"Smart people (like smart lawyers) can come up with very good explanations for mistaken points of view."

- Richard P. Feynman, Physicist

"There is a danger in clarity, the danger of over looking the subtleties of truth."

-Alfred North Whitehead

July 18, 2010

Tests for Alcohol Use

Anyone involved in the criminal justice system is familiar with the use of chemical blood tests to detect the use of illegal substances. Often, the actual drug is not identified in the blood, but rather a metabolite of a particular drug is detected. The presence of that metabolite is evidence that a subject had used a particular drug within a period of time before the taking of the sample. These tests are often used in monitoring individuals on probation or those participating in a drug court.

We all are also familiar with blood, breath, and even urine tests for detecting the presence of alcohol. These tests show the presence of ethanol which indicates recent use of alcohol. The problem with these tests is that alcohol is rapidly metabolized by the body, and if the sample is not taken within hours of the consumption of alcohol, the test will be negative. The use of such devices such as the SCRAM bracelet, discussed in an earlier blog entry, can also be used to monitor alcohol consumption.

However, a recent research article discussed the use of detecting metabolites of alcohol, specifically ethyl glucuronide (EtG) and ethyl sulfate (EtS). [i] According to this article, EtG and EtS can be present in urine for almost a week after alcohol use stops. Hair testing for these metabolites is also being perfected and should be commercially available soon.

The draw-backs to the use of these metabolites are that many products used by humans contain alcohol which could result in a false positive. Research is being done to develop cutoff levels to protect against false positives. The authors of this article stress that the use of these metabolite tests must include an agreement with the subject to not use articles that contain alcohol.

Tests for EtG and EtS require sending urine samples to labs for analysis. There are no field tests. The costs for these tests range from $15 to $75. These tests may be another tool for the Department of Corrections for monitoring defendants convicted of alcohol related crimes.



[i] Skipper, Gregory E. M.D. and Robert L. Du Pont M.D. and William L. White M.A., 2008. “Testing for Recent Alcohol Use”, Employee Assistance Digest, 28(1), 15-21.

The views expressed in this blog are solely the views of the author(s) and do not represent the views of any other public official or organization.

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