Hair tests for "drugs" have become more popular because they are supposedly harder to beat than urine tests and can determine use months prior to the test and are thus even less relevant to on the job performance. In addition, coarse black hair holds "drug" residues longer than thin blond hair. This has the added advantage of increasing the power of the state over minorities.

" It's a major problem" warned J. Michael Walsh, executive director of the President's Drug Advisory Council under Presidents Reagan and Bush and now a consultant to the urinalysis industry." From the perspective of those like Walsh, whose focus is on middle class marijuana use this indeed can be a problem. Also they show hard drug use that would be missed by urine tests. However, they do not detect any use in the last week.

About 20 million Americans undergo drug tests each year, according to the Institute for a Drug-Free Workplace, a Washington-based prohibitionist lobby. The majority are job applicants without rights of appeal.

About 80 percent of companies that test for drugs rely solely on urine, and only 2 percent use hair. One reason is legality. Urine tests have universal acceptance in courts, while skepticism about the science behind hair tests persists. The other reason is politics. Employers, state regulators and courts want approval from federal public-health experts before they go ahead with hair testing. And the regulators remain skeptical. To date, "hair analysis for the presence of drugs is unproven, unsupported by scientific literature or controlled trials," Food and Drug Administration spokes-woman Sharon Snider said. 

Hair tests are becoming more popular. That's partly because the tests turn up more drug users than urinalysis and counter some of urine testing's shortcomings. Also important are sustained lobbying and marketing efforts by Psychemedics Corp. of Cambridge, Mass, which dominates the hair-testing market.

A decade ago, Psychemedics' biggest customers were Nevada casinos. Today, they include Anheuser-Busch, the Federal Reserve System and General Motors. Florida entrepreneur H. Wayne Huizenga, founder of Blockbuster Entertainment, gets much of the credit. He led a group of investors that bought Psychemedics out of debt in 1989. With Blockbuster as a mainstay customer, the firm grew to more than 750 clients, according to its 1996 Securities and Exchange Commission filings. (Huizenga sold Blockbuster, he is now the nation's largest used car salesman.)

In that year, Florida legislators, pushed by Huizenga's lobbyists, (He owns the Dolphins.) approved hair testing in the state. The law grandfathered Psychemedics' patented hair-testing process and set high hurdles for future competitors. By the end of 1997, according to company general counsel William Thistle, Psychemedics had 1,000 clients. Thistle and other Psychemedics executives insist patented methods are unbiased and produce no "false positives" from innocent drug exposure. If hair testing were to supplant urine testing for drugs, Thistle ventured in an interview, from three to 10 times more illicit drug users would be caught. The result could be a new epoch in the nation's drug-war history: "Drug users wouldn't be employed," Thistle said flatly, "or they'd be in rehabilitation programs."

"Hair testing may turn out to have a complementary role in workplace testing," said Robert Stevenson, deputy director of the Workplace Programs Division of the federal Center for Substance Abuse Prevention. "But we have yet to resolve remaining questions about its fairness and the ability to interpret results consistently."