Historical Concerns for Passive Exposure in Urinalysis

A third example was the presence of cocaine in an individual s urine due to accidental ingestion. Inca tea, a tea made from purportedly decocainized cocaine leaves purchased in a health food store, was brewed and ingested by an individual who was later found to be positive for cocaine. If the cocaine had been removed from the leaves as stated, the product would have been perfectly legal and could not have contributed to a positive urinalysis (low probability event number one). Likewise, if the individual had not been tested within a few hours of consuming the tea, the results probably would have been negative (low probability event number two). In this case, a sample of the tea bag was produced, analyzed, and found to contain cocaine in sufficient quantities to cause a positive urinalysis (low probabihty event number three). Further investigation revealed that Inca tea leaves were ground and dried cocaine leaves and not decocainized. The product was immediately removed from the market. -  

The most frequently cited low probability event, that became apparent as a defense argument for urinalysis, was passive exposure to marijuana smoke. An explanation for a marijuana positive urinalysis was that the service member was exposed to significant quantities of marijuana sidestream smoke in close proximity to the service member. Because this defense may have had validity, the Navy commissioned subsequent scientific studies to resolve this issue. These studies showed conclusively that environmental exposure would result in a marijuana positive, providing the exposure was severe enough. However, in the experiment the exposure needed to be repeated for many hours and at a level such that the subjects needed to wear eye goggles to protect themselves from the marijuana smoke. Exposures at these levels could hardly be considered to be inadvertent or unwilling. As a result of these studies, cutoff levels could be defended and the credibUity of the passive exposure defense was diminished. 

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