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Substituted Urine Debate DOT definition of substituted specimen: Creatinine <= 5 AND specific gravity <=1.001 or >=1.020 The data: NLCP: State of the Science – Update #1, Urine Specimen Validity Testing, Evaluation of the Scientific Data Used to Define a Urine Specimen as Substituted DOT water loading study: Paired Measurements of Creatinine and Specific Gravity after Water Loading Barbanel study published in the Journal of Occupational and Environmental Medicine, Vol. 44, No. 5, May 2002, pp. 407 – 416 Anecdotal report of “Water Load Study” on Julia Jones, May 28, 2002 Anecdotal report of water loading study on Joan Goodwin, January 8, 2003 Both anecdotal reports of the flight attendants indicate that, in extreme cases, the human kidney can produce urine that meets the DOT definition of a substituted specimen. This is in contrast to the DOT study of 480 specimens and the Barbanel study of 13,467 specimens in which NONE of the specimens met the DOT criteria for substitution. In the flight attendant cases both individuals consumed approximately 2 liters of water (1,868 ml and 2,000 ml) over 2 hours. In both cases this represents the total quantity of water that humans typically consume in 24 hours. [Eight 8ounce glasses of water (1,891 ml) is the “recommended” amount of water per day.] In the case of Julia Jones she started her study with a highly dilute urine since her initial creatinine and specific gravity were 4.4 and 1.002 before consuming the 1,868 ml of water. Whether or not that is her normal state or she purposely over hydrated prior to the study is not known. We do not have a preloading value for either creatinine or specific gravity in Joan Goodwin’s case. In neither of these cases so we find the kind of controls required for even the most basic of controlled scientific studies. What we have, at best, are two isolated anecdotes that show that in extreme situations of rapid hydration the human kidney can produce urine that falls in the range designated by DOT as “substituted”. These results are in contrast to ZERO cases in a group of 13,467 specimens meeting the criteria for a substituted urine specimen. Whether one produces a “substituted” specimen by rapid over hydration (drinking the entire day’s water supply in two hours) or by bringing in a diluted specimen or by diluting the specimen during the collection process makes little difference. In each case the specimen is not “normal” and was not produced by a “normal” physiologic process. What these two anecdotes show is that there is a wide range of human physiology possible. Just as it is possible to have a positive marijuana urine drug test from passive inhalation in extreme cases, so it is possible to reach such a dilution of urine as to meet the substituted criteria. But in neither situation is it likely or even probable. Just as passive inhalation is not a valid explanation for a positive marijuana, so should the extreme situation required to reach the substituted criteria for urine concentration not be used to explain the substituted urine specimen. The DOT makes accommodation for the rare individual who might unwittingly produce a urine specimen meeting the substituted criteria by allowing such an individual to demonstrate, under the supervision of a physician, that they can physiologically produce a “substituted” urine specimen. This seems an adequate safeguard for the very rare individual who might inadvertently provide an extremely dilute urine specimen meeting the substituted criteria while preserving the standard for the multitude of drug users who are trying to beat a positive drug test by purposefully creating a highly diluted urine specimen.