Science has come a long way when it comes to illicit drug testing. These days, using hair samples to screen for drug abuse is rather common.
Yet new research by scientists at the American Chemical Society shows when it comes to drug detection, pretreatment methods that wash away external contaminates from samples may actually alter test results.
During this recent study, researchers specifically looked at hair forensics and cocaine. This drug works as a stimulant and is made from the leaves of the coca plant that's native to South America. The illegal drug is highly addictive and can produce short-term feelings of euphoria and extreme energy. However, it can also cause a raising heart, high blood pressure and, in more severe instances, an increased risk of a heart attack.
Cocaine hits the central nervous system, increasing levels of the neurotransmitter dopamine in the brain, which are related to both pleasure and movement. While dopamine is normally released by neurons that flood these circuits in response to potential rewards, and then recycled back in the cell from which it was released, shutting off the signal between neurons, cocaine keeps the dopamine cycle going. Thus, excess dopamine signals build up, disrupting normal brain communication and creating the high associated with the drug.
During this recent study, researchers tested individual hair locks for drug abuse. Testing hair samples over urine and blood analyses holds an advantage, as it's non-invasive and provides a record of use over a longer period than samples from bodily fluids.
The problem, however, with using hair samples comes when a non-drug user is in the same room with a drug user and/or illicit substance. Because of this, the non-user's hair can be externally contaminated even if he or she did not use any drugs present. To make sure no one is wrongfully accused based on incorrect test results, researchers wash hair samples to get rid of potential external contaminants.
However, researchers found that even after following standard procedures for washing off cocaine from non-users' hair, cross sections of the samples showed that the drug had made its way into the participants' hair shafts.
As decontaminating hair can actually have the opposite effect when it comes to clearing a non-user's name, researchers said they are hopeful that their findings could help with testing for future hair analyses.
The study was published today in the journal Analytical Chemistry.
