Both the Boston and New York police departments, 10 to 15 % of Fortune 500 companies, court systems, federal reserve banks, the FBI, and numerous high schools use hair to test for drug abuse. But, is this method as reliable as most have accepted it be?
The hair test was developed in the 1960's by Austrian chemist Werner Baumgartner. Baumgartner realized that substances floating around the blood eventually get incorporated into hair as the hair grows. He figured it'd be harder to cheat on a hair test than saliva or urine test since drugs linger longer in a hair test sample. He went on to start the company, Psychemedics, the main company for hair drug testing. Psychemedics, after receiving a client's sample, washes it to remove external contaminants, dissolves the sample, and then analyzes it using GCMS. So what's the big issue?
Before Keri Hogan, a police candidate in Boston, could officially become a police officer, she had to submit a sample of her hair to the city of Boston for testing. Her hair tested positive. The only problem is, Hogan attests to never having used cocaine. After sending her hair to a private testing company, the test came back negative. she and nine other officers are suing the city of Boston for discriminatory drug testing practices. The test, they say, unfairly targets black those with dark hair.
A navy chemist by the name of David Kidwell decided to explore Psychedemics in 1985. In 1995 he published some his experiments he ran which showed that after thoroughly rinsing hair soaked in cocaine, the test came back positive. The cocaine wasn't in the bloodstream but in the environment. Kidwell argues that melanin binds with cocaine both externally and from the bloodstream. Specifically, the sub-type eumelanin, binds particularly well with cocaine and amphetamines. Kidwell's research has also shown that the amount of melanin in the hair and some chemical treatment involved in styling affects how much contamination the hair can absorb. Furthermore, researchers aren't sure whether hair can ever be washed clean of any and all drugs it could have come into contact with from the outside. This would of course prove Psychemedics' test as flawed. Although the possibility of false positives continue to exist, hair drug tests are still widely relied on.
Very interesting topic. Very relevant to public perception of chemistry as reliable. Good title and graphic. Good explanation of the chemistry. It would be helpful to include a link to your source in the text.
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