Even though hair analysis has been used in scientific investigations of heavy metal deposition in humans since the 1950s, its application to drugs of abuse testing was not mentioned in the literature for nearly another 3 decades, but its popularity, especially for workplace drug testing, did not occur until later.
United States statistics for drug usage in the workplaces shows that the employers need to perform drug testing routinely. According to the results of workplace urine drug tests, the positivity rate for the combined US workforce of federally mandated, safety sensitive workers and the general US workforce was as high as 13.6% in 1988, but has remained below 5% since 1997. In 2006, a record low 3.8% positivity rate was reported by the Quest Diagnostic Drug Testing Index, representing 9 million workplace urine drug tests. The 2005 National Survey on Drug Use and Health (NSDUH) estimated that among unemployed adults, 17.1% were current illicit drug users, while an estimated 12.9 million (5.3%) illicit drug users were employed either full or part time. The Substance Abuse and Mental Health Services Administration (SAMHSA) has estimated that nearly half of full-time employees are subjected to a workplace drug-testing program utilizing urine testing.
Drugs commonly detected in workplace drug-testing programs include amphetamines, cocaine, cannabis, phencyclidine, and opiates. Many employers also add benzodiazepines, oxycodone, methadone and hydrocodone to their testing list of possibly abused drugs. Specific hair analytes commonly used for workplace drug testing are listed in Table 6-l. Prevalence rates of different drugs as reported by large workplace population studies from several countries are shown in Table 6.2. In general, hair testing shows a higher prevalence rate than does urinalysis in populations in which urine and hair analysis results were reported. For example, Mieczkowski reported that the mean rate for hair analysis drug-positive specimens for a population of law enforcement officers was found to be 1.36 times that for urinalysis. The positive rates for applicants for probationary officer positions with hair testing were about 2 times higher than that found with urine tests.
A drug-free workplace program creates a protected workplace environment, offersing support for employees who have a substance abuse problem, and protecting the employees, customers, and the public from the deleterious effects of drugs and alcohol at work. Workplace drug testing increases a company’s overall productivity while decreasing theft, accidents, and compensation claims. Air testing may lend itself to pre-employment, random, return-to-duty, and follow-up testing, although the first 2 applications appear to be most appropriate. Hair analysis is not useful to document drug use in a workplace setting for acute occurrences such as post-accident and reasonable suspicion or cause.
In 2007, Donna Bush of the Division of Workplace Programs (DWP), SAMHSA, US Department of Health and Human Services (HHS) published an article entitled, “The U.S. Mandatory Guidelines for Federal Workplace Drug Testing Programs: Current status and future considerations”. In this article, Bush stated that HHS was committed to maintaining the integrity of the Federal Drug-Free Workplace Program by identifying and using the most accurate and reliable drug-testing technology available including new analytical technologies utilizing alternate matrices. Bush also stated:
The adding of alternative specimens and drug testing technologies would harmonize the existing urine drug testing program and aid in combating the threat from n counter-industries devoted to beating drug tests. This proposal 13 April 2004, HHS published a notice in the Federal Register for U.S. mandatory Guidelines for Federal Workplace Drug Testing Programs was issued with the fundamental understanding that the window of drug detection for urine, hair, oral fluid, and sweat patch specimens are neither equal nor identical, but the results from each specimen can be used in a complementary manner. Urine is generally useful for detecting drug ingestion for a Midday integral preceding the specimen collection. Hair is useful for detecting drug use for a longer time period generally ranging from weeks to months (but not the first week), depending on the length of the hair tested.
The main reason of workplace drug testing is one of deterrence to promote a drug-free workplace. Hair as an alternate matrix for drug testing offers greater deterrence because of its ability to document drug use for a longer period of time.
Other reasons companies seek to use hair for their workplace drug-testing programs include:
1. Specimen can be taken at the worksite, and the individual is not required to physically go to a collection site for sample donation. This saves the employer time and money by reducing the nonproductive time associated with the testing;
2 An observed collection reduces the problems associated with sample substitution or adulteration, which can occur when urine is the test matrix;
3. The collection itself is noninvasive and may be preferred by some subjects.
The acceptability of hair analysis in American courts has been aided by recent changes in the acceptance criteria. At first, the admissibility of hair analyses was based on the Frye standard of 1923 that required the scientific principles supporting the test be sufficiently established so that there was general acceptance by the scientific community. In 1975, the Federal Rules of Evidence were adopted, allowing expert witnesses to give testimony “in the form of opinion or otherwise” if it assisted “the trier-of-fact to understand the evidence or to determine a fact in issue”. However, these rules were not utilized until l993 after a Supreme Court ruling in the Daubert vs Merrell Dow case. This newly implemented standard allowed the judge to determine whether or not hair analysis evidence would lend understanding to the case, hence superseding the “general acceptance” approach for admissibility. Legally, this decision catapulted hair analysis into presently judicial settings making hair-testing results forensically defensible evidence in hundreds of legal cases. Many states including Florida, New York, and Texas have legislated hair analysis for workplace drug testing to varying degrees. Currently, almost all United States allow the use of hair in the non-regulated, private-sector workplace drug-testing programs. In April, 2004 the DWP of SAMHSA proposed the Mandatory Guidelines for Federal Workplace Drug Testing Programs, suggesting screening and confirmatory cutoff concentrations for amphetamines, cocaine, opiates, cannabinoids, and phencyclidine in hair. The proposed Mandatory Guidelines are still in effect as a proposal to change the existing Mandatory Guidelines for Federal Workplace Drug Testing Programs (1994). In June 2006, the Office of Management and Budget (OMB) published a notice that SAMHSA/HHS’s final work product concerning the incorporation of alternative specimens.
Similar hair drug-testing guidelines have been published in European countries. In 1998, cutoff concentrations for initial and confirmatory hair testing were published for Germany by the Society of Toxicological and Forensic Chemistry (Gesellschaft fur Firensischeund Toxikologische Chemie, GTFCh). Six years later, the international Society of Hair Testing, (SoHT) and the French Society of Analytical Forensic Toxicology (Societe Francaise de Toxicologie Analytique, (SFTA) published similar cutoff drug concentrations for hair testing. The cutoff concentrations recommended by American and International governmental and professional organizations are summarized in Table 6.1.