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Surveillance & Society 1(1): 86-101 www.surveillance-and-society.org

Technical Review. Hair Testing: just how accurate is it?
Jason Ditton1

Abstract Extensive forensic examination of the hair of 209 “ecstasy” (MDMA) users demonstrated virtually no correlation between self-reported tablet use, and traces of MDMA in the hair of users. Why should this be so? Three answers are possible, andall true. First, self-report is fallible; second, tablet strength varies enormously; and third, forensic analysis is of unknown accuracy. The first two are well known. Forensic analysis, however, typically presents itself as impeccably precise. The review demonstrates that not only is this claim spectacularly untrue, but also that validation of forensic analysis (and, thus, indirectly, selfreport)lies in the very blind intra - and inter- laboratory comparisons that are never undertaken.

Introduction Although the results of testing hair for the presence of poisons have been accepted - at least in American courts - for over a century (Mieczkowski, 1996: 61), hair testing for evidence of the use of drugs has not yet reached that degree of full judicial acceptability (Huestis, 1996a),although there are various reports of quasi-judicial use (Tagliaro, et al., 1997; Moeller, 1996; Moeller, et al., 1993; and Lewis, et al., 1997). Hair testing began slowly about 20 years ago, initiated, perhaps, by Baumgartner's pioneering article (Baumgartner, et al., 1978). Sachs (1997: 8-9) suggests an erratic growth thereafter, with a "gold rush" period between 1986 and 1992 typified by relativelyuncritical use of hair testing, followed by a "hang over" period between 1992 and 1996 characterised by more critical reflection. It seems that a renewed "gold rush" - at least of published papers if not of conclusive results - began thereafter. Hair allegedly offers one crucial potential advantage when compared to, for example, urine as a medium for divination - the long time window. Whereas urinecan only indicate use for 2-3 days for opiates, cocaine and the amphetamines, hair offers the possibility of retrospective use examination for at least 3 months, and possibly as long as 12 months. Indeed, Baumgartner, et al. (1989:1447-8) claim to have tested 5 hairs, 7.6cm
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Department of Law, University of Sheffield, UK; and Director, Scottish Centre for Criminology, Glasgow, UK. E-mail:jasonditton@lineone.net © 2002 Surveillance & Society and the author(s). All rights reserved. ISSN: 1477-7487

Ditton: Hair Testing

in length, from Keats, and, 167 years l ter, discovered the presence of opiates therein. a Specifically, hair offers the opportunity to examine evidence of drug use for each of the months separately, rather than merely for all of the months together. A number ofother advantages of hair are sometimes cited (difficult to falsify, easy to store, lengthy shelf life, low body invasion), but for others, these apparent benefits merely offer more opportunity to trammel with people's civil liberties for longer periods (Huestis, 1996; Evans, et al.,1994; Kidwell & Blank, 1996). Head hair has been examined for the presence of, amongst other substances, heroin(Baumgartner, et al., 1978; Goldberger, et al., 1991;); cocaine (Baer, et al, 1991; Baumgartner, 1982; Blank & Kidwell, 1993; Cone, et al., 1991; Garside & Goldberger, 1996; Graham, et al., 1989; Harkey, et al., 1991; Kauert & Röhrich, 1996; Marques, et al., 1993; Marques, 1993; Marques, et al., 1994; Mieczkowski, et al., 1991; Mieczkowski, 1992; Mieczkowski, 1992a; Mieczkowski & Newell, 1994; Pepin &Gaillard, 1997;); PCP (Baumgartner, 1981; Nakahara, et al., 1995; Sakamoto & Tanaka, 1996); MDMA (Cirimele, et al., 1995; Kikura, et al., 1997; Kintz & Cirimele, 1997; Moeller, et al., 1992; Röhrich & Kauert, 1997; Rothe, et al., 1997); cannabis (Cirimele, et al., 1996;); morphine (Cone & Mitchell, 1989; Cone, 1990; Marigo, et al., 1986); codeine (Cone & Mitchell, 1989;); methamphetamine and/or...