Download Substituted Urine Debate

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.