Drug tests are administered in a variety of everyday contexts -- especially in the job market. Here we discuss the subject as it applies to the criminal justice system. Probably the most common use of drug testing is for people who have been placed on probation. Often people are required to submit to drug tests even if the crime they were convicted for had nothing to do with drugs.

Example: Jonah was convicted of burglary. A probation report disclosed that Jonah had a history of cocaine use. The court sentenced Jonah to jail for a brief period, to be followed by a three-year period of probation. One of the conditions of probation was that Jonah submit to periodic and random drug testing.

Even assuming a good reason for testing people on probation, the tests must be reliable for testing to make sense. While the reliability of the standard urine drug test is aggressively asserted by the companies that make money off the testing, the tests, as administered, are not scientifically assessed for reliability.

The legal community has a term for procedures that pretend to be science but can't stand up to scientific scrutiny: junk science. Some now claim that drug testing is a perfect example of it.

One such soul is Dr. Kent Holtorf, who gives plenty of ammunition for his views in a book with the quirky title, Ur-ine Trouble, published by Vandalay Press and now in its second edition. Holtorf begins by pointing out the myriad ways in which drug testing laboratories can and do make mistakes. Holtorf also deals with an even more troubling aspect of drug testing: the false positive. A false positive occurs when a test erroneously indicates the presence of an illegal substance. For instance, a test can come out positive for marijuana as the result of ingesting ibuprofin, found in Advil and Motrin. A number of over-the-counter medications may produce a positive test result for amphetamines.

Holtorf claims that more false positives than accurate tests are reported by drug testing laboratories. He devotes an entire chapter to the various substances that have been shown to cause false positives for various substances.

Holtorf also points out that secondhand smoke from marijuana and crack cocaine is taken up in a person's hair, which produces a positive test result when hair is sampled for drugs. The more melanin in a person's hair, claims Holtorf, the greater the concentration of the illegal substance. And since African-Americans tend to have higher concentrations of melanin in their hair, the chances are also great that they are at much greater risk than whites of testing positive when their hair is tested -- even if the substance got there through secondhand smoke.