcohol researcher, Wayne Jones, which illustrates several issues that can arise in a DUI/DWI case. The study is:
JONES, A.W. “Ultra-rapid Rate of Ethanol Elimination from Blood in Drunken Drivers with Extremely High Blood-Alcohol Concentrations”, International Journal of Legal Medicine, 122: 129-34, 2008 (2 tables, 1 figure, 2 references) (WOA10406)
In this study, the rate of alcohol elimination was determined in 1,090 arrested drinking drivers in Sweden in which 2 blood samples were collected approximately 1 hour apart. The mean rate of alcohol elimination for all drivers was 0.019 g/100mL/h and the 97.5 percentile range was between 0.011 and 0.033 g/100mL/h. Twenty-one drivers (1.9%) with the highest BACs had a higher rate of elimination of alcohol as shown in the following Table;
The following Table provides a summary of some of the characteristics of these drivers:
There are several interesting observations one can make from these Tables regarding drivers with very high BACs, not the least of which is that they, no doubt, are alcoholic or at least alcohol-dependant. Here are some of the others:
As expected, the number of male drivers is much higher than female drivers
The female drivers tend to be younger than male drivers. There are some studies that suggest than female alcoholics die at a younger age than male.
The BACs obtained by male or female drivers is virtually the same which indicates that female drivers can “hold their liquor” as well as male drivers
All things being equal, the mean rate of alcohol elimination in female drivers tends to be higher than for male drivers. This is because women have more liver tissue in comparison to a smaller distribution volume than men (WOA10305, 10306)
As shown in other studies and posted on my blog on October 1st 2013-“Drinking and Driving – Not Just a Night Thing”, alcoholic drivers can be found with high BACs at virtually any time of the day.
Jones suggests that the high rate of alcohol elimination is related to induction of the microsomal enzyme pathway (CYP2E1) due to the continuous heavy drinking of these drivers. However, the rate of alcohol elimination reverts to normal after reduction/abstinence of alcohol of relatively short duration. Jones also shows the reliability of using 2 blood samples to determine the rate of alcohol elimination by comparing the rates to that obtained in 5 drivers in which 3 blood samples were obtained and showing there is no significant differences in using 2 or 3 blood samples. This study answers 2 issues that are sometimes raised in criminal trials of drinking drivers. These issues have been raised at trials in which I have testified.
That the blood alcohol analysis must be wrong because anyone with a BAC > 0.350 g/100mL would be dead and could not be driving.
In cases in which several blood samples were collected, the alcohol analysis must be wrong if it shows a rate of alcohol elimination > 0.030 g1/00mL/h
This study (as with numerous other studies), of course, confirms that these issues are not forensically valid.