People might have their hair analyzed for a variety of reasons. Employers can require a hair analysis test to screen for drug use. People also might have hair tested in attempt to quantify levels of exposure to environmental toxins or to find nutritional deficiencies. Unfortunately, a hair analysis is not always a reliable tool in the latter cases.
Benefits
When an employer looks at possible drug use, analysis of a person's hair will provide a longer "testing window" than other drug testing methods, such as urine testing. This gives a drug use history that can go back as far as 90 days, according to the U.S. Department of Labor. Hair testing provides evidence of past use of a specific drug, but doesn't give evidence of current impairment. It also cannot detect alcohol use. Privacy issues are decreased with hair testing because it's the least invasive drug testing form, reports the DOL.
Identification
A hair sample is used for a hair analysis. This is a collection of hair strands, usually that have been cut from a person's head. The samples usually have hair that's grown during the past year, which is about 5 inches of hair. Laboratories measure substances in the hair sample and provide an analysis, according to the Agency for Toxic Substances and Disease Registry (ATSDR).
Considerations
There are problems with using hair samples to determine environmental exposure and nutrition deficiency issues. There are no standards that specify how hair samples are collected, stored or analyzed. That means two laboratories may report different results for one person's hair samples. This variation makes it tough for health care professionals to really know what results mean, advises ATSDR. The use of shampoos and hair dyes can influence tests as well, and since the sample might be several weeks old it possibly does not indicate the person's current state of health, report Jordan Rubin and Joseph Brasco in their book, "Restoring Your Digestive Health."
Significance
Some practitioners tell patients that a hair mineral analysis can reveal whether the patient is predisposed to getting certain maladies, despite issues with consistency in hair analysis. Nine labs in the United States are responsible for performing an average of 225,000 hair mineral tests each year at a cost of $9.6 million each year, reports ABC News.
History
Heavy metals were the first substances that could be detected in a hair analysis. As technology developed, other substances could be detected. In 1979, scientists figured out how to test for heroin use. The mechanism by which drugs enter hair, however, is still unknown, according to Marie Balíková's 2005 article, "Hair Analysis for Drugs of Abuse," in the "Biomedical Papers of the Medical Faculty of the University of Palacky, Olomouc, Czech Republic."
Expert Insight
A 2001 study published in the "Journal of the American Medical Association" recommends that the U.S. government should not certify hair analysis labs without first developing standards for testing. Lead researcher S. Seidel also notes that health care practitioners should not use such analyses to assess a person's nutritional status or any suspected environmental exposures.
References
- "Journal of the American Medical Association:" Assessment of commercial laboratories performing hair mineral analysis; S. Seidel et. al.; Jan. 3, 2001
- ABC News: Hair test labs are unreliable
- "Restoring Your Digestive Health;" Jordan Rubin and Joseph Brasco; 2003
