Concentration Distribution of the Marijuana Metabolite Δ9-Tetrahydrocannabinol-9-Carboxylic Acid and the Cocaine Metabolite Benzoylecgonine in the Department of Defense Urine Drug-Testing Program

Urine drug testing has been employed for punitive purposes by the Department of Defense since December 1981 (Memorandum 62884, Deputy Secretary of Defense Frank C. Carlucci). Federal Workplace Drug Testing Programs were initiated in response to Executive Order 12564 issued on September 15, 1986, that required Drug-Free Federal Workplaces be established. In their respective programs, a positive urine drug test may be referred to a military court martial or to an administrative board. To address safety and insurance requirements, the testing of civilians has expanded beyond Federal Programs to include pre-employment and post-accident urine drug testing. During adjudication, an Expert Toxicologist may be asked to opine what can be discerned from the concentration of drug or drug metabolite found in the urine. Little can be opined with certainty from a positive urine drug test as to the amount of drug ingested, when the drug was ingested, and in most instances, whether the individual felt the effects of the drug, or was under the influence of the drug found in the urine. What may be useful to both the Expert and to the Trier-of-Facts is the frequency that a particular urine drug concentration is encountered in positive drug tests. The finding that 50% of all positive marijuana and cocaine urine metabolite concentrations in the military testing program over the three-year period of October 1, 2004 through September 30, 2007, are below a median value of 65 and 968 ng/mL, respectively, provide reference points. A median drug concentration combined with the percentile or frequency that a particular urine drug concentration occurs may provide evaluative information for a determination of the facts and the outcome of judicial or administrative proceedings. This may be especially useful to jurors when the concentration of marijuana or cocaine metabolite is perceptibly low. The information would also be applicable to medical review officers, medical examiners, drug treatment professionals, probation officers, and program analysts coordinating drug policy decisions.